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New Delhi metallo β-lactamase-1 is one of the carbapenemases, causing hydrolysis of almost all β-lactamase antibiotics. Seventeen different NDM variants have been reported so far, they varied in their sequences either by single or multiple amino acid substitutions. Hence, it is important to understand its structural and functional relation. In the earlier studies role of active site residues has been studied but non-active site residues has not studied in detail. Therefore, we have initiated to further comprehend its structure and function relation by mutating some of its non-active site residues. A laboratory mutant of NDM-1 was generated by PCR-based site-directed mutagenesis, replacing Q to A at 123 position. The MICs of imipenem and meropenem for NDM-1 Q123A were found increased by 2 fold as compare to wild type and so the hydrolytic activity was enhanced (Kcat/Km) as compared to NDM-1 wild type. GOLD fitness scores were also found in favour of kinetics data. Secondary structure for α-helical content was determined by Far-UV circular dichroism (CD), which showed significant conformational changes. We conclude a noteworthy role of non-active-site amino acid residues in the catalytic activity of NDM-1. This study also provides an insight of emergence of new variants through natural evolution. [ABSTRACT FROM AUTHOR]

A new route to fabricate cotton cloth (CC) as easily removable substrate for the synthesis of copper nanoparticles on its surface and its utilization in a toxic dye reduction is reported herein. A 1 wt% chitosan (Chi) aqueous solution was prepared and coated onto CC surface to prepare the ions affinity Chi-CC material. The Chi-CC was then kept in copper sulphate solution with three different concentrations (0.05 M, 0.1 M and 0.2 M) to interact with Cu 2+ ions through –NH and –OH functional groups of the Chi chain. After sufficient time of the Cu 2+ uptake, the Chi-CC was treated with 0.1 M NaBH 4 solution which turned its color indicating well organization of the adsorbed ions into Cu-nanoparticles. The bare CC, Chi-CC and Cu/Chi-CC were spectroscopically examined via scanning electron microscopy, X-ray diffractometry, energy dispersive X-ray spectroscopy and thermo-gravimetric analysis. Afterward, Cu/Chi-CC was used in the Congo red (CR) dye reduction by NaBH 4 as catalyst. The performance of the amount of the catalyst and its usage in a series of similar dye reduction was evaluated. [ABSTRACT FROM AUTHOR]

The present study is aimed to evaluate the microwave–enforced sorption approach (MES) for instantaneous extraction and removal of trace concentration of metal ions using microwave-synthesized titanium oxide nanoparticles-bonded-chitosan nanolayer (NTiO 2 -NCh). The proposed and designed nanocomposite was characterized by different techniques. The coveted ions were allowed to heat in presence of NTiO 2 -NCh nanocomposite inside a microwave apparatus for 5–20 s to execute the sorption process. The contribution of microwave warming time, nanocomposite dose, concentration of Cd(II) and Cu(II) ions, pH and interfering ions were explored and optimized. Sorption of Cd(II) was characterized as 1050 and 1150 μmol g − 1 and those of Cu(II) were identified as 450 and 800 μmol g − 1 using 5 and 20 s of microwave heating time, respectively. Optimization of the nanocomposite dose factor was found to enhance the metal uptake values of Cd(II) to 1800 μmol g − 1 using 5.0 mg. The potential utilization of MES technique for removal and extraction of Cd(II) and Cu(II) at low concentration levels (mg L − 1 ) from water samples was also explored. The percentage extraction values of Cu(II) and Cd(II) from water and wastewater samples were ranged as 86.80–88.01% and 72.56–70.67%, respectively using 60–70 s heating via MES technique. [ABSTRACT FROM AUTHOR]

The major problems of porphyrins as promising materials for photodynamic therapy (PDT) are their low solubility, subsequently aggregation in biological environments, and a lack of tumor selectivity. With this in mind, a chitosan-based hydrogel conjugated with tetrakis(4-aminophenyl)porphyrin (NH 2 -TPP) and 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine (TRIPOD) via Schiff base linkage, functionalized with folate was designed and synthesized as a pH-sensitive, self-healable and injectable targeted PS delivery system. This new hydrogel was characterized by FT-IR, 1 H NMR, SEM, UV-vis, fluorescence spectroscopy and zeta potential. Formation of imine bonds with the aldehyde group of TRIPOD and amine group of NH 2 -TPP and chitosan, as a dynamic connection, was approved by rheological analysis. Spectroscopic characterizations revealed that aggregation of porphyrin in aqueous media was eliminated due to diminished π stacking interaction of porphyrin in 3D cross-linked hydrogel structure. Hydrogel 3D microporous structure efficiently transfers the excitation energy to the porphyrin unit, yielding improvement singlet oxygen releases. Cytotoxicity and phototoxicity analysis of the CS/NH 2 -TPP/FA hydrogels indicating an excellent capability to kill cancer cells selectively and prevent damage to normal cells. This work presents a new and efficient model for the preparation of highly efficient and targeting photosensitizer delivery system. [ABSTRACT FROM AUTHOR]

