XANTHONES AND VISMIONES FROM PSOROSPERMUM-FEBRIFUGUM

Two novel xanthones, psorofebrin and 5'-hydroxyisopsorofebrin, contain ing a fused tetrahydrofurobenzofuran ring system, two new members of t he dihydrofuranoxanthone group, 4'-O-acetyl-3',4'-deoxypsorospermin-3' ,4'-diol and 3',4'-deoxypsorospermin-3',4',5'-triol, a known xanthone and the known vismiones D and F were isolated from an ethanol extract of the roots of Psorospermum febrifugum. Structures were assigned by a nalysis of spectral data and chemical correlations. One of the dihydro furanoxanthones exhibited significant cytotoxicity in the HT-29 human colon adenocarcinoma in vitro cell line.