Study Of The Chemical Constituents In Dioscorea Opposita Thunb. & The Interaction Between Natural Phenolic Compounds With Protein

This thesis deals with the investigation on the chemical constituents of Dioscorea Opposite Thunb and studys the interactions between 5,7-dihydroxy-4′-methoxy flavanone, (-)-epicatechin and bovine serum albumin using fluorescence, electrochemical method ,UV absorption and NMR spectroscopy. The main contents are as follows:Chapter 1: Study of the chemical constituents in Dioscorea opposita Thunb1. Two methods were used to methylate the fatty acid in Dioscorea opposita Thunb. The methylated fatty acids were analyzed by GC-MS.2. Nine chemical constituents were isolated and repeatedly purified on silica gel col- umn and the structures of seven chemical constituents were identified as cyclo-(Phe- -Tyr), 6-methyl citrate1,5-dimethyl citrate,trimethyl citrate,β-sitosterol ,β-daucosterol, stigmasterol with NMR IR, MS, UV.3. A new iron(Ⅲ)- Dioscorea opposita Thunb. Polysaccharide complex was synthesizd using FeCl3 and Dioscorea opposita Thunb. Polysaccharide and some physicochemical properties including the content of iron(Ⅲ) were also studied.Chapter 2: The interaction between natural phenol compound with protein1. The intereaction between isosakuranetin (ISO) and bovine serum albumin(BSA) has been investigated by fluorescence, UV absorption and NMR spectroscopy. The results show that the mechanism of quenching the inner fluorescence of BSA is due to the combination of BSA with ISO which results in static quenching procedure. The binding constant is 7.41×1011 L/mol and the number of binding sites is 1.98. The active groups of ISO interacting with BSA are 7-OH and 5-OH, and 7-OH is more active than 5-OH. With the increase of ISO concentration, the conformation of BSA has been changed.2. The interaction of (-)-epicatechin (EC) and bovine serum albumin (BSA) was...