Thiazolyl and benzothiazolyl Schiff bases as novel possible lipoxygenase inhibitors and anti inflammatory agents. Synthesis and biological evaluation.

Several thiazolyl derivatives are reported to act as lipoxygenase inhibitors affecting inflammation and/or psoriasis. Two series of new thiazolyl and benzothiazolyl Schiff bases have been designed, synthesized and identified. RM values were determined as an expression of lipophilicity. The compounds were screened for their reducing activity (with the stable free radical 1,1-diphenyl-2-picrylhydrazyl DPPH), for radical scavenging activity (with the xanthine/xanthine oxidase system for O2.-) and for inhibition of soybean lipoxygenase (LO). Anti inflammatory activity was examined in vivo, using the carrageenin induced mice paw edema (24-71.8% inhibition was observed). The results are discussed in terms of structural and physicochemical characteristics of the compounds. Comparing the results among all tests, the benzothiazolyl derivatives seem to be more potent.