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Wu Z, Dou J, Nguyen KU, Eppley JC, Siwawannapong K, Zhang Y, Lindsey JS. Tailoring the AIE Chromogen 2-(2-Hydroxyphenyl)benzothiazole for Use in Enzyme-Triggered Molecular Brachytherapy. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248682. [PMID: 36557815 PMCID: PMC9786593 DOI: 10.3390/molecules27248682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
A targeted strategy for treating cancer is antibody-directed enzyme prodrug therapy, where the enzyme attached to the antibody causes conversion of an inactive small-molecule prodrug into an active drug. A limitation may be the diffusion of the active drug away from the antibody target site. A related strategy with radiotherapeutics entails enzymatically promoted conversion of a soluble to insoluble radiotherapeutic agent, thereby immobilizing the latter at the target site. Such a molecular brachytherapy has been scarcely investigated. In distinct research, the advent of molecular designs for aggregation-induced emission (AIE) suggests translational use in molecular brachytherapy. Here, several 2-(2-hydroxyphenyl)benzothiazole substrates that readily aggregate in aqueous solution (and afford AIE) were elaborated in this regard. In particular, (1) the 2-(2-hydroxyphenyl) unit was derivatized to bear a pegylated phosphodiester that imparts water solubility yet undergoes enzymatic cleavage, and (2) a p-phenol unit was attached to the benzo moiety to provide a reactive site for final-step iodination (here examined with natural abundance iodide). The pegylated phosphodiester-iodinated benzothiazole undergoes conversion from aqueous-soluble to aqueous-insoluble upon treatment with a phosphatase or phosphodiesterase. The aggregation is essential to molecular brachytherapy, whereas the induced emission of AIE is not essential but provides a convenient basis for research development. Altogether, 21 compounds were synthesized (18 new, 3 known via new routes). Taken together, blending biomedical strategies of enzyme prodrug therapy with materials chemistry concerning substances that undergo AIE may comprise a step forward on the long road toward molecular brachytherapy.
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Bates JS, Khamespanah F, Cullen DA, Al-Omari AA, Hopkins MN, Martinez JJ, Root TW, Stahl SS. Molecular Catalyst Synthesis Strategies to Prepare Atomically Dispersed Fe-N-C Heterogeneous Catalysts. J Am Chem Soc 2022; 144:18797-18802. [PMID: 36215721 PMCID: PMC9888425 DOI: 10.1021/jacs.2c08884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report a strategy to integrate atomically dispersed iron within a heterogeneous nitrogen-doped carbon (N-C) support, inspired by routes for metalation of molecular macrocyclic iron complexes. The N-C support, derived from pyrolysis of a ZIF-8 metal-organic framework, is metalated via solution-phase reaction with FeCl2 and tributyl amine, as a Brønsted base, at 150 °C. Fe active sites are characterized by 57Fe Mössbauer spectroscopy and aberration-corrected scanning transmission electron microscopy. The site density can be increased by selective removal of Zn2+ ions from the N-C support prior to metalation, resembling the transmetalation strategy commonly employed for the preparation of molecular Fe-macrocycles. The utility of this approach is validated by the higher catalytic rates (per total Fe) of these materials relative to established Fe-N-C catalysts, benchmarked using an aerobic oxidation reaction.
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Affiliation(s)
- Jason S. Bates
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Fatemeh Khamespanah
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - David A. Cullen
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Abdulhadi A. Al-Omari
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| | - Melissa N. Hopkins
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Jesse J. Martinez
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Thatcher W. Root
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, WI 53706, USA,Corresponding Authors
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Abstract
A growing theme in chemistry is the joining of multiple organic molecular building blocks to create functional molecules. Diverse derivatizable structures—here termed “scaffolds” comprised of “hubs”—provide the foundation for systematic covalent organization of a rich variety of building blocks. This review encompasses 30 tri- or tetra-armed molecular hubs (e.g., triazine, lysine, arenes, dyes) that are used directly or in combination to give linear, cyclic, or branched scaffolds. Each scaffold is categorized by graph theory into one of 31 trees to express the molecular connectivity and overall architecture. Rational chemistry with exacting numbers of derivatizable sites is emphasized. The incorporation of water-solubilization motifs, robust or self-immolative linkers, enzymatically cleavable groups and functional appendages affords immense (and often late-stage) diversification of the scaffolds. Altogether, 107 target molecules are reviewed along with 19 syntheses to illustrate the distinctive chemistries for creating and derivatizing scaffolds. The review covers the history of the field up through 2020, briefly touching on statistically derivatized carriers employed in immunology as counterpoints to the rationally assembled and derivatized scaffolds here, although most citations are from the past two decades. The scaffolds are used widely in fields ranging from pure chemistry to artificial photosynthesis and biomedical sciences.
