Abstract: The Application of ESI-MS on the Saponin GlycosideAuthor Xu Yongzhen,Ma Ji,Wang Wenjie,Wu Houming\=(State Key Laboratory of Bio-Organic and Natural Products Chemistry,Shanghai Institute of Organic Chemistry,the Chinese Academy of Sciences,Shanghai 200032,China)\=\=Received 1999-01-04 \=\= Abstract \;The application of ESI-MS on the glycosides was demonstrated using sixteen saponin compounds as examples,which contain one to five sugar residues and possess steroidal or triterpenoidal aglycon moiety.The features of the ESI-MS spectra of these compounds were disscussed on the basis of aglycone type and fragmentation,which afforded additional evidence for the structure determination of these compounds.Furthermore,the structure of agrostemmoside A,an alleopathic component from the seeds of agrostemma githago,was confirmed by the ESI-MS data of the compound and its normal and anormalic peracetylation product.\=\;Key Words: saponin glycoside,ESI-MS, determination of molecular weight