16-O-去甲基乌头碱的生物转化及电喷雾质谱研究

Studies on the Biotransformation of 16-O-Demethylaconitine and Electrospray Ionization Tandem Mass Spectrometry

采用乌头碱和人肠内细菌体外温孵的方法,探讨乌头碱在肠内的生物转化规律.乌头类生物碱在ESI正离子模式条件下形成质子化分子[M+H]+,利用离子阱电喷雾串联质谱和傅立叶离子回旋共振电喷雾串联质谱方法可以直接分析乌头碱的转化产物.本文首次报道了乌头碱在人肠内菌群环境中产生16-O-去甲基乌头碱,16-O-去甲基乌头碱可进一步被肠内细菌转化,通过脱乙酰基、脱苯甲酰基、脱甲基、脱羟基以及酯化反应,产生新型的单酯型、双酯型和20余种脂类生物碱等转化产物.

To study the biotransformation of 16-O-demethylaconitine in human intestine, aconitine was incubated with human intestinal bacteria in vitro. The metabolites of 16-O-demethylaconitine were investigated using ion trap and Fourier transform ion cyclotron resonance electrospray ionization tandem mass spectrometry directly. Aconitum alkaloids formed protonated molecule [M＋H]^＋ in the positive ion mode. It was found that 16-O-demethylaconitine from biotransformation of aconitine could be further transformed by human intestinal bacteria. There are new metabolites such as mono-ester alkaloids, diester alkaloids and lipo-alkaloids produced by deacetylation, debenzoylation, dehydroxylation, demethylation and more than twenty kinds of esterification in the further transformation process of the 16-O-demethylaconitine. The 16-O- lipodemethylaconitines have been first reported as a metabolite of aconitine by human intestinal bacteria.