Cytotoxic activity of macrocyclic metabolites from fungi.

The cytotoxic effect of 7 macrocyclic fungal metabolites on HeLa cells has been determined. The authors noted great differences in the cytotoxic activity of the substances investigated. Least effective had proved the metabolites curvularin and zearalenone which kept exhibiting ED50 at a concentration of 2 X 10(-4)M and at a concentration of 7.5 X 10(-5)M respectively, whereas the most effective cyanein and monorden gave rise to 50% inhibition of multiplication of HeLa cells at a thousandfold lower concentration than zearalenone. Cytochalasins A, B and D brought about 50% inhibition of proliferation of HeLa cells at concentrations of the same order, with ED50 ranging between 1.2-2.1 X 10(-6)M. The different biological activity of the studied macrocyclic fungal metabolites is discussed in connection with their chemical structure.