title: Triterpenoids and a sterol from the stem-bark of Styrax japonica and their protein tyrosine phosphatase 1B inhibitory activities.
abstract: Five pentacyclic triterpenoids (1-5) and a sterol (6) were isolated from the stem-bark of Styrax japonica. The six compounds, 1-6, were determined to be 3beta-acetoxy-28-hydroxyolean-12-ene (1), 3beta-acetoxyolean-12-en-28-acid (2), 3beta-acetoxyolean-12-en-28-aldehyde (3), 3beta-acetoxy-17beta-hydroxy-28-norolean-12-ene (4), taraxerol (5) and stigmasterol (6), respectively, by spectroscopic means, including the 2D-NMR technique. Compound 4 is a newly discovered natural compound. The protein tyrosine phosphatase 1B (PTP1B) inhibitory activities of the isolated compounds (1-6) were determined in vitro. Among the isolated compounds, 3beta-acetoxyolean-12-en-28-acid (2) and 3beta-acetoxyolean-12-en-28-aldehyde (3) had the most potent inhibitory PTP1B activity, with IC50 values of 7.8 and 9.3 microm, respectively.
authors.affiliation: College of Pharmacy, Catholic University of Daegu, Gyeongbuk 712-702, Korea.
authors.forename: Joo-Hee
authors.initials: JH
authors.lastname: Kwon
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Chang
authors.forename: Hyo-Won
authors.initials: HW
authors.lastname: Seo
authors.forename: Jeong-Hun
authors.initials: JH
authors.lastname: Lee
authors.forename: Byung-Sun
authors.initials: BS
authors.lastname: Min
authors.forename: MinKyun
authors.initials: M
authors.lastname: Na
authors.forename: Jin Cheol
authors.initials: JC
authors.lastname: Kim
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Woo
authors.forename: Jae Sue
authors.initials: JS
authors.lastname: Choi
authors.forename: Hyeong Kyu
authors.initials: HK
authors.lastname: Lee
authors.forename: KiHwan
authors.initials: K
authors.lastname: Bae
mesh_terms: D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D024301:Plant Bark / Q000737:chemistry*; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D021241:Spectrometry, Mass, Electrospray Ionization; D013261:Sterols / Q000302:isolation & purification / Q000494:pharmacology*; D032362:Styrax / Q000737:chemistry*; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D013261:Sterols; D014315:Triterpenes; D017027:Protein Tyrosine Phosphatases