Amino Acid Content in Different Cultivars of Liriope platyphylla

摘要

Liriope platyphylla is a well-known herb in traditional Chinese medicine and its root has been clinically demonstrated to be effective in the treatment of metabolic and neural disorders. The present study investigated the variation in amino acids from different cultivars of L. platyphylla. Twenty amino acids were detected in four different cultivars of L. platyphylla. The presence and amounts of amino acids varied greatly among the cultivars. Seongsoo contained the highest total amount of amino acids with 2.18, 1.77 and 1.762 times the total amino acid levels observed in the Liriope Tuber No. 1, Cheongsim and Cheongyangjaerae cultivars, respectively. The Seongsoo cultivar contained the highest levels of 13 different amino acids, with a marked variation observed in the amount of glutamine. The Seongsoo cultivar contained 2.84,2.01 and 1.85 times the amount of glutamine detected in the Liriope Tuber No. 1, Cheongyangjaerae and Cheongsim cultivars, respectively. Furthermore, in the Seongsoo cultivar, the levels of asparagine, arginine, threonine, γ-aminobutyric acid, leucine and lysine were 3.04, 2.75, 1.89, 1.73, 1.74 and 1.68 times, respectively, higher than that in the Cheongsim cultivar, which showed the lowest amino acid content of all cultivars. The cultivar Cheongyangjaerae contained the highest levels of six different amino acids: histidine, alanine, tyrosine, cysteine, valine and isoleucine. The levels of tyrosine, alanine, valine, isoleucine, cysteine and histidine were 1.79, 1.72, 1.67, 1.61, 1.36 and 1.28 times, respectively, higher than that in the Cheongsim cultivar. Although the Cheongsim cultivar contained the lowest total amount of amino acids and the levels of most of the amino acids were the lowest, the tubers of this cultivar contained the highest level of glutamate. Our results dierefore demonstrate that L. platyphylla cultivars contain varying amounts of amino acids and suggested diat the Cheongsim cultivar shows excellent potential to serve as a source of amino acids.