No abstract

Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

Azo dyes are the main group of dyes used in different industrial applications. These dyes are highly toxic for aquatic life, so their removal is of utmost importance before they can be disposed of in a main water body. The present study focused on degrading/mineralizing the synthetic reactive dye wastewater. Initial experiments were done with four indigenous white rot fungi. P. chrysosporium (PC) showed more potential toward degradation of synthetic dye wastewater than other three fungal strains, so it was selected for further optimization of different fermentation parameters. Maximum decolorization (84.8%) of reactive dye wastewater was obtained at pH 5, inoculum size 4 mL, and 30ºC. After optimizing experimental parameters, the effects of different nutritional factors like carbon and nitrogen sources were also studied. Decolorization of synthetic dye wastewater was increased from 84.8 to 89.2%, when rice bran was used as an additional carbon source. However, no increase in decolorization of synthetic dye wastewater was observed in the presence of nitrogen supplements. The screened fungal strain decolorized the wastewater up to 90%. The effect of different nutritional factors enhanced the degradation capability of the fungal strain under study. UV-visible and FTIR analyses confirmed the degradation of synthetic dye wastewater into simpler, non-toxic products.

No abstract

In this study Cu-chitosan nanoparticles (Cu-CNP) have been employed as eco-friendly and safer priming agents to induce salt and PEG-induced hyperosmotic stress tolerance in wheat seedlings. Seed priming is a facile on-farm stress management technique that requires a little amount of priming agent and minimizes the eco-toxicological effects on soil fertility. The wheat seeds were primed with 0.12% and 0.16% Cu-CNP for eight hours and were allowed to germinate under normal, PEG-induced hyperosmotic stress (15% PEG-6000  – 3.0 Mpa) and salt stress (150 mM). For comparison, non-primed and hydro-primed seeds were also allowed to germinate as control under the same conditions. The biochemical analyses suggested the priming treatments enhanced the POD activity under salt stress but it was decreased under PEG-induced hyperosmotic stress. Priming with 0.12% Cu-CNP induced a significant increase in CAT while the opposite effect was observed in 0.16% treated seedling under stress and non-stress conditions. Both priming treatments did not allow the over-expression of SOD under both stress conditions. The total phenolic contents were also decreased significantly under all conditions. Except for priming with 0.16% Cu-CNP under PEG-induced hyperosmotic stress, a suppression in MDA was observed under both stress conditions. Surprisingly, the Cu-CNP priming induced a significant increase in β-carotenoids, total carotenoids, chlorophyll a, b and total chlorophyll under normal and stress conditions. In conclusion, the controlled expression of enzymatic antioxidants, low contents of non-enzymatic antioxidants and suppression of MDA mirror the stress mitigating role of Cu-CNP against PEG-induced hyperosmotic stress and salinity. The stress-insulating potential has also been reinforced by the enhanced production of plant and photosynthetic pigments. All these priming-induced biochemical changes produced positive effects on growth and germinating parameters in wheat seedlings under PEG-induced hyperosmotic stress as well as salinity.