Combination effects of antifungal nagilactones against Candida albicans and two other fungi with phenylpropanoids.

Antifungal activity of three nagilactones isolated from the root bark of Podocarpus nagi (Podocarpaceae), alone and in combination with a variety of phenylpropanoids, was investigated against three fungi, Candida albicans, Saccharomyces cerevisiae, and Pityrosporum ovale. Nagilactone E [2], the most abundant norditerpene dilactone, showed moderate to weak activity against these fungi. This activity was dramatically enhanced by several naturally occurring phenylpropanoids such as anethole [5] and isosafrole. For example, anethole enhanced the activity of nagilactone E as much as 128-fold for C. albicans, decreasing the MIC of this nagilactone from 800 to 6.25 micrograms/ml.