title: Absolute configuration of antifibrotic (+)-episesamin isolated from Lindera obtusiloba BLUME.
abstract: Fractionation of a 70% ethanolic extract from twigs of Lindera obtusiloba BLUME (Japanese spicebush, Tohaku) yielded five fractions of different polarity. The antifibrotic activity within the chloroform phase was best assessed by an in vitro bioassay using rat hepatic stellate cell (HSC) proliferation and their autocrine transforming growth factor beta (TGF-beta) expression as sensitive fibrosis-associated read out. Chromatography of the chloroform extract on Sephadex LH-20 or liquid-liquid extractions yielded a crystalline compound as an active principle, which was identified from NMR and ESI-MS analyses, its melting point, and its optical rotation as (7S,7'R,8R,8'R)-3,4:3',4'-bis(methylenedioxy)-7,9':7',9-diepoxy-lignane [(+)-episesamin]. X-Ray diffraction confirmed the structure and provided, for the first time, directly its absolute configuration. (+)-Episesamin blocked proliferation and the profibrotic autocrine TGF-beta expression HSC without significant cytotoxicity.
authors.affiliation: Beuth Hochschule für Technik Berlin, Luxemburger Str. 10, D-13353 Berlin, Germany. kienast@beuth-hochschule.de
authors.forename: Wolfram
authors.initials: W
authors.lastname: Trowitzsch-Kienast
authors.forename: Martin
authors.initials: M
authors.lastname: Rühl
authors.forename: Ki Y
authors.initials: KY
authors.lastname: Kim
authors.forename: Franziska
authors.initials: F
authors.lastname: Emmerling
authors.forename: Ulrike
authors.initials: U
authors.lastname: Erbenb
authors.forename: Rajan
authors.initials: R
authors.lastname: Somasundaram
authors.forename: Christian
authors.initials: C
authors.lastname: Freise
mesh_terms: D002478:Cells, Cultured; D004149:Dioxoles / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005355:Fibrosis / Q000517:prevention & control*; D017705:Lignans / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D027443:Lindera / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004149:Dioxoles; D017705:Lignans; C054125:sesamin