6453-67-4Relevant articles and documents
Selective synthesis of C32- and C20-monoiodinated chlorophyll derivatives
Oba, Toru,Miyata, Kota,Masuya, Takuto,Yasuda, Satoru,Ito, Satoshi
, p. 999 - 1003 (2015)
A chlorophyll derivative possessing an iodine atom at the C3-moiety was synthesized from methyl pyropheophorbide-a for the first time using phenyliodine bis(trifluoroacetate) and I2. The use of larger amounts of reagents resulted in additional iodination at the C20-position, thus affording the 3,20-diiodo derivative. The iodine atom at the C3-moiety of the 3,20-diiodo derivative could be removed selectively by treating with NaN3, thus affording the 3-vinyl-20-iodo derivative.
Chlorophylls. IX. the first phytochlorin-fullerene dyads: Synthesis and conformational studies
Helaja, Juho,Tauber, Andrei Y.,Abel, Yvonne,Tkachcnko, Nikolai V.,Lemmetyinen, Helge,Kilpelaeinen, Ilkka,Hynnincn, Paavo H.
, p. 2403 - 2408 (1999)
The first chlorin-fullerene electron donor-acceptor (DA) compounds have been synthesized. The synthesis produced C-2′ R and Sepimers, both of which exhibited atropisomerism regarding the mutual orientation of the fullerene ball and the propionic acid residue of the phytochlorin unit. The atropisomerism arises from the short linkage between the Ceo ball and the chlorin ring, which hinders free rotation of the bulky ball. Dynamic H NMR and molecular modelling were used in concert to investigate the atropisomerism in the metal-free DA molecules 5. The dynamic NMR-measurements showed a lower energy barrier [Ea = 21.4(5) kcal mol 1] for one stereoisomer and a higher one [￡a = 23.0(8) kcal mol1] for the three other stereoisomers. MM+ molecular mechanic calculations were performed for each C-2 epimer to assess the potential energy as a function of the angle of rotation about the C3-C2 single bond. For the C-2 R and Sepimers, these calculations produced two potential energy curves that showed a near mirror-image relationship. Solvation phenomena were proposed to play an essential role in the stabilization of the isomers. Fast intramolecular photoinduced electron transfer from the chlorin donor to the fullerene acceptor was observed in polar solvents. Copyright 1999 by the Royal Society of Chemistry.
Nickel complexes of chlorophyll derivatives
Belykh,Tarabukina,Matveev,Kuchin
, p. 1300 - 1307 (2007)
Nickel complexes of certain phorbine and amide derivatives of chlorophyll a were synthesized. Most of the chlorophyll a derivatives studied form nickel complexes when boiled in toluene with an equimolar amount of nickel acetylacetonate in high yield. The yields of the nickel complexes of the chlorophyll derivatives are determined by the stability of the starting ligand under the reaction conditions.
Photosensitizers derived from 132-oxo-methyl pyropheophorbide-a: Enhanced effect of indium(III) as a central metal in in vitro and in vivo photosensitizing efficacy
Rosenfeld, Andrew,Morgan, Janet,Goswami, Lalit N.,Ohulchanskyy, Tymish,Zheng, Xiang,Prasad, Paras N.,Oseroff, Allan,Pandey, Ravindra K.
, p. 626 - 634 (2006)
The effects of an additional keto group on absorption wavelength and the corresponding metal complexes Zn(II), Cu(II) In(III) on singlet oxygen production and photodynamic efficacy were examined among the alkyl ether analogs of pyropheophorbide-a. For the preparation of the desired photosensitizers, the methyl 132-oxo-pyropheophorbide-a obtained by reacting methyl pyropheophorbide-a with aqueous LiOH-THF was converted into a series of alkyl ether analogs. These compounds were evaluated for photophysical properties and in vitro (by means of the MTT assay and intracellular localization in RIF cells) and in vivo (in C3H mice implanted with RIF tumors) photosensitizing efficacy. Among the alkyl ether derivatives, the methyl 3-decyloxyethyl-3-devinyl-13 2-oxo-pyropheophorbide-a was found to be most effective and the insertion of In(III) into this analog further enhanced its in vitro and in vivo photosensitizing efficacy. Fluorescence microscopy showed that, in contrast to the hexyl and dodecyl ether derivatives of HPPH (which localize in mitochondria and lysosomes, respectively), the diketo-analogs and their In(III) complexes localized in Golgi bodies. The preliminary in vitro and in vivo results suggest that, in both free-base and metalated analogs, the introduction of an additional keto group at the five-member exocyclic ring in pyropheophorbide-a diminishes its photosensitizing efficacy. This may be due to a shift in subcellular localization from mitochondria to the Golgi bodies. The further introduction of In(III) enhances photoactivity, but not by shifting the localization of the photosensitizer.
Transformation of carbonyl to vinylidene groups in the π-conjugated peripheral substituent of chlorophyll derivatives by Tebbe reagent
Tamiaki, Hitoshi,Tsuji, Kazuki,Machida, Shinnosuke,Teramura, Misato,Miyatake, Tomohiro
, p. 788 - 790 (2016)
The 131-oxo-moiety of chlorophyll-a derivatives including methyl (pyro)pheophorbides-a, mesopyropheophorbide-a, and bacteriopheophorbide-d possessing vinyl, ethyl, and 1-hydroxyethyl groups, respectively, at the 3-position was transformed into the corresponding exo-methylene group by treatment of Tebbe reagent. The synthetic procedures were useful for the regioselective conversion of the carbonyl to vinylidene group at the 3-position and naturally occurring chlorophyll-d (3-CHO) was successfully modified to chlorophyll-a (3-CH=CH2). Under the methylenation conditions, ester-carbonyl, hydroxy, and allyl groups in the peripheral substituents were tolerant as well as an acid-labile magnesium at the central position of chlorophylls.
