title: Beccaridiol, an unusual 28-nortriterpenoid from the leaves of Diplectria beccariana.
abstract: A C29-triterpene, beccaridiol (1), a dihydrochalcone natural product, 2',4'-dihydroxy-3-(4-methoxyphenyl)-propiophenone (2), as well as three known compounds, 4'-hydroxy-1',2'-dihydro-beta-ionone, 4'-O-methyldavidigenin (3), and ursolic acid, have been isolated from an EtOAc-soluble extract of the leaves of Diplectria beccariana. Beccaridiol (1) was characterized as an ursane-type 28-nortriterpene possessing an unusual aromatic E-ring by spectroscopic data interpretation. The relative configuration of this unusual isolate was established by analyzing the observed NOESY NMR correlations, and the absolute stereochemistry of 1 was then determined based on the circular dichroism (CD) spectrum of its 2,3-di-p-bromobenzoate (1b) derivative. All isolates were evaluated for their potential cancer chemopreventive properties utilizing a cell culture assay to determine quinone reductase induction.
authors.affiliation: Program for Collaborative Research in the Pharmaceutical Sciences, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Dae Sik
authors.initials: DS
authors.lastname: Jang
authors.forename: Bao-Ning
authors.initials: BN
authors.lastname: Su
authors.forename: Alison D
authors.initials: AD
authors.lastname: Pawlus
authors.forename: Young-Hwa
authors.initials: YH
authors.lastname: Kang
authors.forename: Leonardus B S
authors.initials: LB
authors.lastname: Kardono
authors.forename: Soedarsono
authors.initials: S
authors.lastname: Riswan
authors.forename: Johar J
authors.initials: JJ
authors.lastname: Afriastini
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: D004790:Enzyme Induction; D035322:Melastomataceae / Q000737:chemistry*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000096:biosynthesis; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D014315:Triterpenes; C514301:beccaridiol; D016660:NAD(P)H Dehydrogenase (Quinone)