Isoprenoid phenol and quinone precursors of ubiquinones and dihydroubiquinones [ubiquinones(H2)] in fungi

Abstract

1. Ten moulds and two yeasts were analysed for the presence of 2-polyprenylphenols, 2-polyprenyl(H2)phenols, 6-methoxy-2-polyprenylphenols, 6-methoxy-2-polyprenyl(H2)phenols, 6-methoxy-2-polyprenyl-1,4-benzoquinones, 6-methoxy-2-polyprenyl(H2)-1,4-benzoquinones, 5-demethoxyubiquinones, 5-demethoxyubiquinones(H2), ubiquinones and ubiquinones(H2). 2. The organisms were found to be of three types: (a) those that contained only ubiquinones (Aspergillus fumigatus and Penicillium brevi-compactum) or ubiquinones(H2) (Alternaria solani, Claviceps purpurae and Penicillium stipitatum); (b) those that contained 5-demethoxyubiquinones and ubiquinones (Agaricus campestris, Aspergillus niger, Phycomyces blakesleeanus, Rhodotorula glutinis and Saccharomyces cerevisiae) or 5-demethoxyubiquinones(H2) and ubiquinones(H2) (Aspergillus quadrilineatus and Neurospora crassa); (c) one that contained 2-decaprenyl(H2)phenol, 6-methoxy-2-decaprenyl(H2)phenol, 6-methoxy-2-decaprenyl(X-H2)-1,4-benzoquinone, 5-demethoxyubiquinone-10(X-H2) and ubiquinones(H2) (Aspergillus flavus). 3. Studies were made on the biosynthesis of ubiquinones and ubiquinones(H2) by Asp. flavus, Phyc. blakesleeanus and S. cerevisiae. These provided evidence that in Phyc. blakesleeanus 5-demethoxyubiquinone-9 is a precursor of ubiquinone-9 and that in S. cerevisiae 5-demethoxyubiquinone-6 is a precursor of ubiquinone-6. In addition they yielded results that may be interpreted as providing evidence that in Asp. flavus 6-methoxy-2-decaprenyl(X-H2)-1,4-benzoquinone and 5-demethoxyubiquinone-10(X-H2) are precursors of ubiquinone-10(X-H2).