title: Activity-guided fractionation of the leaves of Ormosia sumatrana using a proteasome inhibition assay.
abstract: Activity-guided fractionation of a chloroform-soluble extract of the leaves of Ormosia sumatrana, using a proteasome inhibition assay, led to the isolation of a new A-type proanthocyanidin derivative, 3'-O-cinnamoylprocyanidin A-2 (1), and a new cerebroside, sumatranoside (2). The structures of these two isolates were determined as epicatechin-(2 beta-->O-->7',4 beta-->8')-epicatechin-3'-O-cinnamate (1) and 1-O-(beta-d-glucopyranosyl)-(2S,3S,4R)-2N-[(2'R)-2'-hydroxy-tetracosanoyl]-9Z-octadecene-1,3,4-triol (2), respectively, by spectroscopic and chemical methods. Sumatranoside (2) exhibited proteasome inhibitory activity with an IC(50) value of 30 microM.
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, Illinois 60612, USA.
authors.forename: Bao-Ning
authors.initials: BN
authors.lastname: Su
authors.forename: Bang Yeon
authors.initials: BY
authors.lastname: Hwang
authors.forename: Heebyung
authors.initials: H
authors.lastname: Chai
authors.forename: Esperanza J
authors.initials: EJ
authors.lastname: Carcache-Blanco
authors.forename: Leonardus B S
authors.initials: LB
authors.lastname: Kardono
authors.forename: Johar J
authors.initials: JJ
authors.lastname: Afriastini
authors.forename: Soedarsono
authors.initials: S
authors.lastname: Riswan
authors.forename: Robert
authors.initials: R
authors.lastname: Wild
authors.forename: Naomi
authors.initials: N
authors.lastname: Laing
authors.forename: Norman R
authors.initials: NR
authors.lastname: Farnsworth
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Cordell
authors.forename: Steven M
authors.initials: SM
authors.lastname: Swanson
authors.forename: A Douglas
authors.initials: AD
authors.lastname: Kinghorn
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002554:Cerebrosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007887:Fabaceae / Q000737:chemistry*; D007214:Indonesia; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D061988:Proteasome Inhibitors; D013237:Stereoisomerism
chemical_list: C494657:3'-O-cinnamoylprocyanidin A-2; D002554:Cerebrosides; D004791:Enzyme Inhibitors; D061988:Proteasome Inhibitors; C494658:sumatranoside; D002392:Catechin