1
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Monzón González CR, Sánchez Vergara ME, Elías-Espinosa MC, Rodríguez-Valencia SA, López-Mayorga BJ, Castillo-Arroyave JL, Toscano RA, Flores OL, Álvarez Toledano C. Design of Promising Uranyl(VI) Complexes Thin Films with Potential Applications in Molecular Electronics. ChemistryOpen 2024; 13:e202300219. [PMID: 38180301 DOI: 10.1002/open.202300219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/07/2023] [Indexed: 01/06/2024] Open
Abstract
In this work, it is proposed the development of organic semiconductors (OS) based on uranyl(VI) complexes. The above by means of the synthesis and the characterization of the complexes by Infrared spectroscopy, Nuclear magnetic resonance spectroscopy, mass spectrometry, and X-ray diffraction. Films of these complexes were deposited and subsequently, topographic and structural characterization was carried out by Scanning Electron Microscopy, X-ray diffraction, and Atomic Force Microscopy. Additionally, the nanomechanical evaluation was performed to know the stiffness of uranyl films using their modulus of elasticity. Also, the optical characterization took place in the devices and their bandgap value ranges between 2.40 and 2.93 eV being the minor for the film of the uranyl complex with the N on pyridine in position 4 (2 c). Finally, the electrical behavior of the uranyl(VI) films was evaluated, and important differences were obtained: the uranyl complex with the N on pyridine in position 2 (2 a) film is not influenced by changes in lighting and its current density is in the order of 10-3 A/cm2. The film with uranyl complex with the N on pyridine in position 3 (2 b) and 2 c presents a greater current flow under lighting conditions and two orders of magnitude larger than in film 2 a. In these films 2 b and 2 c, ohmic behavior occurs at low voltages, while at high voltages the charge transport changes to space-charge limited current behavior.
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Affiliation(s)
- César Raúl Monzón González
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n. C.U., Delegación Coyoacán, C.P., 04510, Ciudad de México, México
| | - María Elena Sánchez Vergara
- Facultad de Ingeniería, Universidad Anáhuac México, Avenida Universidad Anáhuac 46, Col. Lomas Anáhuac, Huixquilucan, Estado de México, 52786, México
| | - Milton Carlos Elías-Espinosa
- Tecnológico de Monterrey, Escuela de Ingeniería y Ciencias, Av. Carlos Lazo 100, Santa Fe, La Loma, Ciudad de México, México, 01389
- Tecnológico de Monterrey, Escuela de Ingeniería y Ciencias, Calle del Puente, Ejidos de Huipulco, Tlalpan, Ciudad de México, México, 14380
| | - Sergio Arturo Rodríguez-Valencia
- Tecnológico de Monterrey, Escuela de Ingeniería y Ciencias, Carr. Lago de Guadalupe Km. 3.5, Col. Margarita Maza de Juárez, Atizapán de Zaragoza, Estado de México, México, 52926
| | - Byron José López-Mayorga
- Escuela de Química, Facultad de Ciencias Químicas y Farmacia, Universidad de San Carlos de Guatemala, 11 avenida, Ciudad de Guatemala, Guatemala, 01012
| | - José León Castillo-Arroyave
- Escuela de Química, Facultad de Ciencias Químicas y Farmacia, Universidad de San Carlos de Guatemala, 11 avenida, Ciudad de Guatemala, Guatemala, 01012
| | - Rubén Alfredo Toscano
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n. C.U., Delegación Coyoacán, C.P., 04510, Ciudad de México, México
| | - Octavio Lozada Flores
- Facultad de Ingeniería, Universidad Panamericana, Augusto Rodin 498, Ciudad de México, 03920, México
| | - Cecilio Álvarez Toledano
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n. C.U., Delegación Coyoacán, C.P., 04510, Ciudad de México, México
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2
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Shenvi RA. Natural Product Synthesis in the 21st Century: Beyond the Mountain Top. ACS CENTRAL SCIENCE 2024; 10:519-528. [PMID: 38559299 PMCID: PMC10979479 DOI: 10.1021/acscentsci.3c01518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 04/04/2024]
Abstract
Research into natural products emerged from humanity's curiosity about the nature of matter and its role in the materia medica of diverse civilizations. Plants and fungi, in particular, supplied materials that altered behavior, perception, and well-being profoundly. Many active principles remain well-known today: strychnine, morphine, psilocybin, ephedrine. The potential to circumvent the constraints of natural supply and explore the properties of these materials led to the field of natural product synthesis. This research delivered new molecules with new properties, but also led to fundamental insights into the chemistry of the nonmetal elements H, C, N, O, P, S, Se, and their combinations, i.e., organic chemistry. It also led to a potent culture focused on bigger molecules and races to the finish line, perhaps at the expense of actionable next steps. About 20 years ago, the field began to contract in the United States. Research that focused solely on chemical reaction development, especially catalysis, filled the void. After all, new reactions and mechanistic insight could be immediately implemented by the chemistry community, so it became hard to justify the lengthy procurement of a complex molecule that sat in the freezer unused. This shift coincided with a divestment of natural product portfolios by pharmaceutical companies and an emphasis in academic organic chemistry on applications-driven research, perhaps at the expense of more fundamental science. However, as bioassays and the tools of chemical biology become widespread, synthesis finds a new and powerful ally that allows us to better deliver on the premise of the field. And the hard-won insights of complex synthesis can be better encoded digitally, mined by data science, and applied to new challenges, as chemists perturb and even surpass the properties of complex natural products. The 21st century promises powerful developments, both in fundamental organic chemistry and at the interface of synthesis and biology, if the community of scientists fosters its growth. This essay tries to contextualize natural product synthesis for a broad audience, looks ahead to its transformation in the coming years, and expects the future to be bright.
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Affiliation(s)
- Ryan A. Shenvi
- Department
of Chemistry, Scripps Research, La Jolla, California 92037, United States
- Graduate
School of Chemical and Biological Sciences, Scripps Research, La Jolla, California 92037, United States
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3
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Jospe-Kaufman M, Ben-Zeev E, Mottola A, Dukhovny A, Berman J, Carmeli S, Fridman M. Reshaping Echinocandin Antifungal Drugs To Circumvent Glucan Synthase Point-Mutation-Mediated Resistance. Angew Chem Int Ed Engl 2024; 63:e202314728. [PMID: 38161189 DOI: 10.1002/anie.202314728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/26/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
Echinocandins are a class of antifungal drugs that inhibit the activity of the β-(1,3)-glucan synthase complex, which synthesizes fungal cell wall β-(1,3)-glucan. Echinocandin resistance is linked to mutations in the FKS gene, which encodes the catalytic subunit of the glucan synthase complex. We present a molecular-docking-based model that provides insight into how echinocandins interact with the target Fks protein: echinocandins form a ternary complex with both Fks and membrane lipids. We used reductive dehydration of alcohols to generate dehydroxylated echinocandin derivatives and evaluated their potency against a panel of Candida pathogens constructed by introducing resistance-conferring mutations in the FKS gene. We found that removing the hemiaminal alcohol, which drives significant conformational alterations in the modified echinocandins, reduced their efficacy. Conversely, eliminating the benzylic alcohol of echinocandins enhanced potency by up to two orders of magnitude, in a manner dependent upon the resistance-conferring mutation. Strains that have developed resistance to either rezafungin, the most recently clinically approved echinocandin, or its dehydroxylated derivative RZF-1, exhibit high resistance to rezafungin while demonstrating moderate resistance to RZF-1. These findings provide valuable insight for combating echinocandin resistance through chemical modifications.
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Affiliation(s)
- Moriah Jospe-Kaufman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Efrat Ben-Zeev
- The Whol Drug Discovery institute of the Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Austin Mottola
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Anna Dukhovny
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Judith Berman
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Shmuel Carmeli
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Micha Fridman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
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4
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Gillard RM, Zhang J, Steel R, Wang J, Strull JL, Cai B, Chakraborty N, Boger DL. Aryl Annulation: A Powerful Simplifying Retrosynthetic Disconnection. SYNTHESIS-STUTTGART 2024; 56:118-133. [PMID: 38144170 PMCID: PMC10745204 DOI: 10.1055/a-1959-2088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Retrosynthetic deconstruction of a core aromatic ring is an especially simplifying retrosynthetic step, reducing the complexity of the precursor synthetic target. Moreover, when implemented to provide a penultimate intermediate, it enables late-stage divergent aryl introductions, permitting deep-seated core aryl modifications ordinarily accessible only by independent synthesis. Herein, we highlight the use of a ketone carbonyl group as the functionality to direct such late-stage divergent aryl introductions onto a penultimate intermediate with a projected application in the total synthesis of vinblastine and its presently inaccessible analogs containing indole replacements. Although the studies highlight this presently unconventional strategy with an especially challenging target in mind, the increase in molecular complexity (intricacy) established by the synthetic implementation of the powerful retrosynthetic disconnection, the use of a ketone as the precursor enabling functionality, and with adoption of either conventional or new wave (hetero)aromatic annulations combine to define a general and powerful strategy suited for wide-spread implementation with near limitless scope in target diversification.
