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Minnick JL, Raincrow J, Meinders G, Latifi R, Tahsini L. Synthesis, Characterization, and Spectroscopic Studies of 2,6-Dimethylpyridyl-Linked Cu(I)-CNC Complexes: The Electronic Influence of Aryl Wingtips on Copper Centers. Inorg Chem 2023; 62:15912-15926. [PMID: 37715709 DOI: 10.1021/acs.inorgchem.3c01973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/18/2023]
Abstract
Six new Cu(I) complexes containing pincer ligands of the type 2,6-bis(3-alkyl/arylimidazol-2-ylidene) methylpyridine I(R/R'Ar) ĈN̂C, where R = trifluoroethyl (TFE) and R' = 4-CF3, 4-NO2, 4-CN, 4-H, and 4-CH3, have been synthesized. These complexes, namely, [Cu(I(TFE)ĈN̂C)]PF6, 1-TFE; [Cu(ICF3Ar ĈN̂C]PF6, 2-CF3; [Cu(INO2Ar ĈN̂C)]PF6, 3-NO2; [Cu(ICNAr ĈN̂C]PF6, 4-CN; [Cu(IHAr ĈN̂C)]2(PF6)2, 5-H; and [Cu(ICH3Ar ĈN̂C)]2(PF6)2, 6-CH3, were fully characterized by 1H, 13C, and HMBC NMR spectroscopy, elemental analysis, electrochemical studies, and single-crystal X-ray crystallography. The crystallographic data revealed different structures and copper nuclearities for the complexes bearing aryl wingtips with electron-withdrawing (2-CF3, 3-NO2, and 4-CN) and electron-donating (5-H and 6-CH3) substituents. The solution-phase conductivity measurements in acetonitrile revealed a mix-electrolyte behavior for these complexes, supporting the presence of both mono- and binuclear forms of each complex. The fast monomer-dimer equilibrium of the Cu-CNC complexes at room temperature is reflected in their simple 1H NMR spectra in acetonitrile. However, both mono- and binuclear forms were identifiable in 1H diffusion-ordered spectroscopy (DOSY) at low temperatures. The dynamic behavior of these complexes in solution was further examined by variable-temperature 1H NMR (VT 1H NMR) experiments, and the relevant thermodynamic parameters were determined. The process was also probed by one-dimensional rotating-frame Overhauser enhancement spectroscopy (1D ROESY) experiments to elucidate the coexisting species in solution. The 2,6-dimethylpyridyl-linked Cu-CNC complexes also presented a quasi-reversible Cu(II)/Cu(I) couple in cyclic voltammetry studies, wherein a clear influence of the aryl wingtips on the E1/2 values was observed. Furthermore, the percent buried volumes (% Vbur) of the complexes were calculated, showing a similar steric hindrance around copper in all complexes. These findings support the importance of electronic effects, induced by the aryl wingtips, on the preferred coordination geometry, copper nuclearity, and redox properties of the Cu-CNC complexes.
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Affiliation(s)
- Jennifer L Minnick
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - John Raincrow
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Grace Meinders
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Reza Latifi
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Laleh Tahsini
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States
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2
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Hegde M, Girisa S, Naliyadhara N, Kumar A, Alqahtani MS, Abbas M, Mohan CD, Warrier S, Hui KM, Rangappa KS, Sethi G, Kunnumakkara AB. Natural compounds targeting nuclear receptors for effective cancer therapy. Cancer Metastasis Rev 2023; 42:765-822. [PMID: 36482154 DOI: 10.1007/s10555-022-10068-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 11/03/2022] [Indexed: 12/13/2022]
Abstract
Human nuclear receptors (NRs) are a family of forty-eight transcription factors that modulate gene expression both spatially and temporally. Numerous biochemical, physiological, and pathological processes including cell survival, proliferation, differentiation, metabolism, immune modulation, development, reproduction, and aging are extensively orchestrated by different NRs. The involvement of dysregulated NRs and NR-mediated signaling pathways in driving cancer cell hallmarks has been thoroughly investigated. Targeting NRs has been one of the major focuses of drug development strategies for cancer interventions. Interestingly, rapid progress in molecular biology and drug screening reveals that the naturally occurring compounds are promising modern oncology drugs which are free of potentially inevitable repercussions that are associated with synthetic compounds. Therefore, the purpose of this review is to draw our attention to the potential therapeutic effects of various classes of natural compounds that target NRs such as phytochemicals, dietary components, venom constituents, royal jelly-derived compounds, and microbial derivatives in the establishment of novel and safe medications for cancer treatment. This review also emphasizes molecular mechanisms and signaling pathways that are leveraged to promote the anti-cancer effects of these natural compounds. We have also critically reviewed and assessed the advantages and limitations of current preclinical and clinical studies on this subject for cancer prophylaxis. This might subsequently pave the way for new paradigms in the discovery of drugs that target specific cancer types.
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Affiliation(s)
- Mangala Hegde
- Cancer Biology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Sosmitha Girisa
- Cancer Biology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Nikunj Naliyadhara
- Cancer Biology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Aviral Kumar
- Cancer Biology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Mohammed S Alqahtani
- Radiological Sciences Department, College of Applied Medical Sciences, King Khalid University, Abha, 61421, Saudi Arabia
- BioImaging Unit, Space Research Centre, University of Leicester, Michael Atiyah Building, Leicester, LE1 7RH, UK
| | - Mohamed Abbas
- Electrical Engineering Department, College of Engineering, King Khalid University, Abha, 61421, Saudi Arabia
- Electronics and Communications Department, College of Engineering, Delta University for Science and Technology, 35712, Gamasa, Egypt
| | | | - Sudha Warrier
- Division of Cancer Stem Cells and Cardiovascular Regeneration, School of Regenerative Medicine, Manipal Academy of Higher Education (MAHE), Bangalore, 560065, India
- Cuor Stem Cellutions Pvt Ltd, Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education (MAHE), Bangalore, 560065, India
| | - Kam Man Hui
- Division of Cellular and Molecular Research, Humphrey Oei Institute of Cancer Research, National Cancer Centre, Singapore, 169610, Singapore
| | | | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore.
| | - Ajaikumar B Kunnumakkara
- Cancer Biology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
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3
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Dembitsky VM. Bioactive Steroids Bearing Oxirane Ring. Biomedicines 2023; 11:2237. [PMID: 37626733 PMCID: PMC10452232 DOI: 10.3390/biomedicines11082237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 07/24/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
This review explores the biological activity and structural diversity of steroids and related isoprenoid lipids, with a particular focus on compounds containing an oxirane ring. These natural compounds are derived from fungi, fungal endophytes, as well as extracts of plants, algae, and marine invertebrates. To evaluate their biological activity, an extensive examination of refereed literature sources was conducted, including in vivo and in vitro studies and the utilization of the QSAR method. Notable properties observed among these compounds include strong anti-inflammatory, antineoplastic, antiproliferative, anti-hypercholesterolemic, antiparkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout this review, 3D graphs illustrating the activity of individual steroids are presented, accompanied by images of selected terrestrial or marine organisms. Furthermore, this review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review are of scientific interest to the academic community and carry practical implications in the fields of pharmacology and medicine. By analyzing the biological activity and structural diversity of steroids and related isoprenoid lipids, this review offers valuable insights that contribute to both theoretical understanding and applied research. This review draws upon data from various authors to compile information on the biological activity of natural steroids containing an oxirane ring.
