Mannich bases

Mannich bases of sparfloxacin were synthesized from the reaction of 5-acetylamino-1-cyclopropyl-7-(3΄,5΄-dimethyl-piperazin-1-yl)-6,8-difluoro-4-oxo1,4-dihydro-quinoline-3-carboxylic acid with formaldehyde and several isatin derivatives. The structures of the synthesized compounds were elucidated from the IR, 1H NMR, 13C NMR and FAB Mass data. The synthesized compounds were evaluated for the antibacterial, antitubercular and anticancer activity. The compounds showed good activity against Gram-positive bacteria and moderate activity against tested Gram-negative bacteria. The MIC for the compounds against M. tuberculosis H37Rv strain was 50 µg/mL. The most potent compound in this series 3c exhibited enhanced antibacterial activity than sparfloxacin against S. aureus, Bacillus Sp while the anticancer activity was in the range of 18.31- 23.61 µg/mL.

Three novel Mannich bases 5-[(4-chlorophenyl)-(4-methylpiperazin-1-yl)-methyl]-pyrimidine-2,4,6-trione :CBzBAPz(NM), 5-[(4-nitrophenyl)-(4-methylpiperazin-1-yl)-methyl]-pyrimidine-2,4,6-trione: NBzBAPz(NM) and 5-[(phenyl)-(4-methylpiperazin-1-yl)-methyl]-pyrimidine-2,4,6-trione: BzBAPz(NM) are prepared by the condensation of N-methyl piperazine with p-chlorobenzaldehyde / p-nitro benzaldehyde / benzaldehyde and barbituric acid and  characterized by physico-chemical,  spectroscopic, and powder X-ray diffraction studies. Further, Cu (II), Cd (II) and Pd (II) complexes of titled ligands are synthesized and characterized. Based on the experimental results, the chelating (bidentate) behavior of the ligands is accessed. The X-band e.p.r.spectrum, electrochemical studies of the Cu (II) complex have been carried out and discussed. Three novel Mannich bases and their complexes exhibit comparable potential cytotoxicity against breast cancer cell line (MCF-7), particularly, strong cytotoxicity is observed in the case of palladium. Morphological features of cells used for the study is photographed. Use of fluorochromesacridine orange and ethidium bromide reveals apoptotic morphological features.

  The most significant synthesis of isoindoles (phthalimides) is the dehydrative condensation of phthalic anhydride at high temperature with primary amines (adenine). Novel isoindole analogues with adenine can be synthesized through condensation of phthalic anhydride or substituted phthalic anhydride and purine (adenine). In this study only one type of isoindole analogues (phthalimides) were synthesized using mono bromo phthalic anhydride with primary amine (adenine). Different Mannich bases of isoindole analogues were synthesized using various types of aliphatic amines with variable yields (60- 80%). These Mannich bases were identified and confirmed by FT-IR, NMR and elemental analysis. The antimicrobial assay of these synthesized analogues was tested against H. pylori, E. coli, P. auroginosa, S. typhi, B. subtilis, B. threogensis, S. aureus, MRSA, A. niger, and were found to be active at Minimum Inhibitory Concentration [MIC] range of 125-1000 µg/ml. The most active compounds in the series was S-3 which has shown antibacterial activity against H. pylori at MIC of 125 µg/ml. This compound was identified as lead compounds and further molecular modification is in progress.