Rapid Recognition and Targeted Isolation of Anti-HIV Daphnane Diterpenes from Daphne genkwa Guided by UPLC-MSn
Rapid Recognition and Targeted Isolation of Anti-HIV Daphnane Diterpenes from Daphne genkwa Guided by UPLC-MSn
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DOI：
10.1021/acs.jnatprod.9b00993
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发表时间：
2020-01-01
影响因子：
5.1
通讯作者：
Chen, Dao-Feng
中科院分区：
文献类型：
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作者：
Zhao, Hua-Ding;Lu, Yan;Chen, Dao-Feng
具有5/7/6-三环系统的瑞香烷二萜显示出有效的抗HIV活性，但作为植物天然产物以低丰度被发现。本研究利用质谱裂解途径，从芫花中特异性识别并分离出抗HIV化合物。简而言之，通过超高效液相色谱-离子阱串联质谱法（UPLC-IT-MSn），基于m/z 323 -> 295 -> 267或m/z 253 -> 238 -> 197的特征离子碎片，阐明了参比类似物的裂解途径，然后将其用于区分C-12位含氧基团或不含氧基团的物质。结果表明，从石杉的石油醚提取物中分离出27个瑞香烷型二萜化合物。芫花，包括一些潜在的新的化合物和异构体，不能准确地确定只从离子碎片。采用高速逆流色谱（HSCCC）和制备型HPLC对这些目标化合物进行进一步分离，分离出3个新化合物（11、25和27）和14个已知化合物，其结构经MS、NMR和电子圆二色谱（ECD）鉴定和确认。分离株在纳摩尔浓度下表现出抗HIV活性。实验结果表明，该方法用于快速识别和分离瑞香烷型二萜是可行和可靠的。芫花
Daphnane diterpenes with a 5/7/6-tricyclic ring system exhibit potent anti-HIV activity but are found in low abundance as plant natural products. In this study, an effective approach based on mass spectrometric fragmentation pathways was conducted to specifically recognize and isolate anti-HIV compounds of this type from Daphne genkwa. Briefly, the fragmentation pathways of reference analogues were elucidated based on characteristic ion fragments of m/z 323 -> 295 -> 267 or m/z 253 -> 238 -> 197 by ultra-high-performance liquid chromatography-ion trap tandem mass spectrometry (UPLC-IT-MSn) and then applied to the differentiations of substances with or without an oxygenated group at C-12. Twenty-seven daphnane diterpenes were successfully recognized from a petroleum ether extract of D. genkwa, including some potential new compounds and isomers that could not be identified accurately only from the ion fragments. Further separation of these target compounds using high-speed countercurrent chromatography (HSCCC) and preparative HPLC led to the isolation of three new (11, 25, and 27) and 14 known compounds, whose structures were identified and confirmed based on MS, NMR, and electronic circular dichroism (ECD) spectroscopy. The isolates exhibited anti-HIV activities at nanomolar concentrations. The results demonstrated that this strategy is feasible and reliable to rapidly recognize and isolate daphnane diterpenes from D. genkwa.