Grace-Anne Bent
The University of the West Indies, West Indies
Title: Towards a deeper understanding of the mechanisms of interaction between acryl amide and key body-fluid thiols
Biography
Biography: Grace-Anne Bent
Abstract
Exposure to acrylamide (AA) or its metabolite glycidamide (GA), in foodstuffs, is a major concern today. This paper communicates recent developments concerning the role that AA and its metabolite GA, potentially toxic food contaminants, produced on frying, steaming (heat treatments above 100oC) carbohydrate-based foodstuff via Maillard reaction involving asparagine and reducing sugars. It has been proposed that detoxification of AA and GA occurs primarily via conjugation with thiols via the Michael-addition reaction. Recent investigations to study the reactivity of thiols towards AA and GA included the use of: glutathione (GSH), L-cysteine (CySH) and captopril (CapSH). GSH and CySH are naturally occurring in the body while CapSH is synthetic and usually administered in the form of a drug used for the treatment of congestive heart failure. The kinetic rates of conjugation reactions follow: CySH>GSH>CapSH as opposed to CySH>CapSH>GSH expected based on molecular sizes. Preliminary comparative DFT (density functional theory) calculations on AA and thiols provide information that close hydrogen interactions between GSH and AA; which is absent in CySH and CapSH explains the observed rate trend. Furthermore, preliminary DFT calculations show that there is an open question of H-transfer via intra-molecular GSH or H-transfer via solvent water molecules.