Biosynthesis of terpenes and steroids. Part VIII. The synthesis and metabolism in Saccharomyces cerevisiae of ergosta-7,22,24(28)-trien-3β-ol

Side chain azasteroids and thiasteroids as sterol methyltransferase inhibitors in ergosterol biosynthesis

“…The predominant sterols found in the untreated control cultures were (in decreasing order): dehydroergosterol (the direct precursor of ergosterol in its biosynthesis), ergosterol, 5-dehydroepisterol and ergosta-5,8,22,24(28)-tetraen-3-ol. Azasterols and the thiasterol 16 at about MIC concentrations significantly increased the relative content of the C 27 -D24-sterols cholesta-5,7,24-trien-3b-ol (22) (Fig. 3), and (to a lesser extent) cholesta-7,24-trien-3b-ol, thus leading to the same effects as previously described for a ERG 6 mutant of the yeast S. cerevisiae.…”

“…The selective reduction of the aldehyde 3 to the corresponding primary alcohol 12 was performed with sodium borohydride in chloroform/methanol as previously reported. 22 Using methyltriphenoxy-phosphonium iodide, 23 the alcohol 12 was converted into the corresponding iodide derivative 13 in 88% yield. Subsequent treatment with lithium n-butanethiolate, formed in situ from n-butanethiol and n-butyllithium, to give the thioether 14 in chloroform/methanol afforded the thioether 15 in 71% overall yield.…”

Penicillium digitatum Metabolites on Synthetic Media and Citrus Fruits

“…Identification of the sterols and oxygenated triterpenes from P . digitatum biomass has been made by interpretation of the characteristic mode of fragmentation of their TMS-ethers when subjected to GC−MS ( − ), and by comparison of RI and mass spectra with those from standards.…”