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Sollert C, Kocsi D, Jane RT, Orthaber A, Borbas KE. C-glycosylated pyrroles and their application in dipyrromethane and porphyrin synthesis. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s1088424621500723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pyrrole C-glycosylated in either the 2- or the 3-position could be prepared by the acid-catalyzed reaction between trichloroacetimidate glycosyl donors and pyrrole, or [Formula: see text]-phenyl-tri?uoroacetimidate glucosyl donor and [Formula: see text]-TIPS pyrrole, respectively. Pyrroles carrying glucose, mannose, galactose and lactose in the 2-position, and glucose in the 3-position were obtained. The configurations of the products could be assigned using a combination of 1D and 2D NMR spectroscopy. A number of undesired background reactions yielding a variety of stereo- and regioisomers were identified; in several cases these could be eliminated. Glycosylpyrroles could be incorporated into mono- and diglycosylated dipyrromethanes, a diglycosylated BODIPY dye, and a monoglycosylated Zn(II) porphyrin without damaging the sugar unit.
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Affiliation(s)
- Carina Sollert
- Department of Chemistry, Ångström Laboratory, Box 523, Uppsala University, 75120 Uppsala, Sweden
| | - Daniel Kocsi
- Department of Chemistry, Ångström Laboratory, Box 523, Uppsala University, 75120 Uppsala, Sweden
| | - Reuben T. Jane
- Department of Chemistry, Ångström Laboratory, Box 523, Uppsala University, 75120 Uppsala, Sweden
| | - Andreas Orthaber
- Department of Chemistry, Ångström Laboratory, Box 523, Uppsala University, 75120 Uppsala, Sweden
| | - K. Eszter Borbas
- Department of Chemistry, Ångström Laboratory, Box 523, Uppsala University, 75120 Uppsala, Sweden
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Matsumoto N, Taniguchi M, Lindsey JS. Bioconjugatable synthetic chlorins rendered water-soluble with three PEG-12 groups via click chemistry. J PORPHYR PHTHALOCYA 2020. [DOI: 10.1142/s1088424619501219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chlorins provide many ideal features for use as red-region fluorophores but require molecular tailoring for solubilization in aqueous solution. A chlorin building-block bearing 18,18-dimethyl, 15-bromo and 10-[2,4,6-tris(propargyloxy)phenyl] substituents has been transformed via click chemistry with CH3(OCH2CH[Formula: see text]-N3 followed by Suzuki coupling with 3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)propanoic acid, thereby installing a water-solubilization motif and a bioconjugatable handle, respectively. In toluene, [Formula: see text]-dimethylformamide (DMF) or water, the resulting facially encumbered free base chlorin exhibits characteristic chlorin absorption ([Formula: see text] [Formula: see text]412, 643 nm) and fluorescence ([Formula: see text] [Formula: see text]645 nm) spectra with only modest variation in fluorescence quantum yield ([Formula: see text] values (0.24, 0.25 and 0.19, respectively). The zinc chlorin derived therefrom exhibits similar spectral constancy ([Formula: see text] [Formula: see text]414 and 613 nm, [Formula: see text] [Formula: see text]616 nm) and [Formula: see text] 0.094, 0.10 and 0.086 in the three solvents. The results together indicate the viability of the molecular design and synthetic methodology to create red-region fluorophores for use in diverse applications.
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Affiliation(s)
- Nobuyuki Matsumoto
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
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Zhang Y, Wu Z, Takashima I, Nguyen KU, Matsumoto N, Lindsey JS. Engineering of an archaeal phosphodiesterase to trigger aggregation-induced emission (AIE) of synthetic substrates. NEW J CHEM 2020. [DOI: 10.1039/d0nj03208e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aggregation-induced emission (AIE) probes that can be triggered by enzymatic activity are valuable for applications across the life sciences.
