title: Photochemical generation of nitric oxide from 6-nitrobenzo[a]pyrene.
abstract: Photolabile 6-nitrobenzo[a]pyrene (6-nitroBaP) released nitric oxide (NO) under visible-light irradiation. The generation of NO and the concomitant formation of the 6-oxyBaP radical were confirmed by ESR. BaP quinones were also detected as further oxidized products of the 6-oxyBaP radical. No such photodegradation was observed with other nitrated BaPs, such as 1-nitroBaP and 3-nitroBaP. DNA-strand breakage, caused by photoexcited 6-nitroBaP, was closely related to its NO-releasing activity. MO calculations of nitrated BaP suggest that the perpendicular conformation of the nitro substituent to the aromatic ring is important for the release of NO with light. These findings may be useful for the development of a new type of NO donor.
authors.affiliation: Division of Organic Chemistry, National Institute of Health Sciences, Setagaya, Tokyo 158-8501, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fukuhara
authors.forename: M
authors.initials: M
authors.lastname: Kurihara
authors.forename: N
authors.initials: N
authors.lastname: Miyata
mesh_terms: D001580:Benzopyrenes / Q000737:chemistry* / Q000528:radiation effects*; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D009569:Nitric Oxide / Q000737:chemistry*; D010777:Photochemistry
chemical_list: D001580:Benzopyrenes; D009569:Nitric Oxide; C034699:6-nitrobenzo(a)pyrene; D004247:DNA