Covalently linked pyropheophorbide dimers as models of the special pair in the photosynthetic reaction center

Osuka, Atsuhiro; Wada, Yoshinori; Shinoda, Satoshi

doi:10.1016/0040-4020(96)00131-7

Cited by 52 publications

(35 citation statements)

References 23 publications

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“…Methyl pyropheophorbides-a/d (2, 3; IUPAC-IUB nomenclature recommends methyl 13 2 -demethoxycarbonyl-pheophorbides-a/d; the prefix 'pyro' denotes substitution of the 13 2 -methoxycarbonyl group for the hydrogen atom) are related to such chlorophylls. Compounds 2 and 3 have played important roles as key compounds for preparing models of photosynthetic light-harvesting antennae [3][4][5][6][7][8][9][10] and charge transfer reaction centres [11][12][13][14][15][16]. The corresponding chlorophyll-related porphyrins 5 and 6 (see Fig.…”

Section: Introductionmentioning

confidence: 99%

Facile Synthesis of 13¹-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Tamiaki

Watanabe

Miyatake

1999

J. Porphyrins Phthalocyanines

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Methyl protopyropheophorbides-a/d were prepared by modification of readily available chlorophyll-a. The key step was oxidation of 131-oxo-chlorin to the corresponding porphyrin, and 2,3-dichloro-5,6-dicyano-p-benzoquinone was effective for 17,18-dehydrogenation. A reduction in oxidation potential of the chlorin was necessary for the oxidation. Facile oxidation was achieved by insertion of zinc as the central metal, reduction of the 13-carbonyl group and/or aggregation by high concentration. The synthetic 131-oxo-porphyrins had vinyl and formyl groups at the 3-position. These groups were very reactive in the molecule and selectively converted to other functional groups.

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Section: Introductionmentioning

confidence: 99%

Facile Synthesis of 13¹-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Tamiaki

Watanabe

Miyatake

1999

J. Porphyrins Phthalocyanines

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“…The solid was chromatographed over silica gel with elution by CCl 4 :acetone (20:1). The effluent containing the main product was evaporated and reprecipitated from CHCl 3 by pentane to afford 7, 49 mg (30%), C 41 H 50 N 6 The yield of 7 from alkylation of 6 by allyliodide under analogous conditions was 5%. Alkylation of 6 by allylchloride under these conditions was unsuccessful.…”

Section: Methodsmentioning

confidence: 99%

“…Methylpheophorbide a (1) was prepared from spirulina blue-green alga according to the literature method [6];…”

Section: Methodsmentioning

confidence: 99%

Synthesis of chlorins with a distal vinyl group

2007

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A series of chlorins containing a vinyl group on the periphery of the chlorin ring that was attached by linkers of various length, potential monomers for synthesis of polymers containing chlorin via copolymerization, was synthesized from methylpheophorbide a.Key words: methylpheophorbide a, chlorin e 6 , chlorins with a distal vinyl group, monomers for copolymerization.Porphyrins and their analogs grafted to polymers are promising photosensitizers for photodynamic sterilization of donor blood [1]. In particular, the synthesis of polymers with natural chlorins, especially the most abundant chlorophyll a and its derivatives, are of great interest. These compounds are attractive for synthesizing photosensitizers because, on one hand, they have good spectral properties and low toxicity [2] and, on the other, they have many reactive centers that enable various chemical transformations to be performed [3]. The vinyl group intrinsic to chlorophyll a and its derivatives can be used for copolymerization only with difficulty because it is bonded directly to the chlorin macrocycle and significant steric hindrances arise if it is used for the polymerization. A vinyl group distant from the macrocycle must be introduced into natural chlorin so that it can be used in copolymerization. Thus, the development of a method for synthesizing chlorins with a distal vinyl group is of great interest.Chlorophyll a itself is rarely used as starting material for chemical transformations because of its poor stability and difficulties with preparing it pure.Herein methylpheophorbide a (1), which is much more stable than chlorophyll a and is readily prepared pure while at the same time has the same reactive centers as chlorophyll a, is used as starting material for synthesizing chlorins with a vinyl group distant from the macrocycle. An allyl moiety was introduced on the periphery of the chlorin ring (4, 5, 7) by reactions at the exocycle and the 17-ester of 1. Chemical transformations were used both for introducing the vinyl group on the periphery of the chlorin ring and for introducing a reactive center distant from the macrocycle.The exocycle of chlorophyll a and its analogs, which have the same substituents in them, can be opened by primary and secondary amines [3]. This forms an amide bond at the 13-position. Substituents on the amine N atom end up bonded to the chlorin macrocycle. This reaction was used to synthesize from 1 chlorin e 6 13-amides with substituents of various hydrophilicity on the amide N atom [4,5].We synthesized chlorin e 6 13-amide (5), in which the vinyl group is bonded to the chlorin macrocycle by a 3-atom linker, by reacting 1 and allylamine. The action of certain amines on 1 is known to open the exocycle and convert the ester to an amide [5]. In this instance, this process would have been undesirable because introducing more than one distal vinyl group into chlorin could lead to formation of cross-linked polymers. The presence in the PMR spectrum of the main reaction product of singlets for the methyls of both ester...

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“…At first the vinyl group in 1 was converted to aldehyde 3 [18] and then it was oxidized to carboxylic acid by sodium chlorite treatment. [19] The obtained acid (4) was activated by disuccinimidyl carbonate (DSC) and conjugated with octadecylamine to form the octadecylamide (5) in 56 % yield (Figure 2). Presence of carboxyl group in 17 3 -position allows further modification of the molecule.…”

Section: Natural Chlorins Octadecylamidesmentioning

confidence: 99%

Natural Chlorins Octadecylamides - Upconversion Nanoparticles Complexes for the Study of Energy Transfer Process

Нечаев¹,

Nikolaeva²,

Asharchuk³

et al. 2016

MHC

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A series of natural chlorins with octadecylamine residue in pyrrole rings A and D have been prepared on the basis of chlorophyll a derivatives. The compounds are capable to form intermolecular conjugates with upconversion nanoparticles (UCNP) due to hydrophobic interactions with oleic acid on the surface of nanocrystals. Coincidence of the intensive chlorin absorption band with UCNP fluorescence in red range of spectrum results in Förster resonance energy transfer (FRET).

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Covalently linked pyropheophorbide dimers as models of the special pair in the photosynthetic reaction center

Cited by 52 publications

References 23 publications

Facile Synthesis of 13¹-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Facile Synthesis of 13¹-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Synthesis of chlorins with a distal vinyl group

Natural Chlorins Octadecylamides - Upconversion Nanoparticles Complexes for the Study of Energy Transfer Process

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Covalently linked pyropheophorbide dimers as models of the special pair in the photosynthetic reaction center

Cited by 52 publications

References 23 publications

Facile Synthesis of 131-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Facile Synthesis of 131-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Synthesis of chlorins with a distal vinyl group

Natural Chlorins Octadecylamides - Upconversion Nanoparticles Complexes for the Study of Energy Transfer Process

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Facile Synthesis of 13¹-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins

Facile Synthesis of 13¹-Oxo-porphyrins Possessing Reactive 3-Vinyl or 3-Formyl Group, Protochlorophyll-a/dDerivatives by 17,18-Dehydrogenation of Chlorins