Triterpeneglycosideg as Inhibitors of Fungal Growth and Metabolism

Ergosterol was found to be the main sterol in the mycelia of Opbiobolus graminis, Neurospora crassa, and Aspsrgillus niger, A correlation was found between the amount of sterols in the mycelia of different fungi and the inhibitory effect of aescin. Aescin treatment caused a reduction of the amount of extractable sterols in the mycelia. The sterols seemed to be located mainly in the plasma membranes, and only trace amounts were Found in the mitochondrial membranes. The relative amount of sterols in the plasma membrane was found to be higher in O. graminis than in N. crassa and A. niger. Ca²⁺ interfered with the interaction, of sterols and aescin. In N. crassa the decreased inhibitory effect of aescin in the presence of Ca²⁺ was due to the reduced binding of the inhibitor to the sterols in the plasma membrane.