Antimicrobial activity of 2-vinylfuran derivatives.

2-Vinylfuran derivatives were found to inhibit algal and yeast growth. Experiments with a respiratory type of Saccharomyces cerevisiae DT XII, its respiration-deficient mutant DT XII A, and Candida albicans showed that all 2-vinylfurans are inhibitors of key processes of energy metabolism (especially glycolysis). The properties determining the inhibitory activity are chemical reactivity and lipophilicity. The reactivity of the studied derivatives was characterized by second-order rate constants kappa (L. mol-1.2-1) for reaction with mercaptoacetic acid (as a model thiol), and the lipophilicity by calculated sigma pi i-constants. An equation correlating the structure and the activity of 2-vinylfurans was derived. The significance of reactions of 2-vinylfurans with thiols or other nucleophilic groups of cell components is stressed. The reaction centre of 2-vinylfurans in these reactions is the electrophilic exocyclic double bond. The presence of a nitro group in position 5 of the furan ring is not indispensable for biological activity of 2-vinylfurans.