Fabrication of a magnetic Mn(ii) cross-linked chitosan-amine/glutaraldehyde nanocomposite for the rapid degradation of dyes and aerobic selective oxidation of ethylbenzene.

Owing to the great demand for using sustainable, renewable, and widely available materials in catalytic systems for the conversion of waste/toxic material to high value-added and harmless products, biopolymers derived from natural sources have demonstrated great promise as an alternative to state-of-the-art materials that suffer from high costs and limitations. These have encouraged us to design and fabricate a new super magnetization of Mn-Fe3O4-SiO2/amine-glutaraldehyde/chitosan bio-composite (MIOSC-N-et-NH2@CS-Mn) for advanced/aerobic oxidation process. The morphological and chemical characterization of the as-prepared magnetic bio-composite was assessed using ICP-OES, DR UV-vis, BET, FT-IR, XRD, FE-SEM, HR-TEM, EDS, and XPS techniques. The PMS + MIOSC-N-et-NH2@CS-Mn system was capable of degrading methylene orange (98.9% of removal efficiency) and selectively oxidizing ethylbenzene to acetophenone (conversion 93.70%, selectivity 95.10% and TOF 214.1 (103 h-1) within 8.0 min and 5.0 h, respectively. Moreover, MO was efficiently mineralized (TOC removal of ∼56.61) by MIOSC-N-et-NH2@CS-Mn with 60.4%, 5.20, 0.03 and 86.02% of the synergistic index, reaction stoichiometric efficiency, specific oxidant efficiency, and oxidant utilization ratio in wide pH ranges, respectively. An understanding of its vital parameters and relationship of catalytic activity with structural, environmental factors, leaching/heterogenicity test, long-term stability, inhibitory effect of anions in water matrix, economic study and response surface method (RSM) were evaluated in detail. Overall, the prepared catalyst could be employed as an environmentally friendly and low-cost candidate for the enhanced activation of PMS/O2 as an oxidant. Additionally, MIOSC-N-et-NH2@CS-Mn exhibited great stability, high recovery efficiency, and low metal leaching, which eliminated the harsh condition reaction and supplied practical application performance for water purification and selective aerobic oxidation of organic compounds.

Synthesis and characterization of a lactose-based biosurfactant by a novel nanodendritic catalyst and evaluating its efficacy as an emulsifier in a food emulsion system.

Nonionic lactose fatty acid esters are a class of synthetic biosurfactants with various uses in the food, pharmaceutical, personal care, and cosmetic industries. The objective of this research was the preparation and full characterization of a series of novel metallic encapsulated magnetic core/dendrimer shell composites as catalysts (CoII/MnII G2.0L1/2@SCMBNP) and their use in the chemo- and regioselective synthesis of a biosurfactant for the first time. Surface-active properties (such as contact angle (CA), surface tension (SFT), interfacial tension (IFT), critical micelle concentration (CMC), hydrophilic-lipophilic balance (HLB), foamability (FA) & foam stability (FS), emulsion ability (EmA) & emulsion stability (EmS), surface excess (Γ) and free energy of adsorption (ΔG) were also determined for all synthesized biosurfactants. In comparison to other works, these results suggested that the synthesized lactose fatty acid esters have potential application as synthetic emulsifiers featuring surface properties and are comparable with Ryoto sugar ester L-1695 (sucrose laurate) & Tween-20 (polysorbate 20) as industrial emulsifiers. The optimized conditions for biosurfactant syntheses are 8 days at 2 : 1 molar ratio of lactose sugar to lauric acid at 50 °C. Lactose ester as a biosurfactant exhibited a decrease of SFT & IFT and was able to stabilize a 20% soybean O/W emulsion. Furthermore, high conversion & yield, excellent chemo- and regioselectivity, and high operational stability over 5 runs were achieved for CoII/MnII-G2.0L1/2@SCMBNP, indicating the suitable efficiency of the catalytic process.

Super-magnetization of Co-pectin/gelatin biocomposite for selective synthesis vitamin K3: Design, fabrication and revealing role of the stabilizers.