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Affiliation(s)
- Valery M Dembitsky
- Centre for Applied Research, Innovation and Entrepreneurship, Lethbridge College, 3000 College Drive South, Lethbridge, AB T1K 1L6, Canada
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4
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Wieske LHE, Peintner S, Erdélyi M. Ensemble determination by NMR data deconvolution. Nat Rev Chem 2023:10.1038/s41570-023-00494-x. [PMID: 37169885 DOI: 10.1038/s41570-023-00494-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2023] [Indexed: 05/13/2023]
Abstract
Nuclear magnetic resonance (NMR) is the spectroscopic technique of choice for determining molecular conformations in solution at atomic resolution. As solution NMR spectra are rich in structural and dynamic information, the way in which the data should be acquired and handled to deliver accurate ensembles is not trivial. This Review provides a guide to the NMR experiment selection and parametrization process, the generation of viable theoretical conformer pools and the deconvolution of time-averaged NMR data into a conformer ensemble that accurately represents a flexible molecule in solution. In addition to reviewing the key elements of solution ensemble determination of flexible mid-sized molecules, the feasibility and pitfalls of data deconvolution are discussed with a comparison of the performance of representative algorithms.
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Affiliation(s)
| | - Stefan Peintner
- Department of Chemistry-BMC, Uppsala University, Uppsala, Sweden
| | - Máté Erdélyi
- Department of Chemistry-BMC, Uppsala University, Uppsala, Sweden.
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5
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Festa C, De Marino S, Zampella A, Fiorucci S. Theonella: A Treasure Trove of Structurally Unique and Biologically Active Sterols. Mar Drugs 2023; 21:md21050291. [PMID: 37233485 DOI: 10.3390/md21050291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/27/2023] Open
Abstract
The marine environment is considered a vast source in the discovery of structurally unique bioactive secondary metabolites. Among marine invertebrates, the sponge Theonella spp. represents an arsenal of novel compounds ranging from peptides, alkaloids, terpenes, macrolides, and sterols. In this review, we summarize the recent reports on sterols isolated from this amazing sponge, describing their structural features and peculiar biological activities. We also discuss the total syntheses of solomonsterols A and B and the medicinal chemistry modifications on theonellasterol and conicasterol, focusing on the effect of chemical transformations on the biological activity of this class of metabolites. The promising compounds identified from Theonella spp. possess pronounced biological activity on nuclear receptors or cytotoxicity and result in promising candidates for extended preclinical evaluations. The identification of naturally occurring and semisynthetic marine bioactive sterols reaffirms the utility of examining natural product libraries for the discovery of new therapeutical approach to human diseases.
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Affiliation(s)
- Carmen Festa
- Department of Pharmacy, University of Naples, Via Domenico Montesano, 49, 80131 Naples, Italy
| | - Simona De Marino
- Department of Pharmacy, University of Naples, Via Domenico Montesano, 49, 80131 Naples, Italy
| | - Angela Zampella
- Department of Pharmacy, University of Naples, Via Domenico Montesano, 49, 80131 Naples, Italy
| | - Stefano Fiorucci
- Department of Medicine and Surgery, University of Perugia, Piazza L. Severi, 1, 06132 Perugia, Italy
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6
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Imtiaz S, Ali SM. Atom accurate structure determination of alprazolam/cyclodextrin inclusion complexes by ROESY and computational approaches. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2021.100299] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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7
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Demonstrating accuracy of the already proposed protocol for structure elucidation of cyclodextrin inclusion complexes by validation using quantitative ROESY analysis. J INCL PHENOM MACRO 2021. [DOI: 10.1007/s10847-021-01047-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Imtiaz S, Banoo S, Muzaffar S, Ali SM. Structural determination of midazolam/beta-cyclodextrin inclusion complex by an already proposed protocol and molecular docking studies by quantitative analysis. Struct Chem 2021. [DOI: 10.1007/s11224-021-01727-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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Four new polyhydroxylated steroids from the South Sea sponge Plakortis sp. Chin J Nat Med 2020; 18:844-849. [PMID: 33308606 DOI: 10.1016/s1875-5364(20)60026-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Indexed: 10/22/2022]
Abstract
Four new polyhydroxylated steroids plaksterols A-D (1-4), together with two known related steroids ergost-7,9(11),22-trien-3β,5α,6α-triol (5) and ergosta-6β-methoxy-7,22-diene-3β,5α-diol (6), were isolated from methanol extract of the South China Sea marine sponge Plakortis sp. Their structures were identified by spectroscopic analysis, including NMR, MS, and IR. The cytotoxicity of the polyhydroxylated steroids were evaluated, and compound 6 showed moderate inhibitory activities against K562, HL-60 and BEL-7402 cells.
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10
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Bilonda MK, Mammino L. Computational studies of biologically active alkaloids of plant origin: an overview. PHYSICAL SCIENCES REVIEWS 2020. [DOI: 10.1515/psr-2019-0132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Computational studies nowadays constitute a crucial source of information for drug development, because they provide information on many molecular properties and also enable predictions of the properties of not-yet-synthesized compounds. Alkaloids are a vast group of natural products exhibiting a variety of biological activities, many of which are interesting for drug development. On the other hand, computational studies of biologically active alkaloids have so far mostly focused on few particularly relevant or “popular” molecules, such as quinine, caffeine, or cocaine, with only few works on the other molecules. The present work offers an overview of existing computational studies on alkaloid molecules, from the earliest ones to the most recent, and considering all the theoretical approaches with which studies have been performed (both quantum mechanics and molecular dynamics). The considered studies are grouped according to their objectives and outcomes, such as conformational analysis of alkaloid molecules, effects of selected solvents on their properties, docking studies aimed at better understanding of the interactions between alkaloid molecules and biological targets, studies focusing on structure activity relationships, and computational studies performed to confirm experimental results. It is concluded that it would be important that computational studies on many other alkaloid molecules are performed and their results made available, covering their different classes as well as the variety of their biological activities, to attain better understanding of the properties not only of individual molecules, but also of groups of related molecules and of the overall alkaloids family.
