1. Academic Validation
  2. 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

  • J Nat Prod. 2020 Jan 24;83(1):134-141. doi: 10.1021/acs.jnatprod.9b00993.
Hua-Ding Zhao 1 Yan Lu 1 Min Yan 1 Chin-Ho Chen 2 Susan L Morris-Natschke 3 Kuo-Hsiung Lee 3 4 Dao-Feng Chen 1
Affiliations

Affiliations

  • 1 School of Pharmacy, Institutes of Integrative Medicine , Fudan University , Shanghai 201203 , People's Republic of China.
  • 2 Duke University Medical Center , Box 2926, SORF, Durham , North Carolina 27710 , United States.
  • 3 Natural Products Research Laboratories, UNC Eshelman School of Pharmacy , University of North Carolina , Chapel Hill , North Carolina 27599-7568 , United States.
  • 4 Chinese Medicine Research and Development Center , China Medical University and Hospital , Taichung 40402 , Taiwan.
Abstract

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.

Figures