CHARACTERIZATION OF CHEMICAL PRINCIPLES OF FOOD BIOACTIVE CONSTITUENTS: ISOTHIOCYANATES AS H2S DONORS AND DIGESTIVE ENZYME INHIBITORS FROM ACORNS OF QUERCUS FABRI HANCE

Abstract

This thesis documented my findings on chemical characterizations of food bioactive compounds and their action mechanisms. In the first part of this thesis, the underlying chemical principles of dietary isothiocyanates (ITCs, R-NCS) act as hydrogen sulfide donors have been elaborated. Besides, the relationship between para-substituents of aryl isothiocyanates and their hydrogen sulfide release rates has been established based on a Hammett plot. In the second part of this thesis, the digestive enzyme inhibitors in acorns of Quercus fabri Hance were investigated. Ellagitannins in extract of acorns were found to be major contributors to the inhibition of starch hydrolase. Besides, the 28-β-D-glucopyranosyl-2α, 3β, 19α-trihydroxyolean-12-ene-24, 28-dioic acid ester with gallic acid was isolated as a pancreatic lipase inhibitor.