Regioselective and stereoselective photodimerization of securinine-type and norsecurinine-type alkaloids

The photodimerization of both securinine-type and norsecurinine-type alkaloids has been investigated. The dimers of these alkaloids were obtained in a unique form of anti-head-head with high regioselectivity and stereoselectivity. Different reaction conditions were investigated and thermodynamical calculation was also carried out. It is believed that the selective dimer formation is related to the thermodynamical stability of dimeric products and the steric hindrance caused by the complex bridge rings and particular spatial structure. In addition, the norsecurinine-type alkaloids are more prone to dimerize under photochemical conditions than securinine-type alkaloids, which might result from the transannular conjugation confirmed in the securinine-type molecules.     

体液中-叶萩碱检测方法的研究

本文报道了用气相色谱(GC)及气相色谱-质谱联用(GC/MS)检出人体液中一叶萩碱的方法.尿样经碱化后用乙醚直接萃取,回收率为72.1％;血浆样品用Sep-pak小柱提取,回收率为 43.9％,GC/MS的检测限为 20ng.方法快速、简便、准确.