Synthesis and investigation of antimicrobial and antioxidant activity of anthraquinonylhydrazones

The new anthraquinonylhydrazones were obtained by the interaction of 9,10-dioxoanthracene-1-diazonium sulfates with a number of α- and β-carbonyl-containing compounds under modified conditions of the Japp–Klingemann reaction, and a probable mechanism of the formation has been proposed. It was found that hydrazones, unsaturated in the second position of the anthraquinone ring, containing acetyl or ethoxycarbonyl moieties in the ylidene part of the molecule, are capable of eliminating these fragments. It has been experimentally established that hydrazones, free rotation around the N=C bond of which is possible, exist as one isomer due to the presence of an intramolecular hydrogen bond in the molecule. The anthraquinonylhydrazone of dimedone with action against the bacteria strains of Staphylococcus aureus 209-P, Mycobacterium luteum B-917, and fungus Candida tenuis VKM Y-70 was found. The hydrazones of dimedone and barbituric acid with a higher trolox equivalent antioxidant coefficients of antioxidant action were found using CUPRAC assay. In addition, the hydrazones of dimedone and barbituric acid exhibited better activity against catalase enzyme. Correlations between the structure of the synthesized hydrazones and their antioxidant activity have been defined. Graphical abstract: .