High pollution and low productivity of the traditional method for synthesis of vitamin group K require an efficient, low-cost, and environmentally sustainable biocatalyst as a greener process. These have encouraged us to design and fabricate a series of novel Co NPs impregnated pectin-gelatin (Co@PTNC, Co@GTNC & Co@PT0.7GT0.3NC) and grafted pectin-gelatin modified magnetic beads (Co@MPT0.7GT0.3NC) by the in situ reduction-precipitation procedure and chemical application in the selective synthesis of vitamin K3 without any promoters or ligands. The chemical structure and morphological properties were fully characterized. Additionally, the influence of structural parameters (i.e., kind of stabilizer with different ratio (nPT/nGT), amount of Co loading, durability, size, distribution, and Leaching test) and operating parameters (i.e., reaction time, reaction temperature, nature of the solvent, and concentration of oxidant) on the efficacy of the biocatalysts was evaluated in detail. The green synthesis involves several advantages, like the heterogeneous nature of catalysts, environmentally-friendly and mild conditions, high recovery efficiency due to superparamagnetism, high activity, and the sustainable performance of the biocatalyst.

Synthesis and characterization of cobalt-supported catalysts on modified magnetic nanoparticle: Green and highly efficient heterogeneous nanocatalyst for selective oxidation of ethylbenzene, cyclohexene and oximes with molecular oxygen.

In this study, a new supported cobalt nanocatalyst has been described. The Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) modified by SiO2/aminopropyl trimethoxy silane/cyanuric chloride (Fe3O4@SiO2-APTMS/CC) utilized for anchoring metformin-cobalt complex (Fe3O4 Ms@SiO2-APTMS/CC/Met@Co(II)). The structure of novel complex well defined by elemental analysis, ICP, AAS, BET, FT-IR, EDX, SEM, TEM, DLS, XRD, TG-DTG, VSM and XPS. The catalytic efficiency of the synthesized cobalt nanocatalyst was studied in the oxidation of ethylbenzene (EB), cyclohexene (CYHE) and various oximes using molecular oxygen as ecofriendly oxidant and high catalytic activity and selectivity toward oxidation is observed. Selective aerobic oxidation of EB and CYHE and various oximes catalyzed by the cobalt nanocatalyst without any reducing agent by using N-hydroxyphthalimide (NHPI), gave acetophenone (AcPO), 2-cyclohexene-1-one and corresponding carbonyl compounds respectively, as major products. To achieve high level of efficiency of heterogeneous nanocatalyst, various parameters such as the ratio and amount of nanocatalyst/NHPI, reaction time, temperature and solvents were evaluated. The easily preparation from inexpensive and commercially available reagent, thermal stability, suitable performance in reusability, high efficiency and selectivity in oxidation reactions, short reaction time, easy recovery and separation from reaction mixture, are advantages of this novel catalyst.

Evaluation of the effects of acyclovir and/or human amniotic membrane on herpes virus culture and quantitative virus inactivity by real-time polymerase chain reaction.

AIM: To investigate the permeability of amniotic membrane in herpes virus cell culture to acyclovir with real time polymerase chain reaction (RT-PCR). METHODS: Madin-Darby Bovine Kidney (MDBK) cell culture and Bovine Herpes Virus (BHV1) type 1 were used in the study. Cell cultures were grouped into two on the basis of herpes virus inoculation. Each group was sub-grouped into three. Amniotic membrane (V-HAM), acyclovir (V-A), and amniotic membrane and acyclovir (V-HAM-A) were applied to these subgroup cultures, respectively. After the application of the membrane and the drug, the cultures were evaluated at 24 and 48h for cytopathic effect positive (CPE+) with a tissue culture microscope. In the CPE (+) samples, the DNA was extracted for viral DNA analysis by RT-PCR. RESULTS: In control cultures without herpes virus CPE was not detected. Besides, amniotic membrane and acyclovir did not have cytotoxic effect on cell cultures. CPE were detected in Bovine Herpesvirus type-1 inoculated cell cultures after amniotic membrane and/or acyclovir application. DNA analysis with RT-PCR indicated that Cycle threshold (Ct) values were lower in the BHV1 and membrane applied group (amniotic membrane group < acyclovir group < membrane and acyclovir group). This showed that membrane did not have antiviral effect. The membrane and acyclovir cell culture groups with high Ct values indicated that membrane was permeable and had a low barrier effect to drug. CONCLUSION: In our in-vitro study, we found that amniotic membrane, which can be used in the treatment of corneal diseases, did not have antiviral effect. Besides, we detected that amniotic membrane was permeable to acyclovir in BHV-1 inoculated MDBK cell culture. However, more studies are necessary to investigate the quantitative effects of amniotic membrane and acyclovir.