1957 年 77 巻 9 号 p. 950-954
In order to obtain melanocyte stimulating hormone (MSH) of high purity, extraction of bovine posterior pituitary gland was carried out. Crude MSH of 20-30γ/U. was obtained from gland by extracting with 0.5% acetic acid, water and dehyd. ethanol successively. The crude MSH was submitted to repeated countercurrent distribution with butanol-acetic acid-water (4:1:5) mixture as a solvent and 11-26 tubes, and purified MSH of the highest purity of 1.88γ/U, or ca. 550U/mg., was obtained. This purified MSH was submitted to paper electrophoresis at pH 11.15, 8.7, 4.0, and 3.15, and a ninhydrin-coloring substance was isolated, besides the main spot, in those at pH 11.15 and 4.0. The composite amino acids of MSH were examined by the ring chromatography of its hydrolyzate and the presence of 18 kinds of amino acids was detected. The unit of potency was expressed by the potency of MSH corresponding to 0.5mg. of the Posterior Pituitary Reference Standard J. P. VI, as 1 unit.