New antifungal xanthones from the seeds of Rhus coriaria L

Phytochemical investigations of the ethanolic extract of the seeds of Rhus coriaria L. (Anacardiaceae) led to the identification of four new xanthones, characterized as 2,3-dihydroxy-7-methyl xanthone (1), 2,3,6-trihydroxy-7-hydroxymethylene xanthone-1-carboxylic acid (2), 2-methoxy-4-hydroxy-7-methyl-3-O-beta-D-glucopyranosyl xanthone-1,8-dicarboxylic acid (4), and 2-hydroxy-7-hydroxymethylene xanthone-1,8-dicarboxylic acid 3-O-beta-D-glucopyranosyl-(2'-->3")-3"-O-stigmast-5-ene (5), along with the known steroidal glucoside beta-sitosterol-beta-D-glucoside (3). The structures of the isolated compounds have been identified on the basis of spectral data analysis and chemical reactions. All xanthones were active against Aspergillus flavus.