A diterpenoid with diverse biological activities a hydrolysis product of stevioside scavenges hydroxyl and superoxide radicals in cell-free assays (IC50s 76.92 and 91.7 Ug/ml respectively) inhibits DNA polymerase a B and λ as well as topoisomerase II (IC50s 64 177 103 and 190 UM respectively) active against various bacteria and fungi (MICs 8-250 and 62.5-500 Ug/ml Ug/ml respectively) induces relaxation of isolated rat aortic strips precontracted with vasopressin an effect that can be reversed by glibenclamide or apamin but not charybdotoxin reduces plasma glucose levels in the intravenous glucose tolerance test in Zucker diabetic rats at 5 and 10 mg/kg has been used in the synthesis of isosteviol glycosides with anticancer activity