The role of the arylidene linkage on the antimicrobial enhancement of new tert-butylcyclohexanone-based polyketones

Abstract

Six promising biologically active polymers based on a 4-tert-butylcyclohexanone moiety have been synthesized through the Friedel–Crafts reaction as new polyketone derivatives. The polymerization occurred by the interaction of three different arylidene-based monomers, with adipoyl and sebacoyl diacid chlorides. The role of such arylidene linkages on the overall performance of these new polyketones was investigated with a special attention to its antimicrobial enhancement probability. The resulting polyketones were characterized by common characterization techniques including solubility, FTIR, X-ray diffraction, and morphological properties. The thermal properties of all the resulting polyketones were evaluated using TGA and associated with their structural units. The PDTmax results indicated that all the polymers had almost similar PDTmax patterns, which appeared in the range from 440 to 630 °C. The biological activity of all the synthesized polyketones was examined and showed that most of the synthesized polyketones had antibacterial activity against microbial strains. The role of the arylidene linkage on the antimicrobial enhancement of these new polyketone derivatives was also evaluated. The tested polyketones showed significant activity against most microbial strains, and the maximum activity was observed against E. coli and P. Aeruginosa. Polymer 5b showed the maximum inhibition zone of 13 mm amongst the other polymers. Furthermore, the tested polyketones showed no significant activity against B. subtilis or the fungus C. albicans. Furthermore, molecular docking studies were applied to all polymers with the “5FSA” protein, and the results have been investigated. Polymer 5b also showed the highest docking score of − 5.84 kcal/mol. Therefore, polymer 5b was classified as a promising biologically active polymer.