Bisanthraquinone glycosides of Hypericum perforatum with binding inhibition to CRH-1 receptors

Four new bisanthraquinone glycosides, S-(+)-skyrin-6-O-beta -glucopyranosid e (1), R-(-)-skyrin-6-O-beta -glucopyranoside (2), S-(+)-skyrin-6-O-beta -x ylopyranoside (3) and S-(+)-skyrin-6-O-beta-alpha -arabinofuranoside (4), h ave been isolated from an ethanol-water (1:1, v/v) dry extract of the aeria l parts of Hypericum perforatum L. The structures were elucidated by spectr oscopic methods, mainly NMR and mass spectrometry. Circular dichroism was u sed to determine, their axial stereochemistry revealing 1 and 2 to be atrop isomers. 1 and 2 inhibited [(125) I]sauvagine binding to corticotropin rele asing hormone (CRH-1) receptors. (C) 2000 Elsevier Science Ltd. All rights reserved.