实时直接分析质谱分析中草药多糖

建立了一种机械力化学提取法和实时直接分析质谱(DART-MS)分析相结合的中草药多糖分析方法,同时测定了黄芪、银耳、百合、茯苓、鼓槌石斛、金钗石斛、铁皮石斛和党参8种中草药多糖。比较了机械力化学提取(MCE)法与传统方法的提取效果,并优化了MCE法的提取参数。通过体积排阻色谱分离中草药多糖,建立分子质量校准曲线,估算了多糖分子质量。利用DART-MS直接裂解多糖大分子,可瞬时获得m/z<350的碎片离子,不同的中草药多糖得到的特征性的质谱离子峰可用于多糖样品的有效区分。该方法具有简单、快速、高通量、无需预消化的特点,是直接从复杂多糖大分子中获取特征指纹图谱的有力工具。

Analysis of Herbal Polysaccharides by Direct Analysis in Real Time-Mass Spectrometry

A direct analysis in real time-mass spectrometry(DART-MS)combined with mechanochemical extraction(MCE)was developed for the analysis of polysaccharides.Eight kinds of herbal polysaccharides including Astragalus membranaceus,Tremella fuciformi,Lilium brownii,Poria cocos,Dendrobium chrysotoxum,Dendrobium nobile,Dendrobium officinale and Codonopsis pilosula were investigated.The extraction results were compared among MCE and traditional extraction methods,and the MCE method was validated and systematically optimized.The polysaccharides were separated by size exclusion chromatography,and the molecular weight calibration curves were constructed,from which the extracted polysaccharide molecular weights were estimated.Meanwhile,DART-MS was used to break down the large polysaccharides into fragment ions m/z<350 in seconds.Different herbal polysaccharides produced characteristic ions which could be used for the efficient identification and differentiation of polysaccharide species.The method,with the characteristics of simplicity,rapidness and no need of sample pre-digestion,is a powerful tool for the direct acquirement of distinguished fingerprints from large and complex polysaccharides.