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Affiliation(s)
- Rachel M. Gillard
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jianjun Zhang
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Richard Steel
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jocelyn Wang
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jessica L. Strull
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Bin Cai
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nilanjana Chakraborty
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dale L. Boger
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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5
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Tong G, Griffin S, Sader A, Crowell AB, Beavers K, Watson J, Buchan Z, Chen S, Shenvi RA. C5 methylation confers accessibility, stability and selectivity to picrotoxinin. Nat Commun 2023; 14:8308. [PMID: 38097583 PMCID: PMC10721898 DOI: 10.1038/s41467-023-44030-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/28/2023] [Indexed: 12/17/2023] Open
Abstract
Minor changes to complex structures can exert major influences on synthesis strategy and functional properties. Here we explore two parallel series of picrotoxinin (PXN, 1) analogs and identify leads with selectivity between mammalian and insect ion channels. These are the first SAR studies of PXN despite its >100-year history and are made possible by advances in total synthesis. We observe a remarkable stabilizing effect of a C5 methyl, which completely blocks C15 alcoholysis via destabilization of an intermediate twist-boat conformer; suppression of this secondary hydrolysis pathway increases half-life in plasma. C5 methylation also decreases potency against vertebrate ion channels (γ-Aminobutyric acid type A (GABAA) receptors) but maintains or increases antagonism of homologous invertebrate GABA-gated chloride channels (resistance to dieldrin (RDL) receptors). Optimal 5MePXN analogs appear to change the PXN binding pose within GABAARs by disruption of a hydrogen bond network. These discoveries were made possible by the lower synthetic burden of 5MePXN (2) and were illuminated by the parallel analog series, which allowed characterization of the role of the synthetically simplifying C5 methyl in channel selectivity. These are the first SAR studies to identify changes to PXN that increase the GABAA-RDL selectivity index.
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Affiliation(s)
- Guanghu Tong
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Samantha Griffin
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana, 46268, USA
| | - Avery Sader
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana, 46268, USA
| | - Anna B Crowell
- Department of Chemistry and Biochemistry, Oberlin College, 119 Woodland Street, Oberlin, Ohio, 44074, USA
| | - Ken Beavers
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana, 46268, USA
| | - Jerry Watson
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana, 46268, USA
| | - Zachary Buchan
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana, 46268, USA
| | - Shuming Chen
- Department of Chemistry and Biochemistry, Oberlin College, 119 Woodland Street, Oberlin, Ohio, 44074, USA.
| | - Ryan A Shenvi
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA.
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6
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Kotesova S, Shenvi RA. Inner- and Outer-Sphere Cross-Coupling of High F sp3 Fragments. Acc Chem Res 2023; 56:3089-3098. [PMID: 37889168 PMCID: PMC10979517 DOI: 10.1021/acs.accounts.3c00543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Natural product research originates from a desire to explore, understand, and perturb biological function with atomic precision. To reach these goals at all, let alone efficiently, requires thoughtful and creative problem solving. Often this means bold disconnections that would simplify access to complex structures, if only the methods existed to bridge these theoretical gaps. Whereas biological interrogations provide long-term intellectual value and impetus, methods come as attractive fringe benefits of natural product synthesis. This Account describes strategic, methodological solutions to the syntheses of natural products [(-)-eugenial C, Galbulimima alkaloids GB18, GB22, GB13, and himgaline] featuring new, convergent disconnections as important problem-solving steps, which themselves were inspired by recent methods that arose from our group. Each target required the invention of first-row transition metal-catalyzed cross-coupling procedures to satisfy the biological goals of the project. In these cases, synthetic strategy identified the methodological gap (the absence of stereo- and chemoselective couplings of appropriate fragments), but the tactical advantage conferred by first-row metals met the challenge. These methods were competent to handle the dense, sterically encumbered motifs common to natural products due to, in many cases, elementary steps that did not require bond formation between the hindered substrate and the metal center. Instead, these sterically lenient reactions appeared to involve metal-ligand-substrate reactions (i.e., outer-sphere steps), in contrast to the metal-substrate, coordinative reactions of precious metals (i.e., inner-sphere steps). Key observations from our previous studies, combined with the observations in seminal publications from other laboratories (Mattay, Weix, and MacMillan), led to the optimization of ligand-controlled, stereoselective reactions and the introduction of complementary catalytic cycles that revealed new modes of reactivity and generated novel structural motifs. Optimized access to bioactive natural product space accelerated our timeline of biological characterization, fulfilling a common premise of natural products research. The integration of methodology, complex natural product synthesis, diversification, and bioassay into a single Ph.D. dissertation would have been unmanageable in a prior era. The unique ability of first-row transition metals to effect Csp3-Csp3 cross-coupling with high chemo- and stereoselectivity has significantly lowered the barrier to reach the avowed goal of natural product synthesis and reduced the burden (real or perceived) of integrating natural products into functional campaigns.
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Affiliation(s)
- Simona Kotesova
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
- Graduate School of Chemical and Biological Sciences, Scripps Research, La Jolla, California 92037, United States
| | - Ryan A. Shenvi
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
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7
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Woo J, Stein C, Christian AH, Levin MD. Carbon-to-nitrogen single-atom transmutation of azaarenes. Nature 2023; 623:77-82. [PMID: 37914946 PMCID: PMC10907950 DOI: 10.1038/s41586-023-06613-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 09/05/2023] [Indexed: 11/03/2023]
Abstract
When searching for the ideal molecule to fill a particular functional role (for example, a medicine), the difference between success and failure can often come down to a single atom1. Replacing an aromatic carbon atom with a nitrogen atom would be enabling in the discovery of potential medicines2, but only indirect means exist to make such C-to-N transmutations, typically by parallel synthesis3. Here, we report a transformation that enables the direct conversion of a heteroaromatic carbon atom into a nitrogen atom, turning quinolines into quinazolines. Oxidative restructuring of the parent azaarene gives a ring-opened intermediate bearing electrophilic sites primed for ring reclosure and expulsion of a carbon-based leaving group. Such a 'sticky end' approach subverts existing atom insertion-deletion approaches and as a result avoids skeleton-rotation and substituent-perturbation pitfalls common in stepwise skeletal editing. We show a broad scope of quinolines and related azaarenes, all of which can be converted into the corresponding quinazolines by replacement of the C3 carbon with a nitrogen atom. Mechanistic experiments support the critical role of the activated intermediate and indicate a more general strategy for the development of C-to-N transmutation reactions.
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Affiliation(s)
- Jisoo Woo
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Colin Stein
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | | | - Mark D Levin
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
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8
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Zhou X, Huang Q, Guo J, Dai L, Lu Y. Molecular Editing of Pyrroles via a Skeletal Recasting Strategy. ACS CENTRAL SCIENCE 2023; 9:1758-1767. [PMID: 37780359 PMCID: PMC10540293 DOI: 10.1021/acscentsci.3c00812] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Indexed: 10/03/2023]
Abstract
Heterocyclic scaffolds are commonly found in numerous biologically active molecules, therapeutic agents, and agrochemicals. To probe chemical space around heterocycles, many powerful molecular editing strategies have been devised. Versatile C-H functionalization strategies allow for peripheral modifications of heterocyclic motifs, often being specific and taking place at multiple sites. The past few years have seen the quick emergence of exciting "single-atom skeletal editing" strategies, through one-atom deletion or addition, enabling ring contraction/expansion and structural diversification, as well as scaffold hopping. The construction of heterocycles via deconstruction of simple heterocycles is unknown. Herein, we disclose a new molecular editing method which we name the skeletal recasting strategy. Specifically, by tapping on the 1,3-dipolar property of azoalkenes, we recast simple pyrroles to fully substituted pyrroles, through a simple phosphoric acid-promoted one-pot reaction consisting of dearomative deconstruction and rearomative reconstruction steps. The reaction allows for easy access to synthetically challenging tetra-substituted pyrroles which are otherwise difficult to synthesize. Furthermore, we construct N-N axial chirality on our pyrrole products, as well as accomplish a facile synthesis of the anticancer drug, Sutent. The potential application of this method to other heterocycles has also been demonstrated.
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Affiliation(s)
- Xueting Zhou
- Joint
School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, Fujian 350207, China
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Qingqin Huang
- Joint
School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, Fujian 350207, China
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Jiami Guo
- Joint
School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, Fujian 350207, China
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Lei Dai
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Yixin Lu
- Joint
School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, Fujian 350207, China
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
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9
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Elgindy C, Levin MD. A focus on 1-azahomocubane: the new kid on the block. Chem Sci 2023; 14:7608-7610. [PMID: 37476719 PMCID: PMC10355093 DOI: 10.1039/d3sc90114a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023] Open
Abstract
Strained hydrocarbons have recently regained interest as potential drug candidates. However, the study of their heteroatom analogs has remained limited, despite differing by only a single atom. The first synthesis of 1-azahomocubane by Williams, Eaton and co-workers (T. Fahrenhorst-Jones et al., Chem. Sci., 2023, 14, 2821-2825, https://doi.org/10.1039/D3SC00001J) is discussed within the context of nitrogen scanning of strained hydrocarbons.
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Affiliation(s)
- Cecile Elgindy
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
| | - Mark D Levin
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
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10
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Pyae NYL, Maiuthed A, Phongsopitanun W, Ouengwanarat B, Sukma W, Srimongkolpithak N, Pengon J, Rattanajak R, Kamchonwongpaisan S, Ei ZZ, Chunhacha P, Wilasluck P, Deetanya P, Wangkanont K, Hengphasatporn K, Shigeta Y, Rungrotmongkol T, Chamni S. N-Containing α-Mangostin Analogs via Smiles Rearrangement as the Promising Cytotoxic, Antitrypanosomal, and SARS-CoV-2 Main Protease Inhibitory Agents. Molecules 2023; 28:molecules28031104. [PMID: 36770770 PMCID: PMC9919084 DOI: 10.3390/molecules28031104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
New N-containing xanthone analogs of α-mangostin were synthesized via one-pot Smiles rearrangement. Using cesium carbonate in the presence of 2-chloroacetamide and catalytic potassium iodide, α-mangostin (1) was subsequently transformed in three steps to provide ether 2, amide 3, and amine 4 in good yields at an optimum ratio of 1:3:3, respectively. The evaluation of the biological activities of α-mangostin and analogs 2-4 was described. Amine 4 showed promising cytotoxicity against the non-small-cell lung cancer H460 cell line fourfold more potent than that of cisplatin. Both compounds 3 and 4 possessed antitrypanosomal properties against Trypanosoma brucei rhodesiense at a potency threefold stronger than that of α-mangostin. Furthermore, ether 2 gave potent SARS-CoV-2 main protease inhibition by suppressing 3-chymotrypsinlike protease (3CLpro) activity approximately threefold better than that of 1. Fragment molecular orbital method (FMO-RIMP2/PCM) indicated the improved binding interaction of 2 in the 3CLpro active site regarding an additional ether moiety. Thus, the series of N-containing α-mangostin analogs prospectively enhance druglike properties based on isosteric replacement and would be further studied as potential biotically active chemical entries, particularly for anti-lung-cancer, antitrypanosomal, and anti-SARS-CoV-2 main protease applications.
