Study On The Hygroscopicity Of Amino Acid In Yiganning Extract Which Was Purified By Chitosan Flocculation Clarification

Objective:To determine on total free-amino acid in Yiganning aqueous extract. Establish a method for getting the high pure amino acids from the Yiganning aqueous extract. Investigate the hydroscopicity of Yiganning extract which was isolated and purificated, so was20kinds of common amino acids. Research on variation of content of the strong hydroscopic amino acids with two purification methods. Explore the effects of amino acids hydroscopicity with the chitosan flocculation clarification process and alcohol precipitation process in Yiganning aqueous extract.Methods:Spectrophotometer was applied to measure the content of total free-amino acid in Yiganning aqueous extract, and alcohol precipitation, cation exchange resin, activated carbon adsorption, macroporous resin were used to separate amino acids in Yiganning aqueous extract.20kinds of amino acids which were classified as acidic amino acids, basic amino acids, non-polar neutral amino acids, polar neutral amino acids, mixed amino acids were measured moisture percentage and critical relative humidity, further study the hygroscopic moisture inspection law of a single amino acid; Precolumn derivatization RP-HPLC with phenyl isothiocyanate(PITC) was used to detect the content of strong hygroscop-ic amino acids in Yiganning aqueous extract, and the content change of strong hygroscopic amino acids in Yiganning extract puritied by chitosan flocculation clarification process and alcohol precipitation process.Results:The content of total free-amino acid was1.48%in Yiganning raw medicinal herbs,5.65%in extract of Yiganning by nihydrin colorimetry. After Yiganning aqueous extract was preconcentrated by cation exchange resin and decolourizated by active carbon, total free-animo acid isolate at41.3%purity was obtained. The results of the percentage moisture showed that this isolate had much stronger hygroscopic than untreated Yiganning aqueous extract. There were20kinds of common amino acids, only Arg, Pro and Lys were hygroscopic, the hygroscopicity of Pro and Lys were stronger than fructose. Compare to Yiganning aqueous extract, the percentage moisture of ethanol precipitation samples was higher, while chitosan clarification samples’s was lower, and the increase rate of the former was higher than the latter’s. It had more pro and less Arg, Lys in the ethanol precipitation samples th-an the extract of Yiganning. The content of Arg, Pro and Lys in the chito-san clarifyication samples slightly improved.Conclusion:The hygroscopicity of twenty common amino acid were determined, so was the change of the amino acid’s content in Yiganning aqueous extract by purification of chitosan flocculation clarification and alcohol precipitation. The research results not only provided experimental basis for the mechanism of lowing the hygroscopicity of TCM solid by chitosan flocculation clarification, but also provided reference for TCM production.