The influence of newly synthesised fenporpimorph derivatives on some pathogen yeasts.

The effect of minimum inhibitory concentrations (MICs) of six novel fenpropimorph derivatives on lipid and sterol composition of Candida albicans, Cryptococcus neoformans, Malassezia pachydermatis and Malassezia furfur was investigated. The MICs for the most effective derivatives were found in the range from 3.7 to 56.7 microM and were 2-3 times lower compared to the commercial fungicide bifonazol. The more efficient fenpropimorph derivatives were the piperidine derivative for C. albicans and the allylamine derivative for Cr. neoformans, M. pachydermatis and M. furfur. The inhibitor in the growth medium reduced the unsaturation index of the total lipid content in M. furfur and C. albicans.

Influence of methylfenpropidine on growth, sterol content and fatty acid composition of Candida albicans.

The effect of methylfenpropidine on growth, lipid contents, sterol and fatty acid composition was investigated in 5 strains of Candida albicans. The sensitivity of the strains decreased in the order: wild strains > erg+ ade nysR > ade nysR erg (defective delta (8-7)-isomerase) > ade nysR erg (defective delta 5-desaturase). The presence of the inhibitor influenced fecosterol isomerization, episterol dehydrogenation, zymosterol transmethylation, ignosterol reduction and squalene epoxidation. Methylfenpropidine also induced changes in fatty acid composition, causing a reduction of the palmitic and oleic acid content with a concomitant elevation of stearic, linoleic and linolenic acid levels. The lipid unsaturation index slightly increased. Morphological changes of wild strains were observed after the fungicide treatment.

The content of prostaglandins and their precursors in Mortierella and Cunninghamella species.

Five strains of filamentous fungi belonging to the genera Mortierella and Cunninghamella were examined for the content of dihomo-gamma-linolenic, arachidonic, eicosapentaenoic acids and prostaglandins (type E2 and F2 alpha). Prostaglandins were detected using an ELISA method in mycelia of all tested strains (range 50-4800 ng g-1 of PGE2 and 6-30 ng g-1 of PGF2 alpha). Several micro-organisms also produced prostaglandins in the culture medium (2.2-137.6 micrograms 1-1 for PGE2 and 0.4-7.8 micrograms 1-1 for PGF2 alpha).

Influence of new fenpropimorph fungicides on the growth and sterol composition in Saccharomyces cerevisiae: relationship between structure and activity.

The toxicity of fenpropimorph and seven newly synthesized analogues against Saccharomyces cerevisiae has been determined in liquid media. The inhibitory effect of the most efficient derivative is 120 times more than that of standard fenpropimorph. The non-linear relationship between hydrophobicity and toxicity indicates that the binding of the compounds to the receptors does not differ and so the differences in toxicity reflect changes in the rate of metabolism. The presence of inhibitors in the fermentation medium resulted in a reduction in harvested biomass and lipid yield, and changes in sterol composition -- the amount of ergosterol decreased whereas the amounts of lanosterol, dihydroergosterol and squalene increased. The toxicity of the compounds was most influenced by their lipophilicity. Use of this information could lead to development of more potent ergosterol inhibitors.

Effect of salt stress on fatty acid alterations in some strains of Dipodascopsis and Dipodascus spp.

The effect of salt stress (8% w/v NaCl) on fatty acid composition of eight strains of Dipodascus and Dipodascopsis spp. varied from being of slight influence only (Dipodascopsis uninucleata), to decreasing the content of 18:2 (D. reesii, D. tetrasperma and D. australiensis) and to decreasing both 18:1 and 18:2 (D. tothii and D. aggregatus) with a concomitant rise of 14:1 and 16:1. With the exception of D. aggregatus, NaCl inhibited lipid accumulation in all strains. Only trace amounts of fatty acids over C18 in chain length were found.