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Liu R, Lindsey JS. Single-Polymer-Single-Cargo Strategy Packages Hydrophobic Fluorophores in Aqueous Solution with Retention of Inherent Brightness. ACS Macro Lett 2019; 8:79-83. [PMID: 35619412 DOI: 10.1021/acsmacrolett.8b00907] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A strategy for encapsulating hydrophobic organic entities in aqueous solution has been developed through use of a self-assembling heterotelechelic amphiphilic random copolymer. The polymer (∼40 kDa), prepared by living radical polymerization, contains orthogonally reactive terminal groups and pendant hydrophobic (dodecyl), nonionic hydrophilic (PEG9), and ionic hydrophilic (sulfonate-terminated) groups. Covalent conjugation of a hydrophobic entity to the polymer terminus has been demonstrated for 8 classes of organic fluorophores. The resulting "pod-fluorophore" architecture is unimeric (∼15 nm in diameter) in aqueous solution with spectral features and fluorescence brightness resembling those of the benchmark fluorophore in organic solution. This strategy separates the functional design of the packaged molecular entity ("cargo") from the often vexing challenge of water solubilization and in so doing creates a unitary (one-pod-one-cargo) platform architecture for potential applications in cytometry, biomedical imaging, environmental sensing, and supramolecular chemistry.
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Wu Z, Fujita H, Magdaong NCM, Diers JR, Hood D, Allu S, Niedzwiedzki DM, Kirmaier C, Bocian DF, Holten D, Lindsey JS. New molecular design for blue BODIPYs. NEW J CHEM 2019. [DOI: 10.1039/c9nj01114e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Dihydro analogues of BODIPYs exhibit spectral features (Φf ∼ 0.4–0.9) resembling aminocoumarins and suggest applications for broad-band photosensitization or where large Stokes shifts are desired.
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Fujita H, Jing H, Krayer M, Allu S, Veeraraghavaiah G, Wu Z, Jiang J, Diers JR, Magdaong NCM, Mandal AK, Roy A, Niedzwiedzki DM, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Annulated bacteriochlorins for near-infrared photophysical studies. NEW J CHEM 2019. [DOI: 10.1039/c9nj01113g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Bacteriochlorins with phenaleno or benzo annulation absorb at 913 or 1033 nm and exhibit excited-state lifetimes of 150 or 7 ps, suggesting applications in photoacoustic imaging.
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Liu R, Vairaprakash P, Lindsey JS. Self-assembly with fluorescence readout in a free base dipyrrin–polymer triggered by metal ion binding in aqueous solution. NEW J CHEM 2019. [DOI: 10.1039/c9nj01787a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Profound morphological and fluorogenic changes ensue upon binding of a zinc ion by two polymers, each of which bears a single dipyrrin at one terminus, forming the bis(dipyrrinato)Zn(ii) complex.
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Hughes RA, Jin X, Zhang Y, Zhang R, Tran S, Williams PG, Lindsey JS, Miller ES. Genome sequence, metabolic properties and cyanobacterial attachment of Porphyrobacter sp. HT-58-2 isolated from a filamentous cyanobacterium–microbial consortium. Microbiology (Reading) 2018; 164:1229-1239. [DOI: 10.1099/mic.0.000706] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Jiang J, Matula AJ, Swierk JR, Romano N, Wu Y, Batista VS, Crabtree RH, Lindsey JS, Wang H, Brudvig GW. Unusual Stability of a Bacteriochlorin Electrocatalyst under Reductive Conditions. A Case Study on CO2 Conversion to CO. ACS Catal 2018. [DOI: 10.1021/acscatal.8b02991] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Yuen JM, Diers JR, Alexy EJ, Roy A, Mandal AK, Kang HS, Niedzwiedzki DM, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Origin of Panchromaticity in Multichromophore-Tetrapyrrole Arrays. J Phys Chem A 2018; 122:7181-7201. [PMID: 30152691 DOI: 10.1021/acs.jpca.8b06815] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Panchromatic absorbers that have robust photophysical properties enable new designs for molecular-based light-harvesting systems. Herein, we report experimental and theoretical studies of the spectral, redox, and excited-state properties of a series of perylene-monoimide-ethyne-porphyrin arrays wherein the number of perylene-monoimide units is stepped from one to four. In the arrays, a profound shift of absorption intensity from the strong violet-blue (B y and B x) bands of typical porphyrins into the green, red, and near-infrared (Q x and Q y) regions stems from mixing of chromophore and tetrapyrrole molecular orbitals (MOs), which gives multiplets of MOs having electron density spread over the entire array. This reduces the extensive mixing between porphyrin excited-state configurations and the transition-dipole addition and subtraction that normally leads to intense B and weak Q bands. Reduced configurational mixing derives from moderate effects of the ethyne and perylene on the MO energies and a more substantial effect of electron-density delocalization to reduce the configuration-interaction energy. Quantitative oscillator-strength analysis shows that porphyrin intensity is also shifted into the perylene-like green-region absorption and that the ethyne linkers lend absorption intensity. The reduced porphyrin configurational mixing also endows the S1 state with bacteriochlorin-like properties, including a 1-5 ns lifetime.
