A Determination of the Hydroxy Amino Acids of Insulin

Abstract

have demonstrated, in a series of experiments in which the relationship of the starting material to the product of bio-transformation is not subject to question, that bacterial reduction of A4-3-ketosteroids of the hormone series follows an entirely different course, in which the A4-double bond invariably is saturated prior to reduction of the C3-carbonyl group. The bioreduction of androstenedione and of testosterone was studied in a number of instances, but in no case was dehydroisoandrosterone or other A6-unsaturated steroid encountered as a reduction product.Of still greater significance to the question of the origin of the dehydroisoandrosterone found in urine, is the direct experiment of N. H. Callow [Biochem. J., 33, 559 (1939)]. Callow found that administration of testosterone propionate to a male patient resulted in an unmistakable increase in the urinary excretion of androsterone and 3 -hydroxyaetiocholanone-17, but that there was no evidence of the conversion of the administered A4-3-ketosteroid into dehydroisoandrosterone. Thus the present evidence, in our opinion, is contradictory to Marker's hypothesis.