Radio-detection high-performance liquid chromatographic enzyme assay for inhibitors of fungal sterol delta 14-reductase

An enzyme assay for inhibitors of fungal sterol delta 14-reductase employing isocratic reversed-phase high-performance liquid chromatography is described. A Hypersil 5-microns octadecylsilyl (ODS) column (250 mm x 4.6 mm I.D.) was used and a mobile phase consisting of methanol-water-ethanol (86:4:10, v/v) was pumped at a flow-rate of 1.5 ml/min. Typical analysis times were 15 min. Using 4-14C]ignosterol as a substrate and an enzyme preparation from Saccharomyces cerevisiae, this method was used to compare the inhibition of sterol delta 14-reductase by the fungicides fenpropidin and fenpropimorph with three N-substituted 8-azadecaline compounds.