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Affiliation(s)
- Yunlong Zhang
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Zhiyuan Wu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Ippei Takashima
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
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Bornhof AB, Xiong R, Borbas KE. Rational Synthesis of 2-Bromoporphyrins and 2,12-Dibromoporphyrins. J Org Chem 2017; 82:12908-12913. [PMID: 29094938 DOI: 10.1021/acs.joc.7b02404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bromoporphyrins were prepared by the metal-mediated self-condensation of brominated 1-formyldipyrromethanes. Depending on the conditions, Mg(II)-2,12-dibromoporphyrin and Mg(II)-2-bromoporphyrin could be obtained in up to 11% and 17% isolated yield, respectively. Zn(II) was also a viable templating metal. The positions of the bromine substituents were confirmed by 2D-NMR spectroscopic analysis and the X-ray crystal structure of a derivative. Suzuki and Sonogashira reactions of the bromoporphyrins yielded 2-substituted or 2,12-disubstituted porphyrins with red-shifted absorption and emission spectra. This method provides access to the minimalist core of β-mono- and β,β'-disubstituted porphyrins from readily available starting materials.
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Affiliation(s)
- Anna-Bea Bornhof
- Department of Chemistry, Ångström Laboratory, Uppsala University , Box 523, 751 20 Uppsala, Sweden
| | - Ruisheng Xiong
- Department of Chemistry, Ångström Laboratory, Uppsala University , Box 523, 751 20 Uppsala, Sweden
| | - K Eszter Borbas
- Department of Chemistry, Ångström Laboratory, Uppsala University , Box 523, 751 20 Uppsala, Sweden
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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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Affiliation(s)
- Yizhou Liu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | | | | | - Don Hood
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | - James R. Diers
- Department of Chemistry
- University of California
- Riverside
- USA
| | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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Taniguchi M, Lindsey JS. Synthetic Chlorins, Possible Surrogates for Chlorophylls, Prepared by Derivatization of Porphyrins. Chem Rev 2016; 117:344-535. [DOI: 10.1021/acs.chemrev.5b00696] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
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Liu M, Chen CY, Mandal AK, Chandrashaker V, Evans-Storms RB, Pitner JB, Bocian DF, Holten D, Lindsey JS. Bioconjugatable, PEGylated Hydroporphyrins for Photochemistry and Photomedicine. Narrow-Band, Red-Emitting Chlorins. NEW J CHEM 2016; 40:7721-7740. [PMID: 28154477 DOI: 10.1039/c6nj01154c] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chromophores that absorb and emit in the red spectral region (600-700 nm), are water soluble, and bear a bioconjugatable tether are relatively rare yet would fulfill many applications in photochemistry and photomedicine. Here, three molecular designs have been developed wherein stable synthetic chlorins - analogues of chlorophylls - have been tailored with PEG groups for use in aqueous solution. The designs differ with regard to order of the installation (pre/post-formation of the chlorin macrocycle) and position of the PEG groups. Six PEGylated synthetic chlorins (three free bases, three zinc chelates) have been prepared, of which four are equipped with a bioconjugatable (carboxylic acid) tether. The most effective design for aqueous solubilization entails facial encumbrance where PEG groups project above and below the plane of the hydrophobic disk-like chlorin macrocycle. The chlorins possess strong absorption at ~400 nm (B band) and in the red region (Qy band); regardless of wavelength of excitation, emission occurs in the red region. Excitation in the ~400 nm region thus provides an effective Stokes shift of >200 nm. The four bioconjugatable water-soluble chlorins exhibit Qy absorption/emission in water at 613/614, 636/638, 698/700 and 706/710 nm. The spectral properties are essentially unchanged in DMF and water for the facially encumbered chlorins, which also exhibit narrow Qy absorption and emission bands (full-width-at-half maximum of each <25 nm). The water-solubility was assessed by absorption spectroscopy over the concentration range ~0.4 μM - 0.4 mM. One chlorin was conjugated to a mouse polyclonal IgG antibody for use in flow cytometry with compensation beads for proof-of-principle. The conjugate displayed a sharp signal when excited by a violet laser (405 nm) with emission in the 620-660 nm range. Taken together, the designs described herein augur well for development of a set of spectrally distinct chlorins with relatively sharp bands in the red region.
