Studies on the Constituents of Pinus densiflora SIEB. et ZUCC. Leaves. II. On the Ethanol-Extractable Amino Acids Compared with Pinus thunbergii PARL. Leaves

In order to identify the constituents of ethanol-extractable amino acids (free amino acids) from Pinus densiflora Sieb. et Zucc. and Pinus thunbergii Parl. leaves, analytical studies were performed by the use of high performance liquid chromatography. According to the results obtained, 29 amino acids in Pinus densiflora (the tree aged 3), 27 amino acids in Pinus thunbergii (the tree aged 3) and 25 amino acids in both pine (the tree aged 25) were confirmed. The total amounts of free amino acids in Pinus densiflora were found to be more rich than in Pinus thunbergii. The peaks of many free amino acids in Pinus densiflora (the tree aged 3) were found in February, but in Pinus thunbergii (the tree aged 3) the peaks of free amino acids were observed in May and from February to April. The mode of occurrence of asparagine at germination of buds explains clearly the distinction between Pinus densiflora and Pinus thunbergii.