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Zhang Y, Zhang R, Hughes RA, Dai J, Gurr JR, Williams PG, Miller ES, Lindsey JS. Quantitation of Tolyporphins, Diverse Tetrapyrrole Secondary Metabolites with Chlorophyll-Like Absorption, from a Filamentous Cyanobacterium-Microbial Community. PHYTOCHEMICAL ANALYSIS : PCA 2018; 29:205-216. [PMID: 29110356 DOI: 10.1002/pca.2735] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/07/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
INTRODUCTION Tolyporphins are unusual tetrapyrrole macrocycles produced by a non-axenic filamentous cyanobacterium (HT-58-2). Tolyporphins A-J, L, and M share a common dioxobacteriochlorin core, differ in peripheral substituents, and exhibit absorption spectra that overlap that of the dominant cyanobacterial pigment, chlorophyll a. Identification and accurate quantitation of the various tolyporphins in these chlorophyll-rich samples presents challenges. OBJECTIVE To develop methods for the quantitative determination of tolyporphins produced under various growth conditions relative to that of chlorophyll a. METHODOLOGY Chromatographic fractionation of large-scale (440 L) cultures afforded isolated individual tolyporphins. Lipophilic extraction of small-scale (25 mL) cultures, HPLC separation with an internal standard, and absorption detection enabled quantitation of tolyporphin A and chlorophyll a, and by inference the amounts of tolyporphins A-M. Absorption spectroscopy with multicomponent analysis of lipophilic extracts (2 mL cultures) afforded the ratio of all tolyporphins to chlorophyll a. The reported absorption spectral data for the various tolyporphins required re-evaluation for quantitative purposes. RESULTS AND DISCUSSION The amount of tolyporphin A after 50 days of illumination ranged from 0.13 nmol/mg dry cells (media containing nitrate) to 1.12 nmol/mg (without nitrate), with maximum 0.23 times that of chlorophyll a. Under soluble-nitrogen deprivation after 35-50 days, tolyporphin A represents 1/3-1/2 of the total tolyporphins, and the total amount of tolyporphins is up to 1.8-fold that of chlorophyll a. CONCLUSIONS The quantitative methods developed herein should facilitate investigation of the biosynthesis of tolyporphins (and other tetrapyrroles) as well as examination of other strains for production of tolyporphins. Copyright © 2017 John Wiley & Sons, Ltd.
