Composition and content analysis of amino acid in authentic Angelica dahurica of Hunan.

Angelica dahurica is a kind of Chinese herbal medicine. The effective components of A. dahurica, commonly known as coumarin, have drawn attention because of their wide spectrum of biological effects that might be mainly related to some chemical components with antispasmodic and analgesic activities like some volatile oils such as isoimperatorin, imperatorin and so on. But it is unclear what the components and mechanism of analgesia in A. dahurica are, and whether there are other substances just like some drug-effective amino acids have also some pharmacological effects can make nothing of it. In this study, the contents and composition of protein amino acids and free amino acids in Chaling A. dahurica of Hunan were determined by amino acid analyzer, and analysised of its amino acid composition. Amongtotal amino acids, 16 kinds of amino acids except for An were detected, and the content of Arg was the highest and accounted for 31.21 % close to 1/3 at the ratio of the total amino acids. The content of the essential amino acid reached 27.01% , and the content of Leu is the highest, and accounted for the ratio of the total amino acids up to 24.14%. A higher proportion of essential amino acid are respectively 73.89 % and 85.78% in total amino acids by the acid-catalysed hydrolysing and free amino acids, in which the content of Arg was the highest as 1.383 g . 100 g^-1 , and accounted for 42.24%. The content of gamma aminobutyric acid and ornithine in free amino acid was also to a high content. And in addition, a small amount of homocysteine and anserine free non protein amino acids and peptides were detected. The essential amino acid composition was close to the recommendations of the WHO/FAO uptake value. But Met+Cys had minimum RC value, and was the first limiting amino acid. The results showed that these drug-effective and free amino acids might be one cause that Chaling dahurica has good physiological function. Futhermore, the amino acid composition and ratio of Chaling A. dahuricae were relatively reasonable and according with the human body needs. Based on strengthening the sulfur-containing amino acid, Chaling A. dahurica has potential to develope as a new type of health food of edible and pharmaceutical. In addition, the study will also be a theory basis for further study on the pharmacological effects of dahuricae. [ABSTRACT FROM AUTHOR]