Please use this identifier to cite or link to this item:
|Title:||Assay-guided fractionation study of α-amylase inhibitors from Garcinia mangostana pericarp||Authors:||Loo, A.E.K.
|Issue Date:||28-Nov-2007||Citation:||Loo, A.E.K., Huang, D. (2007-11-28). Assay-guided fractionation study of α-amylase inhibitors from Garcinia mangostana pericarp. Journal of Agricultural and Food Chemistry 55 (24) : 9805-9810. ScholarBank@NUS Repository.||Abstract:||α-Amylase inhibitor (α-AI) activity of Garcinia mangostana, commonly known as mangosteen, pericarp extracts was studied by assay guided fractionations from lipophilic to hydrophilic using combined solvent extraction and Amberlite XAD2 adsorption chromatography. Neither the lipophilic, xanthone containing fraction, nor the highly polar fraction, which has no affinity on Amberlite XAD2, showed any α-AI. The fraction that shows very high inhibitory activity contains primarily polyphenols and can be adsorbed on Amberlite XAD2. The IC50 of 5.4 μg/mL of this fraction is comparable to that of acarbose, a prescribed α-AI used in the control of type II diabetes, at 5.2 μg/mL. Total phenolic content (TPC) of each fraction was measured and the TPC has no correlation with the α-AI activity. The lipophilic fraction contains mainly xanthones as revealed by HPLC-MS analysis. Colorimetric analysis coupled with UV-vis and IR spectroscopic analysis demonstrated that the fractions with high α-AI activity are primarily oligomeric proanthocyanidins (OPCs) with little gallate moiety. There is also evidence to show that the α-AI by these OPCs is not purely by nonspecific protein complexation. Both tannic acid and G. mangostana OPCs precipitate BSA equally well but G. mangostana OPCs are 56 times more effective in inhibiting α-amylase. © 2007 American Chemical Society.||Source Title:||Journal of Agricultural and Food Chemistry||URI:||http://scholarbank.nus.edu.sg/handle/10635/93141||ISSN:||00218561|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Feb 28, 2018
WEB OF SCIENCETM
checked on Jul 17, 2019
checked on Oct 12, 2019
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.