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Affiliation(s)
- Mireille K. Bilonda
- School of Mathematical and Natural Sciences, University of Venda , Thohoyandou , South Africa
- Faculty of Science, University of Kinshasa , Kinshasa , Democratic Republic of Congo
| | - Liliana Mammino
- School of Mathematical and Natural Sciences, University of Venda , Thohoyandou , South Africa
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11
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Shin AY, Lee HS, Lee YJ, Lee JS, Son A, Choi C, Lee J. Oxygenated Theonellastrols: Interpretation of Unusual Chemical Behaviors Using Quantum Mechanical Calculations and Stereochemical Reassignment of 7 α-Hydroxytheonellasterol. Mar Drugs 2020; 18:md18120607. [PMID: 33265994 PMCID: PMC7760259 DOI: 10.3390/md18120607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 01/02/2023] Open
Abstract
A total of eight new oxygenated 4-exo-methylene sterols, 1–8, together with one artifact 9 and six known sterols 11–16, were isolated from the marine sponge Theonella swinhoei collected from the Bohol province in Philippines. Structures of sterols 1–8 were determined from 1D and 2D NMR data. Among the sterols, 8α-hydroxytheonellasterol (4) spontaneously underwent an allylic 1,3-hydroxyl shift to produce 15α-hydroxytheonellasterol (9) as an artifact; this was rationalized by quantum mechanical calculations of the transition state. In addition, the 1,2-epoxy alcohol subunit of 8α-hydroxy-14,15-β-epoxytheonellasterol (5) was assigned using the Gauge-Independent Atomic Orbital (GIAO) NMR chemical shift calculations and subsequent DP4+ analysis. Finally, comparison of the 13C chemical shifts of isolated 7α-hydroxytheonellasterol (6) with the reported values revealed significant discrepancies at C-6, C-7, C-8, and C-14, leading to reassignment of the C-7 stereochemistry in the known structure.
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Affiliation(s)
- A-Young Shin
- Korea Institute of Ocean Science & Technology (KIOST), Busan 49111, Korea; (A-Y.S.); (H.-S.L.); (Y.-J.L.); (J.S.L.)
- Department of Marine Biotechnology, University of Science & Technology, Daejeon 34113, Korea
| | - Hyi-Seung Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan 49111, Korea; (A-Y.S.); (H.-S.L.); (Y.-J.L.); (J.S.L.)
- Department of Marine Biotechnology, University of Science & Technology, Daejeon 34113, Korea
| | - Yeon-Ju Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan 49111, Korea; (A-Y.S.); (H.-S.L.); (Y.-J.L.); (J.S.L.)
- Department of Marine Biotechnology, University of Science & Technology, Daejeon 34113, Korea
| | - Jong Seok Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan 49111, Korea; (A-Y.S.); (H.-S.L.); (Y.-J.L.); (J.S.L.)
- Department of Marine Biotechnology, University of Science & Technology, Daejeon 34113, Korea
| | - Arang Son
- Department of Radiation Oncology, Samsung Medical Center, Seoul 06351, Korea; (A.S.); (C.C.)
| | - Changhoon Choi
- Department of Radiation Oncology, Samsung Medical Center, Seoul 06351, Korea; (A.S.); (C.C.)
| | - Jihoon Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan 49111, Korea; (A-Y.S.); (H.-S.L.); (Y.-J.L.); (J.S.L.)
- Department of Marine Biotechnology, University of Science & Technology, Daejeon 34113, Korea
- Correspondence: ; Tel.: +82-51-664-3343
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12
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Structure elucidation of small organic molecules by contemporary computational chemistry methods. Arch Pharm Res 2020; 43:1114-1127. [DOI: 10.1007/s12272-020-01277-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
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13
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Muzaffar S, Imtiaz S, Ali SM. Demonstrating accuracy of the proposed protocol for structure elucidation of cyclodextrin inclusion complexes by validation using DFT studies. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128419] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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14
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Abstract
Nuclear Overhauser Effect (NOE) methods in NMR are an important tool for 3D structural analysis of small molecules. Quantitative NOE methods conventionally rely on reference distances, known distances that have to be spectrally separated and are not always available. Here we present a new method for evaluation and 3D structure selection that does not require a reference distance, instead utilizing structures optimized by molecular mechanics, enabling NOE evaluation even on molecules without suitable reference groups. A quantitative Nuclear Overhauser Effect (NOE) analysis approach that avoids the use of and internal reference distance to perform molecular configuration selection.![]()
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Affiliation(s)
- Martin R M Koos
- Department of Chemistry, Carnegie Mellon University 4400 Fifth Avenue Pittsburgh Pennsylvania 15213 USA
| | - Karl H G Schulz
- Department of Chemistry, Carnegie Mellon University 4400 Fifth Avenue Pittsburgh Pennsylvania 15213 USA
| | - Roberto R Gil
- Department of Chemistry, Carnegie Mellon University 4400 Fifth Avenue Pittsburgh Pennsylvania 15213 USA
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15
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Meng XH, Chai T, Shi YP, Yang JL. Bungsteroid A: One Unusual C 34 Pentacyclic Steroid Analogue from Zanthoxylum bungeanum Maxim. J Org Chem 2020; 85:10806-10812. [PMID: 32702985 DOI: 10.1021/acs.joc.0c01312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Bungsteroid A (1), possessing an unreported carbon skeleton, was isolated from the pericarps of Zanthoxylum bungeanum Maxim. It represents the first carbon skeleton of a C34 steroid analogue featuring a unique 6/6/6/6/5-fused pentacyclic skeleton, which has been determined by spectroscopic methods, quantum-chemical 13C NMR, ECD calculations, and calculations of optical rotations. Bungsteroid A showed the antiproliferative effects against HepG2, MCF-7, and HeLa cell lines with the IC50 values of 56.3 ± 1.1, 64.2 ± 0.9, and 74.2 ± 1.3 μM, respectively.
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Affiliation(s)
- Xian-Hua Meng
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000, People's Republic of China
| | - Tian Chai
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000, People's Republic of China
| | - Yan-Ping Shi
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000, People's Republic of China
| | - Jun-Li Yang
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Lanzhou 730000, People's Republic of China
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16
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De Vita S, Terracciano S, Bruno I, Chini MG. From Natural Compounds to Bioactive Molecules through NMR and
In Silico
Methodologies. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000469] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Simona De Vita
- Department of Pharmacy University of Salerno Via Giovanni Paolo II, n°132 84084 Fisciano (SA) Italy
| | - Stefania Terracciano
- Department of Pharmacy University of Salerno Via Giovanni Paolo II, n°132 84084 Fisciano (SA) Italy
| | - Ines Bruno
- Department of Pharmacy University of Salerno Via Giovanni Paolo II, n°132 84084 Fisciano (SA) Italy
| | - Maria Giovanna Chini
- Department of Biosciences and Territory University of Molise C.da Fonte Lappone‐ 86090 Pesche (IS) Italy
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17
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Lauro G, Bifulco G. Elucidating the Relative and Absolute Configuration of Organic Compounds by Quantum Mechanical Approaches. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901878] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Gianluigi Lauro
- Department of Pharmacy; University of Salerno; Via Giovanni Paolo II 132 84084 Fisciano (SA) Italy
| | - Giuseppe Bifulco
- Department of Pharmacy; University of Salerno; Via Giovanni Paolo II 132 84084 Fisciano (SA) Italy
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18
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Dewis L, Crouch R, Russell D, Butts C. Improving the accuracy of 1 H- 19 F internuclear distance measurement using 2D 1 H- 19 F HOESY. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2019; 57:1143-1149. [PMID: 31237710 DOI: 10.1002/mrc.4904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/11/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
With the rise in fluorinated pharmaceuticals, it is becoming increasingly important to develop new 19 F NMR-based methods to assist in their analysis. Crucially, obtaining information regarding the conformational dynamics of a molecule in solution can aid the design of strongly binding therapeutics. Herein, we report the development of a 2D 1 H-19 F Heteronuclear Overhauser Spectroscopy (HOESY) experiment to measure 1 H-19 F internuclear distances, with accuracies of ~5% when compared with 1 H-19 F internuclear distances calculated by quantum chemical methods. We demonstrate that correcting for cross-relaxation of 1 H, using the diagonal peaks from the 2D 1 H-1 H Nuclear Overhauser Enhancement Spectroscopy (NOESY), is critical in obtaining accurate values for 1 H-19 F internuclear distances. Finally, we show that by using the proposed method to measure 1 H-19 F internuclear distances, we are able to determine the relative stereochemistry of two fluorinated pharmaceuticals.
