Abstract
在本篇論文中，成功的合成出包含有benzene，fluorene，以及 fluorenone環的一系列含氮亞硝基試劑，並發現此類化合物在照光的條件 之下可以切割去氧核醣核酸。這些含氮亞硝基試劑在磷酸鹽緩衝溶液(pH 5.0-8.0)之中，以及有氧的條件下照射紫外光 (312nm) 兩小時可以進行 對去氧核醣核酸 [fX174 RFI DNA (form I;50mM/base pair)]的單股切割 。紫外光在此可以當作驅動切割去氧核醣核酸反應的"板機"。在 N- methyl-N-nitroso-9-fluorenone carboxamide (14c)照光的過程中，會 產生可以切割去氧核醣核酸的NO*。我們可以利用電子順磁共振光譜儀以 及消除劑2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide( PTIO)來證明NO*的存在。在(PTIO)不存在之下N-methyl-N-nitroso-9- fluorenone carboxamide (14c)會先進行分解再重組變成nitric oxide radical (18)並且可以電子順磁共振光譜儀偵測。 A series of N-nitroso compounds containing a benzene, fluorene, orfluorenone ring was synthesized and found to possess DNA-cleaving capabilityunder photolytic conditions. Irrediation of these N-nitroso compounds in a phosphate buffer (pH 5.0-8.0) containing the supercoiled fX174 RFI DNA (form I;50 uM/base pair) with UV light (312nm) under aerobic conditions for 2.0 hresulted in the single-strand scission of DNA. The light functioned as a "trigger" to initiate the DNA cleavage process. The DNA cleaving speices NO'was generated during irradiation of N-methyl-N-nitroso-9-fluorenone carboxamide (14c). Its presence was proven by an EPR method involving theuse of 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) as atrapping agent. In the absence of PTIO, N-methyl-N-nitroso-9- fluorenone carboxamide (14c) underwent decomposition followed by recombination to givea nitric oxide radical (18), as detected by an EPR method.