Potentiation of antifungal activity of sesquiterpene dialdehydes against Candida albicans and two other fungi.

The antifungal activity of two drimane sesquiterpene dialdehydes, polygodial (1) and warburganal (2), alone and in combination with several other substances, was examined against three fungi, Candida albicans, Saccharomyces cerevisiae and Pityrosporum ovale employing a broth dilution method. Anethole significantly synergized the activity of the two sesquiterpenoids against C. albicans and S. cerevisiae; however, it had only an additive effect against P. ovale. By contrast, two antioxidants, ascorbic acid (vitamin C) and BHA (butylated hydroxyanisole), noticeably enhanced the activity of the sesquiterpenoids against P. ovale, but had no effect against C. albicans and S. cerevisiae.