Photochemical Activities of N‐Nitroso Carboxamides and Sulfoximides and Their Application to DNA Cleavage |
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| Authors: | Jih Ru Hwu Prof. Joseph Jen‐Tse Huang Dr. Fu‐Yuan Tsai Dr. Shwu‐Chen Tsay Dr. Ming‐Hua Hsu Dr. Kuo Chu Hwang Dr. Jia‐Cherng Horng Dr. Ja‐an Annie Ho Dr. Chun‐Cheng Lin Dr. |
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| Affiliation: | 1. Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (ROC), Fax: (+886)?3‐572‐1594;2. Department of Chemistry, National Central University, Jhongli 32001, Taiwan (ROC);3. Institute of Chemistry, Academia Sinica, Nankang 11529, Taiwan (ROC) |
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| Abstract: | N‐Nitroso compounds containing benzene, fluorene or fluorenone rings were synthesized. Photolysis of these compounds with 312‐nm UV light provided the NO . species, the presence of which was corroborated by use of an EPR method and of 2‐phenyl‐4,4,5,5‐tetramethylimidazolin‐1‐oxyl 3‐oxide (PTIO) as a trapping agent. During irradiation of N‐methyl‐N‐nitroso‐9‐fluorenone carboxamide ( 14 c ) in the absence of PTIO, it underwent decomposition followed by recombination to give the heterocyclic nitric oxide radical 15 . Incorporation of intercalating moieties endowed the N‐nitroso compounds with DNA‐cleaving ability through single‐strand scission upon UV irradiation in a phosphate buffer (pH 5.0–8.0) under aerobic conditions. |
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| Keywords: | DNA cleavage EPR spectroscopy nitric oxide radical reactions |
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