Metal Complexes Immobilized on Magnetic Nanoparticles

The reusability of valuable catalysts in organic reaction without change in properties is known as an important feature in the evolution of green processes. The imobilization of metal catalysts on magnetic nanoparticles makes them recoverable and can be used as building blocks for the fabrication of various functional systems, which are applied in several fields such as catalysis, environmental remediation magnetic resonance imaging, data storage, and biotechnology. Applying magnetic nanoparticles in organic reaction as a scaffold for the immobilization of metal complexes is reviewed as well as the improvement of the methods of production and applying catalysts with magnetic properties in organic reaction

Are Algae the Future Source of Enzymes?

Various proteins and enzymes produced during algal photosynthesis can be used in economic development and environment management, such as in wastewater treatment, production of fine chemicals, and biodiesel production. This mini-review presents various enzymes isolated from algae and suggests that algae, given their unique properties, could be explored for large-scale production of enzymes as future biocatalyst factories.HighlightsVarious proteins and enzymes are produced during algal photosynthesis.Algae use phosphoglycolate phosphatase and glycolate oxidase as metabolizing enzymes.Algae possess the ability to produce commercial enzymes.Out of the 10,000 algae species, only a few are cultivated on an industrial scale.Algal wastes can be manipulated and recycled for production of various enzymes.

Peptide-Catalysis in Asymmetric Organic Synthesis

Stereo-selectivity is an important feature in the development of the synthesis of biologically active organic compounds. In this process, (bio) catalysts exhibit substrate specificity that allows high levels of chemo- and regio-selectivity. Over the past decade, several peptides have been developed as effective bio-catalysts for a range of synthetically valuable reactions. In comparison with proteins owing a large number of amino acids and high molecular weights, peptide-catalysts possess only a few amino acid residues, which may adopt a secondary structure suitable for synthesis of desired chiral products. In addition, the flexible nature of peptides consents for tuning of reactivity and selectivity by replacing amino acid residues. These unique aspects provide attractive biocatalysts platform for asymmetric syntheses.HighlightsAsymmetric catalysis has an impressive progression in the manufacture of pharmaceuticals.Enzymes and natural/synthetic peptides are attractive biocatalysts of the chiral reactions.Peptides show unique features compared with other catalysts in asymmetric catalysis.

Ionic Liquids and their Toxicity on the Enzyme Activity and Stability

Molecular interactions are crucial between the enzyme molecules and the surrounding solution in an enzymatic catalysis. Although aqueous solutions used as conventional enzymatic reaction media, non-aqueous enzymology emerges as a major area of biotechnology research and development. Ionic liquids, as new generation of promising alternatives to traditional organic solvents, possess potential industrial enzymatic applications. Enzymes in ionic liquids present enhanced activity, stability, and selectivity. In addition, the potential of ionic liquids in bio-catalysis is raised by high ability of dissolving a wide variety of substrates and their extensively tunable solvent properties through appropriate modification of the cations and anions. However, despite the bio-friendly nature of ionic liquids for enzymatic reactions, their growing interests increase concerns associated with toxicity and environmental pollution of such compounds. This mini-review presents a brief highlight of the contemporary knowledge of enzymes activity and stability in ionic liquids and the environmental influences regarding the potential risks related to the growing applications of these green solvents.HIGHLIGHTS•Conventional organic solvents can be replaced by ionic liquids as green solvents.•Ionic liquids are used as additives, catalysts, or reaction media in industries.•Advantages and disadvantages of ionic liquids are discussed.•Potential environmental hazards linked to application of ionic liquids are highlighted.•The environmental fate needs to be considered in designing safer ionic liquids

Immobilization of Laccase in Alginate-Gelatin Mixed Gel and Decolorization of Synthetic Dyes

Alginate-gelatin mixed gel was applied to immobilized laccase for decolorization of some synthetic dyes including crystal violet. The immobilization procedure was accomplished by adding alginate to a gelatin solution containing the enzyme and the subsequent dropwise addition of the mixture into a stirred CaCl2 solution. The obtained data showed that both immobilized and free enzymes acted optimally at 50°C for removal of crystal violet, but the entrapped enzyme showed higher thermal stability compared to the free enzyme. The immobilized enzyme represented optimum decolorization at pH 8. Reusability of the entrapped laccase was also studied and the results showed that ca. 85% activity was retained after five successive cycles. The best removal condition was applied for decolorization of seven other synthetic dyes. Results showed that the maximum and minimum dye removal was related to amido black 10B and eosin, respectively

Antioxidant plants and diabetes mellitus

The incidence of diabetes mellitus (DM) is increasing rapidly and it is expected to increase by 2030. Other than currently available therapeutic options, there are a lot of herbal medicines, which have been recommended for its treatment. Herbal medicines have long been used for the treatment of DM because of the advantage usually having no or less side-effects. Most of these plants have antioxidant activities and hence, prevent or treat hard curable diseases, other than having the property of combating the toxicity of toxic or other drugs. In this review other than presenting new findings of DM, the plants, which are used and have been evaluated scientifically for the treatment of DM are introduced

Effect of post-harvest conditions on antioxidant enzyme activity in Dunaliella tertiolecta biomass

Microalgae biomass is considered a sustainable feedstock to produce high-value compounds including enzymatic and non-enzymatic antioxidants, which are widely used for food, pharmaceuticals, textile, leather, and in the chemical industries. Suitable post-harvest storage conditions to minimise deterioration of enzyme activity is therefore crucial. In this study, the effect of storage temperature over time on antioxidant enzyme activity (catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) in four D. tertiolecta samples (whole wet cells, freeze-dried whole cells, crude extract and freeze-dried crude extract) were evaluated. Antioxidant enzyme activities in freshly harvested whole cells or in the crude extract stored at -20 °C were retained only for up to one month but when stored at -80 °C, both CAT and SOD activities remained unchanged for four months. Moreover, in the freeze dried whole cell samples, CAT and SOD activities were retained for 8 months at -20 °C, however, when a crude extract was prepared and freeze dried, enzyme activities decreased. Therefore, careful control of storage temperature could prevent unfavourable changes to antioxidant activity in harvested cells thereby increasing shelf-life and the value of this type of biomass. This study recommends a suitable post-harvest storage temperature for preservation of Dunaliella biomass for both short-term and long-term stability of antioxidant enzyme activities. Our results strongly indicate that fresh whole cell extracts should be used in antioxidant enzyme assays, but if storage is necessary, whole fresh cells should be freeze dried and stored at -80 °C. Crude extracts prepared should be used in antioxidant enzyme assays within 24 h of preparation