[Inactivation mechanism of polyene antibiotics. The change in the functional component of levorin during inactivation].

The inactivation process of levorin, a polyenic antibiotic was studied in the presence of oxygen. It was found that the biological activity did not sufficiently correlate with the optical density of the antibiotic solution. This indicates that destruction of the double bonds was not the only process resulting in the biological activity loss. In this connection methods for qualitative determination of the levorin main functional groups, i.e. aromatic and aliphatic amines and carbonyl groups were developed. The methods were used for the control of the changes in these functional groups on levorin inactivation. It was found that the inactivation level was directly proportional to the amount of the oxygen absorbed, 1 molecule of oxygen being required for inactivation of 2 levorin molecules. The number of the carbonyl groups and aromatic amines did not change during the inactivation process. In the first stages of inactivation the biological activity was directly proportional to the level of amino sugars. If the heptaen chromophore is not absorbed, 3 double bonds remain in inactivated levorin.