Kaumil Navnitbhai Modi, Palakben K. Parikh, Hiren M. Marvaniya, Dhrubo Jyoti Sen
Kaumil Navnitbhai Modi*, Palakben K. Parikh, Hiren M. Marvaniya and Dhrubo Jyoti Sen
Department of Pharmaceutical Chemistry, Shri Sarvajanik Pharmacy College, Gujarat Technological University, Arvind Baug, Mehsana-384001, Gujarat, India,
Volume - 4,
Issue - 5,
Year - 2011
9-methyl-1,5-diphenyl-3H,7H- pyrazolo-[1,2-a][1,2,4,6]-tetrazepine-3,7-dione ring system has been synthesised by the reaction between hydrazine and ethyl acetoacetate produced pyrazolone moiety which on benzoylation produced dibenzoyl derivative which on condensation with urea produced 9-methyl-1,5-diphenyl-3H,7H- pyrazolo-[1,2-a][1,2,4,6]-tetrazepine-3,7-dione ring which on alkaline oxidation with KMnO4/KOH produced carboxylic moiety. Treatment with thionyl chloride of produced acid chloride derivative. This on condensation with Mannich base produced by benzaldehyde with urea/thiourea/guanidine produced the desired moiety.
The synthesised compounds were characterised by N% and spectral datas and antimicrobial and antifungal screening has been performed by zone of inhibition studies and MIC calculation with standard antibiotic/antifungal drug against (gram+ve) and (gram–ve) bacterial and fungal strains on agar media after 24 hours incubation at 37°C for antimicrobial activity and 24°C for antifungal activity. Gram positive: Staphylococcus aureus ATCC 9144, Bacillus subtilis ATCC 6633, Gram negative: Escherichia coli ATCC 25922, Fungal strain: Candida albicans ATCC 10231
It has been observed that the Compound-2 (X=S) showed maximum antibacterial activity against Escherichia coli, Compound-1 (X=O) and against Bacillus subtilis and Compound-1 (X=O) and against Staphylococcus aureus. Oxygen and Sulphur has two lone pairs whereas Nitrogen has one lone pair of electrons but the electronegativity of Oxygen (X=O; 3.5), electronegativity of Sulphur (X=S; 2.4) and electronegativity of Nitrogen (X=N+H; 3.1+2.2=5.3). MIC value of all the compounds have been found as 250µg as Minimum Inhibitory Concentration by serial dilution method and MIC of Cloxacillin is 250µg and for Fluconazole is 5.5µg.
Cite this article:
Kaumil Navnitbhai Modi, Palakben K. Parikh, Hiren M. Marvaniya, Dhrubo Jyoti Sen. Structure Activity Relationship Studies of Substituted Mannich Bases of Pyrazolo [1, 2-A][1,2,4,6]-Tetrazepine-3,7-Dione Ring System with Variable Electronegative Atoms (Urea/Thiourea/Guanidine) for Antimicrobial and Antifungal Activity. Asian J. Research Chem. 4(5): May, 2011; Page 838-844.