Biologically active Mannich bases derived from nitroxoline

A series of compounds with various basic side chains were derived from 5-nitro-8-hydroxyquinoline (nitroxoline). Aminomethylation of nitroxoline led exclusively to the formation of o-substituted phenolic Mannich bases. Depending on the kind of the primary or secondary amine participating in the Mannich reaction differently substituted compounds were prepared in order to study the influence of the basic side chain on their biological activity. The compound with N-bis(2-hydroxyethyl)amino group exhibited the highest mitodepressant activity determined in a phyto test on Lepidium sativum L. Preliminary test for antibacterial and antifungal activities using standard test microorganisms indicate rather strong antimicrobial properties of several synthesized compounds.