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Affiliation(s)
- Nan Yadanar Lin Pyae
- Pharmaceutical Sciences and Technology Program, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
- Natural Products and Nanoparticles Research Unit (NP2), Chulalongkorn University, Bangkok 10330, Thailand
| | - Arnatchai Maiuthed
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand
- Centre of Biopharmaceutical Science for Healthy Ageing, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand
| | - Wongsakorn Phongsopitanun
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Bongkot Ouengwanarat
- Natural Products and Nanoparticles Research Unit (NP2), Chulalongkorn University, Bangkok 10330, Thailand
| | - Warongrit Sukma
- Pharmaceutical Sciences and Technology Program, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
- Natural Products and Nanoparticles Research Unit (NP2), Chulalongkorn University, Bangkok 10330, Thailand
| | - Nitipol Srimongkolpithak
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani 12120, Thailand
| | - Jutharat Pengon
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani 12120, Thailand
| | - Roonglawan Rattanajak
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani 12120, Thailand
| | - Sumalee Kamchonwongpaisan
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani 12120, Thailand
| | - Zin Zin Ei
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Preedakorn Chunhacha
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Patcharin Wilasluck
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence for Molecular Crop, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Peerapon Deetanya
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence for Molecular Crop, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kittikhun Wangkanont
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence for Molecular Crop, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kowit Hengphasatporn
- Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan
| | - Yasuteru Shigeta
- Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan
| | - Thanyada Rungrotmongkol
- Center of Excellence in Biocatalyst and Sustainable Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Bioinformatics and Computational Biology, Graduate School, Chulalongkorn University, Bangkok 10330, Thailand
| | - Supakarn Chamni
- Pharmaceutical Sciences and Technology Program, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
- Natural Products and Nanoparticles Research Unit (NP2), Chulalongkorn University, Bangkok 10330, Thailand
- Correspondence: ; Tel.: +662-218-8357
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11
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Abstract
Positional analogue scanning (PAS) is an accepted strategy for multiparameter lead optimization (MPO) in drug discovery. Small structural changes as introduced by PAS can lead to 10-fold changes in binding potency in ∼10-20% of cases, a significant parameter shift irrespective of other MPO objectives. Sometimes performing a complete PAS is challenging due to resource and time constraints, building block availability, or difficulty in synthesis. Calculating relative binding free energies (RBFEs) for all positions can contribute to prioritizing the most promising analogues for synthesis. We tested a well-established RBFE calculation method, Amber GPU-TI, for 20 positional analogue scans in 14 test systems (cyclin-dependent kinase 8 (CDK8), hepatitis C virus nonstructural protein 5B (HCV NS5B), tankyrase, RAC-α serine/threonine-protein kinase (Akt), phosphodiesterase 1B (PDE1B), orexin/hypocretin receptor type 1 (OX1R), orexin/hypocretin receptor type 2 (OX2R), histone acetyltransferase K (lysine) acetyltransferase 6A (KAT6A), peroxisome proliferator-activated receptor γ (PPARγ), extracellular signal-regulated kinases (ERK1/2), coactivator-associated arginine methyltransferase 1 (PRMT4), αvβ6, bromodomain 1 (BD1), human immunodeficiency virus-1 (HIV-1) entry) involving nitrogen, methyl, halogen, methoxy, and hydroxyl scans with at least four analogues per set. Among the 66 analogue positions explored, we found that in 18 cases Amber GPU-TI calculations predicted a more than 10-fold change in potency. In all of these cases, the experimentally observed direction of potency changes agreed with the predictions. In 16 cases, more than 10-fold changes in experimental potency were observed. Again, in all of these cases, Amber GPU-TI predicted the direction of the potency changes correctly. In none of these cases would a decision made for or against synthesis based on a 10-fold change in potency have resulted in missing an important analogue. Therefore, in silico RBFE calculations using Amber GPU-TI can meaningfully contribute to the prioritization of positional analogues before synthesis.
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Affiliation(s)
- Yuan Hu
- Alkermes, Inc., 852 Winter Street, Waltham, Massachusetts 02451-1420, United States
| | - Ingo Muegge
- Alkermes, Inc., 852 Winter Street, Waltham, Massachusetts 02451-1420, United States
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12
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Woo S, Shenvi RA. Synthesis and target annotation of the alkaloid GB18. Nature 2022; 606:917-921. [PMID: 35551513 PMCID: PMC10036212 DOI: 10.1038/s41586-022-04840-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/06/2022] [Indexed: 11/08/2022]
Abstract
Ingestion of alkaloid metabolites from the bark of Galbulimima (GB) sp. leads to psychotropic and excitatory effects in humans1-4. Limited, variable supply of GB alkaloids5, however, has impeded their biological exploration and clinical development6. Here we report a solution to the supply of GB18, a structural outlier and putative psychotropic principle of Galbulimima bark. Efficient access to its challenging tetrahedral attached-ring motif required the development of a ligand-controlled endo-selective cross-electrophile coupling and a diastereoselective hydrogenation of a rotationally dynamic pyridine. Reliable, gram-scale access to GB18 enabled its assignment as a potent antagonist of κ- and μ-opioid receptors-the first new targets in 35 years-and lays the foundation to navigate and understand the biological activity of Galbulimima metabolites.
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Affiliation(s)
- Stone Woo
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Ryan A Shenvi
- Department of Chemistry, Scripps Research, La Jolla, CA, USA.
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13
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Onuska NPR, Pierce JG. Synthesis reveals unexpected biological targets of a traditional medicine. Nature 2022; 606:869-870. [PMID: 35760965 DOI: 10.1038/d41586-022-01740-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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15
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Logviniuk D, Jaber QZ, Dobrovetsky R, Kozer N, Ksiezopolska E, Gabaldón T, Carmeli S, Fridman M. Benzylic Dehydroxylation of Echinocandin Antifungal Drugs Restores Efficacy against Resistance Conferred by Mutated Glucan Synthase. J Am Chem Soc 2022; 144:5965-5975. [PMID: 35347986 PMCID: PMC8991007 DOI: 10.1021/jacs.2c00269] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Each year, infections caused by fungal pathogens claim the lives of about 1.6 million people and affect the health of over a billion people worldwide. Among the most recently developed antifungal drugs are the echinocandins, which noncompetitively inhibit β-glucan synthase, a membrane-bound protein complex that catalyzes the formation of the main polysaccharide component of the fungal cell wall. Resistance to echinocandins is conferred by mutations in FKS genes, which encode the catalytic subunit of the β-glucan synthase complex. Here, we report that selective removal of the benzylic alcohol of the nonproteinogenic amino acid 3S,4S-dihydroxy-l-homotyrosine of the echinocandins anidulafungin and rezafungin, restored their efficacy against a large panel of echinocandin-resistant Candida strains. The dehydroxylated compounds did not significantly affect the viability of human-derived cell culture lines. An analysis of the efficacy of the dehydroxylated echinocandins against resistant Candida strains, which contain mutations in the FKS1 and/or FKS2 genes of the parental strains, identified amino acids of the Fks proteins that are likely to reside in proximity to the l-homotyrosine residue of the bound drug. This study describes the first example of a chemical modification strategy to restore the efficacy of echinocandin drugs, which have a critical place in the arsenal of antifungal drugs, against resistant fungal pathogens.
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Affiliation(s)
- Dana Logviniuk
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Qais Z Jaber
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roman Dobrovetsky
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Noga Kozer
- The Wohl Drug Discovery institute of the Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ewa Ksiezopolska
- Barcelona Supercomputing Centre (BSC-CNS), Jordi Girona, 29, Barcelona 08034, Spain.,Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain
| | - Toni Gabaldón
- Barcelona Supercomputing Centre (BSC-CNS), Jordi Girona, 29, Barcelona 08034, Spain.,Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Passeig de Lluís Companys, 23, Barcelona 08010, Spain.,Centro Investigación Biomédica En Red de Enfermedades Infecciosas, Madrid 28029, Spain
| | - Shmuel Carmeli
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Micha Fridman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
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16
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Luu QH, Li J. A C-to-O atom-swapping reaction sequence enabled by Ni-catalyzed decarbonylation of lactones. Chem Sci 2022; 13:1095-1100. [PMID: 35211275 PMCID: PMC8790783 DOI: 10.1039/d1sc06968c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/06/2022] [Indexed: 12/31/2022] Open
Abstract
Advances in site-selective functionalization reactions have enabled single atom changes on the periphery of a complex molecule, but reaction manifolds that enable such changes on the core framework of the molecule remain sparse. Here, we disclose a strategy for carbon-to-oxygen substitution in cyclic diarylmethanes and diarylketones to yield cyclic diarylethers. Oxygen atom insertion is accomplished by methylene and Baeyer-Villiger oxidations. To remove the carbon atom in this C-to-O "atom swap" process, we developed a nickel-catalyzed decarbonylation of lactones to yield the corresponding cyclic diaryl ethers. This reaction was enabled by mechanistic studies with stoichiometric nickel(ii) complexes that led to the optimization of a ligand capable of promoting a challenging C(sp2)-O(aryl) reductive elimination. The nickel-catalyzed decarbonylation was applied to 6-8 membered lactones (16 examples, 32-99%). Finally, a C-to-O atom-swapping reaction sequence was accomplished on a natural product and a pharmaceutical precursor.
