[关键词]
[摘要]
目的 对野苏麻Isodon coetsa中分离得到的5个7,20-环氧对映-贝壳杉烷二萜化合物(细锥香茶菜乙素、大锥香茶菜乙素、细锥香茶菜甲素、紫毛香茶菜N和大锥香茶菜甲素)质谱裂解规律进行初步研究。方法 采用超高效液相色谱-四级杆-飞行时间质谱(UHPLC-Q-TOF-MS2)技术,通过比较5个单体化合物质谱图谱,根据其二级质谱裂解碎片推测裂解过程。结果 负离子模式下,高质量区,该类二萜化合物以连续丢掉C-1、7位上取代基及C-20位氧桥为主,且根据C-1位取代基不同,断裂顺序有所区别;中低质量区的碎片离子信息提示断裂顺序为A环到B环再到C环。结论 该质谱裂解规律可为7,20-环氧对映-贝壳杉烷二萜化合物结构鉴定提供实验依据。
[Key word]
[Abstract]
Objective To study the fragmentation pathways of five 7,20-cyclo-ent-kaurane diterpenoid compounds (rabdocoetsin B, megathyrin B, rabdocoetsin A, enanderianin N, and megathyrin A) in Isodon coetsa. Methods The samples were analyzed by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS2). According to the fragment in MS2 of five compounds, the possible fragmentation pathways of these diterpenoid compounds were inducted. Results In negative mode, the typical fragmentation pathways of these compounds in high-quality areas were mainly loss of substituents on C-1, C-7, and the oxygen bridge on C-20. The fragmentation pathways were different as a result of the difference of the substituents on C-1. The fragment, which in medium and low quality areas, suggested that fracture order of these compounds were A ring to B and then to C ring. Conclusion The study on fragmentation pathways contributed to the structural identification of 7,20-cyclo-ent-kaurane diterpenoid compounds.
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[基金项目]
贵州省中医药管理局中医药、民族医药科学技术研究课题([2015]Z59号);贵中医科院内科研项目([2015]45号)