1. Academic Validation
  2. Hydrolyzable tannins from the fruits of Terminalia chebula Retz and their α-glucosidase inhibitory activities

Hydrolyzable tannins from the fruits of Terminalia chebula Retz and their α-glucosidase inhibitory activities

  • Phytochemistry. 2017 May:137:109-116. doi: 10.1016/j.phytochem.2017.02.006.
Dong Young Lee 1 Hyun Woo Kim 1 Heejung Yang 2 Sang Hyun Sung 3
Affiliations

Affiliations

  • 1 College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 151-742, Republic of Korea.
  • 2 College of Pharmacy, Kangwon National University, Chuncheon, 200-701, Republic of Korea.
  • 3 College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 151-742, Republic of Korea. Electronic address: shsung@snu.ac.kr.
Abstract

Nine hydrolyzable tannins, including three previously unknown and six artifacts, were isolated, together with thirty-nine known ones, from the fruits of Terminalia chebula Retz. (Combretaceae). They were identified as 1,2,3-tri-O-galloyl-6-O-cinnamoyl-β-d-glucose, 1,2,3,6-tetra-O-galloyl-4-O-cinnamoyl-β-d-glucose, 4-O-(2″,4″-di-O-galloyl-α-l-rhamnosyl)ellagic acid, 1'-O-methyl neochebulanin, dimethyl neochebulinate, 6'-O-methyl neochebulagate, dimethyl neochebulagate, dimethyl 4'-epi-neochebulagate, and methyl chebulagate by the spectroscopic interpretation. After evaluation for α-glucosidase inhibition of all isolated compounds, 1,2,3,6-tetra-O-galloyl-4-O-cinnamoyl-β-d-glucose and 4-O-(2″,4″-di-O-galloyl-α-l-rhamnosyl)ellagic acid showed significant inhibitory activities with IC50 values of 2.9 and 6.4 μM, respectively. In addition, inhibition kinetic studies showed that both compounds have mixed-type inhibitory activities with the inhibition constants (Ki) of 1.9 and 4.0 μM, respectively.

Keywords

Combretaceae α-glucosidase; Hydrolyzable tannin; IC(50) value; Terminalia chebula.

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