Study On The Synthesis Of New Stable Vitamin C Derivatives

Vitamin C is also called as ascorbic acid,which is a cyclopent-ester,with a hydroxy group in each carbon atom of the carbon-carbon double bond.For its special structure,it is easily affected by light,heat,oxygen,huminity,pH and metal cations.For its easily to be oxidated,unstable to heat ,it is urgent to develop new vitamin C source.In this article we have studied two kinds of new stable vitamin Cs synthesis,they are ascorbyl polyphosphate(AsPP)and ascorbyl palmitate(AP).We have also studied the stability of ascorbyl polyphosphate. In this article,we used two kinds of phosphate agent to react with vitamin C to prepare ascorbyl polyphosphate.(1)We used sodium hexmetaphosphate as phosphate agent,using single -factor experimental method,successfully synthesized the expected product.(2)Using sodium trimetaphosphate as phosphate agent ,we used orthogal design to seek the best synthetic methodology of ascorbyl polyphosphate.When the molar ratio of L-ascorbic acid and sodium trimetaphosphate was 1.00:1.30,pH=10.00,the temperature of the solution was 34℃,with no catalyst ,we got a high yield 99.8% and with high quality.The structure of the product has been confirmed by IR and C-NMR. In this article,we used two different methods to synthesis ascorbyl palmitate.(1)ester-exchange method.First,palmitic acid was esterified and methyl palmitate was obtained.Then ascorbyl palmitate was prepared through methyl palmitate with ascorbic acid at the presence of high concentrated sulfic acid.(2)Acyl esterific method.First,palmitic acid was acylated and palmitoyl chrolide was obtained.Then ,L-ascorbyl palmitate was prepared through palmitoyl chrolide reating with L-ascorbic acid.The IR and C-NMR spectra of the product was identified.