The isolation and identification of a novel intermediate in ubiquinone-6 biosynthesis by Saccharomyces cerevisiae

Summary The mutant strain of Saccharomyces cerevisiae E3-24 is unable to synthesize ubiquinone-6. When this mutant is grown in the presence of p-hydroxybenzoate-U- 14 C or p-hydroxybenzoate-7- 14 C, radioactive 3,4-dihydroxy-hexaprenylbenzoate accumulates. This new metabolite has been isolated and found to have the same R f as a synthetic homologue on thin layer chromatography with 4 solvent systems. Further, it shows an identical fragmentation pattern in the mass spectrometer. Its presence in S. cerevisiae establishes an alternate pathway for ubiquinone biosynthesis in eukaryotic organisms.