Journal of Organic Chemistry p. 6041 - 6049 (2002)
Update date:2022-07-29
Topics:
Adam, Waldemar
Hartung, Jens
Okamoto, Hideki
Marquardt, Stefan
Nau, Werner M.
Pischel, Uwe
Saha-Moeller, Chantu R.
Spehar, Kristina
UVA-irradiation of the photo-Fenton reagents N-isopropoxypyridone 2b and N-isopropoxythiazole2(3H)-thione 3b releases radicals which induce strand breaks. Transient spectroscopy establishes N-O bond scission [ΦN-O = (75 ± 8)% for 2b and (65 ± 7)% 3b] as the dominating primary photochemical process to afford the DNA-damaging radicals. Product studies and laser-flash experiments reveal that the thiazolethione 3b leads primarily to the disulfide 5, from which through C-S bond breakage, the bithiazyl 6, the thiazole 7, and the isothiocyanate 8 are derived. Upon irradiation of pyridone 2b (300 nm) in aqueous media, a mixture of isopropoxyl and 2-hydroxyprop2-yl radicals is formed, as confirmed by trapping with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and EPR spectroscopy. In contrast, the photolysis of the thiazolethione 3b (350 nm) affords exclusively the DMPO adducts of the isopropoxyl radicals. Control experiments disclose that the thiazolethione-derived photoproduct disulfide 5, or the intermediary thiyl radicals B, scavenge the carbon-centered 2-hydroxyprop-2-yl radicals, which are generated from the isopropoxyl radicals by hydrogen shift. With supercoiled pBR 322 DNA in a 60:40 mixture of H2O-MeCN, the pyridone 2b and the thiazolethione 3b display moderate strand-break activity (17% open-circular DNA for 2b and 12% for 3b). In pure water, however, the pyridone 2b photoinduces substantially more DNA cleavage (32% open-circular DNA), which is attributed to the peroxyl radicals generated from the 2-hydroxyprop-2-yl radicals by oxygen trapping. The lower strand-break activity of the thiazolethione 3b derives presumably from isopropoxyl radicals, because only these are detected in the photolysis of this photo-Fenton reagent.
View MoreNanjing Xi Ze Biological Technology Co., Ltd
Contact:86-025-66023220
Address:Address: Nanjin Qixia District Maigaoqiao R & D base in Pioneer Park Chun Yin Road 18-A928
Contact:+86-13914766747
Address:Floors 21&22, Jin Cheng Tower, No. 216 Middle Longpan Road, Nanjing
SEA BRGIHT INDUSTRY CO.,LIMITED
Contact:0086 755 8622 3990
Address:Rm 17B3,GuangCaiXinTianDi Bldg,GuiMiao Rd,NanShan District,Shenzhen,China
Contact:+86 021-51698675
Address:1701, Jielong Plaza, No.618 Pingliang Rd, ShangHai,China
ShangHai Soyoung Biotechnology Inc
website:http://www.soyoungbio.com
Contact:+86-21-69893009
Address:shanghai
Doi:10.1016/S0040-4020(02)00473-8
(2002)Doi:10.1134/S0020168507010074
(2007)Doi:10.1021/jo011094d
(2002)Doi:10.1002/hlca.19590420626
(1959)Doi:10.1016/S0040-4020(02)00348-4
(2002)Doi:10.1021/acs.chemmater.5b04767
(2016)