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Hood D, Sahin T, Parkes‐Loach PS, Jiao J, Harris MA, Dilbeck P, Niedzwiedzki DM, Kirmaier C, Loach PA, Bocian DF, Lindsey JS, Holten D. Expanding Covalent Attachment Sites of Nonnative Chromophores to Encompass the C‐Terminal Hydrophilic Domain in Biohybrid Light‐Harvesting Architectures. CHEMPHOTOCHEM 2018. [DOI: 10.1002/cptc.201700182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Taniguchi M, Lindsey JS. Database of Absorption and Fluorescence Spectra of >300 Common Compounds for use in Photochem
CAD. Photochem Photobiol 2018; 94:290-327. [DOI: 10.1111/php.12860] [Citation(s) in RCA: 236] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/22/2017] [Indexed: 12/11/2022]
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Taniguchi M, Du H, Lindsey JS. PhotochemCAD 3: Diverse Modules for Photophysical Calculations with Multiple Spectral Databases. Photochem Photobiol 2018; 94:277-289. [DOI: 10.1111/php.12862] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/22/2017] [Indexed: 01/13/2023]
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Zhang Y, Zhang R, Nazari M, Bagley MC, Miller ES, Williams PG, Muddiman DC, Lindsey JS. Mass spectrometric detection of chlorophyll a and the tetrapyrrole secondary metabolite tolyporphin A in the filamentous cyanobacterium HT-58-2. Approaches to high-throughput screening of intact cyanobacteria. J PORPHYR PHTHALOCYA 2018. [DOI: 10.1142/s108842461750078x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Tolyporphins are unusual tetrapyrrole macrocycles produced by the filamentous cyanobacterium–microbial community HT-58-2, the only known source to date. Numerous cyanobacterial samples have been collected worldwide but most have not been screened for secondary metabolites. Identification of tolyporphins typically has entailed lipophilic extraction followed by chromatographic fractionation and spectroscopic and/or mass spectrometric analysis. For quantitation, lengthy lipophilic extraction, sample processing and HPLC separation are needed. Examination by MALDI-TOF-MS (with the matrix 1,5-diaminonaphthalene) of lipophilic crude extracts of small-scale HT-58-2 samples (2 mL) without chromatographic fractionation enabled semi-quantitation of tolyporphin A over a 41-day growth period. Screening for tolyporphin A in intact or slightly sheared and vortexed HT-58-2 samples (no lipophilic extraction), and confirmation of identity by tandem MS, were carried out by IR-MALDESI-FTMS. Tolyporphin A was identified by the molecular ion and four characteristic fragments. The molecular ion of chlorophyll [Formula: see text] also was observed. The sheared and vortexed sample contained substantial numbers of intact cells as demonstrated by regrowth of the filamentous cyanobacterium–microbial culture. The semi-quantitative and rapid qualitative methods developed herein should facilitate examination of other tolyporphin-producing organisms among the vast worldwide strains of cyanobacteria as well as investigation of the biosynthesis of tolyporphins.
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Liu R, Liu M, Hood D, Chen CY, MacNevin CJ, Holten D, Lindsey JS. Chlorophyll-Inspired Red-Region Fluorophores: Building Block Synthesis and Studies in Aqueous Media. Molecules 2018; 23:molecules23010130. [PMID: 29320445 PMCID: PMC6017558 DOI: 10.3390/molecules23010130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/04/2018] [Accepted: 01/06/2018] [Indexed: 02/04/2023] Open
Abstract
Fluorophores that absorb and emit in the red spectral region (600-700 nm) are of great interest in photochemistry and photomedicine. Eight new target chlorins (and 19 new chlorins altogether)-analogues of chlorophyll-of different polarities have been designed and synthesized for various applications; seven of the chlorins are equipped with a bioconjugatable tether. Hydrophobic or amphiphilic chlorins in a non-polar organic solvent (toluene), polar organic solvent (DMF), and aqueous or aqueous micellar media show a sharp emission band in the red region and modest fluorescence quantum yield (Φf = 0.2-0.3). A Poisson analysis implies most micelles are empty and few contain >1 chlorin. Water-soluble chlorins each bearing three PEG (oligoethyleneglycol) groups exhibit narrow emission bands (full-width-at-half maximum <25 nm). The lifetime of the lowest singlet excited state and the corresponding yields and rate constants for depopulation pathways (fluorescence, intersystem crossing, internal conversion) are generally little affected by the PEG groups or dissolution in aqueous or organic media. A set of chlorin-avidin conjugates revealed a 2-fold increase in Φf with increased average chlorin/avidin ratio (2.3-12). In summary, the chlorins of various polarities described herein are well suited as red-emitting fluorophores for applications in aqueous or organic media.
