title: Aldose reductase and protein tyrosine phosphatase 1B inhibitory active compounds from Syzygium cumini seeds.
abstract: BACKGROUND
  Syzygium cumini (L.) Skeels (Myrtaceae), commonly known as jamun, is an Indian plant, traditionally well known for its medicinal properties including antidiabetic activity.
  
  
  OBJECTIVE
  To isolate the antidiabetic compounds from Syzygium cumini seeds and evaluate their activity using aldose reductase (AR) and protein-tyrosine phosphatase 1B (PTP1B) inhibition assays.
  
  
  METHODS
  The dried seeds were extracted with methanol and partitioned with ethyl acetate, butanol, and water. The extracts were screened for antidiabetic activity at a concentration of 100 µg/mL using in vitro AR and PTP 1B inhibition assays.
  
  
  CONCLUSIONS
  The highly enriched fractions obtained from broad ethyl acetate fraction yielded maslinic acid (1), 5-(hydroxymethyl) furfural (2), gallic acid (3), valoneic acid dilactone (4), rubuphenol (5), and ellagic acid (6). Structures were elucidated by (1)H-NMR and (13)C-NMR. The initial ethyl acetate fraction showed AR inhibitory activity with the IC50 value of 2.50 μg/mL and PTP1B enzyme inhibition with the IC50 value of 26.36 μg/mL. Compounds 3, 4, 5, and 6 were found to inhibit AR with IC50 values of 0.77, 0.075, 0.165, and 0.12 μg/mL while the compounds 4, 5, and 6 inhibited PTP1B with IC50 values of 9.37, 28.14, and 25.96 μg/mL, respectively.
  
  
  CONCLUSIONS
  The results of this study demonstrate that the isolated constituents show promising in vitro antidiabetic activity and, therefore, can be candidates for in vivo biological screening using relevant models to ascertain their antidiabetic activity.
authors: R&D Centre, Natural Remedies Pvt. Ltd. , Bangalore, Karnataka , India.
authors: Laxman
authors: L
authors: Sawant
authors: Vineet Kumar
authors: VK
authors: Singh
authors: Shekhar
authors: S
authors: Dethe
authors: Anirban
authors: A
authors: Bhaskar
authors: Jaya
authors: J
authors: Balachandran
authors: Deepak
authors: D
authors: Mundkinajeddu
authors: Amit
authors: A
authors: Agarwal
mesh_terms: D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D008297:Male; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012639:Seeds; D027842:Syzygium
chemical_list: D010936:Plant Extracts; D000449:Aldehyde Reductase; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; C516610:Ptpn1 protein, rat
keywords: Aldose reductase; Syzygium cumini; bioassay-guided fractionation; protein-tyrosine phosphatase 1B; rubuphenol; valoneic acid dilactone