171598-60-0Relevant articles and documents
meso- and β-Pyrrole-Linked Chlorin-Bacteriochlorin Dyads for Promoting Far-Red FRET and Singlet Oxygen Production
Dukh, Mykhaylo,Tabaczynski, Walter A.,Seetharaman, Sairaman,Ou, Zhongping,Kadish, Karl M.,D'Souza, Francis,Pandey, Ravindra K.
, p. 14996 - 15006 (2020)
A series of chlorin-bacteriochlorin dyads (derived from naturally occurring chlorophyll-a and bacteriochlorophyll-a), covalently connected either through the meso-aryl or β-pyrrole position (position-3) via an ester linkage have been synthesized and characterized as a new class of far-red emitting fluorescence resonance energy transfer (FRET) imaging, and heavy atom-lacking singlet oxygen-producing agents. From systematic absorption, fluorescence, electrochemical, and computational studies, the role of chlorin as an energy donor and bacteriochlorin as an energy acceptor in these wide-band-capturing dyads was established. Efficiency of FRET evaluated from spectral overlap was found to be 95 and 98 % for the meso-linked and β-pyrrole-linked dyads, respectively. Furthermore, evidence for the occurrence of FRET from singlet-excited chlorin to bacteriochlorin was secured from studies involving femtosecond transient absorption studies in toluene. The measured FRET rate constants, kFRET, were in the order of 1011 s?1, suggesting the occurrence of ultrafast energy transfer in these dyads. Nanosecond transient absorption studies confirmed relaxation of the energy transfer product, 1BChl*, to its triplet state, 3Bchl*. The 3Bchl* thus generated was capable of producing singlet oxygen with quantum yields comparable to their monomeric entities. The occurrence of efficient FRET emitting in the far-red region and the ability to produce singlet oxygen make the present series of dyads useful for photonic, imaging and therapy applications.
Syntheses of Chalcone-Type Chlorophyll Derivatives Possessing a Bacteriochlorin, Chlorin or Porphyrin π-System and Their Optical Properties
Ohashi, Kota,Kinoshita, Yusuke,Tamiaki, Hitoshi
, p. 755 - 761 (2019)
C3-(Trans-2-arylethenyl)carbonylated chlorophyll derivatives possessing a bacteriochlorin or chlorin π-system were synthesized by cross-aldol (Claisen–Schmidt) condensation of methyl pyrobacteriopheophorbide-a or 3-acetyl-3-devinyl-pyropheophorbide-a bearing the C3-acetyl group with p-(un)substituted benzaldehydes under basic conditions. The corresponding porphyrin-type chlorophyll derivatives were prepared by the oxidation (17,18-didehydrogenation) of the chlorin-type. Their Qy absorption and fluorescence emission maxima in dichloromethane correlated well with Hammett substituent constants of the p-substituents. Several electron-withdrawing p-substituents suppressed the emission due to photoinduced electron transfer quenching in a molecule. The substitution sensitivities for their maxima and fluorescence quantum yields decreased in the order of bacteriochlorin-, chlorin- and porphyrin-type derivatives.
Structural and Epimeric Isomers of HPPH [3-Devinyl 3-{1-(1-hexyloxy) ethyl}pyropheophorbide-a]: Effects on Uptake and Photodynamic Therapy of Cancer
Saenz, Courtney,Cheruku, Ravindra R.,Ohulchanskyy, Tymish Y.,Joshi, Penny,Tabaczynski, Walter A.,Missert, Joseph R.,Chen, Yihui,Pera, Paula,Tracy, Erin,Marko, Aimee,Rohrbach, Daniel,Sunar, Ulas,Baumann, Heinz,Pandey, Ravindra K.
, p. 933 - 946 (2017)
The tetrapyrrole structure of porphyrins used as photosentizing agents is thought to determine uptake and retention by malignant epithelial cancer cells. To assess the contribution of the oxidized state of individual rings to these cellular processes, bacteriochlorophyll a was converted into the ring D reduced 3-devinyl-3-[1-(1-hexyloxy)ethyl]pyropheophorbide-a (HPPH) and the corresponding ring B reduced isomer (iso-HPPH). The carboxylic acid analogs of both ring B and ring D reduced isomers showed several-fold higher accumulation into the mitochondria and endoplasmic reticulum by primary culture of human lung and head and neck cancer cells than the corresponding methyl ester analogs that localize primarily to granular vesicles and to a lesser extent to mitochondria. However, long-term cellular retention of these compounds exhibited an inverse relationship with tumor cells generally retaining better the methyl-ester derivatives. In vivo distribution and tumor uptake was evaluated in the isogenic model of BALB/c mice bearing Colon26 tumors using the respective 14C-labeled analogs. Both carboxylic acid derivatives demonstrated similar intracellular localization and long-term tumor cure with no significant skin phototoxicity. PDT-mediated tumor action involved vascular damage, which was confirmed by a reduction in blood flow and immunohistochemical assessment of damage to the vascular endothelium. The HPPH stereoisomers (epimers) showed identical uptake (in vitro & in vivo), intracellular retention and photoreaction.
Ti3C2TxMXene nanosheets hybridized with bacteriochlorin-carotenoid conjugates for photocatalytic hydrogen evolution
Fujii, Ritsuko,Kitao, Osamu,Li, Yuanlin,Sasaki, Shin-Ichi,Sun, Xiaoli,Wang, Xiao-Feng,Yamano, Yumiko
, p. 2166 - 2177 (2022/02/14)
Development of efficient photocatalysts with a wide spectral range for the photocatalytic hydrogen evolution reaction (HER) is a promising way to address the current energy and environmental crises. In particular, utilization of natural photosynthetic pigments in the artificial HER is a rational approach to explore better photocatalysts toward practical applications. In this work, bacteriochlorophyll-a (BChl-a) derivatives combined with a series of carotenoids were synthesized and deposited on the surface of Ti3C2Tx MXenes to prepare organic-inorganic composites as noble metal-free photocatalysts for the HER. The optical properties of six kinds of dye-sensitizers, namely, methyl bacteriopyropheophorbide-a (Dye-1), four bacteriochlorin-carotenoid dyads (Dyes-2-5), and a triad (Dye-6) were investigated both in solutions and in solid thin films, and the composites (Dye@Ti3C2Tx) were used as photocatalysts for the HER under white light irradiation (λ > 420 nm) in an aqueous suspension system in the presence of ascorbic acid at pH = 2.8. Among the Dyes-1-6 possessing different side chains at the C17-propionate terminal of bacteriochlorin chromophores, the Ti3C2Tx hybrid photocatalyst composed of Dye-4 with a siphonaxanthin analog unit showed the highest hydrogen evolution efficiency, and its best value was 5 times larger compared to that of Dye-1@MXene without a conjugated carotenoid chromophore. Other Dye@Ti3C2Tx composites showed enhanced H2 evolution abilities over Dye-1@MXene, depending on the structural characteristics of dye-sensitizers composed of bacteriochlorin and different kinds of carotenoids. The observed high activity of Dye-4@MXene for the HER is attributed to the panchromatic light absorption ability of Dye-4 through the visible to near-infrared range as well as the desirable charge separation at the Dye-4@Ti3C2Tx interface. This study provides new insights into utilizing photosynthetic dyes to construct MXene hybrid structures suitable for photocatalytic water-splitting H2 production.