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Hu G, Kang HS, Mandal AK, Roy A, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Synthesis of arrays containing porphyrin, chlorin, and perylene-imide constituents for panchromatic light-harvesting and charge separation. RSC Adv 2018; 8:23854-23874. [PMID: 35540249 PMCID: PMC9081848 DOI: 10.1039/c8ra04052d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 06/15/2018] [Indexed: 12/14/2022] Open
Abstract
Achieving solar light harvesting followed by efficient charge separation and transport is an essential objective of molecular-based artificial photosynthesis. Architectures that afford strong absorption across the near-UV to near-infrared region, namely panchromatic absorptivity, are critically important given the broad spectral distribution of sunlight. A tetrapyrrole–perylene pentad array was synthesized and investigated as a means to integrate panchromatic light harvesting and intramolecular charge separation. The pentad consists of three moieties: (1) a panchromatically absorbing triad, in which a porphyrin is strongly coupled to two perylene-monoimides via ethyne linkages; (2) a perylene-diimide electron acceptor; and (3) a chlorin hole-trapping unit. Integrating the three components with diphenylethyne linkers generates moderate electronic coupling for intramolecular energy and hole/electron transfer. The construction of the array relies on a stepwise strategy for incorporating modular pigment building blocks. The key building blocks include a trans-A2BC porphyrin, a chlorin, a perylene-monoimide, and a perylene-diimide, each bearing appropriate (halo, ethynyl) synthetic handles for Pd-catalyzed Sonogashira coupling reactions. One target pentad, three tetrads, four triads, and four monomeric benchmark compounds were synthesized from six building blocks (three new, three reported) and 10 new synthetic intermediates. Four of the tetrapyrrole-containing arrays are zinc chelated, and four others are in the free base form. Absorption and fluorescence spectra and fluorescence quantum yields were also measured. Collectively, investigations of the arrays reveal insights into principles for the design of novel reaction centers integrated with a panchromatic antenna for artificial photosynthetic studies. Twelve arrays containing porphyrin, chlorin, and/or perylene-imide units were synthesized to investigate panchromatic absorption integrated with charge separation.![]()
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Mandal AK, Diers JR, Niedzwiedzki DM, Hu G, Liu R, Alexy EJ, Lindsey JS, Bocian DF, Holten D. Tailoring Panchromatic Absorption and Excited-State Dynamics of Tetrapyrrole–Chromophore (Bodipy, Rylene) Arrays—Interplay of Orbital Mixing and Configuration Interaction. J Am Chem Soc 2017; 139:17547-17564. [DOI: 10.1021/jacs.7b09548] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Mancini JA, Kodali G, Jiang J, Reddy KR, Lindsey JS, Bryant DA, Dutton PL, Moser CC. Multi-step excitation energy transfer engineered in genetic fusions of natural and synthetic light-harvesting proteins. J R Soc Interface 2017; 14:rsif.2016.0896. [PMID: 28179548 DOI: 10.1098/rsif.2016.0896] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/16/2017] [Indexed: 11/12/2022] Open
Abstract
Synthetic proteins designed and constructed from first principles with minimal reference to the sequence of any natural protein have proven robust and extraordinarily adaptable for engineering a range of functions. Here for the first time we describe the expression and genetic fusion of a natural photosynthetic light-harvesting subunit with a synthetic protein designed for light energy capture and multi-step transfer. We demonstrate excitation energy transfer from the bilin of the CpcA subunit (phycocyanin α subunit) of the cyanobacterial photosynthetic light-harvesting phycobilisome to synthetic four-helix-bundle proteins accommodating sites that specifically bind a variety of selected photoactive tetrapyrroles positioned to enhance energy transfer by relay. The examination of combinations of different bilin, chlorin and bacteriochlorin cofactors has led to identification of the preconditions for directing energy from the bilin light-harvesting antenna into synthetic protein-cofactor constructs that can be customized for light-activated chemistry in the cell.