A novel method of laccase immobilization on epoxy-functionalized silica particles was developed. Laccase from Myceliophthora thermophila was covalently immobilized onto epoxy-functionalized matrix by nucleophilic attack of amino groups of laccase to epoxy groups of the support. The enzyme loading on the support was about 30 mg/g under the optimum conditions (pH 4.5, 24 h). The effect of pH, temperature and organic solvent on immobilized enzyme activity was determined and compared with those of free enzyme. In general the immobilized enzyme was found to be stabilized compared to the free enzyme. Lineweaver-Burk plots were used to calculate kinetic parameters for ABTS oxidation. K M values were 24.0 and 25.3 μM while v max values were 10.0 and 1.6 μM min −1 for free and immobilized laccase, respectively. The performance of the biocatalyst was evaluated by the degradation of phenolic compounds including phenol, p -chlorophenol and catechol. The removal efficiency of catechol by immobilized laccase was about 95% after 2 h. [ABSTRACT FROM AUTHOR]

Food is a vital product for the survival of human beings and with passage of time quality concerns of consumers are rising. Edible films and coatings are thin layers applied on food products to protect them and improve their quality. Films/coatings are prepared from naturally occurring renewable sources (polysaccharides, proteins, lipids and composites) which we can eat without disposing them. These films are environment friendly and contain antioxidants, anti-browning agents and colorants. Various methods (spraying, brushing, electro-spraying) are used to apply a coating on food material to protect them from microbial growth, prolonging their shelf life and improving other quality aspects like sensory attributes, appearance, originality and freshness of ingredients. In addition to edible films, some special additives like glycerol, sorbitol etc. is used to improve the efficiency of edible films and coatings. Chemistry and nature of these films and coatings vary in the vast range of hydrophilic and hydrophobic boundaries to cover the whole range of food products. In recent times, herbal coatings are widely used for the coating purposes e.g. Aloe Vera, citral and eugenol essential oils. However, some challenges presented are focusing the scientific attention for viable solution. [ABSTRACT FROM AUTHOR]

Chitosan the second most abundant next to cellulose, naturally occurring amino polysaccharide, derived as a deacetylated form of chitin. Its nontoxic, biocompatible, antibacterial and biodegradable properties have led to significant research towards biomedical and pharmaceutical applications, such as drug delivery, tissue engineering, wound-healing dressing etc. The primary amine group in chitosan are responsible for its various properties such as cationic nature, controlled drug release, muco-adhesion, in situ gelation, antimicrobial, permeation enhancement etc. This review discusses the various forms of chitosan materials such as beads, films, microspheres, nanoparticles, nanofibers, hydrogels, nanocomposites, etc. as drug delivery device and attempted to report the vast literature available on chitosan based materials in drug delivery applications. Moreover, chitosan derivatives and chitosan nanocomposites with different nanofillers and its application in drug delivery have also been reviewed. [ABSTRACT FROM AUTHOR]

Graft copolymerization of chitosan (Ch) with acrylonitrile (AN) prepared by free radical polymerization using potassium persulfate (PPS) as initiator. Optimization of Graft copolymerization of acrylonitrile on to chitosan was performed by studying the main parameters that affecting the grafting process such as initiator and monomer concentrations, reaction time and temperature of the polymerization process to study their influence on percent grafting (G%), grafting efficiency (GE%) and percent homopolymer (H%). Modification of grafted chitosan was done by Schiff’s base derivatives using different aldehydes. They are characterized by FT-IR, X-ray diffraction, thermal analysis and scanning electron microscope. Their antibacterial activities against Streptococcus pneumonia (RCMB 010010) , Staphylococcus aureus (RCMB 010028), as Gram-positive bacteria and Escherichia coli (RCMB 010052) as Gram-negative bacteria and the antifungal activity against Aspergillus fumigatus (RCMB 02568), Candida albicans (RCMB 05036) and Geotricum candidum (RCMB 05097) were examined using the diffusion agar technique. The obtained data proved that modified chitosan by grafting show better antimicrobial activities than Chitosan. Also Schiff base derivatives showed better antimicrobial activities than grafted chitosan. [ABSTRACT FROM AUTHOR]

