title: 8-Methoxypsoralen-nucleic acid photoreaction. Effect of methyl substitution on pyrone vs. furan photoaddition.
abstract: We have synthesized a series of 8-[3H]methoxypsoralens in which methyl and hydrogen are systematically varied at the 4- and 5'-positions. Analysis of the products resulting from the photoaddition of these four psoralens with the nucleic acid poly(dA-dT) reveals that the product distribution depends on the presence or absence of a 4-methyl substituent. Compounds with the 4-methyl group show an overwhelming preference (approximately 98%) for addition to the furan double bond, while compounds without the 4-methyl show a substantial amount (approximately 18%) of addition to the pyrone double bond.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D009682:Magnetic Resonance Spectroscopy; D008730:Methoxsalen / Q000031:analogs & derivatives*; D010777:Photochemistry; D011067:Poly dA-dT; D011089:Polydeoxyribonucleotides; D013329:Structure-Activity Relationship; D014316:Tritium
chemical_list: D011089:Polydeoxyribonucleotides; D014316:Tritium; D011067:Poly dA-dT; D008730:Methoxsalen