ISOLATION AND RELAY SYNTHESIS OF 11-ALPHA-HYDROPEROXY DIACETYL HEDERAGENIN, A NOVEL TRITERPENOID DERIVATIVE FROM SERJANIA-TRIQUETRA (SAPINDACEAE) - BIOGENETIC IMPLICATIONS

Stigmasterol, oleanolic acid, morolic acid, hederagenin, and 11alpha-h ydroperoxy-hederagenin were isolated and characterized as the sapogeni ns present in the aerial parts of the medicinal plant Serjania triquet ra (Sapindaceae). The structure of the novel triterpenoid derivative, 11alpha-hydroperoxy-diacetyl hederagenin, considered as a key biogenct ic and chemical intermediate, was confirmed by relay synthesis from di acetyl hederagenin, via bromo-lactonization, dehydrobromination, and o xidation with H2O2. Biogenetic relationships are briefly described.