目的建立5種貝母藥材的電噴霧離子阱質(zhì)譜(ES I-M S)特征圖譜,用于貝母藥材的品種鑒別.方法用18%氨水潤濕貝母藥材,乙醚-氯仿-乙醇(25:8: 2.5)混合溶劑超聲提取其中貝母生物堿,將提取物直接進樣到電噴霧離子阱質(zhì)譜檢測器進行正離子全掃描分析.結(jié)果在正離子-級質(zhì)譜中,貝母生物堿易形成帶-個正電荷的準分子離子,并且在中性醇溶液中,貝母生物堿易形成二聚體,在酸性介質(zhì)中則無此現(xiàn)象;二級碰撞誘導解離易使貝母生物堿脫去-分子水;5種貝母對照藥材的總生物堿提取液的-級電噴霧質(zhì)譜圖顯示,主要分子離子峰基本相同,但因品種不同相對豐度差異較大.結(jié)論5種貝母藥材生物堿提取物的ESI-MS圖譜特征性較強,重現(xiàn)性與精密度較好,可用于不同品種貝母類藥材的鑒別.

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.

科技部十五攻關(guān)項目(2001BA701A01);湖北省青年杰出人才科學基金項目(2002AC004)