Antioxidant tannins from Syzygium cumini fruit

  • LL Zhang
  • YM Lin
Keywords: Syzygium cumini, tannins, antioxidant activity, MALDI-TOF MS, HPLC.


Hydrolysable and condensed tannins in the fruit of Syzygium cumini were identified using NMR, MALDITOF MS and HPLC analyses. Hydrolysable tannins were identified as ellagitannins, consisting of a glucose core surrounded by gallic acid and ellagic acid units. Condensed tannins were identified as Btype oligomers of epiafzelechin (propelargonidin) with a degree of polymerization up to eleven. The antioxidant activity were measured by two vitro models: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP). Tannins extracted from S. cumini fruit showed a very good DPPH radical scavenging activity and ferric reducing/antioxidant power. The
results are promising thus indicating the utilization of the fruit of S. cumini as a significant source of natural antioxidants.

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eISSN: 1684-5315