Preparation of a novel environmentally friendly hydrophobic deep eutectic solvent ChCl-THY and its application in removal of hexavalent chromium from aqueous solution.

A liquid-liquid extraction methodology was developed for the removal of Cr(VI) from contaminated water using a novel green hydrophobic deep eutectic solvent (DES) as an efficient sole extracting agent. The hydrophobic DES was obtained by mixing choline chloride and thymol in 1:4 molar ratio at 70°C for 10 min and was denoted as ChCl-THY(1:4). The ChCl-THY(1:4) works efficiently for removal of high (20 mg/L) and low (500 µg/L) concentration of Cr(VI) from artificially contaminated natural water with >95% extraction efficiency (E%) at optimized reaction conditions (pH 2-6, 40°C). The DES was characterized by 1 H NMR and FTIR spectroscopy, and the data suggest that interaction occurs between Cl- ion of choline chloride and H atoms of thymol molecules. Physicochemical properties such as density, melting point, moisture, and solubility were studied and discussed. Herein, no sharp melting point was observed for ChCl-THY(1:4) in DSC curve. DES was regenerated using 0.1 M NaOH as stripping agent, and 50%-60% extraction efficiency could be attained in the next cycle. A plausible mechanism of interaction between Cr(VI) species and DES was also explored with the help of FTIR spectroscopy. PRACTITIONER POINTS: A novel hydrophobic DES (ChCl-THY) is prepared by mixing choline chloride and thymol at 1:4 molar ratio. ChCl-THY(1:4) is employed for the first time as sole extracting agent to remove the Cr(VI) from contaminated aqueous solution. >95% extraction efficiency was achieved by ChCl-THY(1:4) in natural water conditions at µg/L and mg/L level of contamination. Both the component used to prepare the DES are naturally abundant; hence, DES is not toxic for biota. The element present in natural water did not show any interference with extraction of Cr(VI).

Advances in developing small molecule SARS 3CLpro inhibitors as potential remedy for corona virus infection.

Originated in China, coronavirus disease 2019 (COVID-19)- the highly contagious and fatal respiratory disease caused by SARS-CoV-2 has already infected more than 29 million people worldwide with a mortality rate of 3.15% (according to World Health Organization's (WHO's) report, September 2020) and the number is exponentially increasing with no remedy whatsoever discovered till date. But it is not the first time this infectious viral disease has appeared, in 2002 SARS-CoV infected more than 8000 individuals of which 9.6% patients died and in 2012 approximately 35% of MERS-CoV infected patients have died. Literature reports indicate that a chymotripsin-like cystein protease (3CLpro) is responsible for the replication of the virus inside the host cell. Therefore, design and synthesis of 3CLpro inhibitor molecules play a great impact in drug development against this COVID-19 pandemic. In this review, we are discussing the anti-SARS effect of some small molecule 3CLpro inhibitors with their various binding modes of interactions to the target protein.

A Low-Cost, Well-Designed Catalytic System Derived from Household Waste "Egg Shell": Applications in Organic Transformations.

A waste feedstock-derived economical basic alternative catalyst is described in this review. Eggshell is one of the household wastes created in tons of weight daily. Therefore, in order to reduce the environmental pollution-related problems, its use in heterogeneous catalysis can be attributed as a great contribution for the chemical and material science society to carry out several known reactions and for the much-needed energy alternative biodiesel production as low-cost catalytic system. Keeping green chemistry in mind, industrial use of these catalysts may also reduce the use of other traditionally used high-cost chemical catalytic systems.