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Affiliation(s)
- Quang H Luu
- Department of Chemistry, Iowa State University Ames IA 50011 USA
| | - Junqi Li
- Department of Chemistry, Iowa State University Ames IA 50011 USA
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17
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Boon BA, Yu YY, Boger DL. Total synthesis of (-)-4-desacetoxy-1-oxovindoline: Single atom exchange of an embedded core heteroatom in vindoline. Tetrahedron 2021; 87:132117. [PMID: 33994597 PMCID: PMC8117404 DOI: 10.1016/j.tet.2021.132117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A concise total synthesis of (-)-4-desacetoxy-1-oxovindoline is disclosed, bearing a single heteroatom exchange in the core structure of the natural product 4-desacetoxyvindoline. Central to the synthesis is powerful oxadiazole intramolecular [4+2]/[3+2] cycloaddition cascade that formed four C-C bonds, created three new rings, and established five contiguous stereocenters about the new formed central 6-membered ring.
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Affiliation(s)
- Byron A. Boon
- Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037
| | - Yi-Yun Yu
- Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037
| | - Dale L. Boger
- Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037
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18
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Abstract
Retrosynthetic analysis emerged in the 1960s as a teaching tool with profound implications. Its educational value can be appreciated by a glance at total synthesis manuscripts over 50 years later, most of which contain a retrosynthesis on page one. Its vision extended to computer language-a pioneering idea in the 20th century that continues to expand the frontiers today. The same principles that guide a student to evaluate, expand, and refine a series of bond dissections can be programmed, so that computer assistance can perform the same tasks but at faster speeds.The slow step in the synthesis of complex structures, however, is seldom route design. Compression of molecular information into close proximity (Cm/Å3) requires exploration and empiricism, a close connection between theory and experiment. Here, retrosynthetic analysis guides the choice of experiment, so that the most simplifying-but often least assured-disconnection is prioritized: a high-risk, high reward strategy. The reimagining of total synthesis in a future era of retrosynthetic software may involve, counterintuitively, target design, as discussed here.Compared to the 1960s, retrosynthetic analysis in the 21st century finds itself among computers of unimaginable power and a biology that is increasingly molecular. Put together, the logic of retrosynthesis, the insight of structural biology, and the predictions of computation have inspired us to imagine an integration of the three. The synthetic target is treated as dynamic-a constellation of related structures-in order to find the nearest congener with the closest affinity but the shortest synthetic route. Such an approach merges synthetic design with structural design toward the goal of improved access for improved function.In this Account, we detail the evolution of our program from its inception in traditional natural product (NP) total synthesis to its current expression through the lens of chemical informatics: a view of NPs as aggregates of molecular parameters that define single points in a chemical space. Early work on synthesis and biological annotation of apparent metal pool binders and nonselective covalent electrophiles (asmarine alkaloids, isocyanoterpenes, Nuphar dimers) gave way to NPs with well-defined protein targets. The plant metabolite salvinorin A (SalA) potently and selectively agonizes the κ-opioid receptor (KOR), rapidly penetrates the brain, and represents an important lead for next-generation analgesics and antipruritics. To synthesize and diversify this lead, we adopted what we now call a dynamic approach. Deletion of a central methyl group stabilized the SalA scaffold, opened quick synthetic access, and retained high potency and selectivity. The generality of this idea was then tested against another neuroactive class. As an alternative hypothesis to TrkB channels, we proposed that the so-called "neurotrophic" Illicium terpenes may bind to γ-aminobutyric acid (GABA)-gated ion channels to cause weak, chronic excitation. Syntheses of (-)-jiadifenolide, 3,6-dideoxy-10-hydroxypseudoanisatin, (-)-11-O-debenzoyltashironin, (-)-bilobalide, and (-)-picrotoxinin (PXN) allowed this hypothesis to be probed more broadly. Feedback from protein structure and synthetic reconnaissance led to a dynamic retrosynthesis of PXN and the identification of 5MePXN, a moderate GABAAR antagonist with greater aqueous stability available in eight steps from dimethylcarvone. We expect this dynamic approach to synthetic target analysis to become more feasible in the coming years and hope the next generation of scientists finds this approach helpful to address problems at the frontier of chemistry and biology.
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Affiliation(s)
- Stone Woo
- Department of Chemistry, Scripps Research, 10550 North Torrey Lines Road, La Jolla, California 92037, United States
| | - Ryan A Shenvi
- Department of Chemistry, Scripps Research, 10550 North Torrey Lines Road, La Jolla, California 92037, United States
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19
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Jena S, Tulsiyan KD, Kar RK, Kisan HK, Biswal HS. Doubling Förster Resonance Energy Transfer Efficiency in Proteins with Extrinsic Thioamide Probes: Implications for Thiomodified Nucleobases. Chemistry 2021; 27:4373-4383. [PMID: 33210381 DOI: 10.1002/chem.202004627] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Indexed: 12/29/2022]
Abstract
Designing a potential protein-ligand pair is pivotal, not only to track the protein structure dynamics, but also to assist in an atomistic understanding of drug delivery. Herein, the potential of a small model thioamide probe being used to study albumin proteins is reported. By monitoring the Förster resonance energy transfer (FRET) dynamics with the help of fluorescence spectroscopic techniques, a twofold enhancement in the FRET efficiency of 2-thiopyridone (2TPY), relative to that of its amide analogue, is observed. Molecular dynamics simulations depict the relative position of the free energy minimum to be quite stable in the case of 2TPY through noncovalent interactions with sulfur, which help to enhance the FRET efficiency. Finally, its application is shown by pairing thiouracils with protein. It is found that the site-selective sulfur atom substitution approach and noncovalent interactions with sulfur can substantially enhance the FRET efficiency, which could be a potential avenue to explore in the design of FRET probes to study the structure and dynamics of biomolecules.
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Affiliation(s)
- Subhrakant Jena
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Jatni, Khurda, Bhubaneswar, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Kiran Devi Tulsiyan
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Jatni, Khurda, Bhubaneswar, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Rajiv K Kar
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Hemanta K Kisan
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel.,Department of Chemistry, Utkal University, 751004, Bhubaneswar, India
| | - Himansu S Biswal
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Jatni, Khurda, Bhubaneswar, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
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20
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Liu Z, Lou J, Xiao J. TBAI/K2S2O8-Promoted [4 + 2] Annulation of Ketene N,S-Acetals and N-Tosylhydrazones toward Pyridazines. Org Lett 2021; 23:1606-1610. [DOI: 10.1021/acs.orglett.1c00026] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Zhuqing Liu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, P. R. China
- Advanced Research Institute for Multidisciplinary Science, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, P. R. China
| | - Jiang Lou
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, P. R. China
| | - Jiaqi Xiao
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, P. R. China
- Advanced Research Institute for Multidisciplinary Science, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, P. R. China
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21
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Anderson LL, Ametovski A, Lin Luo J, Everett-Morgan D, McGregor IS, Banister SD, Arnold JC. Cannabichromene, Related Phytocannabinoids, and 5-Fluoro-cannabichromene Have Anticonvulsant Properties in a Mouse Model of Dravet Syndrome. ACS Chem Neurosci 2021; 12:330-339. [PMID: 33395525 DOI: 10.1021/acschemneuro.0c00677] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cannabis-based products are increasingly being used to treat refractory childhood epilepsies such as Dravet syndrome. Cannabis contains at least 140 terpenophenolic compounds known as phytocannabinoids. These include the known anticonvulsant compound cannabidiol (CBD) and several molecules showing emergent anticonvulsant properties in animal models. Cannabichromene (CBC) is a phytocannabinoid frequently detected in artisanal cannabis oils used in the community by childhood epilepsy patients. Here we examined the brain and plasma pharmacokinetic profiles of CBC, cannabichromenic acid (CBCA), cannabichromevarin (CBCV), and cannabichromevarinic acid (CBCVA) following intraperitoneal administration in mice. The anticonvulsant potential of each was then tested against hyperthermia-induced seizures in the Scn1a+/- mouse model of Dravet syndrome. All phytocannabinoids within the CBC series were readily absorbed and showed substantial brain penetration (brain-plasma ratios ranging from 0.2 to 5.8). Anticonvulsant efficacy was evident with CBC, CBCA, and CBCVA, each significantly increasing the temperature threshold at which Scn1a+/- mice had a generalized tonic-clonic seizure. We synthesized a fluorinated derivative of CBC (5-fluoro-CBC), which showed improved brain penetration relative to the parent CBC molecule but not any greater anticonvulsant effect. Since CBC and derivatives are anticonvulsant in a model of intractable pediatric epilepsy, they may constitute part of the mechanism through which artisanal cannabis oils are anticonvulsant in patients.
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Affiliation(s)
- Lyndsey L. Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
| | - Adam Ametovski
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Jia Lin Luo
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Declan Everett-Morgan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
| | - Iain S. McGregor
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Samuel D. Banister
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Jonathon C. Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
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22
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Wu ZC, Boger DL. The quest for supernatural products: the impact of total synthesis in complex natural products medicinal chemistry. Nat Prod Rep 2020; 37:1511-1531. [PMID: 33169762 PMCID: PMC7678878 DOI: 10.1039/d0np00060d] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Covering: 2000 up to 2020This review presents select recent advances in the medicinal chemistry of complex natural products that are prepared by total synthesis. The underlying studies highlight enabling divergent synthetic strategies and methods that permit the systematic medicinal chemistry studies of key analogues bearing deep-seated structural changes not readily accessible by semisynthetic or biosynthetic means. Select and recent examples are detailed where the key structural changes are designed to improve defined properties or to overcome an intrinsic limitation of the natural product itself. In the examples presented, the synthetic efforts provided supernatural products, a term first introduced by our colleague Ryan Shenvi (Synlett, 2016, 27, 1145-1164), with properties superseding the parent natural product. The design principles and approaches for creating the supernatural products are highlighted with an emphasis on the properties addressed that include those that improve activity or potency, increase selectivity, enhance durability, broaden the spectrum of activity, improve chemical or metabolic stability, overcome limiting physical properties, add mechanisms of action, enhance PK properties, overcome drug resistance, and/or improve in vivo efficacy. Some such improvements may be regarded by some as iterative enhancements whereas others, we believe, truly live up to their characterization as supernatural products. Most such efforts are also accompanied by advances in synthetic organic chemistry, inspiring the development of new synthetic methodology and providing supernatural products with improved synthetic accessibility.
