Targeting pharmacophore with probe‐reactivity‐guided fractionation to precisely identify electrophilic sesquiterpenes and its activity of anti‐TNBC

• Published in: Phytochemical analysis Vol. 31; no. 3; pp. 322 - 332
• Main Authors: Jiang, QingLi, Zhu, ZhiHui, Shou, PanTing, Teng, Fei, Zhu, Ying, Zhao, HuaJun, Yang, Bo
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.05.2020
• Subjects: 4‐bromothiophenol; Acetic acid; Aromatic compounds; Binding sites; Bioactive compounds; Bioassays; Biological activity; Breast cancer; Bromine; Chemical Fractionation; Chromatography, High Pressure Liquid; Chromatography, Liquid; Conjugates; Drug development; electrophilic sesquiterpenes; Ethyl acetate; Eupatorium; Eupatorium chinense L; Fractionation; Glutathione; Humans; Identification methods; Lead compounds; Liquid chromatography; Mass spectrometry; Mass spectroscopy; Natural products; NMR; Nuclear magnetic resonance; Pharmacology; pharmacophore; probe‐reactivity‐guided; Quadrupoles; Reactivity; Sesquiterpenes; Strategy; Triple Negative Breast Neoplasms; Eupatorium chinense L; electrophilic sesquiterpenes; pharmacophore; probe-reactivity-guided; 4-bromothiophenol
• ISSN: 0958-0344; 1099-1565
• DOI: 10.1002/pca.2898

Introduction Innovative strategy is urgently needed to precisely discover novel natural products as lead compounds for development of new drugs against orphan diseases such as triple‐negative breast cancer (TNBC). Herein, we describe a targeting pharmacophore with probe‐reactivity‐guided strategy for the discovery of electrophilic sesquiterpene (ES), a class of bioactive natural product. Objective This study aimed to identify pharmacophore, based on pharmacophore with probe‐reactivity‐guided strategy for precisely discovering ESs from ethyl acetate extract of Eupatorium chinense L. (EEEChL) Methodology MTT assay combined with ultra‐performance liquid chromatography (UPLC) analysis was used to identify pharmacophore. UPLC‐mass spectrometry (MS) was applied to carefully compare the intrinsic reactivity characteristics of two chemoselective nucleophilic probes: glutathione (GSH) and 4‐bromothiophenol (BTP) reaction with ESs. ESs was isolated and identified from EEEChL by phytochemical methods. Furthermore, stoichiometric ratio and binding site of one typical ES 8β‐[4′‐hydroxytigloyloxy]‐5‐desoxy‐8‐desacyleuparotin (HDDE) reaction with BTP were studied by UPLC‐quadrupole time‐of‐flight (Q‐TOF)‐MS and two‐dimensional nuclear magnetic resonance (NMR). Results Eleven ESs were identified from EEEChL, MTT assay illustrated that all of the 11 ESs possess fairly good anti‐TNBC activity Conclusions Electrophilic groups were confirmed as pharmacophore of bioactive compounds contained in EEEChL. An optimised halogenated aromatic probe BTP furnishes ES‐BTP conjugates that are highly conspicuous via MS by virtue of a unique isotopic bromine signature, conjugates also have a considerable separation on C18 column. The new probe‐reactivity‐guided strategy can effectively improve the traditional bioassay‐guided approaches, and significantly increase the probability of obtaining designated bioactive compounds. Innovative strategy is urgently needed to precisely discover novel natural products as lead compounds for development of new drugs against orphan diseases such as triple‐negative breast cancer (TNBC). Herein, we describe a targeting pharmacophore with probe‐reactivity‐guided strategy for the discovery of electrophilic sesquiterpene (ES), a class of bioactive natural product. In this study, 11 ESs were identified from Eupatorium chinense L., and the MTT assay illustrated that all of the 11 ESs possess fairly good anti‐TNBC activity.