Abstract

MANNICH BASES OF 7-HYDROXY COUMARINS AND THEIR BIOLOGICAL ACTIVITY

Touseef Begum*, Tasneem Mohammed, Suroor A. Khan

ABSTRACT

A novel series of coumarin Mannich bases (II i-x) have been synthesized by reacting 7-hydroxy-4-methyl-2H-chromen-2-one (I) with various substituted secondary amines (II i-x) in presence of formaldehyde. The structures of the newly synthesized compounds were characterized by IR, 1H NMR, and MASS data. Title compounds were screened for acute anti-inflammatory activity using the carrageenan-induced rat paw edema assay model. Most active compounds were also tested for their ulcerogenic activity. Among the compounds tested, 7-hydroxy-8-{[(4-methylphenyl)amino]methyl}-4- methyl-2H-chromen-2-one (ii), 7-hydroxy-8-{[(4- methoxylphenyl)amino]methyl}-4-methyl-2H-chromen-2-one (ix) and 7-hydroxy-8-{[(2-bromo-4,6-dinitrophenyl)amino]methyl}-4-methyl-2H-chromen-2-one (x) showed 71.24 , 62.53% and 62.24% inhibition, respectively after 1hr as compared to the standard drug Indomethacin (54.62%). These potent compounds showed reduction in ulcer. However, Compounds IIii, IIix and IIx, would be good candidates for lead molecules for antiinflammatory activity with a larger margin of safety.

Keywords: Coumarins, Anti-inflammatory activity, Ulcerogenic activity, Mannich bases.