Nine new and unique xanthone derivatives, including one novel hybrid monoterpene-tetrahydroxanthone (1), three dihydro-xanthone derivatives (2-4), and five skeleton-rearranged xanthone derivatives (5-9), were obtained from a 95% EtOH extract of Garcinia oligantha leaves by a LC-MS-guided fractionation procedure. The structures of the new compounds were elucidated by analysis of their ID and 2D NMR and MS data. The relative configurations of 2 and 8 were determined via X-ray crystallographic data analysis, while the absolute configurations of 1-2, 5-9 were assigned based on a comparison of calculated and experimental ECD and/or OR data. In SRB, PI-exclusion and Hoechst staining assays, 6 showed strong cytotoxic activities which could dose-dependently induce Taxol-insensitive quiescent LNCaP cell death. Additionally, a preliminary mechanism investigation using immunoblotting and Caspase-3 activity assay, indicated that 6 induced quiescent LNCaP cell death potentially through caspase-dependent mitochondrial apoptosis pathway. (C) 2019 Elsevier Masson SAS. All rights reserved.
[1]Shanghai Univ Tradit Chinese Med, Sch Pharm, Cai Lun Lu 1200, Shanghai 201203, Peoples R China.
[2]Shanghai Univ Tradit Chinese Med, Shuguang Hosp, Inst Cardiovasc Dis Integrated Tradit Chinese & W, Shanghai 201203, Peoples R China.
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