Secretory class V phospholipase A2 (PLA2-V) has been shown to be involved in inflammatory processes in cellular studies, but the biochemical and physical properties of this important enzyme have been unclear. As a first step towards understanding the structure, function and regulation of this PLA2, we report the expression and characterization of PLA2-V from chicken (ChPLA2-V). The ChPLA2-V cDNA was synthesized from chicken heart polyA mRNA by RT-PCR, and an expression construct containing the PLA2 was established. After expression in Pichia pastoris cells, the active enzyme was purified. The purified ChPLA2-V protein was biochemically and physiologically characterized. The recombinant ChPLA2-V has an absolute requirement for Ca 2+ for enzymatic activity. The optimum pH for this enzyme is pH 8.5 in Tris–HCl buffer with phosphatidylcholine as substrate. ChPLA2-V was found to display potent Gram-positive and Gram-negative bactericidal activity and antifungal activity in vitro . The purified enzyme ChPLA2-V with much stronger anticoagulant activity compared with the intestinal and pancreatic chicken PLA2-V was approximately 10 times more active. Chicken group V PLA2, like mammal one, may be considered as a future therapeutic agents against fungal and bacterial infections and as an anticoagulant agent. [ABSTRACT FROM AUTHOR]

Protein glycation with sugars such as glucose start by the initial reaction between the carbonyl group of sugars and the amino group of proteins such as albumin and hemoglobin. This leads to the generation of Schiff base and following that the amadori and advanced glycation end products (AGEs). AGEs products can store in tissues and blood of diabetic patients. So, they play key roles to generate free radicals, which cause the development of diabetes complications. Inhibition of protein glycation plays an important role in controlling diabetes, so the identification of anti-glycation compounds is now receiving considerable interest. In this study, the protection effects of thymoquinone and its mixture with p-cymene on the glycation of bovine serum albumin (BSA) have been investigated by differential pulse voltammetry (DPV) and UV–vis spectrophotometry (UV–vis) techniques. Also, the multivariate curve resolution–alternating least squares (MCR–ALS) method was used since the results of the experimental measurements have a strongly overlapping signals. Molecular docking was applied to determine the site specific binding of inhibitor with residues of BSA. This study demonstrates that thymoquinone and its mixture with p-cymene have the potent ability to use as a dietary adjuvant against glycation. [ABSTRACT FROM AUTHOR]

Antimicrobial nanopackaging films were developed by incorporating clove essential oil (CLO) (15–30% w/w) and graphene oxide (GO) nanosheets (1% w/w) into polylactide (PLA), suitable for use as food packaging, via solution casting. Addition of CLO into PLA matrix improved the flexibility of the composite films by lowering tensile stress, complex viscosity (η*), and glass transition temperature (T g ). GO improved the T g , η* and lowered the oxygen permeability of the plasticized PLA matrix. Optical and anti-UV properties of the film were influenced by both GO and CLO incorporation. FTIR spectra exhibited a change in the molecular organization of the plasticized PLA film after incorporation with CLO. Microstructural studies revealed that the reinforcement of GO prevented porosity of plasticized PLA/CLO film surface. The developed composite film showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli and therefore, has a potential to be used as active packaging material for food safety and preservation. [ABSTRACT FROM AUTHOR]

Water contamination by toxic compounds has become one of the most serious problems worldwide. Catalytic reduction using metal nanoparticles offer opportunities for environmental benefits. In this study, cellulose acetate-ferric oxide nanocomposite (CA/Fe 2 O 3 ) was prepared and used as support for metal nanoparticles. After adsorption of Ag, Cu or Ni ions from aqueous solutions, metal ions associated with CA/Fe 2 O 3 were treated with sodium borohydride to prepare Ag, Cu and Ni nanoparticles loaded CA/Fe 2 O 3 . The CA/Fe 2 O 3 supported Ag, Cu or Ni nanoparticles was evaluated as a catalyst for pollutants degradation. Silver nanoparticles (Ag@CA/Fe 2 O 3 ) exhibit remarkable decomposition for methyl orange dye and p -nitrophenol in short time. The rate constant for methyl orange and p -nitrophenol were 8.58 × 10 −3 and 4.77 × 10 −3 s −1 , respectively. Besides the good catalytic activities of Ag@CA/Fe 2 O 3 , the catalyst could be easily recovered from the reaction medium by pulling the catalyst after completion of the reduction reaction. The recovered catalyst can be recycled several times if their exposure time to air was minimal. [ABSTRACT FROM AUTHOR]