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Affiliation(s)
- Mengran Liu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Chih-Yuan Chen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Amit Kumar Mandal
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889
| | | | | | | | - David F Bocian
- Department of Chemistry, University of California, Riverside, CA 92521-0403
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
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Kumar R, Yadav P, Kumar A, Sankar M. Facile Synthesis and Electrochemical Studies of Diethoxyphosphorylphenyl-substituted Porphyrin and Its Metal Complexes. CHEM LETT 2015. [DOI: 10.1246/cl.150233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ravi Kumar
- Department of Chemistry, Indian Institute of Technology Roorkee
| | - Pinky Yadav
- Department of Chemistry, Indian Institute of Technology Roorkee
| | - Amit Kumar
- Department of Chemistry, Indian Institute of Technology Roorkee
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12
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Lindsey JS. De novo synthesis of gem-dialkyl chlorophyll analogues for probing and emulating our green world. Chem Rev 2015; 115:6534-620. [PMID: 26068531 DOI: 10.1021/acs.chemrev.5b00065] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
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Sahin T, Vairaprakash P, Borbas KE, Balasubramanian T, Lindsey JS. Hydrophilic bioconjugatable trans-AB-porphyrins and peptide conjugates. J PORPHYR PHTHALOCYA 2015. [DOI: 10.1142/s1088424615500121] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Porphyrins bearing a single bioconjugatable group and a single water-solubilization motif in a trans-AB-architecture (with no other substituents) provide a compact design of value for studies in diverse disciplines. Established synthetic methods have been employed to prepare four new free base porphyrins and one Mn ( III ) chelate. The hydrophilic motif includes 4-N-methylpyridinium, 2,4,6-tris(carboxymethoxy)phenyl, 2,6-bis(phosphonomethoxy)phenyl, and carboxy; the bioconjugatable unit includes carboxy, maleimido, and N-hydroxysuccinimido (NHS) ester. Bioconjugation experiments with a protected porphyrin-diphosphate or unprotected porphyrin-diphosphonate were examined in organic solution or water, respectively. Both approaches were employed to conjugate to the ε-amino group of Lys11 in AcKPV- NH 2, a tripeptide fragment [ Ac -α-MSH(11-13)- NH 2] of melanocyte stimulating hormone, yielding porphyrin-peptide conjugates.
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Affiliation(s)
- Tuba Sahin
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | | | - K. Eszter Borbas
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | | | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
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Westmeyer GG, Emer Y, Lintelmann J, Jasanoff A. MRI-based detection of alkaline phosphatase gene reporter activity using a porphyrin solubility switch. ACTA ACUST UNITED AC 2014; 21:422-9. [PMID: 24613020 DOI: 10.1016/j.chembiol.2014.01.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/08/2014] [Accepted: 01/13/2014] [Indexed: 12/23/2022]
Abstract
The ability to map patterns of gene expression noninvasively in living animals could have impact in many areas of biology. Reporter systems compatible with MRI could be particularly valuable, but existing strategies tend to lack sensitivity or specificity. Here we address the challenge of MRI-based gene mapping using the reporter enzyme secreted alkaline phosphatase (SEAP), in conjunction with a water-soluble metalloporphyrin contrast agent. SEAP cleaves the porphyrin into an insoluble product that accumulates at sites of enzyme expression and can be visualized by MRI and optical absorbance. The contrast mechanism functions in vitro, in brain slices, and in animals. The system also provides the possibility of readout both in the living animal and by postmortem histology, and it notably does not require intracellular delivery of the contrast agent. The solubility switch mechanism used to detect SEAP could be adapted for imaging of additional reporter enzymes or endogenous targets.
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Affiliation(s)
- Gil G Westmeyer
- Departments of Brain & Cognitive Sciences, Biological Engineering, and Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 16-561, Cambridge, MA 02139, USA; Department of Nuclear Medicine, Technische Universität München, 81675 Munich, Germany; Institutes of Biological and Medical Imaging and Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Munich/Neuherberg, Germany
| | - Yelena Emer
- Departments of Brain & Cognitive Sciences, Biological Engineering, and Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 16-561, Cambridge, MA 02139, USA
| | - Jutta Lintelmann
- Comprehensive Molecular Analytics Cooperation Group, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Munich/Neuherberg, Germany
| | - Alan Jasanoff
- Departments of Brain & Cognitive Sciences, Biological Engineering, and Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 16-561, Cambridge, MA 02139, USA.
