Lipophilic flavonoids from the fern Woodsia scopulina

Two new flavones with a hydroxymethyl substitution in the B-ring, 8,10-dihydroxy-5-H-isochromeno[4,3-b]chromen-7-one and 8,10-dihydroxy-11wmethoxy-5-H-isochromeno[4,3-b]chromen-7-one and ten B-ring non-substituted dihydrochalcones, chalcones, flavonols including two new flavanonol stereoisomers, cis-3-acetoxy-5,7-dihydroxyflavanone and cis-3-hydroxy-5,7-dimethoxyflavanone, have been isolated from the dichloromethane extract of fronds of the North American fern Woodsia scopulina. Furthermore, two humulane-type sesquiterpenes, humulene-6,7-epoxide and the new compound 6,7-epoxy-5-hydroxyhumula-2,9-diene, were obtained from this plant. Their structures have been identified by spectroscopic analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.