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Jiao J, Yu M, Holten D, Lindsey JS, Bocian DF. Characterization of Hydroporphyrins Covalently Attached to Si(100). J PORPHYR PHTHALOCYA 2017. [DOI: 10.1142/s1088424617500547] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Attachment of synthetic analogs of natural tetrapyrroles to electroactive surfaces enables physicochemical interrogation and may provide material for use in catalysis, diagnostics, and energy conversion. Six synthetic zinc chlorins and one free base bacteriochlorin, tailored analogs of chlorophyll and bacteriochlorophyll, respectively, have been attached to Si(100) via a high-temperature (400°C) baking method. The hydroporphyrins bear diverse functional groups that enable surface attachment (vinyl, acetyl, triisopropylsilylethynyl, pentafluorophenyl, and hydroxymethylphenyl) and a geminal dimethyl group in each reduced ring for stabilization toward adventitious dehydrogenation. The films were examined by cyclic voltammetry, FTIR spectroscopy, X-ray photoelectron spectroscopy, and ellipsometry. Monofunctionalized and difunctionalized hydroporphyrins gave monolayer and multilayer films, respectively, indicating robustness of the hydroporphyrin molecules, but in each case the film was more heterogeneous than observed with comparable porphyrins. The data suggest that some amount of unattached molecules remain intercalated with surface-attached molecules. Additional molecular designs will need to be examined to develop a deep understanding of the structure-activity relationship for formation of homogeneous monolayers and multilayers of synthetic hydroporphyrins.
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Hood D, Niedzwiedzki DM, Zhang R, Zhang Y, Dai J, Miller ES, Bocian DF, Williams PG, Lindsey JS, Holten D. Photophysical Characterization of the Naturally Occurring Dioxobacteriochlorin Tolyporphin A and Synthetic Oxobacteriochlorin Analogues. Photochem Photobiol 2017; 93:1204-1215. [DOI: 10.1111/php.12781] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/04/2017] [Indexed: 01/21/2023]
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Maher AG, Passard G, Dogutan DK, Halbach RL, Anderson BL, Gagliardi CJ, Taniguchi M, Lindsey JS, Nocera DG. Hydrogen Evolution Catalysis by a Sparsely Substituted Cobalt Chlorin. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00969] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Reddy MN, Zhang S, Kim HJ, Mass O, Taniguchi M, Lindsey JS. Synthesis and Spectral Properties of meso-Arylbacteriochlorins, Including Insights into Essential Motifs of their Hydrodipyrrin Precursors. Molecules 2017; 22:molecules22040634. [PMID: 28420113 PMCID: PMC6154299 DOI: 10.3390/molecules22040634] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 11/16/2022] Open
Abstract
Synthetic bacteriochlorins-analogues of bacteriochlorophylls, Nature's near-infrared absorbers-are attractive for diverse photochemical studies. meso-Arylbacteriochlorins have been prepared by the self-condensation of a dihydrodipyrrin-carbinol or dihydrodipyrrin-acetal following an Eastern-Western (E-W) or Northern-Southern (N-S) joining process. The bacteriochlorins bear a gem-dimethyl group in each pyrroline ring to ensure stability toward oxidation. The two routes differ in the location of the gem-dimethyl group at the respective 3- or 2-position in the dihydrodipyrrin, and the method of synthesis of the dihydrodipyrrin. Treatment of a known 3,3-dimethyldihydrodipyrrin-1-carboxaldehyde with an aryl Grignard reagent afforded the dihydrodipyrrin-1-(aryl)carbinol, and upon subsequent acetylation, the corresponding dihydrodipyrrin-1-methyl acetate (dihydrodipyrrin-acetate). Self-condensation of the dihydrodipyrrin-acetate gave a meso-diarylbacteriochlorin (E-W route). A 2,2-dimethyl-5-aryldihydrodipyrrin-1-(aryl)carbinol underwent self-condensation to give a trans-A₂B₂-type meso-tetraarylbacteriochlorin (N-S route). In each case, the aromatization process entails a 2e-/2H⁺ (aerobic) dehydrogenative oxidation following the dihydrodipyrrin self-condensation. Comparison of a tetrahydrodipyrrin-acetal (0%) versus a dihydrodipyrrin-acetal (41%) in bacteriochlorin formation and results with various 1-substituted dihydrodipyrrins revealed the importance of resonance stabilization of the reactive hydrodipyrrin intermediate. Altogether 10 new dihydrodipyrrins and five new bacteriochlorins have been prepared. The bacteriochlorins exhibit characteristic bacteriochlorophyll-like absorption spectra, including a Qy band in the region 726-743 nm.
