SYNTHESIS AND PHYSIOLOGICAL ACTIVITY OF SOME NEW ANALOGUES OF THYROXINE

Abstract

The lactic acid analogues of 3,5-diiodothyronine, 3,5,3[image]-triiodothyronine and thyroxine have been synthesized and assayed by the goiter prevention method in rats. In this test, the T4 and T3 analogues are considerably less active than either the corresponding acetic or propionic acids. Two new halogenated thyronines have been prepared: 3 ,3[image]-dichloro-5, 5[image]-diiodo-L-thyronine and 3,3[image]-dibromo-5,5[image]diiodo-L-thyronine; both have approximately equal potencies in the goiter prevention test of about 1/6 that L-thyroxine.