Antioxidant properties of polyphenol glycoside catalyzed by transglycosylation reaction of cyclodextrin glucanotransferase derived from Trichoderma viride

Abstract

Cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) is a glucosyltransferase that catalyzes synthesis of polyphenolic into polyphenolic glycosides. The synthesis of glycosides via transglycosylation reaction of Trichoderma viride CGTase was studied in the presence of polyphenolic constituents from Moringa oleifera extract. The transglycosylation products were determined through 1 H and 13C-NMR to be gallic acid-4-O-b-glucopyranoside (GAGP), ellagic acid-4-O-b-glucopyranoside (EAGP) and catechin-40 -Oglucopyranoside (CGP), respectively. The EAGP was furthermore subjected on its antioxidant activities. Results showed that IC50 value of EAGP against 1-diphenyl-2-picryl hydrazyl was higher (46.12 mg/mL) than ascorbic acid (35.96 mg/mL), butylated hydroxytoluene (BHT, 39.73 mg/mL), and a-tocopherol (42.62 mg/mL), respectively. The IC50 of EAGP against 2,20 -azinobis-3-ethylbenzothiazoline-6-sulfonic acid was found to be 64.01 mg/mL as compared to ascorbic acid (30.13 mg/mL), BHT (38.09 mg/mL), and a-tocopherol (54.84 mg/mL), respectively. The IC50 value of EAGP against H2O2 was found to be 51.90 mg/mL, while for BHT and ascorbic acid were 44.18 and 47.18 mg/mL, respectively. Moreover, the IC50 on metal chelating ability of EAGP was found to be 45.42 mg/mL as compared to ethylene diamine tetra acetic acid was 28.24 mg/mL.