Asian Journal of Green Chemistry
Volume:4 Issue: 4, Autumn 2020

In this research study, stability, chemical properties, and thermodynamic parameters nano-derivatives of the cytarabine with the fullerene C60 nanostructure were calculated in the range of 298.15-310.15 K at the B3LYP/6-31G* level of theory. Possible isomers of the cytarabine (four different configurations) with C60 molecule were considered, and the effect of temperature on the thermodynamic parameters was studied. The adsorption energy, Gibbs free energy changes (ΔGad), enthalpy (ΔHad) variations, thermodynamic equilibrium constant, specific heat capacity, chemical hardness, energy gap, and electrophilicity were evaluated, as well. The results indicated that the adsorption of the cytarabine with fullerene C60 is spontaneous. In addition, the calculated specific heat capacity values revealed that, the C60 can be utilized as a sensing material in the construction of thermal biosensors for cytarabine determination.

To make the biodiesel competitive with petroleum diesel, cheap and abundant materials can be utilized as a catalyst and waste oils can be used as resources. In this research study, the potential of waste chicken eggshells was used as a catalyst to produce biodiesel from the rendered chicken fats (RCF). The calcium methoxide catalyst was prepared by calcining the waste eggshells at 900 °C in air for 4 h followed by treatment with methanol under reflux condition. The physico-chemical properties of the prepared catalyst were characterized using the X-ray diffraction (XRD) analysis, Brunner-Emmet-Teller (BET), field emission scanning electron microscopy (FE-SEM), and temperature programmed desorption of carbon dioxide (CO2-TPD). Two-step process including, esterification and transesterification were employed to convert the RCF to fatty acid methyl ester (FAME). Esterification pretreatment with ferric sulfate successfully reduced 75.1% of the FFA content in RCF which enables high biodiesel production. Under the optimal reaction condition, the highest conversion of biodiesel was found to be 90.04% at 1:15 oil to methanol molar ratio, 3 wt% catalyst loading, and 2 h reaction time at 65 °C. The catalyst was successfully used for 4 consecutive cycles with less than 2 mg/kg of Ca was detected in the product.

Ethyl methyl imidazolium hydroxide [EMIM][OH] ionic liquid catalyzed green protocol was developed for efficient and one-pot three-component condensation of various aromatic aldehydes, malononitrile, and dimedone under microwave irradiation for the synthesis of tetrahydrobenzo[b]pyran derivatives. The reaction proceeds in a short time period to afford moderate to excellent yield of products. The ionic liquid was recycled and reused for multiple time significantly, without a change in its catalytic efficiency.

In this work, mesoporous MCM-41 nanoparticles (MCM-41NPs) were synthesized using the rice husk ash (RHA), as the silica source at room temperature. Ag2O quantum dots were prepared using a chemical method in matrix nanoparticles, and used as an antibacterial material. Bactericidal activity of the nanomaterials was investigated against E. coli and S. aureus bacteria. The synthesized materials were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscope (TEM). The minimum concentrations of nanocomposite to inhibit the growth of E. coli and S. aureus strains were 12.5 µg/mL. The Ag2O quantum dots indicated acceptable antimicrobial properties, with an average diameter of 16 mm.

Carbon nanotubes (CNTs) have been extensively explored for adsorption applications due to their well-defined cylindrical hollow structure, large surface area, high aspect ratios, hydrophobic wall, and easily modified surfaces. In the present work, a poly Schiff-base was synthesized with capability to remove the dye pollutant from aqueous solutions. For this propose, firstly, multi-walled carbon nanotube (MWCNT) was modified with melamine, then the melamine-modified MWCNT was further reacted with 3-pyridinecarboxaldehyde to synthesize the final poly Schiff-base. The prepared adsorbent was employed to assess the removal of the dye pollutants from aqueous solutions and Congo red (CR) was selected as typical dye. Different adsorption parameters such as pH, adsorbent amount, initial concentration of the dye, and contact time were investigated and optimized. By adjusting these parameters, the adsorption percentage reached to the value of 92%. Moreover, the adsorption isotherms were studied and fitted with the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. The kinetic studies were carried out by using the Lagergren pseudo-first-order and the Ho pseudo-second-order equations. The adsorbent was also characterized by FT-IR, TGA, and SEM techniques.

