Lenzites betulina

The dimethoxy derivative of polyporic acid, betulinan A (4), is another of the few known />-terphenyls with unsubstituted side rings. It has recently been isolated from fruiting bodies of Lenzites betulina, together with the related betulinan B (113, see Section 4.1) [27], Betulinan A and B are potent inhibitors of lipid peroxidation in rat liver microsomes (thiobarbituric acid method), and 4 showed the highest activity (IC50 = 0.46 pg/mL). 

---