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Taniguchi M, Ptaszek M, Chandrashaker V, Lindsey JS. The Porphobilinogen Conundrum in Prebiotic Routes to Tetrapyrrole Macrocycles. ORIGINS LIFE EVOL B 2017; 47:93-119. [PMID: 27207103 DOI: 10.1007/s11084-016-9506-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/01/2016] [Indexed: 02/05/2023]
Abstract
Attempts to develop a credible prebiotic route to tetrapyrroles have relied on enzyme-free recapitulation of the extant biosynthesis, but this process has foundered from the inability to form the pyrrole porphobilinogen (PBG) in good yield by self-condensation of the precursor δ-aminolevulinic acid (ALA). PBG undergoes robust oligomerization in aqueous solution to give uroporphyrinogen (4 isomers) in good yield. ALA, PBG, and uroporphyrinogen III are universal precursors to all known tetrapyrrole macrocycles. The enzymic formation of PBG entails carbon-carbon bond formation between the less stable enolate/enamine of one ALA molecule (3-position) and the carbonyl/imine (4-position) of the second ALA molecule; without enzymes, the first ALA reacts at the more stable enolate/enamine (5-position) and gives the pyrrole pseudo-PBG. pseudo-PBG cannot self-condense, yet has one open α-pyrrole position and is proposed to be a terminator of oligopyrromethane chain-growth from PBG. Here, 23 analogues of ALA have been subjected to density functional theoretical (DFT) calculations, but no motif has been identified that directs reaction at the 3-position. Deuteriation experiments suggested 5-(phosphonooxy)levulinic acid would react preferentially at the 3- versus 5-position, but a hybrid condensation with ALA gave no observable uroporphyrin. The results suggest efforts toward a biomimetic, enzyme-free route to tetrapyrroles from ALA should turn away from structure-directed reactions and focus on catalysts that orient the two aminoketones to form PBG in a kinetically controlled process, thereby avoiding formation of pseudo-PBG.
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Zhang S, Lindsey JS. Construction of the Bacteriochlorin Macrocycle with Concomitant Nazarov Cyclization To Form the Annulated Isocyclic Ring: Analogues of Bacteriochlorophyll a. J Org Chem 2017; 82:2489-2504. [DOI: 10.1021/acs.joc.6b02878] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Liu Y, Allu S, Nagarjuna Reddy M, Hood D, Diers JR, Bocian DF, Holten D, Lindsey JS. Synthesis and photophysical characterization of bacteriochlorins equipped with integral swallowtail substituents. NEW J CHEM 2017. [DOI: 10.1039/c7nj00499k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The two pyrroline units of bacteriochlorins can now bear gem-dialkyl or diaryl groups (L), which project above and below the macrocycle plane, whereas dimethyl groups generally have been accessible previously.
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Liu M, Chen CY, Hood D, Taniguchi M, Diers JR, Bocian DF, Holten D, Lindsey JS. Synthesis, photophysics and electronic structure of oxobacteriochlorins. NEW J CHEM 2017. [DOI: 10.1039/c6nj04135c] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthetic oxobacteriochlorins exhibit strong absorption in the deep-red window flanked by chlorins to the red and bacteriochlorins to the near-infrared.
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Zhang S, Nagarjuna Reddy M, Mass O, Kim HJ, Hu G, Lindsey JS. Synthesis of tailored hydrodipyrrins and their examination in directed routes to bacteriochlorins and tetradehydrocorrins. NEW J CHEM 2017. [DOI: 10.1039/c7nj01892d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
18 gem-dimethyl stabilized hydrodipyrrins with diverse α-substituents have been prepared and examined in directed syntheses of unsymmetrically substituted hydroporphyrins.
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