59954-18-6Relevant articles and documents
Synthetic zinc tetrapyrroles complexing with pyridine as a single axial ligand
Tamiaki, Hitoshi,Yagai, Shiki,Miyatake, Tomohiro
, p. 2171 - 2178 (1998)
Zinc chlorins were prepared from chlorophyll-a. Visible spectra in benzene showed that synthetic zinc chlorins complexed with pyridine as an axial ligand to form the monopyridine adducts. The equilibrium constants for the complexation were dependent upon the chlorin structure: substitution of electron-withdrawing groups at the peripheral position enhanced the coordinated ability of the central zinc. 1H NMR spectra in benzene-d6 also indicated that single pyridine coordinated to the central zinc. Comparison of the equilibrium constant in a zinc chlorin with those of the corresponding zinc bacteriochlorin (7,8-dihydrochlorin) and porphyrin (17,18-dedihydrochlorin) led to an increase in the saturation and flexibility of the tetrapyrrole π-plane ligands making the central zinc more axial-ligated. All the zinc tetrapyrroles in benzene complexed with pyridine to form 5-coordinated (1:1) complexes, not 6-coordinated bis-adducts. The observed equilibrium constants were consistent with the energy changes of the complexation calculated from molecular modeling. Copyright (C) 1997 Elsevier Science Ltd.
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
, (2020)
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
The in vitro photodynamic activity, photophysical and photochemical research of a novel chlorophyll-derived photosensitizer
Tan, Guanghui,Wang, Qi,Zhang, Hongyue,Cheng, Jianjun,Wang, Zhiqiang,Qu, Fengyu,Guo, Changhong,Jin, Yingxue
, p. 2639 - 2652 (2017)
Chlorophyll has always been used as the leading compound for photodynamic therapy drug development. In this paper, a novel methyl pyropheophorbide-a- derived photosensitizer, 3-acetyl-3-devinyl-131-dicyanomethylene-pyropheophorbide-a was synthesized through modifications at C-131, C-3, and C-17 positions of methyl pyropheophorbide-a. The compound exhibited a longer wavelength absorption at 713 nm (in methanol) than that of methyl pyropheophorbide-a (667 nm) due to the enlarged the aromatic conjugation system by dicyanomethylene, allowing it to be potential in deep tumor treatment. Moreover, benefiting from the carboxylic group at C-17 and the acetyl group at C-3, the title compound was endowed with better water solubility than that of methyl pyropheophorbide-a. Detailed in vitro photodynamic therapy research showed ADCPPa could be uptaken by cancer cells successfully and killed the cancer cells more efficiently than the leading compound methyl pyropheophorbide-a under light (light dose 10 J/cm2) due to the high singlet oxygen quantum yield (65.98%). The excellent anti-photobleaching ability (degradation rate 1.6% in 10 min) also boosted its potential in practical application. In addition, the research has disclosed that during photochemical processes of photodynamic therapy, the formation of singlet oxygen after photodynamic therapy treatment played a major role, comparing with the formation of superoxide anion and radicals. Finally, the real time quantitative polymerase chain reaction (RT-qPCR) experiments have showed that the target compound has important regulating effect on expression of CDK2 and Survivin, consequently leading to apoptosis and cell death.
Synthesis of methyl pyropheophorbide-d derivatives possessing the 3-acyl groups and their electronic absorption spectra
Tamiaki, Hitoshi,Kimura, Yuki,Watanabe, Hiroaki,Miyatake, Tomohiro
, p. 3477 - 3489 (2016)
Methyl 3-acyl-pyropheophorbides-a were prepared by modification of naturally occurring chlorophyll-a through Grignard or Barbier reactions of the 3-formyl group and successive Ley-Griffith or Dess-Martin oxidations of the resulting secondary alcohols. The
Synthesis of methyl bacteriopheophorbide-d with 8-propyl group
Tamiaki, Hitoshi,Tomida, Taro,Miyatake, Tomohiro
, p. 1415 - 1418 (1997)
Methyl bacteriopheopharbide-d possessing propyl and methyl groups at the 8- and 12-positions, respectively, was prepared by modification of chlorophyll-a with 8-ethyl and 12-methyl groups.
Synthesis of regioselectively 18O-labelled chlorophyll derivatives at the 31- and/or 131-positions through one-pot exchange of carbonyl oxygen atoms
Morishita, Hidetada,Tamiaki, Hitoshi
, p. 6097 - 6107 (2005)
31- and/or 131-18O-oxo-labelled methyl pyropheophorbides (84-90% 18O atoms at each position) were prepared by exchanging carbonyl oxygen atoms under biphasic conditions of acidic H 218O (ca. 95% 18O) and dichloromethane. The (un)labelling occurred more rapidly at less sterically hindered (13-CO possessing 132-COOCH3>13-CO lacking it) or more reactive carbonyl groups (formyl>keto group), and not at any hydroxy groups. Reduction of a carbonyl to carbinol group was useful for preparation of regioselectively 18O-labelled chlorophyll derivatives. Following the labelling procedure, 131-18O-pheophytin-a and 3 1-18O-pheophytin-d were obtained. All the synthetic 18O-labelled compounds were characterized by their FAB-mass, 13C NMR and IR spectra. Especially, 18O-labelling induced 0.02 (13C-O) and 0.04-0.05 ppm high field shifts (13CO) in 18O-attached carbon resonances and about 30 cm-1 down-shifts in 18O-labelled carbonyl stretching vibrational bands.
Synthesis of 3/8-carbonylated chlorophyll derivatives and regiodependent reductivity of their carbonyl substituents
Tamiaki, Hitoshi,Hamada, Kazunori,Kunieda, Michio
, p. 5721 - 5727 (2008)
Methyl pyropheophorbide-d possessing a formyl group at the 3-position and its regioisomer having 8-CHO were prepared and their reactivities with a reductant were determined by the 1H NMR technique: 3-CHO>8-CHO. The regioselective reduction of a synthetic 3,8-diformyl-chlorin also supported the higher reactivity in 3-CHO than in 8-CHO. Regiodependent reduction of the corresponding acetyl-chlorins confirmed that carbonyl groups at the 3-position in chlorophyllous pigments were reduced more rapidly than those at the 8-position. From the reports that reactions of 3-CHO with amines were preferable to those of 7-CHO, the C{double bond, long}O functional groups on the pyrrole A-ring of chlorophylls are more reactive than those on the B-ring.
Synthesis and Properties of O- and S-Glycosylated Derivatives of Pyropheophorbide a
Aksenova,Sebyakin,Mironov
, p. 124 - 129 (2001)
New O- and S-glycosylated derivatives of pyropheophorbide a were synthesized in the context of the design of photosensitizers for photodynamic cancer therapy. The resulting amphiphilic conjugates were found to be sufficiently water-soluble and suitable for the study of the photosensitizer penetration and accumulation in tumors.
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
, (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.
