title: Protein tyrosine phosphatase-1B inhibitory activity of isoprenylated flavonoids isolated from Erythrina mildbraedii.
abstract: Inhibition of protein tyrosine phosphatase-1B (PTP1B) has been proposed as a therapy for treatment of type-2 diabetes and obesity. Bioassay-guided fractionation of an EtOAc-soluble extract of the root bark of Erythrina mildbraedii, using an in vitro PTP1B inhibitory assay, resulted in the isolation of three new isoprenylated flavonoids, abyssinone-IV-4'-O-methyl ether (2), 7-hydroxy-4'-methoxy-3'-(3-hydroxy-3-methyl-trans-but-1-enyl)-5'-(3-methylbut-2-enyl)flavanone (3), and abyssinone-VI-4-O-methyl ether (6), along with six known flavonoids, abyssinone-V-4'-O-methyl ether (1), abyssinone-V (4), abyssinone-IV (5), sigmoidin E (7), 4'-hydroxy-5,7-dimethoxyisoflavone (8), and alpinumisoflavone (9). Compounds 1 and 2, 4-7, and 9 inhibited PTP1B activity, with IC50 values ranging from 14.8 +/- 1.1 to 39.7 +/- 2.5 microM. On the basis of the data obtained, flavanones and chalcones with isoprenyl groups may be considered as a new class of PTP1B inhibitors.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology, 52 Eoun-dong, Yuseong-gu, Daejeon 305-333, Korea.
authors.forename: MinKyun
authors.initials: M
authors.lastname: Na
authors.forename: JunPil
authors.initials: J
authors.lastname: Jang
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Njamen
authors.forename: Joseph Tanyi
authors.initials: JT
authors.lastname: Mbafor
authors.forename: Zacharias Tanee
authors.initials: ZT
authors.lastname: Fomum
authors.forename: Bo Yeon
authors.initials: BY
authors.lastname: Kim
authors.forename: Won Keun
authors.initials: WK
authors.lastname: Oh
authors.forename: Jong Seog
authors.initials: JS
authors.lastname: Ahn
mesh_terms: D002163:Cameroon; D004895:Erythrina / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors*
chemical_list: D005419:Flavonoids; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases