Synthesis of Known and New 8-Hydroxyquinoline Mannich Bases and Determination of Their Significant Biological...

Use of 10 different combinations of aldehydes and amines to carry out the Mannich reaction on 8-hydroxyquinoline generated 11 compounds including Mannich bases and imines, 6 of which are new while 5 are known. Their structures were characterized by mass spectroscopy, ¹HNMR, ¹³CNMR including 2D, IR, and EI analysis. Upon screening for their antimicrobial activities, oxidative burst (of whole blood phagocytes, isolated neutrophils and macrophages), on T-cell proliferation, antioxidant and cytotoxic activities, compound 4 (7-[α-(2″,5″-dichloroanilinobenzyl]-8-hydroxyquinoline) a new Mannich base, was found to possess antimicrobial property, immunomodulating potential on chemiluminescence assays, suppressed T-cells and exhibited no cytotoxicity. This novel compound upon in vivo histopathological examination on BALB/c mice showed unaffected kidneys at any of the tested concentration (1.3, 6.67, 33.33, and 166.67 mg/kg), while at different concentrations were found to be cardio-toxic and hepatotoxic. Furthermore, molecular docking simulations determined the probable binding modes of these compounds to their targets.