Isatin

A novel tridentate chelating ligand, (2Z,2Z)-3,3-dimethyl-2-(2-(2-oxoindolin-3-ylidene)hydrazono)butanoic acid and its Co(II), Ni(II), Cu(II) and Zn(II) complexes were synthesized and characterized by elemental analyses, spectral (vibrational, electronic, 1H NMR, 13C NMR and mass) and thermal studies. The interaction of ligand and complexes with calf-thymus DNA (CT-DNA) has been extensively studied using absorption, emission, viscosity and thermal denaturation studies with E. coli DNA. The DNA cleavage ability of ligand and metal complexes were tested using plasmid pBR322 DNA by gel electrophoresis method.

Isatin is an endogeneous and an important class of heterocyclic compound. It possess indole nucleus having both keto and lactam moiety with a diverse pharmacological properties like antimicrobial, antitubercular, anticonvulsant activity etc. Isatin derivatives are synthetically important substrates, which can be used for the synthesis of a large variety of heterocyclic compounds, and as raw material for drug synthesis. Recently, isatin derivatives have attracted strong interest in organic and medicinal chemistry due to their potent biological and pharmacological activities. The purpose of this review is to provide information on the pharmacological activities of isatin and its derivative.

In the present study novel series of 3-((3-((6-benzoyl-1H-benz[d]imidazol-2-yl) amino)-5-mercapto-4H-1, 2, 4-triazol-4-yl)imino)substituted indolin-2-ones have been synthesized in good yields and characterized by IR, NMR and Mass spectral analyses. Compounds were evaluated for their preliminary in vitro cytotoxic activity against HCT-116 (colon), MCF-7 (breast), HeLa (cervical) and HepG2 (hepatocellular) cancer cell lines by standard MTT assay method, antioxidant activity by standard DPPH assay method and also were screened for  in vitro anti-inflammatory activity.

In the present study N-(2-oxosubstitutedindolin-3-ylidine)-2-phenylacetohydrazides (IV a-h) have been synthesized in good yields and characterized by IR, PMR and mass spectral analyses. Compounds were evaluated for their preliminary in vitro cytotoxic activity against HeLa cancer cell lines by standard MTT assay and also were screened for antioxidant activity by DPPH method. Our results shown that two of the analogues IVf and IVc  are potent antioxidant agents and IVb and IVg are potent cytotoxic agents.

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.

  Isatin is an important class of heterocyclic compounds. Recently, heterocyclic compounds analogues and their derivatives have attracted strong interest in medicinal chemistry due to their biological and pharmacological properties. The small and simple isatin nucleus possesses numerous biological properties like -antitumor, antimicrobial, anti-inflammatory, anticonvulsant, antiviral, anti HIV, antioxidant, CNS depressant activities. These activities are also possessed by its substituted derivatives as well. The present review outlines some commonly used procedures to synthesize the isatin moiety and its derivatives, with different biological activities.