6-Amino-2,4-lutidine carboxamides: α-aminoamide derivatives as systemic and topical inflammation inhibitors

Article abstract of DOI:10.1016/S0223-5234(98)80022-6

The development of new potential anti-inflammatory compounds resulting from the incorporation of α-aminoacid residues into 6-amino-2,4-lutidine afforded (N-protected) aminoamides with interesting inhibitory activity. Out of 28 tested compounds, 10 (5a, 5b, 7d, 8a, 8b, 8d, 10a, 11b, 12a and 12b) exerted potent (> 90%) inhibition in the carrageenan foot edema (CFE) rat model after oral administration or 0.4 mmol kg^-1. Except for Cbz-glycyl, Cbz-alanyl, Fmoc-valyl and Cbz-alanyl-glycyl derivatives (5a, 5b, 7d and 11b), N-deprotection afforded more active compounds. Introduction of a glycyl residue in the previously studied highly active 3-fluorobenzamide 2, which led to 10a, maintained potent peripheral edema inhibition but had a detrimental effect in the acute TPA-induced mouse ear-swelling model. Glycylglycinamide 12a, which had an ID₅₀ of 9.0 mg kg^-1 in the CFE test, appeared to be the most efficient compound tested in this new series of non-carboxylic nonsteroidal anti-inflammatory drugs. Glycinamide 8a, although less potent in the same assay (14.3 mg kg^-1), exerted a significant inhihitory effect in acute and chronic ear-swelling tests after topical application of 3 mg/ear.