[Synergistic action of combinations of penicillin and perhydroacridine derivatives]

The effect of combinations of perhydroacridine derivatives such as 10-nitroso-trans-anti-cys-perhydroacridine (MT-2) and 10-isopropylamino-trans-anti-cys-perhydroacridine (MT-6) with benzylpenicillin on growth of two penicillinase-producing strains of Staphylococcus aureus was studied. The combination components were added to the culture simultaneously or at different periods i.e. the second component was added after preliminary exposure of the bacterial cells to the first component for 1-6 hours at 37 degrees C. It was shown that duration and efficacy of the combination synergistic action were directly proportional to the time of the component addition. The highest synergistic action of the combinations was observed when both the components were simultaneously added to the staphylococcal culture. The combinations were less efficient when the bacterial cells were preliminarily incubated with the perhydroacridines. Addition of the perhydroacridine derivatives after the strain contact with the penicillin resulted in elimination of the combination synergistic action. Thin-layer chromatography did not reveal complexing between the penicillin and perhydroacridines.