抄録
Ansamitocins in combination with amphotericin B produced synergistic inhibition on the growth of several yeasts in liquid cultures, Ansamitocin P-3 at 5 μg/ml completely suppressed the growth of Saccharomyces cerevisiae whereas ansamitocin P-3 alone at 50 μg/ml hardly affected growth. Ansamitocin P-4 and maytansine also showed synergistic activity with amphotericin B against S. cerevisiae. The synergism also occurred in cultures of Candida albicans and Hansenula anomala. Combinations of ansamitocin P-3 with various agents revealed that the synergism depended on the specific property of amphotericin B. Ansamitocins showed no interfering activity against regeneration of protoplasts of S. cerevisiae. These results suggest that the limited activity of ansamitocins against these yeasts is due to the membrane permeability barrier of these cells.