[Effect of 2-ethyl-2-ene-1-al and analogous compounds on the growth and ultrastructure of fungi].

Analogs of the natural substance (E)-hex-2-en-1-al which occurs naturally in green plants and is known to have microbiocidal properties were synthesized and studied with respect to their antifungal properties. Saturated and unsaturated aldehydes, alcohols, carbon acids and enolacetate were tested against various fungi by applying these compounds either over the gaseous phase or in suspension. The following ranking was observed on the basis of fungicidal activity: enolacetate of 2-ethylhex-2-enoic acid greater than 2-ethylhex-2-en-1-al greater than 2-ethylhex-2-en-1-al greater than 2-ethylhex-2-en-1-ol. Saturated analogs showed the same order of activity as the unsaturated ones, however, they were less efficient. The effects on the ultrastructural changes were analyzed in Mucor mucedo exposed to concentrations of the analogs that inhibited growth. Main effects were observed on mitochondrial and nuclear membranes. The kind of destruction caused by enolacetate of 2-ethylhex-2-en-1-al differed from the other substances tested. Aspects of the mode of action are discussed.