title: New sesquiterpene alpha-methylene lactones from the Egyptian plant Jasonia candicans.
abstract: Extracts of the plant Jasonia candicans possess antimicrobial activity. ET2O/MeOH extracts were subjected to liquid chromatography, and several sesquiterpenes were isolated and identified including the known compounds confertin [1], 4,11(13)-eudesmadien-12-oic acid [2], and 11-eudesmen-4-ol [3]. Two new diol alpha-methylene lactone antimicrobial agents were identified from nmr and mass spectral data and X-ray crystallography as (4 alpha, 5 alpha, 8 beta, 10 beta)-4,10-dihydroxy-1,11(13)-guaidien-12,8-olide [4] and (4 alpha, 5 alpha, 8 beta, 10 alpha)-4,10-dihydroxyl-1,11 (13)-guaidien-12,8-olide[5], which differ in stereochemistry at the C-10 tertiary alcohol center.
authors.affiliation: Department of Chemistry, Faculty of Science, El-Minia University, Egypt.
authors.forename: A A
authors.initials: AA
authors.lastname: Ahmed
authors.forename: A A
authors.initials: AA
authors.lastname: Mahmoud
authors.forename: H J
authors.initials: HJ
authors.lastname: Williams
authors.forename: A I
authors.initials: AI
authors.lastname: Scott
authors.forename: J H
authors.initials: JH
authors.lastname: Reibenspies
authors.forename: T J
authors.initials: TJ
authors.lastname: Mabry
mesh_terms: D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification*; D010936:Plant Extracts / Q000032:analysis; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D007783:Lactones; D010936:Plant Extracts; D012717:Sesquiterpenes