Post-translational modifications play important roles in conformational properties and aggregation propensities of different peptides and proteins. In the present study, we have investigated the effects of acetylation of lysine residues on the structure and aggregation properties of apomyoglobin (apoMb).All of the 19 lysine residues were modified. Far-, near-UV CD, intrinsic and acrylamide quenching fluorescence studies indicated that acetylation significantly influences conformation of apoMb by altering both its secondary and tertiary structures. A considerable decrease in ANS fluorescence intensity was observed, which also suggested disruption of the heme pocket. Dynamic light scattering indicated partial compaction of protein structure as a consequence of the shielding effect of acetylation. While the presence of well-defined mature fibrils was detected in solutions of native apoMb, acetylation promoted formation of non-toxic amorphous aggregates, with low β-sheets content and decreased affinity for Thioflavin T, an amyloid-specific dye. Results are discussed in terms of the role of surface charge in conformational alterations of proteins and how small changes in ionic networks may affect aggregation pathways and morphology of the resulting aggregates. The physiological significance of the modification process in controlling cytotoxicity of the aggregated species is also discussed. [ABSTRACT FROM AUTHOR]

Disulfide bonds are among the most important factors related to correct folding of the proteins. Protein disulfide isomerase (PDI) is the enzyme responsible for the correct formation and isomerization of these bonds. It is rarely studied so far and none of them showed industrial properties. In this study, the gene encoding for a putative PDI from Bacillus subtilis DR8806 was identified, cloned and expressed in Escherichia coli . It was encoded a 23.26 kDa protein. The enzyme was purified by GST affinity chromatography with a specific activity of 1227 u/mg. It was active and stable over a wide range of temperature (20–85 °C) and pH (4.5–10) with an optimum at 65 °C and pH 5.5. Its activity was enhanced by Mn 2+ and Co 2+ while Ag + and Zn 2+ decreased it. Some of the known PDI inhibitors such as Tocinoic acid and Bactiracin did not affect its activity. In-silico analysis shows the five amino acids changes in the protein sequence regarding to the consensus sequence of PDIs, have a positive impact toward the protein thermal stability. This was further confirmed by molecular dynamics simulations. By considering the overall results, the enzyme might be a potential candidate for applications in the respective industries. [ABSTRACT FROM AUTHOR]

In the present study, novel films based on nanomontmorillonite-chitosan (MMT-Ch) and nanomontmorillonite-carboxymethyl cellulose (MMT-CMC) incorporated with different concentrations of Ziziphora clinopodioides essential oil (ZEO; 0.5, 1 and 2%) alone and in combination with Ficus carica extract (FCH; 1%) were investigated as active packaging materials for minced camel’s meat to increase the shelf life (microbial, chemical and sensory properties) and inhibit the growth of Listeria monocytogenes and Escherichia coli O157:H7 during storage at refrigerated condition. Final microbial populations of meat samples packed in CMC-MMT + ZEO 2% + FCH 1% and Ch-MMT + ZEO 2% + FCH 1% were decreased approximately 1–4 log CFU/g compared to control (P < 0.05). Packed meats with nanocomposite films tended to retard the increases in total volatile base nitrogen (TVB-N), pH, peroxide value (PV), protein carbonyl content and thiobarbituric acid reactive substances (TBARS). Sensory attributes (odor, color and overall acceptability) were significantly enhanced in treated meat samples ( P < 0.05). The results indicated that CMC-MMT + ZEO 2% + FCH 1% and Ch-MMT + ZEO 2% + FCH 1% films could be considered as promising packaging materials for minced camel’s meat. [ABSTRACT FROM AUTHOR]

Cullin (CUL)-RING E3 ubiquitin ligases (CRLs) are attractive therapeutic targets as they regulate diverse biological processes important for cancer cell survival by conferring substrate selectivity for ubiquitination and degradation. Given the complexity of CRL complexes, steps toward the structure-based design of small-molecule inhibitors to modulate their activity have remained elusive. In this study, we explored the structural assembly and interaction details of closely related CUL scaffolds (CUL1, CUL2, CUL3, CUL4A, CUL4B, CUL5 and CUL7) with RBX1 to screen potent small molecules against CRLs. The RING-Box (RBX1 and RBX2) proteins heterodimerize with CULs and dynamically facilitate the ubiquitination process. The docked complexes of conserved CUL C-terminal domains exhibited a common RBX1 binding pattern through the incorporation of intermolecular β-sheet and α/β core, stabilized by hydrophobic contacts. The comparative binding pattern analysis of CUL-RBX1 interfaces revealed a unique structural motif (VLYRLWLN) that directs the binding of RBX1 N-terminal β-strand. Through reinvigorating the subtle structural dynamics of bound complexes and application of structure-based drug design approaches, we proposed a set of inhibitors which could be further optimized to target CRL activity. One reference compound (C64) was extensively characterized for selective binding at the RBX1-binding grooves/VLYRLWLN of CUL1-7. We speculate that mechanistic information of the individual residual contributions through structure-guided approaches could be pivotal for the rational design of more promising and active drug candidates against CRLs. [ABSTRACT FROM AUTHOR]