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Affiliation(s)
- Zhi-Chen Wu
- Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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23
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Gartshore C, Tadano S, Chanda PB, Sarkar A, Chowdari NS, Gangwar S, Zhang Q, Vite GD, Momirov J, Boger DL. Total Synthesis of Meayamycin and O-Acyl Analogues. Org Lett 2020; 22:8714-8719. [PMID: 33074680 DOI: 10.1021/acs.orglett.0c03308] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A short, scalable total synthesis of meayamycin is described by an approach that entails a longest linear sequence of 12 steps (22 steps overall) from commercially available chiral pool materials (ethyl l-lactate, BocNH-Thr-OH, and d-ribose) and introduces the most straightforward preparation of the right-hand subunit detailed to date. The use of the approach in the divergent synthesis of a representative series of O-acyl analogues is exemplified.
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Affiliation(s)
- Christopher Gartshore
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Shinji Tadano
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Prem B Chanda
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Anindya Sarkar
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Naidu S Chowdari
- Bristol Myers Squibb Research & Development, 700 Bay Road, Redwood City, California 94063, United States
| | - Sanjeev Gangwar
- Bristol Myers Squibb Research & Development, 700 Bay Road, Redwood City, California 94063, United States
| | - Qian Zhang
- Bristol Myers Squibb Research & Development, 700 Bay Road, Redwood City, California 94063, United States
| | - Gregory D Vite
- Bristol Myers Squibb Research & Development, 700 Bay Road, Redwood City, California 94063, United States.,Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, New Jersey 08543 United States
| | - Jelena Momirov
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dale L Boger
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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24
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Chow S, Krainz T, Bettencourt CJ, Broit N, Ferguson B, Zhu M, Hull KG, Pierens GK, Bernhardt PV, Parsons PG, Romo D, Boyle GM, Williams CM. Synthetic Tigliane Intermediates Engage Thiols to Induce Potent Cell Line Selective Anti‐Cancer Activity. Chemistry 2020; 26:13372-13377. [DOI: 10.1002/chem.202003221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/31/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Sharon Chow
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 Queensland Australia
| | - Tanja Krainz
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 Queensland Australia
| | - Christian J. Bettencourt
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 Queensland Australia
| | - Natasa Broit
- QIMR Berghofer Medical Research Institute PO Royal Brisbane Hospital Brisbane 4029 Queensland Australia
| | - Blake Ferguson
- QIMR Berghofer Medical Research Institute PO Royal Brisbane Hospital Brisbane 4029 Queensland Australia
| | - Mingzhao Zhu
- Department of Chemistry and Biochemistry CPRIT Synthesis and Drug-Lead Discovery Laboratory) Baylor University 76798 Waco Texas USA
| | - Kenneth G. Hull
- Department of Chemistry and Biochemistry CPRIT Synthesis and Drug-Lead Discovery Laboratory) Baylor University 76798 Waco Texas USA
| | - Gregory K. Pierens
- Centre for Advanced Imaging The University of Queensland Brisbane 4072 Queensland Australia
| | - Paul V. Bernhardt
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 Queensland Australia
| | - Peter G. Parsons
- QIMR Berghofer Medical Research Institute PO Royal Brisbane Hospital Brisbane 4029 Queensland Australia
| | - Daniel Romo
- Department of Chemistry and Biochemistry CPRIT Synthesis and Drug-Lead Discovery Laboratory) Baylor University 76798 Waco Texas USA
| | - Glen M. Boyle
- QIMR Berghofer Medical Research Institute PO Royal Brisbane Hospital Brisbane 4029 Queensland Australia
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane 4072 Queensland Australia
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25
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Moore MJ, Qu S, Tan C, Cai Y, Mogi Y, Jamin Keith D, Boger DL. Next-Generation Total Synthesis of Vancomycin. J Am Chem Soc 2020; 142:16039-16050. [PMID: 32885969 DOI: 10.1021/jacs.0c07433] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A next-generation total synthesis of vancomycin aglycon is detailed that was achieved in 17 steps (longest linear sequence, LLS) from the constituent amino acid subunits with kinetically controlled diastereoselective introduction of all three elements of atropisomerism. In addition to new syntheses of three of the seven amino acid subunits, highlights of the approach include a ligand-controlled atroposelective one-pot Miyaura borylation-Suzuki coupling sequence for introduction of the AB biaryl axis of chirality (>20:1 dr), an essentially instantaneous and scalable macrolactamization of the AB ring system nearly free of competitive epimerization (>30:1 dr), and two room-temperature atroposelective intramolecular SNAr cyclizations for sequential CD (8:1 dr) and DE ring closures (14:1 dr) that benefit from both preorganization by the preformed AB ring system and subtle substituent effects. Combined with a protecting group free two-step enzymatic glycosylation of vancomycin aglycon, this provides a 19-step total synthesis of vancomycin. The approach paves the way for large-scale synthetic preparation of pocket-modified vancomycin analogues that directly address the underlying mechanism of resistance to vancomycin.
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Affiliation(s)
- Maxwell J Moore
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Shiwei Qu
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Ceheng Tan
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Yu Cai
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Yuzo Mogi
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - D Jamin Keith
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dale L Boger
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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26
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Wu ZC, Cameron MD, Boger DL. Vancomycin C-Terminus Guanidine Modifications and Further Insights into an Added Mechanism of Action Imparted by a Peripheral Structural Modification. ACS Infect Dis 2020; 6:2169-2180. [PMID: 32598127 DOI: 10.1021/acsinfecdis.0c00258] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A series of vancomycin C-terminus guanidine modifications is disclosed that improves antimicrobial activity, enhances the durability of antimicrobial action against selection or induction of resistance, and introduces a synergistic mechanism of action independent of d-Ala-d-Ala binding and inhibition of cell wall biosynthesis. The added mechanism of action results in induced bacterial cell permeability, which we show may involve interaction with cell envelope teichoic acid. Significantly, the compounds examined that contain two combined peripheral modifications, a (4-chlorobiphenyl)methyl (CBP) and C-terminus guanidinium modification, offer opportunities for new treatments against not only vancomycin-sensitive but especially vancomycin-resistant bacteria where they act by two synergistic and now durable mechanisms of action independent of d-Ala-d-Ala/d-Lac binding and display superb antimicrobial potencies (MIC 0.6-0.15 μg/mL, VanA VRE). For the first time, we demonstrate that the synergistic behavior of the peripheral modifications examined requires the presence of both the CBP and guanidine modifications in a single molecule versus their combined use as an equimolar mixture of singly modified compounds. Finally, we show that a prototypical member of the series, G3-CBP-vancomycin (15), exhibits no hemolytic activity, displays no mammalian cell growth inhibition, possesses improved and especially attractive in vivo pharmacokinetic (PK) properties, and displays excellent in vivo efficacy and potency against an especially challenging multidrug-resistant (MRSA) and VanA vancomycin-resistant (VRSA) Staphylococcus aureus bacterial strain.
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Affiliation(s)
- Zhi-Chen Wu
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States
| | - Michael D. Cameron
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Dale L. Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States
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27
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Carlström KE, Chinthakindi PK, Espinosa B, Al Nimer F, Arnér ESJ, Arvidsson PI, Piehl F, Johansson K. Characterization of More Selective Central Nervous System Nrf2-Activating Novel Vinyl Sulfoximine Compounds Compared to Dimethyl Fumarate. Neurotherapeutics 2020; 17:1142-1152. [PMID: 32394330 PMCID: PMC7609514 DOI: 10.1007/s13311-020-00855-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Nrf2 transcription factor is a key regulator of redox reactions and considered the main target for the multiple sclerosis (MS) drug dimethyl fumarate (DMF). However, exploration of additional Nrf2-activating compounds is motivated, since DMF displays significant off-target effects and has a relatively poor penetrance to the central nervous system (CNS). We de novo synthesized eight vinyl sulfone and sulfoximine compounds (CH-1-CH-8) and evaluated their capacity to activate the transcription factors Nrf2, NFκB, and HIF1 in comparison with DMF using the pTRAF platform. The novel sulfoximine CH-3 was the most promising candidate and selected for further comparison in vivo and later an experimental model for traumatic brain injury (TBI). CH-3 and DMF displayed comparable capacity to activate Nrf2 and downstream transcripts in vitro, but with less off-target effects on HIF1 from CH-3. This was verified in cultured microglia and oligodendrocytes (OLs) and subsequently in vivo in rats. Following TBI, DMF lowered the number of leukocytes in blood and also decreased axonal degeneration. CH-3 preserved or increased the number of pre-myelinating OL. While both CH-3 and DMF activated Nrf2, CH-3 showed less off-target effects and displayed more selective OL associated effects. Further studies with Nrf2-acting compounds are promising candidates to explore potential myelin protective or regenerative effects in demyelinating disorders.
