Differential selective toxicity of DMS-aureofacin components.

Trimethylammonium methyl esters (DMS) of polyene macrolides are products of the methylation of native polyene antibiotics with dimethyl sulfate. We isolated individual components of the DMS-aureofacin complex and characterized their toxicity and activity to induce permeability changes in cell membranes. The DMS-aureofacin complex contained five components readily separated by thin-layer chromatography on polygram cellulose plates. DMS-Aureofacin A, a major component of the complex (90%), showed poor selective toxicity between yeast cells and mammalian cells grown in culture. DMS-Aureofacin B (6%) and DMS-aureofacin E (4%) exhibited very high biological activities and differed qualitatively in selective toxicity. DMS-Aureofacin B was much more active for mammalian cells than for yeast cells. In contrast, DMS-aureofacin E was much more active for yeast cells than for mammalian cells. DMS-Aureofacin C and D were present in the complex in only minute quantities which did not permit their biological characterization.