title: Antimicrobial abietane diterpenoids from Plectranthus elegans.
abstract: Two novel abietane diterpenoids have been isolated from the aerial material of Plectranthus elegans and identified as 11-hydroxy-12-oxo-7,9(11),13-abietatriene and 7 alpha,11-dihydroxy-12-methoxy-8,11,13-abietatriene. Their structures were determined through rigorous use of spectroscopic methods. Both inhibited spore germination of the fungus Cladosporium cucumerinum, in direct bioautography, at a dose of 1 microgram. The new diterpenes also inhibited the growth of Gram-positive bacteria, in the concentration range 10-40 micrograms ml-1 in broth dilution assay. No effect was observed against Gram-negative bacteria. The ecological implications of these findings are discussed.
authors.affiliation: Department of Pharmaceutical Sciences, University of Strathclyde, Glasgow, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Dellar
authors.forename: M D
authors.initials: MD
authors.lastname: Cole
authors.forename: P G
authors.initials: PG
authors.lastname: Waterman
mesh_terms: D045784:Abietanes; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification*; D002855:Chromatography, Thin Layer; D002963:Cladosporium / Q000187:drug effects; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010944:Plants / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: C103039:11-hydroxy-12-oxo-7,9(11),13-abietatriene; C103038:7,11-dihydroxy-12-methoxy-8,11,13-abietatriene; D045784:Abietanes; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D004224:Diterpenes