目的建立5种贝母药材的电喷雾离子阱质谱(ES I-M S)特征图谱,用于贝母药材的品种鉴别.方法用18%氨水润湿贝母药材,乙醚-氯仿-乙醇(25:8: 2.5)混合溶剂超声提取其中贝母生物碱,将提取物直接进样到电喷雾离子阱质谱检测器进行正离子全扫描分析.结果在正离子-级质谱中,贝母生物碱易形成带-个正电荷的准分子离子,并且在中性醇溶液中,贝母生物碱易形成二聚体,在酸性介质中则无此现象;二级碰撞诱导解离易使贝母生物碱脱去-分子水;5种贝母对照药材的总生物碱提取液的-级电喷雾质谱图显示,主要分子离子峰基本相同,但因品种不同相对丰度差异较大.结论5种贝母药材生物碱提取物的ESI-MS图谱特征性较强,重现性与精密度较好,可用于不同品种贝母类药材的鉴别.

Objective To develop the characteristic ESI-MS spectra of fiveBulbus Fritillariaespecies and to be used for identific-ation ofBulbus Fritillariae species.Methods TheBulbus Fritiliariaemedicinal materials were dipped in 18% ammon-ia solution,then the alkaloids were extracted by ultrasonic using the mixed solvent of ether-chloroform-ethanol(25:8:2.5).The extra-cts were analyzed directly by ESI-MS in positive ion mode.Results Bulbus alkaloids easily formed molecular ions([M+H]⁺ )in MS and dimerized easily in alcohol solution.which did not dimerize in acidity solution.Collision induced dissociation(S-CID)made these alkaloids easily lose a molecule of H₂O.The MS spectra of the extracts of fiveBulbus Fritillariae species indicated that the major molecular ions were similar to each other,but different varieties showed very different relative abundances of these molecular ions.Conclusion The total alkaloid extracts of fiveBulbus Fritillariaespecies have strong characteristic ESI-MS spectra and these spectra are of good reproducibility and precision,respectively.These characteristic spectra are useful for the identification ofBulbus Fritillariaespecies.

科技部十五攻关项目(2001BA701A01);湖北省青年杰出人才科学基金项目(2002AC004)