STARCH HYDROLASE INHIBITORS FROM NATURAL PRODUCTS: SCREENING, ISOLATION, CHARACTERIZATION, AND STRUCTRUAL MODIFICATION

Abstract

Type 2 diabetes is an escalating problem worldwide where the numbers are expected to rise to about 645 million by the year 2040. Inhibitors of starch hydrolase enzymes, like -amylase and -glucosidase, are effective approach to help diabetic patients control post-prandial hyperglycaemia. The objective of this project is to discover new type of starch hydrolase inhibitors from traditional herbs. In this work, structural modification of dracoflavan B isolated from dragon blood, a palm tree resin commonly used as traditional medicine, yielded a number of dracoflavan B derivatives. Among them, dracoflavan B gallate is 3 times more potent than existing anti-diabetic drug acarbose against α-amylase inhibition and thus has promising potential as new anti-diabetic drug. In addition, high throughput assay was applied together with various column fractionations and LCMS to characterise potent -amylase and -glucosidase inhibitors in Madhuca longifolia leaves. Finally, the impact of different mulberry cultivars, parts and extracting solvents on its -glucosidase inhibition were investigated and also used as bioactive ingredients for fortification of flours with different protein content to investigate the effect of food matrix, such as protein, on the starch hydrolase enzymes inhibition. These studies are useful for development of low glycemic index foods targeted for diabetic patients.