1956 年 76 巻 6 号 p. 678-681
Villus gonadotrophic hormone is secreted from the villus tissues of the placenta and excreted in a large amount into the urine. Its isolation is chiefly made from the the urine of a pregnant woman and no attempt has been made to isolate it directly from the placenta itself. In order to study the chemical difference between the gonadotrophic hormone isolated from the urine and that from the placenta, examination was first made for the method of isolating the said hormone from the placenta in a high purity. General method of extracting and purifying proteins was applied to human placenta and the crude product obtained by extraction with ammonia water and precipitation with ethanol was extracted at pH 4.8 with 50% ethanol. This was found to give the best yield of a highly pure product of 400-600 I. U./mg.