Isolation of 5 alpha- and 5 beta-dihydrorubrosterone from Silene otites L.(Wib)

5 alpha -Dihydrorubrosterone (2 beta, 3 beta, 14 alpha, 17 beta -tetrahydro xy-5 alpha -androst-7-ene-6-one a new 19-carbon 5 alpha -ecdysteroid, was i solated together with its 5 beta counterpart from the aerial parts of Silen e otites L. (Wib.) (Caryophyllaceae) by a combination of solvent partition, low-pressure column chromatography, thin-layer chromatography (normal-phas e and reversed-phase) and finally HPLC. Mass spectrometry and nuclear magne tic resonance spectroscopic procedures were used for compound characterizat ion. Copyright (C) 2000 John Wiley & Sons, Ltd.