| Caffeic acid can provided hydrogen atom in the reaction as a phenolic compound, can dissociate hydrogen atoms who shows aromatic ring hydroxylation activity, strong reduction activity, light protection activity, enhanced tissue antioxidant activity. Naturally, most of the coffee acid compounds are present in the form of its derivatives, and caffeic acid derivatives were found to have good biological activities mostly. Wherein the coffee acid esters and amides of caffeic acid derivatives have been proven biological activity strong, so coffee acid esters and amides of caffeic acid derivatives have becoming a hot topic in recent years.In this paper, benzaldehyde and 3,4-hydroxybenzaldehyde were used as raw material to synthesize caffeic ester derivatives: cinnamic acid phenethyl ester, caffeic acid phenethyl ester via chemical synthesis method based on previous studies, and the mass of these products were analyzed by GC-MS and HPLC-MS, the structure of the products were determined via Nuclear Magnetic Resonance(NMR). The effect factors of reaction molar ratio of the raw materia, reaction temperature and reaction time on the different product yield. We also explored when n(cinnamic acid):n(?-phenethyl alcohol):n(thionyl chloride)=1:1.5:3, reaction 120 min at 100 ? in oil bath,then reaction 7.5 h after adding ?-benzyl alcohol. Final the yield of cinnamic acid phenethyl ester was 70.02%; When n(caffeic acid):n(?-phenethyl alcohol):n(thionyl chloride)=1:1.5:2.4 reaction30 min at 100 ? in an oil bath, reaction 8.5 h after adding ?-phenethyl alcohol, and finally get the yield ofcaffeic acid phenethyl ester was 74%.The caffeic acid amide derivatives were also investigated using caffeic acid and amino acid condensation reaction. 12 kinds of amino acids were used in this paper: six kinds of essential amino acids:(phenylalanine, leucine, isoleucine, threonine, lysine and valine), five kinds of nonessential amino acids:(proline, alanine, serine, glycine, and aspartic acid), and an amphoteric amino acids:(arginine), respectively. For obtaining derivatives products via three chemicalmethods, the mass of these products were analyzed by HPLC-MS, the structure of the product were determined via Nuclear Magnetic Resonance(NMR). And effect factors of condensation reagents, reaction molar ratio of the raw material, and reaction time on the yield of the product were explored, then the structure of 10 derivatives were confirmed.. Three factors show great influences on the choice of the reaction. We get the highest yield when condensing agent are IBCF and NMM; It is great discrepancy on the yield of the amide derivatives for different amino acid,The yield of the derivatives instead of increasing inhibited reactions to right in contrast, when increase the reaction molar ratio of caffeic acid; Whole 10 kinds of amide derivatives have higher yield when n(CA):n(AA)=1:1.2, reaction time was 25 h at room temperature,and get the highest yield of caffeic acid serine amide reach to 91.43%. It is not significantly improve the yield of the amide derivatives increasing amount of material caffeic acid when n(CA):n(AA)=1:1.2. There maybe have two main reasons lead to part of the 12 kinds of derivative products in low yield: poor solubility of amino acids and the structure of amino acid itself is not easy to take place condensation reaction with caffeic acid.At last, the study of hypoglycemic pharmacological of caffeic acid, caffeic acid phenethyl ester and 6 kinds of amide derivatives include: caffeic acid arginine amide, caffeic acid serine amide, caffeic acid proline amide, caffeic acid phenylalanine amide, caffeic acid lysine amide and caffeic acid threonine amide on mice were explored. Found that whole of them show the function of reducing blood glucose except caffeic acid serine amide and caffeic acid proline amide,especially caffeic acid phenylalanine amide and caffeic acid lysine amide show a obviously reduce blood glucose function. |
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