Arindam Maity

Amberlite-IRA-402 (OH) ion exchange resin mediated synthesis of indolizines, pyrrolo [1,2-a] quinolines and isoquinolines: Antibacterial and antifungal evaluation of the products

A number of indolizines and pyrrolo[1,2-a]quinolines/isoquinolines were prepared from phenacyl pyridinium, quinolinium and isoquinolinium salts derived from the reaction of the heterocycles with 2-bromo acetophenone with alkynes and alkenes using amberlite-IRA-402 (OH) ion exchange resin as the base. Antibacterial and antifungal studies were carried out against thirteen bacterial and four fungal strains, which revealed that three derivatives (4a, 4b, 7a) out of fifteen are effective against all the thirteen strains and one derivative, 10, showed dual antibactericidal and antifungal efficacy.

Efficient synthesis of 3,3-diheteroaromatic oxindole analogues and their in vitro evaluation for spermicidal potential

Syntheses of 3,3-diheteroaromatic oxindole derivatives has been achieved by coupling indole-2,3-dione (isatin) with differently substituted indoles and pyrrole in presence of I(2) in i-PrOH. The in vitro spermicidal potentials and the mode of spermicidal action of the synthesized analogues were evaluated and the derivative, 3,3-bis (5-methoxy-1H-indol-3-yl) indolin-2-one (3d) exhibited most significant activity.

Cytotoxic potential of dispirooxindolo/acenaphthoquino andrographolide derivatives against MCF-7 cell line

Dispiro andrographolide derivatives have been prepared from isatin/acenaphthoquinone, N-benzyl glycine and andrographolide via azomethine ylide cycloaddition reaction. The cytotoxic effect of the synthesized molecules has been studied against MCF-7 breast cancer cell line. The compounds induced apoptotic cell death as revealed by increased labeling with Annexin-V, decreased polarization of cell mitochondria, and increased reactive oxygen species production. Using FACS and western blot analysis, the compounds were observed to block the cell cycle at S phase. Activation of caspases 7 and 9 suggested that caspase pathways were involved in inducing apoptosis.

Spermicidal and Contraceptive Potential of Desgalactotigonin: A Prospective Alternative of Nonoxynol-9.

Crude decoction of Chenopodium album seed showed spermicidal effect at MIC 2 mg/ml in earlier studies. Systematic isolation, characterization and evaluation revealed that the major metabolite Desgalactotigonin (DGT) is the most effective principle in both in vitro and in vivo studies. The in vitro studies comprises (a) rat and human sperm motility and immobilizing activity by Sander-Cramer assay; (b) sperm membrane integrity was observed by HOS test and electron microscopy; (c) microbial potential was examined in Lactobacillus broth culture, and (d) the hemolytic index was determined by using rat RBCs. The in vivo contraceptive efficacy was evaluated by intra uterine application of DGT in rat. Lipid peroxidation and induction of apoptosis by DGT on human spermatozoa were also studied. The minimum effective concentration (MEC) of DGT that induced instantaneous immobilization in vitro was 24.18 µM for rat and 58.03 µM for human spermatozoa. Microbial study indicated DGT to be friendly to Lactobacillus acidophilus. Implantation was prevented in DGT treated uterine horn while no hindrance occurred in the untreated contra lateral side. At the level of EC50, DGT induced apoptosis in human spermatozoa as determined by increased labeling with Annexin-V and decreased polarization of sperm mitochondria. Desgalactotigonin emerged 80 and 2×104 times more potent than the decoction and Nonoxynol-9 respectively. It possesses mechanism based detrimental action on both human and rat spermatozoa and spares lactobacilli and HeLa cells at MEC which proves its potential as a superior ingredient for the formulation of a contraceptive safer/compatible to vaginal microflora.

I2 catalyzed Friedel–Crafts alkylation reaction of substituted anilines with ninhydrin: formation of novel products and their antimicrobial evaluation

Friedel–Crafts reaction of differently substituted anilines with ninhydrin in the presence of molecular iodine at ambient temperature constitutes a facile, cost effective, and regioselective synthesis of a series of 2-mono/2,2-bis-(amino-phenyl)-indane-1,3-dione derivatives. Under identical conditions, use of different substituents in aniline ring led to the formation of different products, emphasizing the pivotal role of the nature and position of the substituents in product formation. In vitro antimicrobial activity evaluation of the synthesized molecules against eight bacterial and four fungal strains revealed that four of them possess duel efficacies (bactericidal as well as fungicidal). The activities are attributed to the disruption of architecture of the microbes as revealed from ultrastructural studies (SEM).Graphical Abstract

Palladium-Catalyzed 8-Exo Trig Intramolecular Heck Reaction Under Microwave Irradiation in the Presence of Basic Alumina

Abstract The Heck cross-coupling reaction has been employed for efficient conversion of quinolines to benzoxocinoquinoline through a microwave-assisted palladium-catalyzed intramolecular cyclization in the presence of basic alumina. GRAPHICAL ABSTRACT

Chenopodium album metabolites act as dual topoisomerase inhibitors and induce apoptosis in the MCF7 cell line

Desgalactotigonin (DGT) and oleanolic acid 3-O-β-D-glucuronide (OAG) were isolated from Chenopodium album seeds, characterized using spectral analysis and evaluated for cytotoxic activity against various cancer cell lines. DGT and OAG induced apoptosis in a human breast cancer cell line (MCF-7) and were found to effectively inhibit human topoisomerases I and II in vitro. The study of the mode of enzyme inhibition revealed that both acted as catalytic inhibitors. IC50 values for DGT and OAG on MCF-7 cells were found to be 8.27 μM and 11.33 μM respectively. Using FACS and western blot analysis, the compounds were observed to block the cell cycle at S phase. Activation of caspases 7 and 9 suggested that caspase pathways were involved in inducing apoptosis.