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Affiliation(s)
- Lydia Dewis
- Genentech Inc, South San Francisco, CA, USA
- School of Chemistry, University of Bristol, Bristol, UK
| | | | | | - Craig Butts
- School of Chemistry, University of Bristol, Bristol, UK
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19
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Khatri Chhetri B, Lavoie S, Sweeney-Jones AM, Mojib N, Raghavan V, Gagaring K, Dale B, McNamara CW, Soapi K, Quave CL, Polavarapu PL, Kubanek J. Peyssonnosides A-B, Unusual Diterpene Glycosides with a Sterically Encumbered Cyclopropane Motif: Structure Elucidation Using an Integrated Spectroscopic and Computational Workflow. J Org Chem 2019; 84:8531-8541. [PMID: 31244158 PMCID: PMC6614789 DOI: 10.1021/acs.joc.9b00884] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Indexed: 11/30/2022]
Abstract
Two sulfated diterpene glycosides featuring a highly substituted and sterically encumbered cyclopropane ring have been isolated from the marine red alga Peyssonnelia sp. Combination of a wide array of 2D NMR spectroscopic experiments, in a systematic structure elucidation workflow, revealed that peyssonnosides A-B (1-2) represent a new class of diterpene glycosides with a tetracyclo [7.5.0.01,10.05,9] tetradecane architecture. A salient feature of this workflow is the unique application of quantitative interproton distances obtained from the rotating frame Overhauser effect spectroscopy (ROESY) NMR experiment, wherein the β-d-glucose moiety of 1 was used as an internal probe to unequivocally determine the absolute configuration, which was also supported by optical rotatory dispersion (ORD). Peyssonnoside A (1) exhibited promising activity against liver stage Plasmodium berghei and moderate antimethicillin-resistant Staphylococcus aureus (MRSA) activity, with no cytotoxicity against human keratinocytes. Additionally, 1 showed strong growth inhibition of the marine fungus Dendryphiella salina indicating an antifungal ecological role in its natural environment. The high natural abundance and novel carbon skeleton of 1 suggests a rare terpene cyclase machinery, exemplifying the chemical diversity in this phylogenetically distinct marine red alga.
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Affiliation(s)
- Bhuwan Khatri Chhetri
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Serge Lavoie
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Institut
des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, 58, rue Principale, Ripon, Québec J0V 1V0, Canada
| | - Anne Marie Sweeney-Jones
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Nazia Mojib
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Vijay Raghavan
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Kerstin Gagaring
- Calibr
at
The Scripps Research Institute, La Jolla, California 92037, United States
| | - Brandon Dale
- Department
of Dermatology, Center for the Study of Human Health, and Antibiotic
Resistance Center, Emory University, Atlanta, Georgia 30322, United States
| | - Case W. McNamara
- Calibr
at
The Scripps Research Institute, La Jolla, California 92037, United States
| | - Katy Soapi
- Institute
of Applied Sciences, University of South
Pacific, Suva, Fiji
| | - Cassandra L. Quave
- Department
of Dermatology, Center for the Study of Human Health, and Antibiotic
Resistance Center, Emory University, Atlanta, Georgia 30322, United States
| | - Prasad L. Polavarapu
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Julia Kubanek
- School
of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, and School of Biological
Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Parker
H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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20
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Xia Y, Zhang H. 13C NMR chemical shift prediction of diverse chemical compounds. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2019; 30:477-490. [PMID: 31155931 DOI: 10.1080/1062936x.2019.1619621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/13/2019] [Indexed: 06/09/2023]
Abstract
Selection of key descriptors is very important in QSPR analysis. Presence of noise in the subset of descriptors reduces the quality of predictions. A complete set is considered as perfect when it does not include irrelevant or redundant elements. This paper reports complete sets of descriptors used to develop QSPR models for 1786 13C NMR chemical shifts (δC parameters) of carbon atoms in 125 diverse chemical compounds. PBE1PBE/6-311G(2d,2p) and B3LYP/6-31G(d) basis sets were used for quantum chemistry calculations after the molecular structures were optimized with semi-empirical AM1 and B3LYP/6-31G(d). The two complete sets consisting of magnetic shielding elements (σXX, σYY, σZZ) and the chemical shift principal values (σ11, σ22, σ33) were used as the inputs for support vector machine (SVM) models of δC parameters. The four SVM models obtained have the mean root mean square (rms) errors of about 4.5-4.6 ppm. The results suggest that SVM models are accurate and acceptable compared with previous models, although our models are based on a relatively large set of compounds. Our approach is valuable in the selection of important descriptors for QSPR studies of δC parameters.
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Affiliation(s)
- Y Xia
- a China Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, School of Packaging and Materials Engineering , Hunan University of Technology , Zhuzhou , China
| | - H Zhang
- b Chinese Mechanical Engineering Society , Beijing , China
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21
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Ndukwe IE, Brunskill A, Gauthier DR, Zhong YL, Martin GE, Williamson RT, Reibarkh M, Liu Y. 13C NMR-Based Approaches for Solving Challenging Stereochemical Problems. Org Lett 2019; 21:4072-4076. [PMID: 31117703 DOI: 10.1021/acs.orglett.9b01248] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Determining the configuration of proton-deficient molecules is challenging using conventional NMR methods including nuclear Overhauser effect (NOE) and the proton-dependent J-based configuration analysis (JBCA). The problem is exacerbated when only one stereoisomer is available. Alternative methods based on the utilization of 13C NMR chemical shifts, 13C-13C homonuclear couplings measured at natural abundance, and residual chemical shift anisotropy measurements in conjunction with density functional theory calculations are illustrated with a proton-deficient model compound.
