title: New antimicrobial cycloartane triterpenes from Acalypha communis.
abstract: Three new cycloartane-type triterpenes, 16 alpha-hydroxymollic (1), 15 alpha-hydroxymollic (2), and 7 beta,16 beta-dihydroxy-1,23-dideoxyjessic acids (3), were isolated from the aerial parts of Acalypha communis. The structures of the novel triterpenes were determined by spectroscopic methods as well as chemical derivatization. These compounds were tested for their antimicrobial activity against Gram-positive and -negative bacteria. Compounds 1-3 exhibited moderate antimicrobial activity (MIC 8, 32, 8 microg/mL, respectively) against vancomycin-resistant enterococci. In addition, compound 1 was found to be active against methicillin-resistant staphylococci. In contrast, compounds 1-3 were poorly active against Gram-negative bacteria. Compound 3 was tested in an in vivo model; it did not provide protection to mice infected with Staphylococcus aureus.
authors.affiliation: Department of Pharmacology and Toxicology, Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Arizona, 1703 E. Mabel Street, Tucson, Arizona 85721-0207, USA.
authors.forename: Maria-Teresa
authors.initials: MT
authors.lastname: Gutierrez-Lugo
authors.forename: Maya P
authors.initials: MP
authors.lastname: Singh
authors.forename: William M
authors.initials: WM
authors.lastname: Maiese
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; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D013058:Mass Spectrometry; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D008954:Models, Biological; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010946:Plants, Medicinal / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology
chemical_list: C464740:15 alpha-hydroxymollic acid; C464739:16 alpha-hydroxymollic acid; C464741:7beta,16beta-dihydroxy-1,23-dideoxyjessic acid; D000900:Anti-Bacterial Agents; D014315:Triterpenes; D014640:Vancomycin