title: Two new xanthones from Hypericum sampsonii and biological activity of the isolated compounds.
abstract: Phytochemical investigation of the CH(2) Cl(2) extract of the aerial part of Hypericum sampsonii yielded two new prenylated xanthones, hypericumxanthone A and B, together with three known xanthones. Their structures were elucidated by analysis of physical and spectral (UV, IR, mass and NMR) data and comparison of spectroscopic data with those reported previously. All these compounds were evaluated for in vitro antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Two new compounds were also tested for their cytotoxicity against human breast (MCF-7), hepatoma (HepG2), colon (HT-29) and lung (A549) tumour cell lines. Two new compounds showed moderate antibacterial activities at minimum inhibitory concentrations (MIC) of 16 and 32 µg/mL, respectively, whereas the positive standard antibacterial drug, vancomycin, showed an MIC of 8 µg/mL. The other compounds were inactive against MRSA. In addition, hypericumxanthone B showed weak inhibitory activities against four human tumour cell lines.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai 200433, PR China.
authors.forename: Wen-Bo
authors.initials: WB
authors.lastname: Xin
authors.forename: Zhu-Jun
authors.initials: ZJ
authors.lastname: Mao
authors.forename: Gui-Lin
authors.initials: GL
authors.lastname: Jin
authors.forename: Lu-Ping
authors.initials: LP
authors.lastname: Qin
mesh_terms: D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D020902:Hypericum / Q000737:chemistry*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D013057:Spectrum Analysis / Q000379:methods; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D044004:Xanthones