l- Asparaginase (EC 3.5.1.1) is an important medical enzyme that catalysis the hydrolysis of l -asparagine to aspartic acid and ammonium. For over four decades l . asparaginase utic agent for the treatment of a variety of lymphoproliferative disorders and lymphoma such as acute lymphoblastic leukemia. In the present study A. terreus full length l . asparaginase gene, 1179 bp was optimized for expression in Escherichia coli BL21 (DE3) pLysS. The full length A. terreus l . asparaginase gene encoding a protein of 376 amino acids with estimated molecular weight of 42.0 kDa and a theoretical isoelectric point (pI) of 5.0. BLAST and phylogeny analysis revealed that the A. terreus l . asparaginase shared high similarity with other known fungal l . asparaginase (75% homology with A. nomius and 71% with A. nidulans ). The recombinant protein was overexpressed in the form of amorphous submicron proteinaceous inclusion bodies upon induction with 1 mM IPTG at 37 °C for 18 h. [ABSTRACT FROM AUTHOR]

In this work, 1,3,5-triazine-2,4,6-tribenzaldehyde was synthesized and chosen as the cross-linking agent for preparation of novel thermo- and pH-responsive hydrogels based on chitosan. The cross-linking proceeds through formation of imine bond by reaction of amino groups of chitosan with aldehyde groups of the cross-linker. The various amounts (6, 10, 14% w/w) of the cross-linker were used with respect to chitosan to produce three 1,3,5-triazine-2,4,6-tribenzaldehyde cross-linked chitosans. Then, their hydrogel nanocomposites were prepared by crosslinking of chitosan with 1,3,5-triazine-2,4,6-tribenzaldehyde in the presence of 0.1% and 0.3% (w/w) multi-walled carbon nanotubes (MWCNTs). The structure and properties of the hydrogels and their nanocomposites were characterized by FT-IR, 1 H NMR and scanning electron microscopy (SEM). The swelling behavior of prepared hydrogels and their nanocomposites at different pHs and temperatures was investigated. The results showed that they exhibit a pH and temperature-responsive swelling ratio. The swelling behavior of the prepared chitosan hydrogels was strongly dependent on the amounts of cross-linker and MWCNTs. In vitro controlled release behavior of metronidazole model drug was studied with prepared hydrogels and nanocomposite hydrogels. The pH, temperature and wt% of MWCNTs were found to strongly influence the drug release behavior of the hydrogels. [ABSTRACT FROM AUTHOR]

This work investigated the effect of hydroxypropylation on the physicochemical characteristics of Basmati and Irri rice starches with milk and water. The effect of hydroxypropylated starches on the storage, texture stability and sensory characteristics of rice pudding was studied. Pudding was prepared by replacing 3%, 5% and 10% of Irri rice flour with native and hydroxypropylated starches isolated from two predominant rice varieties of Pakistan; Irri and Basmati. Syneresis was not observed in pudding made with hydroxypropylated starches and native basmati starch. On the contrary, pudding prepared with Irri rice flour and Irri starches showed poor keeping quality. Sensory analysis showed that modification of rice starches did not significantly alter the color, flavor, taste and overall acceptability of pudding. The results suggested that rice pudding, a very popular dessert of South Asia could be prepared with improved storage characteristics using hydroxypropylated starches without altering the taste and acceptability of the product. [ABSTRACT FROM AUTHOR]

