Studies in the biosynthesis of fungal metabolites. 2. The biosynthesis of alternariol and its relation to other fungal phenols.

body but rather that both ethyl trichloroand trifluoro-acetate are effective as lipotropic agents because of the CC13 or CF3 group. These groups are larger than the CH3 group and may exert their effects through a steric blockage of an enzyme system. Ethyl dichloroacetate was not only without lipotropic action but was highly toxic when given to rats in an established choline-deficient state. Rats fed on a ration which supported the breeding colony tolerated the same dosage with no noticeable impairment of function. It is probable that it is more .toxic when the quality of protein in the diet is poor since it was also toxic when choline was added to the experimental diet (Kratzing, 1960). Laug (1946) stated that dichloroacetate was a more effective inhibitor of mouse-liver respiration than corresponding concentrations of trichloroacetate, whereas acetate, at the same concentration range, was not inhibitory. But Woodard, Lange, Nelson & Calvery (1941) found that rats tolerated larger oral doses of dichloroacetic acid than they did of trichloroacetic acid or acetic acid before showing signs of toxicity. In general the non-toxicity of the polyhalogen derivatives of acetic acid is in marked contrast to the toxicity of the monohalogen derivatives (Kratzing, 1960).