Dehydrotrametenonic Acid and Dehydroeburiconic Acid from Poria cocos and Their Inhibitory Effects on Eukaryotic DNA Polymerase α and β

Abstract

A new lanostane-type triterpene acid, (20ξ)-3-oxolanosta-7,9(11),24-trien-21-oic acid (1; dehydrotrametenonic acid), along with a known triterpene acid, dehydroeburiconic acid (2), were isolated from the epidermis of the sclerotia of Poria cocos. The structure of 1 was analyzed on the basis of spectroscopic methods. Compounds 1 and 2 inhibited calf DNA polymerase α and rat DNA polymerase β, with the 50% inhibition values of 45.5 μM (1) and 40.8 μM (2), and 86.5 μM (1) and 30.0 μM (2), respectively.