III. The Phytosterol 22, 23-Dihydrostigmasterol
The Authors have studied the role of some general metabolites in the biosynthesis of the 22,23-dihydrostigmasterol in Wistaria Sinensis flowers, gathered during the period April—July. The rate of uptake of the following possible precursors has been investigated: [2-14C] acetate, [2-14C] pyruvate, [2,3-14C] succinate, [1,4-14C] succinate, [1,4-14C] fumarate, [5-14C] ketoglutarate, [1,5-14C] citrate and [2-14C] mevalonate. Metabolism periods of 12, 24, 36, 48 and 72 hours have been used. Mevalonate and acetate have shown the highest degree of incorporation, as in agreement with the known data on their role in the biosynthesis of sterols. The incorporation of radioactivity from [2,3-14C] succinate has been significant from the other compounds negligible. Some metabolic relationships have been found especially among acetate, pyruvate, succinate and the other substances involved in the Krebs cycle.