Custards were prepared using five ingredients: milk powder, modified pearl millet starch, sugar, vanilla essence and water. The effect of adding hydroxypropylated starch (HPS), succinylated starch (SUS), oxidised starch (OXS) and acetylated starch (ACS) on cold storage stability, pasting, textural and sensory properties was studied and compared to custards containing native pearl millet starch (NS). Interestingly, all chemically modified starches reduced syneresis and no water weeping was observed in custard sample incorporating hydroxypropylated starch (HPC) even after 7 days of cold storage. Viscoamylographic analysis revealed that custard containing succinylated starch (SUC) had the highest peak viscosity (108.8 BU), whereas HPC showed the least set back viscosity (19.0 BU). Sensory results suggested that assessors preferred HPC over other custards. Custards are preferred for their chewy semi-solid texture. Incorporation of hydroxypropylated starch (HPS) increased hardness, gumminess and chewiness which subsequently led to higher sensory scores during subjective analysis. Also, no retrogradation peak was observed for HPS and acetylated starch (ACS) when rescanned after 14 days. Thus, it could be concluded that HPS could be used in custards to confer low temperature stability by reducing syneresis. [ABSTRACT FROM AUTHOR]

Increasing body of evidence suggests that polyphenols frequently interacting with amyloid aggregates and/or interfering with aggregate species to bind biomembranes may serve as a therapeutic approach for the treatment of amyloid-related diseases. Hence, in the present study, the possible effects of three naturally occurring polyphenols including Curcumin, Quercetin, and Resveratrol on mitochondrial membrane permeabilization induced by Hen Egg White Lysozyme (HEWL) oligomers were investigated. Our results indicated that pre-incubation of mitochondrial homogenate with polyphenols considerably inhibit membrane permeabilization in a concentration dependent manner. In parallel, HEWL oligomers, which were co-incubated with the polyphenols, showed less effectiveness on membrane permeabilization, suggesting that toxicity of oligomers was hindered. Using a range of techniques including fluorescence quenching, Nile red binding assay, zeta potential and size measurements, CD (far- and near-UV) spectroscopy, and molecular docking, we found that the polyphenols, structure-dependently, interact with and induce conformational changes in HEWL oligomers, thereby inhibit their toxicity. We proposed a mechanism by which selected polyphenols induce their protective effects through binding to mitochondria and interfering with HEWL oligomer-membrane interactions and/or by direct interaction with HEWL oligomers, induction of conformational changes, and generating far less toxic species. However, additional studies are needed to elucidate the detailed mechanisms involved. [ABSTRACT FROM AUTHOR]

In the present paper, porcine pancreas lipase (PPL) was immobilized to a new version of magnetite via a novel stepwise dithiocarbamate/chitosan-based method in alternation to glutaraldehyde. Magnetic chitosan nanocomposite was post-modified to produce dithiocarbamate moieties on the surface through amine functions. Then, immobilization of lipase was successfully achieved on the surface of magnetically separable Fe 3 O 4 @CS/NHCS 2 H via a post-modification. Each step of immobilization was carefully monitored by characterization and all were successfully proved. Comparison of immobilized enzyme with free enzyme showed that the method of immobilization is efficient. [ABSTRACT FROM AUTHOR]

A cellulolytic bacterium was obtained from the digestive tract of Osphranteria coerulescens. The breakdown of woody and cellulosic substances by this insect may be relative in part to its symbiont bacteria. Under optimal cultural conditions the novel isolate produced 5.35 U/ml cellulase after 72 h. The enzyme was purified to 36 fold with a 0.59% yield and showed a specific activity of 9.0 U/mg. It presented its maximum activity at 60 °C and pH 5, while it was stable in a wide range of temperature from 20 to 60 °C and pH from 5 to 10. The purified enzyme had a molecular weight of 42.50 kDa based on SDS-PAGE and zymogram analyses. It demonstrated high ions and solvent stability and its activity was stimulated by Mn 2+ , Na + , DMSO and chloroform. The enzyme could hydrolyze CMC, avicel, cellulose and sawdust. TLC analysis represented the cellobiose as the hydrolytic product of CMC. With regard to endo/exo glucanase activity and wide pH, temperature and solvent stability, it has potential for industrial application. [ABSTRACT FROM AUTHOR]

We report the synthesis of Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids as performance adsorbents for Lincosamides such as Clindamycin antibiotic removal. Isotherms and kinetic studies were determined to understand the adsorption behavior both two adsorbent. At low adsorbent dose, removals are increased in the adsorption process, and performance is better with Ag 2 S-chitosan nanohybrids due to the special surface area increased. The average sizes and surface area of Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids were found as 50 nm, 70 nm and 180.18, 238.24 m 2 g −1 , respectively. In particular, Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids show high maximum Clindamycin adsorption capacity ( q max ) of 153.21, and 181.28 mg g −1 , respectively. More strikingly, Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids are also demonstrated to nearly completely remove Clindamycin from drinking water. The excellent adsorption performance along with their cost effective, convenient synthesis makes this range of adsorbents highly promising for commercial applications in drinking water and wastewater treatment. [ABSTRACT FROM AUTHOR]