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Affiliation(s)
- Karl E Carlström
- Department of Clinical Neurosciences, Section of Neurology, Karolinska Institutet, 17177, Stockholm, Sweden.
| | - Praveen K Chinthakindi
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban, 4000, South Africa
- Department of Medicinal Chemistry, Drug Design and Discovery, Uppsala University, Box 574, 75123, Uppsala, Sweden
| | - Belén Espinosa
- Department of Medical Biochemistry and Biophysics, Division of Biochemistry, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Faiez Al Nimer
- Department of Clinical Neurosciences, Section of Neurology, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Elias S J Arnér
- Department of Medical Biochemistry and Biophysics, Division of Biochemistry, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban, 4000, South Africa
- Department of Medical Biochemistry and Biophysics, Science for Life Laboratory, Drug Discovery and Development Platform and Division of Translational Medicine and Chemical Biology, Karolinska Institutet, 171 21, Solna, Sweden
| | - Fredrik Piehl
- Department of Clinical Neurosciences, Section of Neurology, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Katarina Johansson
- Department of Medical Biochemistry and Biophysics, Division of Biochemistry, Karolinska Institutet, 17177, Stockholm, Sweden
- Pfizer Innovation AB, 19190, Sollentuna, Sweden
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28
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Pennington LD, Aquila BM, Choi Y, Valiulin RA, Muegge I. Positional Analogue Scanning: An Effective Strategy for Multiparameter Optimization in Drug Design. J Med Chem 2020; 63:8956-8976. [PMID: 32330036 DOI: 10.1021/acs.jmedchem.9b02092] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Minimizing the number and duration of design cycles needed to optimize hit or lead compounds into high-quality chemical probes or drug candidates is an ongoing challenge in biomedical research. Small structure modifications to hit or lead compounds can have meaningful impacts on pharmacological profiles due to significant effects on molecular and physicochemical properties and intra- and intermolecular interactions. Rapid pharmacological profiling of an efficiently prepared series of positional analogues stemming from the systematic exchange of methine groups with heteroatoms or other substituents in aromatic or heteroaromatic ring-containing hit or lead compounds is one approach toward minimizing design cycles (e.g., exchange of aromatic or heteroaromatic CH groups with N atoms or CF, CMe, or COH groups). In this Perspective, positional analogue scanning is shown to be an effective strategy for multiparameter optimization in drug design, whereby substantial improvements in a variety of pharmacological parameters can be achieved.
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29
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Chinthakindi PK, Benediktsdottir A, Arvidsson PI, Chen Y, Sandström A. Solid Phase Synthesis of Sulfonimidamide Pseudopeptides and Library Generation. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Praveen K. Chinthakindi
- The Beijer Laboratory; Department of Medicinal Chemistry; Uppsala University; Box 574 75123 Uppsala Sweden
| | - Andrea Benediktsdottir
- The Beijer Laboratory; Department of Medicinal Chemistry; Uppsala University; Box 574 75123 Uppsala Sweden
| | - Per I. Arvidsson
- Science for Life Laboratory; Drug Discovery and Development Platform and Division of Translational Medicine and Chemical Biology; Karolinska Institutet; 17177 Stockholm Sweden
- Catalysis and Peptide Research Unit; Drug Discovery and Development Platform and Division of Translational Medicine and Chemical Biology; University of KwaZulu-Natal; 4000 Durban South Africa
| | - Yantao Chen
- Medicinal Chemistry; Research and Early Development, Cardiovascular, Renal and Metabolism; AstraZeneca; 43183 Gothenburg Sweden
| | - Anja Sandström
- The Beijer Laboratory; Department of Medicinal Chemistry; Uppsala University; Box 574 75123 Uppsala Sweden
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30
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Wu ZC, Isley NA, Okano A, Weiss WJ, Boger DL. C1-CBP-vancomycin: Impact of a Vancomycin C-Terminus Trimethylammonium Cation on Pharmacological Properties and Insights into Its Newly Introduced Mechanism of Action. J Org Chem 2019; 85:1365-1375. [PMID: 31670958 DOI: 10.1021/acs.joc.9b02314] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
C1-CBP-vancomycin (3) was examined alongside CBP-vancomycin for susceptibility to acquired resistance upon serial exposure against two vancomycin-resistant enterococci strains where its activity proved more durable and remarkably better than many current therapies. Combined with earlier studies, this observation confirmed an added mechanism of action was introduced by incorporation of the trimethylammonium cation and that C1-CBP-vancomycin exhibits activity against vancomycin-resistant organisms through two synergistic mechanisms of action, both independent of d-Ala-d-Ala/d-Lac binding. New insights into this added mechanism of action, induced cell membrane permeabilization, can be inferred from studies that show added exogenous lipoteichoic acid reduces antimicrobial activity, rescues bacteria cell growth inhibition, and blocks induced cell permeabilization properties of C1-CBP-vancomycin, suggesting a direct binding interaction with embedded teichoic acid is responsible for the added mechanism of action and enhanced antimicrobial activity. Further studies indicate that the trimethylammonium cation does not introduce new liabilities in common pharmacological properties of the analogue and established that 3 is well tolerated in mice, displays substantial PK improvements over both vancomycin and CBP-vancomycin, and exhibits in vivo efficacy against a challenging multidrug-resistant and vancomycin-resistant S. aureus strain that is representative of the resistant pathogens all fear will emerge in the general population.
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Affiliation(s)
- Zhi-Chen Wu
- Department of Chemistry and Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Nicholas A Isley
- Department of Chemistry and Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Akinori Okano
- Department of Chemistry and Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - William J Weiss
- University of North Texas System , College of Pharmacy , Fort Worth , Texas 76107 , United States
| | - Dale L Boger
- Department of Chemistry and Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
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31
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Norwood VM, Huigens RW. Harnessing the Chemistry of the Indole Heterocycle to Drive Discoveries in Biology and Medicine. Chembiochem 2019; 20:2273-2297. [DOI: 10.1002/cbic.201800768] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Indexed: 01/09/2023]
Affiliation(s)
- Verrill M. Norwood
- Department of Medicinal ChemistryCenter for Natural Products Drug Discovery and Development (CNPD3)University of Florida 1345 Center Drive Gainesville FL 32610 USA
| | - Robert W. Huigens
- Department of Medicinal ChemistryCenter for Natural Products Drug Discovery and Development (CNPD3)University of Florida 1345 Center Drive Gainesville FL 32610 USA
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32
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Zhang J, Shukla V, Boger DL. Inverse Electron Demand Diels-Alder Reactions of Heterocyclic Azadienes, 1-Aza-1,3-Butadienes, Cyclopropenone Ketals, and Related Systems. A Retrospective. J Org Chem 2019; 84:9397-9445. [PMID: 31062977 DOI: 10.1021/acs.joc.9b00834] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A summary of the investigation and applications of the inverse electron demand Diels-Alder reaction is provided that have been conducted in our laboratory over a period that now spans more than 35 years. The work, which continues to provide solutions to complex synthetic challenges, is presented in the context of more than 70 natural product total syntheses in which the reactions served as a key strategic step in the approach. The studies include the development and use of the cycloaddition reactions of heterocyclic azadienes (1,2,4,5-tetrazines; 1,2,4-, 1,3,5-, and 1,2,3-triazines; 1,2-diazines; and 1,3,4-oxadiazoles), 1-aza-1,3-butadienes, α-pyrones, and cyclopropenone ketals. Their applications illustrate the power of the methodology, often provided concise and nonobvious total syntheses of the targeted natural products, typically were extended to the synthesis of analogues that contain deep-seated structural changes in more comprehensive studies to explore or optimize their biological properties, and highlight a wealth of opportunities not yet tapped.
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Affiliation(s)
- Jiajun Zhang
- Department of Chemistry and The Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Vyom Shukla
- Department of Chemistry and The Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Dale L Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
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33
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Radakovic A, Boger DL. Ultra-potent vinblastine analogues improve on-target activity of the parent microtubulin-targeting compound. Bioorg Med Chem Lett 2019; 29:1370-1374. [PMID: 30952593 DOI: 10.1016/j.bmcl.2019.03.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/21/2019] [Accepted: 03/25/2019] [Indexed: 10/27/2022]
Abstract
In recent efforts, several C20' urea vinblastine analogues were discovered that displayed remarkable potency against vinblastine-sensitive tumor cell lines (IC50 50-75 pM), being roughly 100-fold more potent than vinblastine, and that exhibited decreased susceptibility to Pgp efflux-derived resistance in a vinblastine-resistant cell line. Their extraordinary activity indicate that it is not likely or even possible that their cellular functional activity is derived from stoichiometric occupancy of the intracellular tubulin binding sites. Rather, their potency indicates sub-stoichiometric or even catalytic occupancy of candidate binding sites may be sufficient to disrupt tubulin dynamics or microtubule assembly during mitosis. We detail efforts to delineate the underlying behavior responsible for the increased potency and show that the ultra-potent extended C20' ureas retain the mechanistic behavior of vinblastine, display enhanced affinity for tubulin and on-target activity approximately 100-fold both in vitro and in HeLa cells, but do not show evidence of catalytic disassembly of microtubulin. We also use the analogues to show that, in live interphase cells, the effects of the vinblastine class of drugs do not display a catastrophic effect on the microtubule skeleton, but rather a subtler insult to its dynamicity, acting as sub-stoichiometric drugs that inhibit normal microtubulin maturation and dynamics.
