Exploratory photochemistry of 5-azido-8-alkoxy-substituted psoralens free and bound to DNA.
Exploratory photochemistry of 5-azido-8-alkoxy-substituted psoralens free and bound to DNA.
复制标题
游离和与 DNA 结合的 5-叠氮基-8-烷氧基取代的补骨脂素的探索性光化学。
DOI：
10.1111/j.1751-1097.1995.tb09875.x
复制
发表时间：
1995
影响因子：
3.3
通讯作者：
Platz,MS
中科院分区：
文献类型：
--
作者：
Chen,T;Michalak,J;Platz,MS
合成了5-叠氮基-8-烷氧基芘。激光闪光光解（LFP：XeF，351 nm，55 mJ，17 ns）的叠氮化合物在乙腈或苯溶液中生成三重态氮烯和少量的烯酮亚胺。叠氮化物在甲醇或水溶液中的激光闪光光解干净地产生三重态氮宾。在含有高度聚合的小牛胸腺DNA的水溶液中，LFP产生三重态氮烯和烯酮亚胺的混合物，分别对应于自由和结合的芘的光解。这两种瞬态衰减缓慢，但速率不同。通过基质EPR和紫外-可见光谱法确定瞬态光谱的归属。三重氮宾的寿命是相同的缓冲液中，并在小牛胸腺DNA的存在和不存在。结果解释了为什么叠氮磷酰亚胺在UV活化时不能有效地使质粒DNA pBR 322产生切口。
5‐Azido‐8‐alkoxy psoralens were synthesized. Laser flash photolysis (LFP: XeF, 351 nm, 55 mJ, 17 ns) of the azides in acetonitrile or benzene solution produces the triplet nitrene and a small amount of ketenimine. Laser flash photolysis of the azides in methanol or aqueous solution cleanly produces the triplet nitrene. In aqueous solution containing highly polymerized calf thymus DNA, LFP produces a mixture of triplet nitrene and ketenimine corresponding to photolysis of free and bound psoralen, respectively. The two transients decay slowly but at different rates. Assignment of the transient spectra were secured by matrix EPR and UV‐visible spectroscopy. The triplet nitrene lifetime is the same in buffer and in the presence and absence of calf thymus DNA. The results explain why psoralen azides are unable to efficiently nick plasmid DNA pBR322 upon UV activation.