The present work was to develop lipid drug conjugated (LDC) nanoparticles for the potential oral delivery of pemetrexed diacid (PTX) and evaluation of its in vitro , ex vivo and in vivo potentials. The LDC was prepared by salt formation of PTX with stearic acid and followed by cold homogenization technique to produce the LDC nanoparticles. FTIR analysis of LDC proved the presence of amide bond in LDC powder indicating the conjugation between drug and lipid. LDC nanoparticles was found to have particle size 121.9 ± 1.85 nm and zeta potential −51.6 m V ± 1.23 and entrapment efficiency 81.0 ± 0.89%. TEM images revealed spherical morphology and were in corroboration with particle size measurements. Ex vivo gut permeation studies revealed a very good enhancement in permeation of drug present in the LDC as compared to plain drug solution and were confirmed by CLSM. MTT assay conformed significant% toxicity at the end of 24 h and 48 h. Furthermore, the AUC 0-24 of PTX from the optimized LDC nanoparticels was found to be 4.22 folds higher than that from PTX suspension on oral administration. Thus, LDC has high potential for the oral delivery of PTX in cancer therapy and future prospects for the industrial purpose. [ABSTRACT FROM AUTHOR]

Nifurtimox and benznidazole represent the only treatments options available targeting Chagas disease, the most important parasitic infection in the Americas. However, use of these is problematic as they are toxic and ineffective against the more severe stages of the disease. In this work, we used a multidisciplinary approach to characterise the fumarases from Trypanosoma cruzi , the causative agent of Chagas Disease. We showed this trypanosome expresses cytosolic and mitochondrial fumarases that via an iron-sulfur cluster mediate the reversible conversion of fumarate to S-malate. Based on sequence, biochemical properties and co-factor binding, both T. cruzi proteins share characteristics with class I fumarases, enzymes found in bacteria and some other protozoa but absent from humans, that possess class II isoforms instead. Gene disruption suggested that although the cytosolic or mitochondrial fumarase activities are individually dispensable their combined activity is essential for parasite viability. Finally, based on the mechanistic differences with the human (host) fumarase, we designed and validated a selective inhibitor targeting the parasite enzyme. This study showed that T. cruzi fumarases should be exploited as targets for the development of new chemotherapeutic interventions against Chagas disease. [ABSTRACT FROM AUTHOR]

The MnO 2 /Cellulose fiber Nanocomposites have been prepared via the microwave-assisted hydrothermal method. The characteristic structure of MnO 2 /Cellulose fiber Nanocomposites was analyzed using X-ray diffraction, photoluminescence and UV–vis spectra, Transmission electron Microscopy, N 2 adsorption-desorption and Scanning electron microscopy instrumental techniques. BET surface area and crystallite size values of MnO 2 /cellulose fiber nanocomposites have been found as 87.064 m 2 /g and 70.0 nm, respectively. Response Surface Methodology (RSM) has been used for adsorption of Insecticide compound such as Toxaphene by prepared adsorbent. MnO 2 /Cellulose fiber Nanocomposites shows maximum removal of 96.5% at initial Toxaphene concentration of 5.0 mg/L, pH 3 and adsorbent dose of 5.0 g/L. Kinetic and equilibrium data follow pseudo-second order and Langmuir isotherm model, respectively. Adsorption capacity of MnO 2 /Cellulose fiber Nanocomposites has been found to be 5.465 mg/g. [ABSTRACT FROM AUTHOR]

Polylactide (PLA) nanocomposites characterized by antimicrobial properties are gaining increasing attention for food packaging. In this contribution, the PLA based nanocomposite films with multifunctional end-use properties were achieved by incorporating ZnO nanoparticles (NPs) [untreated: ZnO(UT) and 3-methacryloxypropyltrimethoxysilane treated: ZnO(ST)] into polymer matrix via solvent casting method. The ZnO(ST) prevented the degradation of PLA at higher temperature and improved the mechanical property. Color, transparency, and anti-UV properties of composite films were influenced by the incorporation of ZnO NPs. Contrary to untreated ZnO, the treated NPs were more effective in enhancing the tortuosity of the diffusive path for the oxygen molecules to diffuse through the film. The glass transition ( T g ) and crystallization ( T c ) temperatures of composites were improved by the addition of ZnO, whereas a higher T g was recorded for ZnO(ST) loaded films. XRD demonstrated the change in crystallinity of the films with NPs addition. Nanoparticles well distributed in the composite films as observed through SEM however spots of agglomeration were observed for PLA/ZnO(UT) films. Developed films especially incorporated with ZnO(ST) were found to be active against both Gram-negative ( Salmonella Typhimurium) and Gram-positive ( Listeria monocytogenes ) bacteria. Therefore, PLA/ZnO nanocomposite films could be considered as environment-friendly active packaging material for food preservation. [ABSTRACT FROM AUTHOR]