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Affiliation(s)
- Aleksandar Radakovic
- Department of Chemistry and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Dale L Boger
- Department of Chemistry and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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34
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Huffman BJ, Shenvi RA. Natural Products in the "Marketplace": Interfacing Synthesis and Biology. J Am Chem Soc 2019; 141:3332-3346. [PMID: 30682249 PMCID: PMC6446556 DOI: 10.1021/jacs.8b11297] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Drugs are discovered through the biological screening of collections of compounds, followed by optimization toward functional end points. The properties of screening collections are often balanced between diversity, physicochemical favorability, intrinsic complexity, and synthetic tractability (Huggins, D. J.; et al. ACS Chem. Biol. 2011, 6, 208; DOI: 10.1021/cb100420r ). Whereas natural product (NP) collections excel in the first three attributes, NPs suffer a disadvantage on the last point. Academic total synthesis research has worked to solve this problem by devising syntheses of NP leads, diversifying late-stage intermediates, or derivatizing the NP target. This work has led to the discovery of reaction mechanisms, the invention of new methods, and the development of FDA-approved drugs. Few drugs, however, are themselves NPs; instead, NP analogues predominate. Here we highlight past examples of NP analogue development and successful NP-derived drugs. More recently, chemists have explored how NP analogues alter the retrosynthetic analysis of complex scaffolds, merging structural design and synthetic design. This strategy maintains the intrinsic complexity of the NP but can alter the physicochemical properties of the scaffold, like core instability that renders the NP a poor chemotype. Focused libraries based on these syntheses may exclude the NP but maintain the molecular properties that distinguish NP space from synthetic space (Stratton, C. F.; et al. Bioorg. Med. Chem. Lett. 2015, 25, 4802; DOI: 10.1016/j.bmcl.2015.07.014 ), properties that have statistical advantages in clinical progression (Luker, T.; et al. Bioorg. Med. Chem. Lett. 2011, 21, 5673, DOI: 10.1016/j.bmcl.2011.07.074 ; Ritchie, T. J.; Macdonald, S. J. F. Drug Discovery Today 2009, 14, 1011, DOI: 10.1016/j.drudis.2009.07.014 ). Research that expedites synthetic access to NP motifs can prevent homogeneity of chemical matter available for lead discovery. Easily accessed, focused libraries of NP scaffolds can fill empty but active gaps in screening sets and expand the molecular diversity of synthetic collections.
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Affiliation(s)
- Benjamin J. Huffman
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Ryan A. Shenvi
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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35
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Chinthakindi PK, Benediktsdottir A, Ibrahim A, Wared A, Aurell CJ, Pettersen A, Zamaratski E, Arvidsson PI, Chen Y, Sandström A. Synthesis of Sulfonimidamide-Based Amino Acid Building Blocks with Orthogonal Protecting Groups. European J Org Chem 2019. [DOI: 10.1002/ejoc.201801541] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Praveen K. Chinthakindi
- Department of Medicinal Chemistry; Drug Design and Discovery; Uppsala University, Box 574, 75123; Uppsala Sweden
| | - Andrea Benediktsdottir
- Department of Medicinal Chemistry; Drug Design and Discovery; Uppsala University, Box 574, 75123; Uppsala Sweden
| | - Ayah Ibrahim
- Department of Medicinal Chemistry; Drug Design and Discovery; Uppsala University, Box 574, 75123; Uppsala Sweden
| | - Atta Wared
- Department of Medicinal Chemistry; Drug Design and Discovery; Uppsala University, Box 574, 75123; Uppsala Sweden
| | - Carl-Johan Aurell
- Large Scale Chemistry; Early Chemical Development; AstraZeneca; 83 Gothenburg Sweden
| | - Anna Pettersen
- Early Product Development; Pharmaceutical Sciences; IMED Biotech Unit; AstraZeneca; 83 Gothenburg Sweden
| | - Edouard Zamaratski
- Department of Medicinal Chemistry; Drug Design and Discovery; Uppsala University, Box 574, 75123; Uppsala Sweden
| | - Per I. Arvidsson
- Science for Life Laboratory; Drug Discovery and Development Platform and Division of Translational Medicine and Chemical Biology; Department of Medical Biochemistry and Biophysics; Karolinska Institutet; 171 77 Stockholm Sweden
- Catalysis and Peptide Research Unit; University of KwaZulu Natal; 4000 Durban South Africa
| | - Yantao Chen
- Medicinal Chemistry; Cardiovascular Renal and Metabolism; IMED Biotech Unit; AstraZeneca; 431 83 Gothenburg Sweden
| | - Anja Sandström
- Department of Medicinal Chemistry; Drug Design and Discovery; Uppsala University, Box 574, 75123; Uppsala Sweden
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36
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Gorka AP, Nani RR, Schnermann MJ. Harnessing Cyanine Reactivity for Optical Imaging and Drug Delivery. Acc Chem Res 2018; 51:3226-3235. [PMID: 30418020 DOI: 10.1021/acs.accounts.8b00384] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Optical approaches that visualize and manipulate biological processes have transformed modern biomedical research. An enduring challenge is to translate these powerful methods into increasingly complex physiological settings. Longer wavelengths, typically in the near-infrared (NIR) range (∼650-900 nm), can enable advances in both fundamental and clinical settings; however, suitable probe molecules are needed. The pentamethine and heptamethine cyanines, led by prototypes Cy5 and Cy7, are among the most useful compounds for fluorescence-based applications, finding broad use in a range of contexts. The defining chemical feature of these molecules, and the key chromophoric element, is an odd-numbered polymethine that links two nitrogen atoms. Not only a light-harvesting functional group, the cyanine chromophore is subject to thermal and photochemical reactions that dramatically alter many properties of these molecules. This Account describes our recent studies to define and use intrinsic cyanine chromophore reactivity. The hypothesis driving this research is that novel chemistries that manipulate the cyanine chromophore can be used to address challenging problems in the areas of imaging and drug delivery. We first review reaction discovery efforts that seek to address two limitations of long-wavelength fluorophores: undesired thiol reactivity and modest fluorescence quantum yield. Heptamethine cyanines with an O-alkyl substituent at the central C4' carbon were prepared through a novel N- to O-transposition reaction. Unlike commonly used C4'-phenol variants, this new class of fluorophores is resistant to thiol modification and exhibits improved in vivo imaging properties when used as antibody tags. We have also developed a chemical strategy to enhance the quantum yield of far-red pentamethine cyanines. Using a synthetic strategy involving a cross metathesis/tetracyclization sequence, this approach conformationally restrains the pentamethine cyanine scaffold. The resulting molecules exhibit enhanced quantum yield (ΦF = 0.69 vs ΦF = 0.15). Furthermore, conformational restraint improves interconversion between reduced hydrocyanine and intact cyanine forms, which enables super resolution microscopy. This Account then highlights efforts to use cyanine photochemical reactivity for NIR photocaging. Our approach involves the deliberate use of cyanine photooxidation, a reaction previously only associated with photodegradation. The uncaging reaction sequence is initiated by photooxidative chromophore cleavage (using wavelengths of up to 780 nm), which prompts a C-N bond hydrolysis/cyclization sequence resulting in phenol liberation. This approach has been applied to generate the first NIR-activated antibody-drug conjugates. Tumor uptake can be monitored in vivo using NIR fluorescence, prior to uncaging with an external irradiation source. This NIR uncaging strategy can slow tumor progression and increase survival in a MDA-MB-468- luc mouse model. Broadly, the vantage point of cyanine reactivity is providing novel probe molecules with auspicious features for use in complex imaging and drug delivery settings.
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Affiliation(s)
- Alexander P. Gorka
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 20850, United States
| | - Roger R. Nani
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 20850, United States
| | - Martin J. Schnermann
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 20850, United States
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Suen LM, Tekle-Smith MA, Williamson KS, Infantine JR, Reznik SK, Tanis PS, Casselman TD, Sackett DL, Leighton JL. Design and 22-step synthesis of highly potent D-ring modified and linker-equipped analogs of spongistatin 1. Nat Commun 2018; 9:4710. [PMID: 30413713 PMCID: PMC6226463 DOI: 10.1038/s41467-018-07259-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 10/24/2018] [Indexed: 12/03/2022] Open
Abstract
Spongistatin 1 is among the most potent anti-proliferative agents ever discovered rendering it an attractive candidate for development as a payload for antibody-drug conjugates and other targeted delivery approaches. Unfortunately, it is unavailable from natural sources and its size and complex stereostructure render chemical synthesis highly time- and resource-intensive. As a result, the design and synthesis of more acid-stable and linker functional group-equipped analogs that retain the low picomolar potency of the parent natural product requires more efficient and step-economical synthetic access. Using uniquely enabling direct complex fragment coupling crotyl- and alkallylsilylation reactions, we report a 22-step synthesis of a rationally designed D-ring modified analog of spongistatin 1 that is characterized by GI50 values in the low picomolar range, and a proof-of-concept result that the C(15) acetate may be replaced with linker functional group-bearing esters with only minimal reductions in potency.
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Affiliation(s)
- Linda M Suen
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | | | | | | | - Samuel K Reznik
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Paul S Tanis
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Tyler D Casselman
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Dan L Sackett
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - James L Leighton
- Department of Chemistry, Columbia University, New York, NY, 10027, USA.
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38
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Crnovcic I, Gan F, Yang D, Dong LB, Schultz PG, Shen B. Activities of recombinant human bleomycin hydrolase on bleomycins and engineered analogues revealing new opportunities to overcome bleomycin-induced pulmonary toxicity. Bioorg Med Chem Lett 2018; 28:2670-2674. [PMID: 29730026 DOI: 10.1016/j.bmcl.2018.04.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 02/08/2023]
Abstract
The bleomycins (BLMs) are widely used in combination therapies for the treatment of various cancers. Dose-dependent and cumulative pulmonary toxicity is the major cause of BLM-associated morbidity, limiting the broad uses of BLMs as anticancer drugs. The organ specificity of BLM-induced toxicity has been correlated with the expression of the hBLMH gene, encoding the human bleomycin hydrolase (hBLMH), which is poorly expressed in the lung. hBLMH hydrolyzes BLMs into the biologically inactive deamido BLMs, thereby protecting organs from BLM-induced toxicity. Here we report (i) expression of hBLMH and production and isolation of recombinant human bleomycin hydrolase (rhBLMH) from E. coli, (ii) structural characterization of deamido BLM A2 and B2 isolated from rhBLMH-catalyzed hydrolysis of BLM A2 and B2, and (iii) kinetic characterization of the rhBLMH-catalyzed hydrolysis of BLM A2 and B2, in comparison with five BLM analogues. rhBLMH from E. coli catalyzes rapid and efficient hydrolysis of all BLMs tested, exhibiting a superior catalytic efficiency for BLM B2. These findings reveal new opportunities to overcome BLM-induced pulmonary toxicity in chemotherapies, potentially by exploring BLM B2 as the preferred congener, engineering designer BLMs with optimized activity for rhBLMH, or co-administrating rhBLMH directly into the lung as a potential protein therapeutic.
