title: Protein tyrosine phosphatase 1B inhibitory activity of 24-norursane triterpenes isolated from Weigela subsessilis.
abstract: During the screening effort to discover new types of protein tyrosine phosphatase 1B (PTP1B) inhibitors, it was found that a MeOH extract of the leaves and stems of Weigela subsessilis (Caprifoliaceae) inhibited the enzyme activity. By means of an in vitro bioassay-guided fractionation on the MeOH extract, two 24-norursane triterpenes, ilekudinol A (1) and ilekudinol B (2), were isolated as active metabolites. Compounds 1 and 2 inhibited PTP1B with IC(50) values of 29.1 ± 2.8 and 5.3 ± 0.5 μM, respectively. Kinetic studies suggest that both 1 and 2 are non-competitive inhibitors of PTP1B. The findings indicate that the free carboxyl group at C-28 in this type of triterpenes plays a critical role in the inhibition of PTP1B.
authors.affiliation: College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, Korea. mkna@ynu.ac.kr
authors.forename: MinKyun
authors.initials: M
authors.lastname: Na
authors.forename: Phuong Thien
authors.initials: PT
authors.lastname: Thuong
authors.forename: In Hyun
authors.initials: IH
authors.lastname: Hwang
authors.forename: KiHwan
authors.initials: K
authors.lastname: Bae
authors.forename: Bo Yeon
authors.initials: BY
authors.lastname: Kim
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Osada
authors.forename: Jong Seog
authors.initials: JS
authors.lastname: Ahn
mesh_terms: D027922:Caprifoliaceae / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors*; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D014315:Triterpenes; C554977:ilekudinol A; C547257:ilekudinol B; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1