目的 对阿里红中羊毛甾烷三萜类成分在电喷雾-线性离子阱-静电场轨道阱高分辨质谱(ESI-LTQ-Orbitrap-MS)下的多级裂解规律进行探讨。方法 采用ESI-LTQ-Orbitrap-MS高分辨质谱分别在正、负离子模式下对 16个羊毛甾烷三萜类成分进行系统研究。样品通过流动注射泵进样,流速: 5 μL·min^-1。结果 内酯环羊毛甾烷三萜在正离子模式下可识别[M+Na]⁺及[2M+Na]⁺离子,多级裂解丢失的中性分子除支链(丙二酸等)和取代基外还有内酯环中的CO₂。支链羊毛甾烷三萜在负离子模式下可识别[M-H]^-离子,多级裂解丢失的中性分子包括各支链(C₇H₁₂等)、取代基等。两种支链羊毛甾烷三萜相比,羊毛甾-8-烯型三萜较羊毛甾-7,9(11)-二烯型三萜不易裂解脱羟基。结论 该类化合物有着较强的裂解规律,为羊毛甾烷三萜类成分的质谱裂解方式提供补充,并可为羊毛甾烷三萜类成分快速结构鉴定提供新的依据。

OBJECTIVE To explore the fragmentation rules of lanostane triterpenes in Fomitopsis officinalis(Vill.: Fr.)Bond. et Sing. by ESI-LTQ-orbitrap-MS. METHODS Sixteen lanostane triterpenes were systematically investigated by ESI-LTQ-orbitrap-MS in positive and negative mode of electrospray ionization.Samples were injected by a flow injection pump at the flow rate of 5 μL·min^-1. RESULTS The [M+Na]⁺ and [2M+Na]⁺ ions of lanostane triterpenes with lactone ring could be recognized in positive ion mode, and the lost neutral molecules included branch chains (malonic acid, etc.), substituent groups and CO₂, which cracked from the lactone ring. [M-H]^- of lanostane triterpenes with branch chain could be recognized in negative mode. Neutral molecules lost through multi-stage cleavage included branch chains (C₇H₁₂, etc.) and substituent groups. Compared with the lanoster-7, 9 (11)-diene-type triterpenes, lanoster-8-ene-type triterpenes were more difficult to dehydroxylate. CONCLUSION Lanostane triterpenes have strong fragmentation regularity, which provides a supplement for the cleavage of lanostane triterpenes, and provides new evidence for the rapid structure identification of lanostane triterpenes.