title: Antibacterial diterpenoids from Astragalus brachystachys.
abstract: Antibacterial bioassay guided fractionation of acetone extracts of Astragalus brachystachys resulted in isolation of sclareol and two related labdane-type diterpenoids, 14R-epoxysclareol and 6beta-hydroxysclareol. The antibacterial activity of the isolated compounds was measured and it was deduced that the epoxidation at the double bond of sclareol or hydroxylation at C-6 decreased the activity of the resulting compounds. Salvigenin (5-hydroxy-4',6,7-trimethoxyflavone) was also separated from this plant for the first time.
authors.affiliation: Laboratory of Ecological Chemistry, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Jassbi
authors.forename: Simin
authors.initials: S
authors.lastname: Zamanizadehnajari
authors.forename: Parviz Aberoomand
authors.initials: PA
authors.lastname: Azar
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tahara
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D027883:Astragalus Plant / Q000737:chemistry*; D001412:Bacillus subtilis / Q000187:drug effects*; D001681:Biological Assay; D002855:Chromatography, Thin Layer; D004224:Diterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; D010936:Plant Extracts