Identification of α amylase inhibitors from Syzygium cumini Linn seeds

The aqueous extract of S. cumini or Eugenia jambolana seeds and Psidium guajava leaves showed higher inhibition against the porcine pancreatic alpha-amylase among the medicinal plants studied. The a-amylase inhibitors from S.cumini seeds were separated from the extract by preparative thin layer chromatography into fractions with different R-f values. The fraction with Rf value between 0.285 and 0.43, which showed maximum inhibitory activity, was eluted and analyzed through LC-MS. The compounds identified from the seed extract of S. cumini were betulinic acid and 3,5,7,4 '-tetrahydroxy flavanone, which were reported earlier from S. formosanum and other plants. Dixon plot showed that the inhibition was noncompetitive in nature.