Inhibition of α-glucosidase by oleanolic acid and its synthetic derivatives

Abstract Oleanolic acid ( 1 ) and five synthetic derivatives ( 2–6 ) were tested spectrophotometrically for inhibition of urease, β-lactamase, acetyl cholinesterase and α-glucosidase. All products showed a positive response only against α-glucosidase but not against the other enzymes; IC 50 calculations showed that the dihydroxy-olide derivative ( 4 ) was the most potent among all tested samples.