Assessment of<i> in vitro alpha</i>-glucosidase inhibitory activity, phenolics, flavonoidsand antioxidant potential of jamun (<i>Syzygium cumini)</i> seeds

Jamun (Syzygium cumini Linn. Syn. Eugenia jambolana) genotypes collected from different parts of the country were evaluated for in vitro alpha-glucosidase inhibitory activity, polyphenolic content and antioxidant potential along with fruit characters. Results indicated significant variation among genotypes for fruit characters, phenolics, flavonoids, antioxidant potential, and alpha-glucosidase inhibitory potential. Total phenolics and flavonoids in seeds varied between 15.5 mg to 98.7 mg GAE/g and 0.79 mg to 9.03 mg CE/g seeds, respectively. The seeds with a high content of polyphenolic compounds required a very less amount of sample to inhibit alpha-glucosidase enzyme. The genotype Selection 45 recorded the highest alpha-glucosidase inhibitory activity, and required only 50.3 µg of sample to inhibit 50 % of the enzyme activity. Both phenolics and flavonoids content positively correlated with antioxidant potential and negatively correlated with enzyme inhibitory potential. From cluster analysis, the genotypes AJG-85, Kaithanal, Selection-45, Collection-2, and Konkan Bahdoli were identified as superior genotypes having a considerable amount of seeds with alpha glucosidase inhibitory compounds. These genotypes/collections may be effectively utilized for further studies to isolate and characterize the bioactive constituents with alpha-glucosidase inhibitory potential.