Abstract

The determination of α-glucosidase inhibitory activity and isolation of active compounds from Borassus flabellifer Linn. are the main objectives of this study. The colorimetric method and chromatographic technique were done for bioassay and phytochemistry. The results showed that, at concentration of 2 mg/ml, ethyl acetate extract inhibited α-glucosidase equally as positive standard, acarbose as 80% while water and ethanol extracts showed lower activity. Four compounds were isolated as glucosyl-(6-1)-glycerol, mixture of b–sitosterol and stigmasterol, 5-hydroxymethyl-furfural and tyrosol. In addition, 2 isolated compounds, tyrosol and glucosyl-(6-1)-glycerol showed moderate and mild α-glucosidase inhibitory activities with IC₅₀ as 1041.5 ± 205.5 µg/ml and 30% inhibition at 1000 µg/ml, respectively when compared with acarbose (IC₅₀ = 125.6 ± 9.3 µg/ml). Since, B. flabellifer extract and the isolated compounds, tyrosol and glucosyl-(6-1)-glycerol exhibited a–glucosidase inhibition, this plant can be further subjected to in vivo anti-diabetic studies.

Key words:       α-Glucosidase inhibitor, Borassus flabellifer, tyrosol, glucosyl-(6-1)-glycerol, anti-diabetes.