INHIBITION OF STEROL SYNTHESIS IN VITRO BY METABOLITIES OF PHENYLALANINE

Studies with homogenates and 10000 × g supernatants of brain and liver demonstrated that phenylpyruvate, phenyllactate and phenylacetate markedly inhibited the incorporation of [14C]mevalonate into unsaponifiable lipids and digitonin-precipitable sterols. Phenylpyruvate was the most potent of the inhibitory compounds. The deaminated derivatives of phenylalanine blocked the decarboxylation of mevalonic acid pyrophosphate, preventing the formation of light petroleum-soluble polyprenols. In contrast, phenylalanine which also inhibited sterol synthesis in vitro seemed to inhibit at some step beyond the formation of polyprenols. © 1969.