细辛脑中蓝色荧光杂质生成机理与结构鉴定

Formation Mechanism and Structure Identification of Blue Fluorescent Impurity in Asarone

细辛脑原料药中含有一种有害的蓝色荧光杂质且难以去除,但关于其生成机理、分子结构、性质等相关研究尚未见报道。采用气相色谱法考察了α-细辛脑在不同溶剂中的蓝色荧光杂质含量的变化,探讨了蓝色荧光杂质生成条件和机理,合成了蓝色荧光杂质并通过核磁、红外光谱、质谱鉴定了其分子结构。结果表明:蓝色荧光杂质是2,4,5-三甲氧基苯甲醛,由空气氧化细辛脑生成,酸性介质具有催化作用。以细辛脑为原料,高碘酸钠水溶液作氧化剂,在乙酸-甲醇介质中合成了蓝色荧光杂质,产率为5.9%,熔点为111~113℃。

A harmful impurity of blue fluorescence is present in the raw asarone drug and difficult to remove.However,the research on its formation mechanism,formula structure and properties has not yet reported.Gas chromatography was applied to investigate the change of blue fluorescent impurity content ofα-asarone in different solvents.The formation conditions and mechanism of blue fluorescent impurities were investigated.The blue fluorescent impurity was synthesized and its molecular structure was confirmed by NMR,IR and MS.The blue fluorescent impurity is 2,4,5-trimethoxybenzaldehyde,which is formed from the oxidation of asarone by air,acid medium has catalytic effect on the oxidation of asarone.The fluorescent impurity was synthesized from asarone and sodium periodate aqueous solution as oxidant in the medium of CH3COOH/CH3OH,the yield was 5.9%,and the melting point was 111~113℃.