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Affiliation(s)
- Ikenna E Ndukwe
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - Andrew Brunskill
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - Donald R Gauthier
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - Yong-Li Zhong
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - Gary E Martin
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - R Thomas Williamson
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - Mikhail Reibarkh
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
| | - Yizhou Liu
- Analytical Research & Development , Merck & Co. Inc. , Rahway , New Jersey 07065 , United States
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22
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Yu XL, Deng JY, Chen JF, Yang HQ. Prediction of 13C NMR Chemical Shifts of Quinolone Derivatives Based on DFT Calculations. J STRUCT CHEM+ 2019. [DOI: 10.1134/s0022476619050093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Gholivand K, Maghsoud Y, Hosseini M, Kahnouji M. A theoretical study on 1H/13C/31P NMR chemical shifts, and the correlation between 2JP–H and the electronic structure of different phosphoryl benzamide derivatives. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.01.081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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24
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Gholivand K, Maghsoud Y, Hosseini M, Kahnouji M. Toward the comprehensive calculations on the relationship between 1 H, 13 C, 31 P chemical shifts, 2 J PH , and the bonding structure of different phosphoryl benzamides. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2019; 57:S108-S116. [PMID: 30578739 DOI: 10.1002/mrc.4820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
A comprehensive investigation was performed on 1 H, 13 C, and 31 P nuclear magnetic resonance (NMR) chemical shifts (CSs) of phosphoryl benzamide derivatives (C6 H5 C(O)NHP(O)R1 R2 ), (R1 , R2 = aziridine [L1 ], azetidine [L2 ], pyrrolidine [L3 ], piperidine [L4 ], azepane [L5 ], 4-methylpiperidine [L6 ], propane-2-amine [L7 ], and 2-methylpropane-2-amine [L8 ]) by the gauge-independent atomic orbital method (GIAO) to find the most accordant level of theory with the experimental values. To achieve this goal, all the structures were optimized using the B3LYP, BP86, PBE1PBE, M06-2X, MPWB1K, and MP2 methods with 6-31+G* basis set. Computed structural parameters demonstrate that BP86 has the best agreement to the experimental values between the other methods. The def2-TZVP and aug-cc-pVDZ basis sets were also employed to inspect the effect of different types of basis sets with higher polarization and diffuse functions. The correlation between the empirical and computational values attests that 6-31+G* basis set is the optimum case regarding minimization of the costs and results. The comparison between calculated and experimental CSs at all mentioned combinations illustrated that in accordance with structural results, the best level of theory in CSs is also BP86/6-31+G*. Besides, 2 JPH values were computed with an acceptable agreement to experimental data at the optimum level of theory. The dependency between 2 JPH and the bonding structure of studied ligands was also scrutinized by the Natural Bond Orbital (NBO) analysis that interprets the relationship between the electronic properties and 2 JPH values.
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Affiliation(s)
- Khodayar Gholivand
- Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran
| | - Yazdan Maghsoud
- Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran
| | - Mahdieh Hosseini
- Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Kahnouji
- Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran
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Taufa T, Northcote PT, Keyzers RA. Two new 4-methylidene containing steroids, craterol A and B, from the New Zealand two sponge association between Stelletta crater and Desmacella dendyi. Steroids 2019; 141:9-13. [PMID: 30414424 DOI: 10.1016/j.steroids.2018.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/25/2018] [Accepted: 11/05/2018] [Indexed: 10/27/2022]
Abstract
NMR-directed investigation of the two sponge association between Stelletta crater and Desmacella dendyi has resulted in the isolation of two new members of the rare 4-methylidene class of sterols. Craterol A (1) and B (2) represent the first examples of natural products reported from the species S. crater. The isolation of these compounds challenges the role of 4-methylidene sterols as chemotaxonomic markers for the sponge genus Theonella.
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Affiliation(s)
- Taitusi Taufa
- School of Chemical & Physical Sciences, Victoria University of Wellington, Wellington, New Zealand; Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Peter T Northcote
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand; Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, New Zealand
| | - Robert A Keyzers
- School of Chemical & Physical Sciences, Victoria University of Wellington, Wellington, New Zealand; Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, New Zealand.
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26
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Yang Q, Hu K, Yan BC, Liu M, Li XN, Sun HD, Puno PT. Maoeriocalysins A–D, four novelent-kaurane diterpenoids fromIsodon eriocalyxand their structure determination utilizing quantum chemical calculation in conjunction with quantitative interproton distance analysis. Org Chem Front 2019. [DOI: 10.1039/c8qo01007b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Maoeriocalysin A, an unprecedented 4,5-seco-3,5-cyclo-7,20-epoxy-ent-kauranoid, together with three rare 9,10-seco-ent-kauranoids, maoeriocalysins B–D, were isolated.
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Affiliation(s)
- Qian Yang
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
| | - Kun Hu
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
| | - Bing-Chao Yan
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
| | - Miao Liu
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
| | - Han-Dong Sun
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
| | - Pema-Tenzin Puno
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- People's Republic of China
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27
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Xu HC, Hu K, Shi XH, Tang JW, Li XN, Sun HD, Puno PT. Synergistic use of NMR computation and quantitative interproton distance analysis in the structural determination of neokadcoccitane A, a rearranged triterpenoid featuring an aromatic ring D from Kadsura coccinea. Org Chem Front 2019. [DOI: 10.1039/c9qo00281b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel lanostane triterpenoid possessing an aromatic ring D, along with two novel norlanostane triterpenoids, were isolated from Kadsura coccinea.
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Affiliation(s)
- Hou-Chao Xu
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
| | - Kun Hu
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
| | - Xiao-Huo Shi
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
| | - Jian-Wei Tang
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
| | - Han-Dong Sun
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
| | - Pema-Tenzin Puno
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- and Yunnan Key Laboratory of Natural Medicinal Chemistry
- Kunming 650201
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28
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Dembitsky VM, Gloriozova TA, Poroikov VV. Naturally occurring marine α,β-epoxy steroids: Origin and biological activities. VIETNAM JOURNAL OF CHEMISTRY 2018. [DOI: 10.1002/vjch.201800025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Lee J, Joullié MM. Total synthesis of the reported structure of ceanothine D via a novel macrocyclization strategy. Chem Sci 2018; 9:2432-2436. [PMID: 29732118 PMCID: PMC5909672 DOI: 10.1039/c8sc00234g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 01/31/2018] [Indexed: 11/25/2022] Open
Abstract
The first total synthesis of the reported structure of ceanothine D, a cyclopeptide alkaloid found in red root, was achieved using a highly convergent synthetic strategy. Highlights of the synthesis include the first concomitant macrocyclization and formation of the unique chiral tertiary alkyl-aryl ether bond with complete regio- and stereo-control in the presence of a sensitive Z-enamide moiety to access the strained para-cyclophane present in its structure. This synthetic strategy may be broadly applicable in the generation of other structurally similar cyclopeptide alkaloids, enabling further biological and chemical investigations.
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Affiliation(s)
- Jisun Lee
- Department of Chemistry , University of Pennsylvania , 231 S. 34th St. Philadelphia , PA 19104-6323 , USA .
| | - Madeleine M Joullié
- Department of Chemistry , University of Pennsylvania , 231 S. 34th St. Philadelphia , PA 19104-6323 , USA .
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30
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Bame J, Hoeck C, Carrington MJ, Butts CP, Jäger CM, Croft AK. Improved NOE fitting for flexible molecules based on molecular mechanics data – a case study with S-adenosylmethionine. Phys Chem Chem Phys 2018; 20:7523-7531. [DOI: 10.1039/c7cp07265a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using the important biomolecule S-adenosyl methionine as an exemplar, we provide a new, enhanced approach for fitting MD data to high-accuracy NOE data, providing improvements in structure determination.
