Cu/TEMPO catalyzed dehydrogenative 1,3-dipolar cycloaddition in the synthesis of spirooxindoles as potential antidiabetic agents.

A series of spiro-[indoline-3,3'-pyrrolizin/pyrrolidin]-2-ones, 4, 5 and 6 were synthesized in a sequential manner from Cu-TEMPO catalyzed dehydrogenation of alkylated ketones, 1 followed by 1,3-dipolar cycloaddition of azomethine ylides decarboxylative condensation of isatin, 2 and l-proline/sarcosine, 3 in high regioselectivities and yields. The detailed mechanistic studies were performed to identify the reaction intermediates, which revealed that the reaction proceeds dehydrogenative cycloaddition. Additionally, the regio and stereochemistry of the synthesized derivatives were affirmed by 2D NMR spectroscopic studies.

Facile Synthesis of 2-Acylthieno[2,3-]quinolines via Cu-TEMPO-Catalyzed Dehydrogenation, sp-C-H Functionalization (Nucleophilic Thiolation by S) of 2-Haloquinolinyl Ketones.

An efficient, solvent-free synthesis of 2-acylthieno[2,3-]quinolines is reported from 2-halo-quinolinyl ketones through Cu-TEMPO catalyzed dehydrogenation, sp-C-H functionalization using elemental sulfur as thiol surrogate (sulfur source) and tetrabutylammonium acetate as an ionic reaction medium. The optimized reaction conditions give excellent product yields under mild reaction conditions with chemoselectivity and broad functional group tolerance. The synthetic importance of the synthesized molecules is showcased further by Friedländer annulation, reduction, and alkene functionalization reactions.

On water catalyst-free synthesis of benzo[]imidazo[2,1-] thiazoles and novel -alkylated 2-aminobenzo[]oxazoles under microwave irradiation.

A highly efficient unprecedented catalyst-free microwave-assisted procedure for synthesizing benzo[]imidazo[2,1-]thiazoles and -alkylated 2-aminobenzo[]oxazol in green media was developed. The transformation provided rapid access to functionalized benzo[]imidazo[2,1-]thiazoles from 2-aminobenzothiazole and -alkylated 2-aminobenzo[]oxazole from 2-aminobenzoxazole scaffolds under mild transition-metal-free conditions. This synthetic manipulation is expected to greatly expand the repertoire of reaction types in heterocyclic chemistry and pave the way for new syntheses of bioactive compounds.

Evolutionary approaches in protein engineering towards biomaterial construction.

The tailoring of proteins for specific applications by evolutionary methods is a highly active area of research. Rational design and directed evolution are the two main strategies to reengineer proteins or create chimeric structures. Rational engineering is often limited by insufficient knowledge about proteins' structure-function relationships; directed evolution overcomes this restriction but poses challenges in the screening of candidates.

Luminescent bis(benzo[]thiazolyl)quinoxaline: facile synthesis, nucleic acid and protein BSA interaction, live-cell imaging, biopharmaceutical research and cancer theranostic application.

A series of quinoxaline-2-hydroxyphenylbenzothiazole scaffolds were synthesized and characterized using NMR, UV, fluorescence spectroscopy and LCMS. These newly synthesized compounds were found to be cytotoxic in human epithelioid cervix carcinoma (HeLa) and human colon cancer cell lines (Caco-2). Selectivity of the compounds 7e and 7g are more than 9 fold higher in Caco-2 cells with respect to the normal cell line HEK-293.

Efficiency of brown seaweed () polysaccharides encapsulated in nanoemulsion and nanostructured lipid carrier against colon cancer cell lines HCT 116.

Bioactive polysaccharides extracted from brown seaweeds have potent antioxidant, antitumor, antibacterial, antiviral, anti-inflammatory activities and nanomedicine applications. In the present study, we have made an attempt to overcome the instability and bioavailability problem of exopolysaccharides extracted from brown seaweed () by nanoencapsulation technology to enhance its therapeutic applications. Exopolysaccharides was encapsulated in orange oil nanoemulsion (NE) prepared by ultra-sonication method and nanostructured lipid carrier (NLC) prepared by hot solvent diffusion method.