title: A novel antibacterial iridoid and triterpene from Caiophora coronata.
abstract: Bioassay-guided fractionation of the antibacterial CH(2)Cl(2)-MeOH extract obtained from the aerial parts of the Argentinean plant Caiophora coronata led to the isolation of a new triterpene, 1beta,3beta-dihydroxyurs-12-en-27-oic acid, 1, and a new iridoid, 1alpha-methoxy-6alpha,10-dihydroxyisoepiiridomyrmecin (caiophoraenin), 2, along with the known iridoid isoboonein 3. Their structures were established by spectroscopic techniques (1D and 2D NMR, HRFABMS, FTIR). The MIC values of isolated compounds were determined against methicillin-sensitive (MSSA) and -resistant (MRSA) strains of Staphylococcus aureus, Bacillus subtilis (BS), vancomycin-resistant Enterococcus faecium (VREF), Escherichia coli (EC), E. coli imp (ECimp), and Candida albicans (CA). Compound 1 was found active against BS, MSSA, MRSA, VREF, and ECimp with MIC values of 2, 4, 4, 4, and 16 microg/mL, respectively.
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 E Mabel Street, Tucson, Arizona 85721, USA.
authors.forename: Smriti
authors.initials: S
authors.lastname: Khera
authors.forename: Girma M
authors.initials: GM
authors.lastname: Woldemichael
authors.forename: Maya P
authors.initials: MP
authors.lastname: Singh
authors.forename: Enrique
authors.initials: E
authors.lastname: Suarez
authors.forename: Barbara N
authors.initials: BN
authors.lastname: Timmermann
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001118:Argentina; D001412:Bacillus subtilis / Q000187:drug effects; D016984:Enterococcus faecium / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D039823:Iridoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects; D013237:Stereoisomerism; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: C482834:1beta,3beta-dihydroxyurs-12-en-27-oic acid; D000900:Anti-Bacterial Agents; D039823:Iridoids; D014315:Triterpenes; C482835:caiophoraenin