Modes of antifungal action of alkanols against Saccharomyces cerevisiae.

Primary aliphatic alcohols from C(6) to C(13) were tested for their antifungal activity against Saccharomyces cerevisiae. Undecanol was found to be the most potent fungicide followed by decanol. The time-kill curve study showed that undecanol was fungicidal against S. cerevisiae at any growth stages. This fungicidal activity was not influenced by pH values. The alcohols tested inhibited glucose-induced acidification by inhibiting the plasma membrane H(+)-ATPase. The primary antifungal action of amphipathic medium-chain (C(9)-C(12)) alkanols comes mainly from their ability as nonionic surfactants to disrupt the native membrane-associated function of the integral proteins. Hence, the antifungal activity of alkanols is mediated by biophysical process, and the maximum activity can be obtained when balance between hydrophilic and hydrophobic portions becomes the most appropriate.