The isolation and identification of some adrenocorticosteroids released by rat adrenal tissue incubated in vitro.

A lipid extract of the pooled preincubation media of incubated rat adrenal sections or of rat adrenal tissue homogcnates incubated in vitro was chromatographcd on paper chromatograms. Four distinct zones absorbing ultraviolet light were isolated when the chromatograms were run in the toluene-propylene glycol system. These zones were designated as X1, aldosterone, X2 and corticosterone. Aldosterone as the 21-monoacetate and free corticosteronc were isolated in the crystalline state and identified by infrared spectroscopy and other criteria. The two compounds, X1 and X2, were not identified although X2 was crystallized and several of its physical and chemical characteristics noted. One of these was its ability to react with the sulfuric acid phenylhydrazine reagent to yield a chromogen absorbing light at 400–410 mµ. The importance of X2 was discussed from the point of view of its possible physiological significance.