ABSTRACT

The present study describes the synthesis, full characterization and biological evaluation of novel azetidinonyl/formazonyl/thiazolidinonylphenothiazines. The synthesis of these compounds as potential anti-inflammatory agents was carried out using a more efficient and versatile synthetic route. Various 4-substituted phenyl-1-(10’-acetylaminophenothiazinyl)-azetidin-2-ones (9-13), 1-(10’-acetyliminophenothiazinyl)-3-substituted phenyl formazans (14-18) and 3-(10’- acetylamino-phenothiazinyl) -2-substituted phenyl-4-thiazolidinones (19-23)  were synthesized by reacting 10-(various substituted phenylmethyleneimino) aminoacetylphenothiazines (4-8) with triethylamine / acetyl chloride, benzene diazonium chloride and thioglycolic acid / anhydrous zinc chloride, respectively. The structures of these compounds have been interpreted by elemental (C, H, N) and spectral (I.R., 1 H-NMR and mass) analysis. All the compounds were evaluated for their anti-inflammatory activity using rat paw oedema inhibition test and were compared with standard drugs. These compounds were also screened for acute toxicity studies. Compound 22 was the most potent compound of the series, exhibiting 82.44% oedema inhibition, interestingly more potent than the standard drug - phenylbutazone. All compounds showed ALD50 > 1000 mg kg -1 p.o. except compound 22, which exhibited ALD50 > 2000 mg kg -1 p.o.