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Electrochemical and spectroscopic studies of poly(diethoxyphosphoryl)porphyrins. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2011.01.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Synthetic meso-substituted porphyrins offer significant attractions compared with naturally occurring beta-substituted porphyrins. The attractions include the rectilinear arrangement of the four meso substituents and potential synthetic amenability from pyrrole and simple acyl reactants, thereby avoiding the cumbersome syntheses of beta-substituted pyrroles. In practice, however, the classical methods for the synthesis of meso-substituted porphyrins were characterized by high-temperature reactions, limited scope of substituents, and statistical mixtures accompanied by laborious chromatography if porphyrins bearing two different types of substituents were sought. Such methods left unrealized the tremendous utility of meso-substituted porphyrins across the enormously broad field of porphyrin science, which touches pure chemistry; energy, life and materials sciences; and medicine. This Account surveys a set of strategies, developed over a generation, that provide rational access to porphyrins bearing up to four distinct meso substituents. A "2 + 2" route employs a dipyrromethane-1,9-dicarbinol and a dipyrromethane (bearing ABC- and D-substituents, respectively) in a two-step, one-flask process of acid-catalyzed condensation followed by oxidation at room temperature to form the free base "ABCD-porphyrin." A "bilane" route relies on the acid-catalyzed reaction of a 1-acyldipyrromethane (CD substituents) and a 9-bromodipyrromethane-1-carbinol (AB substituents) to form the corresponding 19-acyl-1-bromobilane. Reaction of the latter compound in the presence of MgBr(2), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and toluene at reflux exposed to air affords the corresponding magnesium(II) porphyrin. The two routes are complementary, both in scope and in implementation. A suite of methods also affords trans-A(2)B(2)-porphyrins by reaction of a dipyrromethane and an aldehyde, self-condensation of a dipyrromethane-1-carbinol, or self-condensation of a 1-acyldipyrromethane. These new routes are also useful for preparing sparsely substituted porphyrins, which bear fewer than four meso substituents (e.g., trans-AB-porphyrins, A-porphyrins). Because of their compact size and the ability to incorporate hydrophilic or amphipathic groups, such molecules are ideal for biological applications. The success of these new synthetic strategies has relied on a number of advances including (1) the development of simple yet efficient routes to dipyrromethanes, acyldipyrromethanes, and dipyrromethane-carbinols, (2) the identification of acid catalysts and reaction conditions for condensations of pyrromethane species without accompanying acidolysis (which underlies scrambling and formation of a mixture of porphyrin products), (3) the development of analytical methods to rapidly screen for scrambling and to characterize the distribution of oligopyrromethanes and macrocycles, (4) selection and refinement of synthetic methods to increase yields and to limit or avoid use of chromatography, thereby achieving scalability to multigram levels, and (5) exploitation of discoveries concerning the fundamental chemistry of pyrrolic species. With these developments, the prior era of porphyrin synthesis has been supplanted with rational routes that proceed under very mild conditions and afford a single porphyrin bearing up to four distinct meso substituents. The meso substituents encompass a very wide range of molecular complexity. The resulting porphyrins can serve as building blocks in the construction of model systems, as components of molecular materials, and as surrogates for naturally occurring tetrapyrrole macrocycles.
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Affiliation(s)
- Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204
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Abstract
Three free base porphyrins have been prepared that bear a polar and facially encumbering 2,4,6-tris(carboxymethoxy)phenyl motif at one meso (5-) position. The only other substituent (15-position) comprises phenyl, formyl, or p-aminophenyl. The porphyrins exhibit solubility in water (or aqueous buffer solutions) at pH >/=7 and concentrations >1 mM at room temperature. The concise syntheses, water-solubility, and bioconjugatable handle make these porphyrin constructs suitable for biological applications.
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Borbas KE, Lindsey JS. Swallowtail Bacteriochlorins. Lipophilic Absorbers for the Near-Infrared. Org Lett 2008; 10:1931-4. [DOI: 10.1021/ol800436u] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. Eszter Borbas
- Department of Chemistry, North Carolina State University; Raleigh, North Carolina 27695-8204
| | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University; Raleigh, North Carolina 27695-8204
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Taniguchi M, Cramer DL, Bhise AD, Kee HL, Bocian DF, Holten D, Lindsey JS. Accessing the near-infrared spectral region with stable, synthetic, wavelength-tunable bacteriochlorins. NEW J CHEM 2008. [DOI: 10.1039/b717803d] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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