BETULINAN-A AND BETULINAN-B, 2 BENZOQUINONE COMPOUNDS FROM LENZITES-BETULINA

Two lipid peroxidation inhibitors, designated as betulinans A (1) and B (2), were isolated from the MeOH extract of Lenzites betulina. The s tructures of these compounds have been determined to be 2,5-diphenyl-3 ,6-dimethoxy-p-benzoquinone and 3-methoxy-[1H-2-benzopyran][4,3-e][p]b enzoquinone, respectively, on the basis of various spectral data. Betu linans A and B inhibited lipid peroxidation with IC50 values of 0.46 a nd 2.88 mu g/mL, respectively.