The development of novel compounds, hydrazones have shown that they possess a wide variety of biological activities. Hydrazones/azomethines/imines possess   -NHN=CH- and constitute an important class of compounds for new drug development. We have undertaken a library synthesis of (1H-benzo[d][1,2,3]triazole-5-yl)(phenyl) methanone clubbed 1,3,4-oxadiazole derivatives bearing substituted hydrazone moiety were synthesized. We have synthesized a collection of 14 compounds and characterized by elemental analysis, MS, 1H NMR, and 13C NMR spectral data and were screened, against the anticancer and antituberculosis activity. Where the majority of these compounds showed good anticancer and antitubercular activities against the tested strains of M. tuberculosis H37Rv and lung NCI H-522, ovary PA-1, liver Hep G2 compared with the reference drugs. Compounds 5d, 5e, 5g, and 5n showed excellent potency against M. tuberculosis H37Rv strain compares to standard drugs whereas, against lung NCI H-522 cancer cell lines compounds 5e, against ovary PA-1 cancer cell line compound 5i, and against liver Hep G2 cell line compound 5n showed excellent activity compared to standard drug thus, these studies suggest that (1H-benzo[d][1,2,3]triazol-5-yl)(phenyl)methanone clubbed 1,3,4-oxadiazole derivatives bearing hydrazone moiety are interesting scaffolds for the development of novel antitubercular and anticancer agents.

Optimized desublimation of 2,4-diaminotoluene (4-methylbenzene-1,3-diamine) formed its ultrapure crystals. The collected crystals were analyzed by X-ray crystallography and then directly consumed in a condensation reaction with paraformaldehyde that resulted in the formation of Hünlich’s base. The subsequent one-pot diazotization and coupling reactions produced a new bisazo analog of Tröger’s base in the maximum possible compliance with the principles of green chemistry. The obtained bisazo product was found to be a durable and affordable building block suitable for use in the design of light-driven molecular machines.

Maize is one of the most important agricultural commodities in the world and the third most traded cereal after wheat and rice. Maize contaminated with mycotoxin causes a fundamental problem all over the world. In this study, we assessed the risk of mycotoxin and its management. Mycotoxins are toxic secondary metabolites of fungi that may contaminate the food crops. There are several mycotoxins in crops; however, aflatoxins (produced by Apergillus flavus) and fumonisins (primarily produced by Fusarium verticillioides) are the major concern in maize-based food and feed worldwide. Aflatoxins are hepatotoxic and carcinogenic agents. They are associated with human liver cancer, child growth impairment, and acute toxicoses. Fumosinin may cause esophaseal cancer and neural tube defection in humans, whereas in livestock effects are variable; reproductive disorder, pulmonary edema in swine, leukoencephalomalacia in equines, and reduced feed intake. Management approaches of mycotoxins include cultural and genetic approaches. Cultural practices such as plant quarantine, phytosanitary measures during harvesting and post harvest, and management of insect pest are essential for avoiding contamination of mycotoxin. Development of maize varieties resistant to fungal infection contributes to grow mycotoxins-free maize. Moreover, chemical removal, physical binding or microbial detoxification can be done to avoid mycotoxins contamination. The eating mycotoxins contaminated maize grain was found to be harmful to human and livestock health.Therefore, awareness program on adverse effects of mycotoxins should be provided to public so that the people can be confident that the food they consumed is safe.

In the present study, we have accomplished N,N’-dimethyl formamide (DMF)/trichloroisocyanuric acid and DMF/trichlorotriazine as efficient catalysts for the synthesis of 3,4-dihydropyrimidinones/thiones from one-pot multi-component reaction of β-ketoester, aromatic aldehydes, and urea under reflux condition. The reaction operates also under solvent free microwave condition. The results obtained from this study were compared with those obtained from classical Vilsmeier-Haack adducts (DMF/POCl3 and DMF/SOCl2) as catalysts. Reaction times and product yields observed in this study indicated shorter reaction times and better product yields with modified VH reagents (TCCA/DMF and TCTA/DMF) over classical VH reagents (POCl3/DMF and SOCl2/DMF). The catalytic activity of (TCTA/DMF)>(TCCA/DMF)>(POCl3/DMF>SOCl2/DMF).

In last decades, many efforts have been made to commercialize the silicon (Si) as anode material with a capacity of ten times higher than that of conventional graphite anode to enhance the energy and power density of the state of the art lithium-ion batteries (LIBs). However, the Si anodes suffer from large volume expansion during the charge/discharge process and continuous formation breaking reformation process of solid electrolyte interface (SEI) layer that may cause poor cycle life, hindering the commercialization of the Si anode. Various strategies have been used to overcome the above-mentioned problems, and one of those strategies is the use of the functional electrolyte additives. Among these additives, fluoroethylene carbonate (FEC) has been known as the most effective additive for the Si-based LIBs. This was found to be attributed to the ability of this compound to form a robust and stable SEI layer on the Si surface. This review comprehensively studies the diverse additives used in Si-based LIBs in last years.