36151-62-9

Upstream product

• 186581-53-3 diazomethane 
• 56145-41-6 mesopyropheophorbide-a 
• 6453-67-4 methyl pyropheophorbide a 
• 7664-93-9 sulfuric acid 
• 5594-30-9 methylpheophorbide a 
• 15664-29-6 pheophorbide-a 
• 603-17-8 pheophytin a 
• 59954-18-6 methyl bacteriopheophorbide-d 
• 7647-01-0 hydrogenchloride 
• 58326-67-3 pyropheophorbide-d methyl ester 
• 6453-67-4 3¹,3²-didehydrophytochlorin 
• 6453-67-4 pyropheophorbide a methyl ester 

Downstream Products

• 96806-72-3 methyl δ-meso-nitrosomesopyropheophorbide a 
• 33719-95-8 C₃₅H₃₈N₄O₃ 
• 33719-95-8 Phylloerythrin-methylester 

Relevant academic research and scientific papers

Synthesis, Comparative Photosensitizing Efficacy, Human Serum Albumin (Site II) Binding Ability, and Intracellular Localization Characteristics of Novel Benzobacteriochlorins Derived from vic-Dihydroxybacteriochlorins

In a sequence of reactions, methyl mesopyropheophorbide a, mesochlorin e6 trimethyl ester, mesochlorin p6 trimethyl ester, mesopurpurin-18-N-hexylimide methyl ester, and mesopurpurin-18-N-3,5-bis(trifluoromethyl)benzylimide methyl es

Preparation of mono-vinylated and formylated chlorophyll derivatives and their optical properties

Regioisomeric 3- and 8-vinylchlorins as well as 7- and 12-vinylchlorins were prepared by modifying naturally occurring chlorophylls-a and/or b. The corresponding formylchlorins were synthesized by oxidation of the 3/8-vinyl, 7-hydroxymethyl or 12-methyl groups and readily transformed to the vinylchlorins by Wittig reactions. Their visible absorption, circular dichroism, fluorescence emission spectra in dichloromethane were dependent on the substituents directly conjugated with a chlorin π-system. The substitution with vinyl and formyl groups at the 3- and 12-positions on a molecular y-axis shifted redmost Qy absorption maxima to longer wavelengths than those at 7/8-positions on an?x-axis. The synthetic vinylchlorins were more fluorescent than the corresponding formylchlorins.

In vitro cellular uptake and dimerization of signal transducer and activator of transcription-3 (STAT3) identify the photosensitizing and imaging-potential of isomeric photosensitizers derived from chlorophyll-a and bacteriochlorophyll-a

Among the photosensitizers investigated, both ring-D and ring-B reduced chlorins containing the m-iodobenzyloxyethyl group at position-3 and a carboxylic acid functionality at position-172 showed the highest uptake by tumor cells and light-dependent photoreaction that correlated with maximal tumor-imaging [positron emission tomography (PET) and fluorescence] and long-term photodynamic therapy (PDT) efficacy in BALB/c mice bearing Colon26 tumors. However, among the ring-D reduced compounds, the isomer containing the 1′-m-iobenzyloxyethyl group at position-3 was more effective than the corresponding 8-(1′-m-iodobenzyloxyethyl) derivative. All photosensitizers showed maximum uptake by tumor tissue 24 h after injection, and the tumors exposed with light at low fluence and fluence rates (128 J/cm2, 14 mW/cm2) produced significantly enhanced tumor eradication than those exposed at higher fluence and fluence rate (135 J/cm2, 75 mW/cm 2). Interestingly, dose-dependent cellular uptake of the compounds and light-dependent STAT3 dimerization have emerged as sensitive rapid indicators for PDT efficacy in vitro and in vivo and could be used as in vitro/in vivo biomarkers for evaluating and optimizing the in vivo treatment parameters of the existing and new PDT candidates.

Synthesis of chlorophyll-f analogs possessing the 2-formyl group by modifying chlorophyll-a

A methyl group at the 2-position of methyl mesopyropheophorbide-a was transformed to the 2-formyl group to give methyl mesopyropheophorbide-f, one of the chlorophyll-f analogs. The 2-formylation moved the redmost electronic absorption band in a solution to a longer wavelength and the bathochromic shift was comparable to that by the 3-formylation. Zinc complex of the synthetic compound in solutions showed similar visible absorption spectra as those of naturally occurring chlorophyll-f.

