The dichloromethane extract from the roots of Polygala nyikensis affor
ded four simple xanthones, two of which are new compounds. Their struc
tures were established by chemical and spectroscopic methods (UV, EIMS
, H-1 and C-13 NMR, NOE difference spectroscopy). 1,7-Dihydroxy-4-meth
oxyxanthone and 1,7-dihydroxy-3,5,6-trimethoxyxanthone exhibit antifun
gal activity against the plant pathogenic fungus Cladosporium cucumeri
num.