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

KeyWord:polysaccharide  mechanochemical extraction  fingerprint spectra  direct analysis in real time-mass spectrometry(DART-MS)

Abstract:

      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£¼350 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.