α-Glucosidase inhibitory monoacylated polyhydroxytriterpenoids from the fruits of Barringtonia racemosa

Abstract Chemical investigation of a lipophilic CHCl 3 extract of the dried fruits of Barringtonia racemosa resulted in the isolation of two unusual monoacylated polyhydroxy oleanane triterpenoid congeners named racemosols C–D ( 1 – 2 ) along with three known compounds. Their structures were determined by comprehensive spectroscopic analysis coupled with chemical modifications as 21β-acetoxy-3β, 16α,22α,28-tetrahydroxyolean-12-ene ( 1 ) and 22α-(2-methylbutyryl)-3β, 15α,16α,21β,28-pentahydroxyolean-12-ene ( 2 ). Compounds ( 1 – 3 , 1a , and 2a ) were subjected to α-glucosidase inhibitory assay and 1 showed the most potent α-glucosidase inhibition with an IC 50 value of 5.6 μM.