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Affiliation(s)
- Jessica Bame
- University of Bristol
- School of Chemistry
- Clifton
- Bristol BS8 1TS
- UK
| | - Casper Hoeck
- University of Bristol
- School of Chemistry
- Clifton
- Bristol BS8 1TS
- UK
| | - Matthew J. Carrington
- University of Nottingham
- Department of Chemical and Environmental Engineering
- University Park
- Nottingham
- UK
| | - Craig P. Butts
- University of Bristol
- School of Chemistry
- Clifton
- Bristol BS8 1TS
- UK
| | - Christof M. Jäger
- University of Nottingham
- Department of Chemical and Environmental Engineering
- University Park
- Nottingham
- UK
| | - Anna K. Croft
- University of Nottingham
- Department of Chemical and Environmental Engineering
- University Park
- Nottingham
- UK
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32
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Stork G, Yamashita A, Hanson RM, Phan L, Phillips E, Dubé D, Bos PH, Clark AJ, Gough M, Greenlee ML, Jiang Y, Jones K, Kitamura M, Leonard J, Liu T, Parsons PJ, Venkatesan AM. Synthetic Study toward Total Synthesis of (±)-Germine: Synthesis of (±)-4-Methylenegermine. Org Lett 2017; 19:5150-5153. [PMID: 28876074 DOI: 10.1021/acs.orglett.7b02434] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The total synthesis of 4-methylenegermine is described.
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Affiliation(s)
- Gilbert Stork
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Ayako Yamashita
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Robert M Hanson
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Ly Phan
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Eifion Phillips
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Daniel Dubé
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Pieter H Bos
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Andrew J Clark
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Maxwell Gough
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Mark L Greenlee
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Yimin Jiang
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Keith Jones
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Masato Kitamura
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - John Leonard
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Tongzhu Liu
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Philip J Parsons
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
| | - Aranapakam M Venkatesan
- Department of Chemistry and ‡Chemical Probe Synthesis Facility, Department of Biological Sciences, Columbia University , New York, New York 10027, United States
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33
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Mayer AMS, Rodríguez AD, Taglialatela-Scafati O, Fusetani N. Marine Pharmacology in 2012-2013: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis, and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action. Mar Drugs 2017; 15:md15090273. [PMID: 28850074 PMCID: PMC5618412 DOI: 10.3390/md15090273] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/17/2017] [Accepted: 08/21/2017] [Indexed: 12/23/2022] Open
Abstract
The peer-reviewed marine pharmacology literature from 2012 to 2013 was systematically reviewed, consistent with the 1998–2011 reviews of this series. Marine pharmacology research from 2012 to 2013, conducted by scientists from 42 countries in addition to the United States, reported findings on the preclinical pharmacology of 257 marine compounds. The preclinical pharmacology of compounds isolated from marine organisms revealed antibacterial, antifungal, antiprotozoal, antituberculosis, antiviral and anthelmitic pharmacological activities for 113 marine natural products. In addition, 75 marine compounds were reported to have antidiabetic and anti-inflammatory activities and affect the immune and nervous system. Finally, 69 marine compounds were shown to display miscellaneous mechanisms of action which could contribute to novel pharmacological classes. Thus, in 2012–2013, the preclinical marine natural product pharmacology pipeline provided novel pharmacology and lead compounds to the clinical marine pharmaceutical pipeline, and contributed significantly to potentially novel therapeutic approaches to several global disease categories.
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Affiliation(s)
- Alejandro M S Mayer
- Department of Pharmacology, Chicago College of Osteopathic Medicine, Midwestern University, 555 31st Street, Downers Grove, IL 60515, USA.
| | - Abimael D Rodríguez
- Molecular Sciences Research Center, University of Puerto Rico, 1390 Ponce de León Avenue, San Juan, PR 00926, USA.
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34
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Polyancev FM, Metlushka KE, Sadkova DN, Khisametdinova ZR, Kataeva ON, Alfonsov VA, Latypov SK, Sinyashin OG. The isomeric structure of pentacoordinate chiral spirophosphoranes in solution by the combined use of NMR experiments and GIAO DFT calculations of NMR parameters. Dalton Trans 2017; 46:8146-8156. [PMID: 28607987 DOI: 10.1039/c7dt01605k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The interplay of NMR experiments and DFT calculations of NMR parameters is a reliable method for determining the relative configurations of pentacoordinate chiral spirophosphoranes bearing two six- or five-membered rings at the phosphorus atom in solution. The major product of the Betti based derivatives corresponds to the isomers with both substituents at chiral carbons being opposite to the P-H proton. The next populated product corresponds to the isomer with different chiralities at carbons. The least populated isomer is one with both substituents being at the same side of the heterocycle as the P-H bond.
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Affiliation(s)
- Fedor M Polyancev
- A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center, Russian Academy of Sciences, Arbuzov str. 8, Kazan, 420088, Russian Federation.
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35
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Tormena CF. Conformational analysis of small molecules: NMR and quantum mechanics calculations. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2016; 96:73-88. [PMID: 27573182 DOI: 10.1016/j.pnmrs.2016.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/14/2016] [Accepted: 04/14/2016] [Indexed: 06/06/2023]
Abstract
This review deals with conformational analysis in small organic molecules, and describes the stereoelectronic interactions responsible for conformational stability. Conformational analysis is usually performed using NMR spectroscopy through measurement of coupling constants at room or low temperature in different solvents to determine the populations of conformers in solution. Quantum mechanical calculations are used to address the interactions responsible for conformer stability. The conformational analysis of a large number of small molecules is described, using coupling constant measurements in different solvents and at low temperature, as well as recent applications of through-space and through-hydrogen bond coupling constants JFH as tools for the conformational analysis of fluorinated molecules. Besides NMR parameters, stereoelectronic interactions such as conjugative, hyperconjugative, steric and intramolecular hydrogen bond interactions involved in conformational preferences are discussed.
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Affiliation(s)
- Cláudio F Tormena
- Institute of Chemistry, University of Campinas, PO Box 6154, 13083-970 Campinas, Sao Paulo, Brazil.
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36
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Jones CR, Greenhalgh MD, Bame JR, Simpson TJ, Cox RJ, Marshall JW, Butts CP. Subtle temperature-induced changes in small molecule conformer dynamics – observed and quantified by NOE spectroscopy. Chem Commun (Camb) 2016; 52:2920-3. [DOI: 10.1039/c5cc10509a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
NOE–distance relationships are shown to be sufficiently accurate to monitor very small changes in conformer populations in response to temperature (<0.5%/10 °C) – in good agreement with Boltzmann-predictions.
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Affiliation(s)
- C. R. Jones
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
| | - M. D. Greenhalgh
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
| | - J. R. Bame
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
| | - T. J. Simpson
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
| | - R. J. Cox
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
- Leibniz Universität Hannover
| | - J. W. Marshall
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
| | - C. P. Butts
- School of Chemistry
- University of Bristol Cantocks Close
- Bristol
- UK
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37
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Snyder KM, Sikorska J, Ye T, Fang L, Su W, Carter RG, McPhail KL, Cheong PHY. Towards theory driven structure elucidation of complex natural products: mandelalides and coibamide A. Org Biomol Chem 2016; 14:5826-31. [DOI: 10.1039/c6ob00707d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effectiveness of computational tools in determining relative configurations of complex molecules is investigated, using natural products mandelalides A–D and coibamide A, towards a generalized recipe for the scientific community at large.