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Wasielewski et al.
, p. 1961 (1978)
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Effects of the 13-keto group in the E-ring of zinc chlorophyll derivatives on demetalation kinetics under acidic conditions
Saga, Yoshitaka,Maruko, Akane,Sadaoka, Kana,Takahashi, Naoya
, p. 672 - 674 (2013)
Zinc methyl 131-deoxopyropheophorbide a, which lacked the 13 1-oxo group in the exo five-membered E-ring, exhibited faster demetalation kinetics than zinc methyl pyropheophorbide a under acidic conditions, indicating that the 13-keto group of chlorophyllous pigments was responsible for resistance against removal of the central metal from the chlorin macrocycle.
The synthesis of chlorophyll-a skeleton homologs bearing linear six-carbon chain from methyl pheophorbide-a
Wang,Han,Shim
, p. 965 - 972 (2011)
The synthesis of chlorins bearing 6C-straight chain was accomplished from methyl pheophorbide-a. A series of chemical modifications were employed for the construction of active functional groups, such as bromine atom or aldehyde group, on the periphery of chlorins. These functionalized chlorins further reacted with the reagent containing straight carbon-chain by common chemical reactions to produce target compounds. The structures of all new chlorins were characterized by elemental analysis, IR, UV-Vis and 1H NMR spectra.
Synthesis of methyl (132R/S)-alkyl-pyropheophorbide a and a non-epimerized chlorophyll a mimic
Ogasawara, Shin,Tamiaki, Hitoshi
, p. 6612 - 6621 (2015)
The (132R/S)-methoxycarbonyl group of methyl pheophorbides a/a′ (chlorophyll a/a′ derivatives) was converted to methyl, ethyl, propyl, and isopropyl groups through the C132-alkylation under basic conditions followed by pyrolysis in 2,4,6-collidine with lithium iodide. All the resulting products, methyl 132-alkyl-pyropheophorbides a, predominantly gave the (132R)-stereoisomers with about one tenth of the (132S)-epimers. Their stereochemistry was determined by 1D/2D NMR and their optical properties were characterized by visible absorption and circular dichroism spectroscopy. Methyl (132R)-propyl-pyropheophorbide a was converted to (132R)-propyl-pyrochlorophyll a by ester exchanging and magnesium chelating reactions. The synthetic chlorophyll a analogue showed non-epimerization at the 132-position in pyridine-d5 at 40 °C, while naturally occurring chlorophyll a was easily epimerized under the same conditions to give its epimeric mixture.
Unexpected methylation and propylation of porphyrin E-ring during the hemisynthesis of deoxophylloerythroetioporphyrin (DPEP)
Jeandon, Christophe,Ocampo, Ruben,Callot, Henry J.
, p. 16107 - 16114 (1997)
An improved hemisynthesis of DPEP from chlorophyll a is described. Hydrogenation of the vinyl group avoided the cleavage to a 3-H porphyrin, while heating in triazabicyolodecene performed the decarboxylation of the side-chain and the aromatization of ring D. Under these conditions extensive methylation and propylation of ring E occurred in the presence of CH2X2 (X = Cl, Br).
Synthesis of 20-substituted chlorophyll derivatives with F-ring and optical properties of their less distorted chlorin π-systems
Takarada, Yuki,Doi, Marie,Ogasawara, Shin,Tamiaki, Hitoshi
supporting information, (2021/06/17)
Under acidic conditions, methyl bacteriopheophorbides-d bearing a variety of substituents at the 20-position were dehydrated in a 1-hydroxyethyl group at the 3-position to give methyl 20-substituted pyropheophorbides-a. In the same pot, the resulting 3-vinyl group was successively cyclized at the 5-position to afford the corresponding 3,5-ethano-chlorins as analogs of sedimentary porphyrins with two exo-five-membered rings. The 20-substitution is essential to the cyclization to produce the additionally fused F-ring. After the ring closure, the 20-bromine atom and acetyl group were removed by the action of the same acid to give the 20-unsubstituted product. The steric size of the 20-substituents affected the cyclization as well as the electronic absorption and emission of the 3,5-ethano-chlorins in a solution. The F-ring fusion suppressed the conformational distortion of the chlorin π-plane, partially regulating the optical properties: decrease of red shifts in Qy maxima by the 20-substitution and reduction of almost all Stokes shifts.
Synthetic substituted boronates of dihydroxy-bacteriochlorin absorbing and emitting far-red to near-infrared light as bacteriopheophytin-a analogs
Funakoshi, Daichi,Nomura, Yosaku,Shoji, Sunao,Tamiaki, Hitoshi
, (2019/12/28)
Several substituted boronates of methyl cis-7,8-dihydroxy-pyrobacteriopheophorbide-a possessing the same 3-acetyl-131-oxo-bacteriochlorin π-conjugated system as bacteriopheophytin-a found in type-II reaction centers of anoxygenic photosynthetic
