- Ability of the Putative Decomposition Products of 2,3-dioxetanes of Indoles to Photosensitize Cyclobutane Pyrimidine Dimer (CPD) Formation and its Implications for the “Dark” (Chemisensitized) Pathway to CPDs in Melanocytes?
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The formation of cyclobutane pyrimidine dimers (CPDs) by a “dark” pathway in melanocytes has been attributed to chemisensitization by dioxetanes produced from peroxynitrite oxidation of melanin or melanin precursors. These dioxetanes are proposed to decompose to triplet state compounds which sensitize CPD formation by triplet–triplet energy transfer. To determine whether such compounds are capable of sensitizing CPD formation, the putative decomposition products of 2,3-dioxetanes of variously substituted indoles were synthesized and their triplet state energies determined at 77?K. Their ability to photosensitize CPD formation was determined by an enzyme-coupled gel electrophoresis assay in comparison with norfloxacin (NFX) which has the lowest triplet energy known to sensitize CPD formation. The decomposition products of 2,3-dioxetanes of 5-hydroxy and 5,6-dimethoxy indoles used as models for melanin precursors had lower triplet energies and were incapable of photosensitizing CPD formation. Theoretical calculations suggest that the decomposition products of the 2,3-dioxetanes of melanin precursors DHI and DHICA will have similarly low triplet energies. Decomposition products of the 2,3-dioxetanes of indoles lacking oxygen substituents had higher triplet energies than NFX and were capable of photosensitizing CPD formation, suggesting that peroxynitrite oxidation of tryptophan could play a hitherto unrecognized role in the dark pathway to CPDs.
- Wang, Yanjing,Cacchillo, Elena M.,Niedzwiedzki, Dariusz M.,Taylor, John-Stephen
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p. 442 - 454
(2021/10/14)
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- ANTICANCER AGENT
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An anticancer agent comprising a compound represented by the formula (I) [R1 represents hydrogen atom, hydroxyl group, a C1-6alkoxy group and the like; R2 and R3 represents hydrogen atom, a halogen atom, a C1-6alkyl group and the like; R4 represents hydrogen atom, a C1-6alkyl group, a C1-6alkylsulfonyl group and the like; R5 represents hydrogen atom or a substituent; .... represents a single bond or a double bond; R6 and R7 represents hydrogen atom, a C1-6alkyl group and the like; R8 represents hydrogen atom, a C1-6alkyl group and the like; A represents -O-, -S-, or - CH2-; D represents -C= or -N=; X represents methylene group, -O-, or -CO-; Q represents -N= or -C(R8)=; and Y represents a heterocyclic group or amino group], which shows a superior inhibitory activity against pim-1 kinase.
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Paragraph 0486
(2013/03/26)
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- The first entry to 5,6-dihydroxy-3-mercaptoindole, 5-hydroxy-3-mercaptoindole and their 2-carbomethoxy derivatives by a mild thiocyanation/reduction methodology
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The hitherto unknown 5,6-dihydroxy-3-mercaptoindole (4a) and its 2-carbomethoxy derivative (4b), as well as the analogous 5-hydroxy 3-mercaptoindoles, have been conveniently obtained as O,S-acetyl derivatives 3a-d by thiocyanation of the corresponding acetoxyindoles 1a-d with the NH4SCN/oxone system followed by SmI2 reduction and acetylation.
- Pezzella, Alessandro,Palma, Aniello,Iadonisi, Alfonso,Napolitano, Alessandra,d'Ischia, Marco
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p. 3883 - 3886
(2008/02/03)
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