New Stereoisomeric Glycyrrhetic Acid Derivatives and their Hypoglycemic Activity

New 1-hydroxy-1-en-3-one derivatives of 18 β - and 18 α -glycyrrhetic acids were synthesized via oxidation of the 3-ketotriterpenoids by atmospheric oxygen in the presence of an excess of t- BuOK. 2-Hydroxy-3,11-dioxo-18 αH- olean-1,12-dien-30-oic acid exhibited pronounced hypoglycemic activity and decreased the blood glucose concentration by 42.7% compared with a control after 120 min at a dose of 50 mg/kg in a rat alloxan-induced diabetes model.