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Affiliation(s)
- Ivana Crnovcic
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States
| | - Fei Gan
- California Institute for Biomedical Research, La Jolla, CA 92037, United States
| | - Dong Yang
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States
| | - Liao-Bin Dong
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States
| | - Peter G Schultz
- California Institute for Biomedical Research, La Jolla, CA 92037, United States; Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Ben Shen
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States; Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, United States; Natural Products Library Initiative at The Scripps Research Institute, The Scripps Research Institute, Jupiter, FL 33458, United States.
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39
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Hirasawa S, Cho M, Brust TF, Roach JJ, Bohn LM, Shenvi RA. O6C-20-nor-salvinorin A is a stable and potent KOR agonist. Bioorg Med Chem Lett 2018; 28:2770-2772. [PMID: 29426768 PMCID: PMC6067998 DOI: 10.1016/j.bmcl.2018.01.055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 11/18/2022]
Abstract
Salvinorin A (SalA) is a potent and selective agonist of the kappa-opioid receptor (KOR), but its instability has frustrated medicinal chemistry efforts. Treatment of SalA with weak bases like DBU leads to C8 epimerization with loss of receptor affinity and signaling potency. Here we show that replacement of C20 with H and replacement of O6 with CH2 stabilizes the SalA scaffold relative to its C8 epimer, so much so that epimerization is completely supressed. This new compound, O6C-20-nor-SalA, retains high potency for agonism of KOR.
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Affiliation(s)
- Shun Hirasawa
- The Scripps Research Institute, Department of Chemistry, La Jolla, CA 92037, United States
| | - Min Cho
- The Scripps Research Institute, Department of Chemistry, La Jolla, CA 92037, United States
| | - Tarsis F Brust
- The Scripps Research Institute, Departments of Molecular Medicine and Neuroscience,Jupiter, FL 33458, United States
| | - Jeremy J Roach
- The Scripps Research Institute, Department of Chemistry, La Jolla, CA 92037, United States
| | - Laura M Bohn
- The Scripps Research Institute, Departments of Molecular Medicine and Neuroscience,Jupiter, FL 33458, United States
| | - Ryan A Shenvi
- The Scripps Research Institute, Department of Chemistry, La Jolla, CA 92037, United States.
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40
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Aufiero M, Gilmour R. Informing Molecular Design by Stereoelectronic Theory: The Fluorine Gauche Effect in Catalysis. Acc Chem Res 2018; 51:1701-1710. [PMID: 29894155 DOI: 10.1021/acs.accounts.8b00192] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The axioms of stereoelectronic theory constitute an atlas to navigate the contours of molecular space. All too rarely lauded, the advent and development of stereoelectronic theory has been one of organic chemistry's greatest triumphs. Inevitably, however, in the absence of a comprehensive treatise, many of the field's pioneers do not receive the veneration that they merit. Rather their legacies are the stereoelectronic pillars that persist in teaching and research. This ubiquity continues to afford practitioners of organic chemistry with an abundance of opportunities for creative endeavor in reaction design, in conceiving novel activation modes, in preorganizing intermediates, or in stabilizing productive transition states and products. Antipodal to steric governance, which mitigates destabilizing nonbonding interactions, stereoelectronic control allows well-defined, often complementary, conformations to be populated. Indeed, the prevalence of stabilizing hyperconjugative interactions in biosynthetic processes renders this approach to molecular preorganization decidedly biomimetic and, by extension, expansive. In this Account, the evolution and application of a simple donor-acceptor model based on the fluorine gauche effect is delineated. Founded on reinforcing hyperconjugative interactions involving C(sp3)-H bonding orbitals and C(sp3)-X antibonding orbitals [σC-H → σC-X*], this general stratagem has been used in conjunction with an array of secondary noncovalent interactions to achieve acyclic conformational control (ACC) in structures of interest. These secondary effects range from 1,3-allylic strain (A1,3) through to electrostatic charge-dipole and cation-π interactions. Synergy between these interactions ensures that rotation about strategic C(sp3)-C(sp3) bonds is subject to the stereoelectronic requirement for antiperiplanarity (180°). Logically, in a generic [X-CH2-CH2-Y] system (X, Y = electron withdrawing groups) conformations in which the two C(sp3)-X bonds are synclinal (i.e., gauche) are significantly populated. As such, simple donor-acceptor models are didactically and predictively powerful in achieving topological preorganization. In the case of the gauche effect, the low steric demand of fluorine ensures that the remaining substituents at the C(sp3) hybridized center are placed in a predictable area of molecular space: An exit vector analogy is thus appropriate. Furthermore, the intrinsic chemical stability of the C-F bond is advantageous, thus it may be considered as an inert conformational steering group: This juxtaposition of size and electronegativity renders fluorinated organic molecules unique among the organo-halogen series. Cognizant that the replacement of one fluorine atom in the difluoroethylene motif by another electron withdrawing group preserves the gauche conformation, it was reasoned that β-fluoroamines would be intriguing candidates for investigation. The burgeoning field of Lewis base catalysis, particularly via iminium ion activation, provided a timely platform from which to explore a postulated fluorine-iminium ion gauche effect. Necessarily, activation of this stereoelectronic effect requires a process of intramolecularization to generate the electron deficient neighboring group: Examples include protonation, condensation to generate iminium salts, or acylation. This process, akin to substrate binding, has obvious parallels with enzymatic catalysis, since it perturbs the conformational dynamics of the system [ synclinal-endo, antiperiplanar, synclinal-exo]. This Account details the development of conformationally predictable small molecules based on the [X-Cα-Cβ-F] motif through a logical process of molecular design and illustrates their synthetic value in enantioselective catalysis.
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Affiliation(s)
- Marialuisa Aufiero
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
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Schoppet M, Tailhades J, Kulkarni K, Cryle MJ. Precursor Manipulation in Glycopeptide Antibiotic Biosynthesis: Are β-Amino Acids Compatible with the Oxidative Cyclization Cascade? J Org Chem 2018; 83:7206-7214. [DOI: 10.1021/acs.joc.8b00418] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Melanie Schoppet
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | | | | | - Max J. Cryle
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
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42
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Velcicky J, Schlapbach A, Heng R, Revesz L, Pflieger D, Blum E, Hawtin S, Huppertz C, Feifel R, Hersperger R. Modulating ADME Properties by Fluorination: MK2 Inhibitors with Improved Oral Exposure. ACS Med Chem Lett 2018; 9:392-396. [PMID: 29670707 DOI: 10.1021/acsmedchemlett.8b00098] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 03/16/2018] [Indexed: 02/07/2023] Open
Abstract
MAP-activated protein kinase 2 (MK2) plays an important role in the regulation of innate immune response as well as in cell survival upon DNA damage. Despite its potential for the treatment of inflammation and cancer, to date no MK2 low molecular weight inhibitors have reached the clinic, mainly due to inadequate absorption, distribution, metabolism, and excretion (ADME) properties. We describe here an approach based on specifically placed fluorine within a recently described pyrrole-based MK2 inhibitor scaffold for manipulation of its physicochemical and ADME properties. While preserving target potency, the novel fluoro-derivatives showed greatly improved permeability as well as enhanced solubility and reduced in vivo clearance leading to significantly increased oral exposure.
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Affiliation(s)
- Juraj Velcicky
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Achim Schlapbach
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Richard Heng
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Laszlo Revesz
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Daniel Pflieger
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Ernst Blum
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Stuart Hawtin
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | | | - Roland Feifel
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
| | - Rene Hersperger
- Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland
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43
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Abstract
Although vancomycin has been in clinical use since the late 1950s, resistance due to alteration in the target microbe's peptidoglycan can vary significantly, reducing its activity. Total synthesis of derivatives has now led to a molecule with very significant activity against resistant strains.
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Affiliation(s)
- David J. Newman
- Newman Consulting LLC, Wayne, Pennsylvania 19087, United States
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44
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High expression of class III β-tubulin has no impact on functional cancer cell growth inhibition of a series of key vinblastine analogs. Bioorg Med Chem Lett 2018; 28:863-865. [PMID: 29439899 DOI: 10.1016/j.bmcl.2018.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/03/2018] [Accepted: 02/05/2018] [Indexed: 11/22/2022]
Abstract
Clinical association studies have implicated high expression of class III β-tubulin as a predictive factor for lower response rates and reduced overall survival in patients receiving tubulin binding drugs, most notably the taxanes. Because of the implications, we examined a series of key vinblastine analogs that emerged from our studies in functional cell growth inhibition assays for their sensitivity to high expression of class III β-tubulin (human non-small cell lung cancer cell line A549 vs taxol-resistant A549-T24). Unlike taxol, vinblastine and a set of key analogs 3-10 did not exhibit any loss in sensitivity toward A549-T24. The results suggest that vinblastine and related analogs are not likely prone to resistance derived from high expression of class III β-tubulin unlike the taxanes. Most significant are the results with 4-6, a subset of 20' amide vinblastine analogs. They match or exceed the potency of vinblastine and they display more potent activity against taxol-resistant A549-T24 than even wild type A549 cells (1.2-2-fold), complementing our prior observations that they also display no sensitivity to overexpression of Pgp (HCT116/VM46 vs HCT116) and are not subject to resistance derived from Pgp efflux.
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