title: Structural and stereochemical studies of five new pregnane steroids from the stem bark of Toona ciliata var. pubescens.
abstract: Five new pregnane steroids, toonasterones A (1), B (2), (Z)-aglawone (3), (Z)-toonasterone C (4), and (E)-toonasterone C (5), were isolated from the stem bark of Toona ciliata var. pubescens. Their structures were elucidated by means of detailed spectroscopic (IR, MS, and 2D NMR) analysis, and the stereochemistry of 1 was secured by X-ray diffraction analysis. (Z)-aglawone (3) exhibited moderate inhibitory activity of protein tyrosine phosphatase 1B (PTP1B), a potential drug target for treatment of type-II diabetes and obesity, with an IC(50) value of 1.12 μg/mL.
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhang Jiang High-Tech Park, Shanghai 201203, PR China.
authors.forename: Jian-Rong
authors.initials: JR
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Shen
authors.forename: Li
authors.initials: L
authors.lastname: Fang
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Peng
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Yang
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.forename: Hai-Li
authors.initials: HL
authors.lastname: Liu
authors.forename: Yue-Wei
authors.initials: YW
authors.lastname: Guo
mesh_terms: D001667:Binding, Competitive; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D008968:Molecular Conformation; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011278:Pregnanes / Q000737:chemistry* / Q000302:isolation & purification; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors; D029631:Sapindaceae; D013237:Stereoisomerism
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D011278:Pregnanes; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1