Active Principles of Pituitary Gland

In a previous paper (1) it was shown that the oxytocic principle of the pituitary gland could be extracted, without appreciable loss, from aqueous solution, by butyl alcohol boiling under reduced pressure. By this method about 50 per cent of the total solid matter of the aqueous extract of dry infundibular substance can be eliminated, and the active residue, after removal of the butyl alcohol, is a pale yellow, sticky, hygroscopic, partly crystalline material. The process seemed to be sufficiently promising to warrant the working up of a considerable quantity of dry pituitary powder in the hope of making further progress toward the isolation of the uterine stimulant. About 20 grams of the semi-crystaffine butyl alcohol extract were obtained from 600 grams of dry infundibular substance, and on the general assumption that the active principle is basic in character a variety of attempts at isolation were made. At the outset it was realized that the number of methods available was strictly limited by the unstable nature of the sub-stance in question. It is known from the work of Guggenheim (2) that it is rapidly destroyed by normal sodium hydroxide in the cold, and although stable to sodium carbonate under similar conditions it was found during this work that quite mild treatment with this reagent is sufficient to bring about its decomposition. It is relatively more stable to acids, but is easily destroyed by them as Abel and Nagayama (3) have demonstrated, boiling for thirty minutes with 0.5 per cent hydrochloric acid resulting in its almost complete disappearance. It is also very readily