Photoreduction of zinc 8-vinylated chlorophyll derivative to bacteriochlorophyll-b/g analog possessing an 8-ethylidene group

When a pyridine solution of zinc methyl 8-vinyl-mesopyropheophorbide-a was irradiated with visible light in the presence of ethanol, ascorbic acid and diazabicylo[2.2.2]octane under nitrogen at room temperature, zinc (7R/S,8E)-8-ethylidene-bacteriochlorin was obtained via 1,4-hydrogenation. The 1,4-photoreduction is similar to the enzymatic reduction of 8-vinyl- chlorophyllides to (E)-8-ethylidene-bacteriochlorins in anoxygenic photosynthetic bacteria producing bacteriochlorophylls-b/g. The resulting zinc 8-ethylidene-bacteriochlorin was readily isomerized to the chemically more stable 8-ethyl-chlorin by further illumination. As a by-product, zinc 8-vinyl-7,8-cis-bacteriochlorin was slightly formed by photoinduced 1,2-hydrogenation of zinc 8-vinyl-chlorin.

Synthesis of 20-substituted chlorophyll derivatives with F-ring and optical properties of their less distorted chlorin π-systems

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.

Physicochemical and biochemical properties of synthetic zinc 131-(un)substituted chlorophyll-a derivatives

Zinc methyl pheophorbides a/a’, which possess oxo and methoxycarbonyl groups at the C131- and C132-positions, respectively, on the exo-five membered ring fusing the cyclic tetrapyrrole of their chlorin π-skeletons, were prepared via chemical modifications of chlorophyll a produced in phototrophs. The C131-hydroxylated and unsubstituted analogues were synthesized by reduction of the ketone moiety. The C131- and C132-stereochemistry of these semi-synthetic compounds was confirmed by 1H NMR and circular dichroism spectroscopies. A methoxycarbonyl group at the chiral C132-position in the ketone was stereo-inverted under basic conditions, whereas those in the corresponding alcoholic and dihydro-forms were not. The in vitro BciC enzymatic reaction of the (132R)-ketone was found to stereoselectively hydrolyze the C132-methoxycarbonyl group, followed by spontaneous decarboxylation. Similarly, the (132R)-COOCH3 group in the (131S)-alcohol was hydrolyzed, whereas the (132R)-COOCH3 group in the (131R)-alcohol was not. After the enzymatic reaction of the C131-dihydro-compound, its (132S)-demethoxycarbonylated and hydroxylated product was observed.

Site-selective C20-fluorinations of chlorophyll-a derivatives using N-fluorobenzenesulfonimide and their optical properties

Site-selective fluorinations at the C20 position of methyl pyropheophorbides-a, which is derived from naturally occurring chlorophyll(Chl)-a, were achieved by using N-fluorobenzenesulfonimide (NFSI). All the synthetic Chl-a derivatives possessing a variety of the C3-substituents (vinyl, ethyl, formyl, acetyl, hydroxymethyl, and 1-hydroxyethyl groups) were mono-fluorinated to produce the corresponding 20-fluoro-chlorins as isolated products. These fluorinated products were characterized by 1D/2D NMR, visible absorption, and fluorescence emission spectroscopy. Owing to the strong electronegativity of the C20-fluorine atom, their red-most Qy absorption and fluorescence emission bands were bathochromically shifted except for the C3-acetyl substitutes. This study showed not only tolerance of the chlorin π-skeleton and C3-substituents to NFSI but also potential availability of the fluorinated Chl library.

Synthesis of a chlorophyll-a derivative fused with an additional exo-five-membered ring and its optical properties

A C20-free chlorophyll-a derivative with an additional exo-five-membered ring was successfully prepared using an ethylene linkage at the C3- and C5-positions. A bromination at the C20-position was requisite for the cyclization of a 1-hydroxyethyl or vinyl group at the C3-position of methyl bacteriopheophorbide-d or methyl pyropheophorbide-a, respectively. By comparing optical properties of the cyclized product with those of its 3-ethyl uncyclized analog in a diluted dichloromethane solution, it was shown that the cyclization shifted the Qx and Bx absorption maxima to longer wavelengths and reduced the Stokes shift.

20-(N-Methylpyridiniumyl)ethynylated chlorophyll-a derivative with an intense Qx absorption band at a green to orange region

Methyl 20-substituted mesopyropheophorbides-a were prepared by the chemical modification of natural chlorophyll-a via palladium-catalyzed cross-coupling reactions. The 20-ethynylation and further 2-pyridylation showed bathochromic shifts in their visible absorption bands as well as hyperchromic effects of the Qx bands in a diluted chloroform solution. The protonation and methylation at the nitrogen atom of the 202-pyridyl group induced much larger shifts and effects, especially giving red-shifted and intensified Qx bands.