A novel 29-nor-3,4-seco-friedelane triterpene and a new guaiane sesquiterpene from the roots of Phyllanthus oxyphyllus

An unusual 29-nor-3,4-seco-friedelan-4(23),20(30)-dien-3-oic acid and a new 5-hydroxy-6,9-epoxyguaiane have been isolated along with other rare terpenes and lignans from Phyllanthus oxyphyllus roots. Their structures were elucidated from spectroscopic data. The radical scavenging properties of some of these compounds were evaluated. seco-Isolariciresinol showed strong antioxidant activity (IC50 0.017±0.001 mM).