Identification of 4-methyl-5-oxo-octane-1,8-dioic acid and the derivatives as metabolites of steroidal C,D-ring degradation in Comamonas testosteroni TA441
In this study, we isolated and identified 4-methyl-5-oxo-octane-1,8-dioic acid and 4-methyl-5-oxo-3-octene-1,8-dioic acid from the culture of the ORF3 (scdN)-null mutant as metabolites of steroid degradation (ADD and cholic acid analogues; cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid). In addition of these compounds, UHPLC/MS analysis of the culture of the scdN-null mutant revealed significant accumulation of another compound, which was detected as a dominant peak of m/z 155 ([M-CO2]-) accompanied by a small peak of parental ion (m/z 199 [M-]). On the bases of experimental data, this compound was presumed to be 4-methyl-5-oxo-2-octene-1,8-dioic acid, whose CoA-ester was indicated to be converted by scdN-encoded CoA-hydratase into the CoA-ester of 3-hydroxy-4-methyl-5-oxooctan-1,7-carboxylic acid.
Source: The Journal of Steroid Biochemistry and Molecular Biology - Category: Biochemistry Source Type: research