[Binding of carbonyl-conjugated pentaenes by Saccharomyces cerevisiae yeast cells]

The coefficients of distribution of flavofungin, flavopentin, nigrofungin and brunefungin, antifungal antibiotics, carbonyl-conjugated pentaenes, between water and Saccharomyces cerevisiae cells were determined. The coefficients were shown to increase with a decrease in the cell concentration. Therefore, the minimal concentrations of the antibiotics inhibiting the growth of S. cerevisiae decreased with a fall in the concentration of the yeast cells; the antibiotics with the greatest distribution coefficients had the lowest minimal inhibiting concentrations. The parameters for the binding of the antibiotics by the cells were determined using the equations of Scatchard and Klotz. It is possible that the binding mechanism for flavopentin and brunefungin differs from that for flavofungin and nigrofungin.