title: Isolation and absolute stereochemistry of coussaric acid, a new bioactive triterpenoid from the stems of Coussarea brevicaulis.
abstract: Coussaric acid (1), a triterpenoid based on an ursane skeleton, and an oleanane-type triterpene acid, 3-epi-spathodic acid (2), as well as four known compounds, barbinervic acid, scutellaric acid, stigmasterol and stigmasterol glucoside, have been isolated from an EtOAc-soluble extract of the stems of Coussarea brevicaulis. The structures of compounds 1 and 2 were elucidated on the basis of spectroscopic investigation, and single-crystal X-ray crystallography was used to confirm the structure of 1. The absolute stereochemistry of 1 was established by chemical transformations and by the Mosher ester procedure. The potential of the isolates and chemical transformation products to induce quinone reductase was evaluated in mouse Hepa lclc7 hepatoma cells.
authors.affiliation: Program for Collaborative Research in the Pharmaceutical Sciences and Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Bao-Ning
authors.initials: BN
authors.lastname: Su
authors.forename: Young-Hwa
authors.initials: YH
authors.lastname: Kang
authors.forename: Rosa Elena
authors.initials: RE
authors.lastname: Pinos
authors.forename: Bernard D
authors.initials: BD
authors.lastname: Santarsiero
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Mesecar
authors.forename: D Doel
authors.initials: DD
authors.lastname: Soejarto
authors.forename: Harry H S
authors.initials: HH
authors.lastname: Fong
authors.forename: John M
authors.initials: JM
authors.lastname: Pezzuto
authors.forename: A Douglas
authors.initials: AD
authors.lastname: Kinghorn
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D004790:Enzyme Induction / Q000187:drug effects; D008114:Liver Neoplasms, Experimental; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D018547:Plant Stems / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry; D019666:Rubiaceae / Q000737:chemistry*; D013237:Stereoisomerism; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D014315:Triterpenes; D016660:NAD(P)H Dehydrogenase (Quinone)