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Affiliation(s)
| | - Justyna Sikorska
- Department of Pharmaceutical Sciences
- Oregon State University
- Corvallis
- USA
| | - Tao Ye
- Laboratory of Chemical Genomics
- School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Lijing Fang
- Guangdong Key Laboratory of Nanomedicine
- Institute of Biomedicine and Biotechnology
- Shenzhen Institutes of Advanced Technology
- Chinese Academy of Sciences
- Shenzhen
| | - Wu Su
- Guangdong Key Laboratory of Nanomedicine
- Institute of Biomedicine and Biotechnology
- Shenzhen Institutes of Advanced Technology
- Chinese Academy of Sciences
- Shenzhen
| | - Rich G. Carter
- Department of Chemistry
- Oregon State University
- Corvallis
- USA
| | - Kerry L. McPhail
- Department of Pharmaceutical Sciences
- Oregon State University
- Corvallis
- USA
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38
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Fredersdorf M, Göstl R, Kolmer A, Schmidts V, Monecke P, Hecht S, Thiele CM. Exploring the Conformational Space of Bridge-Substituted Dithienylcyclopentenes. Chemistry 2015; 21:14545-54. [DOI: 10.1002/chem.201501842] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Indexed: 11/08/2022]
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39
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Grimmer CD, Slabber CA. Conformational analysis: ³JHCOC and ³JHCCC Karplus relationships for methylene ¹H nuclei. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:590-595. [PMID: 26017915 DOI: 10.1002/mrc.4264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 04/26/2015] [Accepted: 04/28/2015] [Indexed: 06/04/2023]
Abstract
NAMFIS (NMR Analysis of Molecular Flexibility In Solution) was applied to 1-[2-(benzyloxy)phenyl]ethanone using quantitative (1)H-(1)H NOE distances and (3)J proton-carbon coupling constant (CC) restraints for averaged methylene proton (3)J(HCOC) and (3)J(HCCC) pathways H2-(3)J-X imposed by density functional theory-generated Karplus relationships. Comparison of the NOE-only versus the NOE + CC conformational selections illustrates that the experimentally measured average (3)J coupling constants of methylene protons can be used for solution conformational analysis, potentially valuable in the study of small-molecule drugs and natural products which lack the typically studied H1-(3)J-X Karplus relationships.
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Affiliation(s)
- Craig D Grimmer
- School of Chemistry and Physics, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Cathryn A Slabber
- School of Chemistry and Physics, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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40
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Steroidal scaffolds as FXR and GPBAR1 ligands: from chemistry to therapeutical application. Future Med Chem 2015; 7:1109-35. [DOI: 10.4155/fmc.15.54] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bile acids (BAs) are experiencing a new life. Next to their ancestral roles in lipid digestion and solubilization, BAs are today recognized signaling molecules involved in many physiological functions. These signaling pathways involve the activation of metabolic nuclear receptors, mainly the BA sensor FXR, and the dedicated membrane G protein-coupled receptor, GPBAR1 (TGR5). As a consequence, the discovery of GPBAR1/FXR selective or dual modulators represents an important answer to the urgent demand of new pharmacological opportunity for several human diseases including dyslipidemia, cholestasis, nonalcoholic steatohepatitis, Type 2 diabetes and inflammation. Targeted oriented discovery of natural compounds and medicinal chemistry manipulation have allowed the development of promising drug candidates.
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41
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Ali SM, Shamim S. Quantitative ROESY analysis of computational models: structural studies of citalopram and β-cyclodextrin complexes by (1) H-NMR and computational methods. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:526-535. [PMID: 26105793 DOI: 10.1002/mrc.4250] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/16/2015] [Accepted: 03/21/2015] [Indexed: 06/04/2023]
Abstract
Complexation of racemic citalopram with β-cyclodextrin (β-CD) in aqueous medium was investigated to determine atom-accurate structure of the inclusion complexes. (1) H-NMR chemical shift change data of β-CD cavity protons in the presence of citalopram confirmed the formation of 1 : 1 inclusion complexes. ROESY spectrum confirmed the presence of aromatic ring in the β-CD cavity but whether one of the two or both rings was not clear. Molecular mechanics and molecular dynamic calculations showed the entry of fluoro-ring from wider side of β-CD cavity as the most favored mode of inclusion. Minimum energy computational models were analyzed for their accuracy in atomic coordinates by comparison of calculated and experimental intermolecular ROESY peak intensities, which were not found in agreement. Several least energy computational models were refined and analyzed till calculated and experimental intensities were compatible. The results demonstrate that computational models of CD complexes need to be analyzed for atom-accuracy and quantitative ROESY analysis is a promising method. Moreover, the study also validates that the quantitative use of ROESY is feasible even with longer mixing times if peak intensity ratios instead of absolute intensities are used.
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Affiliation(s)
- Syed Mashhood Ali
- Department of Chemistry, Aligarh Muslim University, Aligarh, 202002, India
| | - Shazia Shamim
- Department of Chemistry, Aligarh Muslim University, Aligarh, 202002, India
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42
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Juárez-González F, Suárez-Ortiz GA, Fragoso-Serrano M, Cerda-García-Rojas CM, Pereda-Miranda R. DFT 1H-1H coupling constants in the conformational analysis and stereoisomeric differentiation of 6-heptenyl-2H-pyran-2-ones: configurational reassignment of synargentolide A. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:203-212. [PMID: 25353378 DOI: 10.1002/mrc.4178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/05/2014] [Accepted: 10/08/2014] [Indexed: 06/04/2023]
Abstract
Density functional theory (DFT) (1) H-(1) H NMR coupling constant calculations, including solvation parameters with the polarizable continuum model B3LYP/DGDZVP basis set together with the experimental values measured by spectral simulation, were used to predict the configuration of hydroxylated 6-heptenyl-5,6-dihydro-2H-pyran-2-ones 1, 2, 4, and 7, allowing epimer differentiation. Modeling of these flexible compounds requires the inclusion of solvation models that account for stabilizing interactions derived from intramolecular and intermolecular hydrogen bonds, in contrast with peracetylated derivatives (3, 5, and 6) in which the solvation consideration can be omitted. Using this DFT NMR integrated approach as well as spectral simulation, the configurational reassignment of synargentolide A (8) was accomplished by calculations in the gas phase among four possible diastereoisomers (8-11). Calculated (3) JH,H values established its configuration as 6R-[4'S,5'S,6'S-(triacetyloxy)-2E-heptenyl]-5,6-dihydro-2H-pyran-2-one (8), in contrast with the incorrect 6R,4'R,5'R,6'R-diastereoisomer previously proposed by synthesis (12). Application of this approach increases the probability for successful enantiospecific total syntheses of flexible compounds with multiple chiral centers.
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Affiliation(s)
- Francisco Juárez-González
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, 04510, DF, Mexico
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43
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Chaudhari SR, Suryaprakash N. J-Edited Pure Shift NMR for the Facile Measurement ofnJHHfor Specific Protons. Chemphyschem 2015; 16:1079-82. [DOI: 10.1002/cphc.201402792] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/21/2014] [Indexed: 11/06/2022]
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44
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Aímola TJ, Lima DJP, Dias LC, Tormena CF, Ferreira MAB. 1H chemical shift differences of Prelog–Djerassi lactone derivatives: DFT and NMR conformational studies. Org Biomol Chem 2015; 13:2140-5. [DOI: 10.1039/c4ob02446j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This work reports an experimental and theoretical study of the conformational preferences of several Prelog–Djerassi lactone derivatives, to elucidate the1H NMR chemical shift differences in the lactonic core that are associated with the relative stereochemistry of these derivatives.
