title: Screening for fractions of Oxytropis falcata Bunge with antibacterial activity.
abstract: Preliminary studies with the four extracts of Oxytropis falcate Bunge exhibited that the chloroform and ethyl acetate extracts showed stronger antibacterial activities against the nine tested Gram-positive and Gram-negative bacteria. The HPLC-scanned and bioassay-guided fractionation led to the isolation and identification of the main flavonoid compounds, i.e. rhamnocitrin, kaempferol, rhamnetin, 2',4'-dihydroxychalcone and 2',4',beta-trihydroxy-dihydrochalcon. Except 2',4',beta-trihydroxy-dihydrochalcon, four other compounds had good antibacterial activities. The minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of the four compounds ranged between 125 and 515 microg mL(-1). Staphylococcus aureus was the most susceptible to these compounds, with MIC and MBC values from 125 to 130 microg mL(-1). This is the first report of antibacterial activity in O. falcate Bunge. In this study, evidence to evaluate the biological functions of O. falcate Bunge is provided, which promote the rational use of this herb.
authors.affiliation: Gansu Academy of Traditional Chinese Medicine, Lanzhou 730050, China. huajiang931@sina.com
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.forename: J R
authors.initials: JR
authors.lastname: Hu
authors.forename: W Q
authors.initials: WQ
authors.lastname: Zhan
authors.forename: X
authors.initials: X
authors.lastname: Liu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D002599:Chalcone / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology*; D044949:Kaempferols / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D033021:Oxytropis / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D005419:Flavonoids; D044949:Kaempferols; D010936:Plant Extracts; C541117:kaempferol-7-methyl ether; D002599:Chalcone; C063423:rhamnetin; C006552:kaempferol; D011794:Quercetin