Design of new hybrid template by linking quinoline, triazole and dihydroquinoline pharmacophoric groups: A greener approach to novel polyazaheterocycles as cytotoxic agents.

A new hybrid template designed by linking three pharmacophoric groups, for example, quinoline, triazole and dihydroquinoline moieties have been used for the generation of a library of molecules as potential cytotoxic agents. Synthesis of these polyazaheterocycles were carried out by using a strategy that involved one-pot sequential azidation and CuAAC in water under mild conditions. A number of 1,4-disubstituted 1,2,3-triazoles possessing quinolinylmethylene at N-1 and 1,2-dihydroquinolinyl methylene at C-4 as different substituents were synthesized and evaluated for their cytotoxic effects against various cancer cells. Some of them showed encouraging activities against lung cancer cells and one of them showed inhibition of PDE4 indicating the potential medicinal value of these novel polyazaheterocycles.

Synthesis of 2,2,4-trimethyl-1,2-dihydroquinolinyl substituted 1,2,3-triazole derivatives: their evaluation as potential PDE 4B inhibitors possessing cytotoxic properties against cancer cells.

The 2,2,4-trimethyl-1,2-dihydroquinolinyl substituted 1,2,3-triazole derivatives were designed as potential inhibitors of PDE4B. These compounds were synthesized via a multi-step sequence consisting of copper-catalyzed azide-alkyne cycloaddition (CuAAC) as a key step in aqueous media. The required alkynes were prepared from nimesulide via N-propargylation and then nitro group reduction followed by a CAN mediated modified Skraup reaction of the resulting amine. All the synthesized compounds showed PDE4B inhibitory properties in vitro at 30µM with two compounds showing >50% inhibition that were supported by the in silico docking results of these compounds at the active site of PDE4B. Three of these PDE4 inhibitors showed promising cytotoxic properties against A549 human lung cancer cells in vitro with IC50 ∼8-9µM.

Evaluation of critical nutritional parameters and their significance in the production of rhamnolipid biosurfactants from Pseudomonas aeruginosa BS-161R.

Eleven biosurfactant producing bacteria were isolated from different petroleum-contaminated soil and sludge samples. Among these 11 isolates, two were identified as promising, as they reduced the surface tension of culture medium to values below 27 mN m(-1) . Besides biosurfactant production property, they exhibited good flocculating activity. Microbacterium sp. was identified as a new addition to the list of biosurfactant and bioflocculant-producers. Optimization of various conditions for rhamnolipid production was carried out for one of the promising isolate, Pseudomonas aeruginosa BS-161R. Bioglycerol (2.5%), as a cheap renewable carbon source, attained better rhamnolipid yield, while sodium nitrate appeared to be the preferable nitrogen source. The optimum carbon to nitrogen (C/N) and carbon to iron (C/Fe) ratios achieved were 15 and 28,350, respectively, which favored rhamnolipid production. Physical parameters like pH, temperature, and agitation speed also affected the production of rhamnolipids. Results from shake flask optimization indicated that the concentration of bioglycerol, sodium nitrate, and iron were the most significant factors affecting rhamnolipid production, which was supported by the results of central composite rotatable design. After optimization of the culture conditions, the production of rhamnolipids increased by ninefold from 0.369 to 3.312 g L(-1) .