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Affiliation(s)
- Túlio J. Aímola
- Laboratório de Química Bio-orgânica e Laboratório de Cristalografia
- Estereodinâmica e Modelagem Molecular
- Universidade Federal de São Carlos
- São Carlos
- Brazil
| | - Dimas J. P. Lima
- Universidade Federal de Alagoas
- Maceió
- Brazil
- Chemistry Institute
- State University of Campinas
| | | | | | - Marco A. B. Ferreira
- Laboratório de Química Bio-orgânica e Laboratório de Cristalografia
- Estereodinâmica e Modelagem Molecular
- Universidade Federal de São Carlos
- São Carlos
- Brazil
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45
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Latypov SK, Polyancev FM, Yakhvarov DG, Sinyashin OG. Quantum chemical calculations of31P NMR chemical shifts: scopes and limitations. Phys Chem Chem Phys 2015; 17:6976-87. [DOI: 10.1039/c5cp00240k] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
High level of theory is not necessarily needed to obtain rather accurate predictions of31P chemical shifts by GIAO method. For example, the PBE1PBE/6-311G(2d,2p)//PBE1PBE/6-31+G(d) combination allowed to obtain good results for variety of middle-size organophosphorus compounds (M= 200–700 Da).
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Affiliation(s)
- Shamil K. Latypov
- A.E. Arbuzov Institute of Organic and Physical Chemistry
- Kazan Scientific Center
- Russian Academy of Sciences
- Kazan
- Russian Federation
| | - Fedor M. Polyancev
- A.E. Arbuzov Institute of Organic and Physical Chemistry
- Kazan Scientific Center
- Russian Academy of Sciences
- Kazan
- Russian Federation
| | - Dmitry G. Yakhvarov
- A.E. Arbuzov Institute of Organic and Physical Chemistry
- Kazan Scientific Center
- Russian Academy of Sciences
- Kazan
- Russian Federation
| | - Oleg G. Sinyashin
- A.E. Arbuzov Institute of Organic and Physical Chemistry
- Kazan Scientific Center
- Russian Academy of Sciences
- Kazan
- Russian Federation
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46
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Ndukwe IE, Butts CP. Pure-shift IMPRESS EXSIDE – Easy measurement of 1H–13C scalar coupling constants with increased sensitivity and resolution. RSC Adv 2015. [DOI: 10.1039/c5ra24926k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Measuring long-range 1H–13C scalar coupling constants, nJCH, is made easier through improved sensitivity and resolution of the SelEXSIDE NMR experiment by incorporation of ‘pure-shift’ homonuclear decoupling and IMPRESS-Hadamard encoding.
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Affiliation(s)
- I. E. Ndukwe
- School of Chemistry
- University of Bristol
- Bristol
- UK
| | - C. P. Butts
- School of Chemistry
- University of Bristol
- Bristol
- UK
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47
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Complexation of (RS)-benzhexol with β-cyclodextrin: structure elucidation of diastereomeric complexes by use of quantitative 1H-1H ROESY and computational methods. MONATSHEFTE FUR CHEMIE 2014. [DOI: 10.1007/s00706-014-1324-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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48
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Burns M, Essafi S, Bame JR, Bull SP, Webster MP, Balieu S, Dale JW, Butts CP, Harvey JN, Aggarwal VK. Assembly-line synthesis of organic molecules with tailored shapes. Nature 2014; 513:183-8. [PMID: 25209797 PMCID: PMC4167605 DOI: 10.1038/nature13711] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 07/23/2014] [Indexed: 12/24/2022]
Abstract
Molecular assembly lines, where molecules undergo iterative processes involving chain elongation and functional group manipulation are hallmarks of many processes found in Nature. We have sought to emulate Nature in the development of our own molecular assembly line through iterative homologations of boronic esters. Here we report a reagent (α-lithioethyl triispopropylbenzoate) which inserts into carbon-boron bonds with exceptionally high fidelity and stereocontrol. Through repeated iteration we have converted a simple boronic ester into a complex molecule (a carbon chain with ten contiguous methyl groups) with remarkably high precision over its length, its stereochemistry and therefore its shape. Different stereoisomers were targeted and it was found that they adopted different shapes (helical/linear) according to their stereochemistry. This work should now enable scientists to rationally design and create molecules with predictable shape, which could have an impact in all areas of molecular sciences where bespoke molecules are required.
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Affiliation(s)
- Matthew Burns
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Stéphanie Essafi
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Jessica R Bame
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Stephanie P Bull
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Matthew P Webster
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Sébastien Balieu
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - James W Dale
- Novartis Horsham Research Centre, Wimblehurst Road, Horsham, West Sussex RH13 5AB, UK
| | - Craig P Butts
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Jeremy N Harvey
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Varinder K Aggarwal
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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49
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Grimmer C, Moore TW, Padwa A, Prussia A, Wells G, Wu S, Sun A, Snyder JP. Antiviral atropisomers: conformational energy surfaces by NMR for host-directed myxovirus blockers. J Chem Inf Model 2014; 54:2214-23. [PMID: 25058809 DOI: 10.1021/ci500204j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Biologically active organic molecules characterized by a high single bond torsional barrier generate isolable isomers (atropisomers) and offer a unique stereochemical component to the design of selective therapeutic agents. The present work presents a nanomolar active inhibitor of myxoviruses, which most likely acts by blocking one or more cellular host proteins but also, serendipitously, exhibits axial chirality with an energy barrier of ΔG((++)) ≥30 kcal/mol. The latter has been probed by variable temperature NMR and microwave irradiation and by high level DFT transition state analysis and force field calculations. Full conformational profiles of the corresponding (aR,S) and (aS,S) atropisomers at ambient temperature were derived by conformer deconvolution with NAMFIS (NMR Analysis by Molecular Flexibility In Solution) methodology to generate seven and eight individual conformations, each assigned a % population. An accurate evaluation of a key torsion angle at the center of the molecules associated with a (3)JC-S-C-H coupling constant was obtained by mapping the S-C bond rotation with the MPW1PW91/6-31G-d,p DFT method followed by fitting the resulting dihedral angles and J-values to a Karplus expression. Accordingly, we have developed a complete conformational profile of diastereomeric atropisomers consistent with both high and low rotational barriers. We expect this assessment to assist the rationalization of the selectivity of the two (aR,S) and (aS,S) forms against host proteins, while offering insights into their divergent toxicity behavior.
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Affiliation(s)
- Craig Grimmer
- School of Chemistry and Physics, University of KwaZulu-Natal , Pietermaritzburg, South Africa
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50
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Tran TD, Pham NB, Quinn RJ. Structure Determination of Pentacyclic Pyridoacridine Alkaloids from the Australian Marine OrganismsAncorina geodidesandCnemidocarpa stolonifera. European J Org Chem 2014. [DOI: 10.1002/ejoc.201402372] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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