A novel nanocomposite has been designed and synthesized via surface crosslinking of chitosan nanolayers (NChit) with titanium oxide nanoparticles (NTiO 2 ) using glutaraldehyde (Glu) as the crosslinking agent. A simple and green surface chemical reaction was accomplished by the aid of microwave heating process to enforce surface encapsulation and functionalization for the production of the aimed NTiO 2 -Glu-NChit nanocomposite. The average particles size of nanocomposite was characterized in the range of 52–58 nm using SEM and confirmed by the HR-TEM. The XRD, TGA and FTIR were also employed to assure the immobilization and crosslinking processes. NTiO 2 -Glu-NChit was studied to estimate the sorption efficiency towards La(III) from aqueous solution by the batch technique under different experimental controlling physicochemical parameters such as, initial pH of metal ion solution, contact time, nanocomposite dosage and initial metal ion concentration. The optimum sorption condition for La(III) as the target metal ion was identified at pH = 1.0, 3.0 and 6.0. The adsorption process of La(III) was characterized to follow the postulates of Langmuir and Freundlich isotherm models and the adsorption mechanisms were identified to obey the pseudo -second order kinetic model based on the best compatible results with the experimental data. [ABSTRACT FROM AUTHOR]

Starches extracted from two dominant varieties of rice, Basmati and Irri were subjected to acid hydrolysis by preparing starch slurry of 35% (w/v) in HCl solutions of concentrations 0.1 M, 0.3 M and 0.8 M. The scanning electron micrographs showed that granular morphology of starches significantly changed after acid hydrolysis. Acid thinning improved the solubility of starches whereas decline was observed in swelling power and water retention capacity. Paste clarity of both acid treated Basmati and Irri rice starches reduced gradually upon cold storage. Also reduction in values of pasting, peak viscosity, hot paste viscosity, cold paste viscosity and set back were observed in acid thinned Basmati and Irri rice starches. The DE values increased with the increase in HCl concentration for both Basmati and Irri starch. The hardness of 0.8 M HCl treated Basmati starch gel was found significantly lower than all treated and untreated starches. The gelatinization enthalpy for Basmati starch significantly reduced after acid hydrolysis with 0.1 M, 0.3 M and 0.8 M HCl solutions at p < 0.05. [ABSTRACT FROM AUTHOR]

This study presents the development of an electrochemical supercapacitor with a cadmium selenide nanoparticles (CdSeNPs) electrode utilizing a straightforward and economical method based on kappa -carrageenan (κ-CGN). The structural, morphological, and optical characteristics of CdSeNPs were assessed. Activated carbon (AC) and green-prepared CdSeNPs were easily mixed to achieve excellent electrochemical properties. The nanoelectrode (AC@CdSe) was tested in an aqueous electrolyte of sodium sulfate (Na 2 SO 4) with a concentration of 1 Molar. Specific capacitance (Csp) for the AC electrode and the AC@CdSe electrode at 1 A g−1 was calculated to be 103 and 480 F g−1, respectively. Besides, the symmetric supercapacitor AC@CdSe/AC@CdSe device has a high specific energy of 52 Wh kg−1 and a maximum specific power of 2880 W kg−1, with a specific capacitance of 115.5 F g−1. With a coulombic efficiency of between 82 % and 100 %, the device continues to maintain excellent capacitance after 10.000 cycles. [ABSTRACT FROM AUTHOR]

Biocomposites are widely used in construction, packaging, and automotive applications such as seatbacks, door panels, headliners, and dashboards, as well as industrial composting. The purpose of this study is to look into the effects of three different boron compounds (borax boric, acid combines, zinc borate, and ulexite) on the mechanical and microstructural properties of flax fiber/PLA biocomposites at different water uptake times. 7 different biocomposites were studied for this purpose: control, 3UF, 5UF, 3ZBF, 3BxBcF, 5BxBcF, and 5ZBF. Extrusion was used to create homogenous chopped flax fiber-reinforced PLA biocomposites, which were then injection molded. Alkali treatment on flax fiber surfaces was applied to improve interfacial adhesion between fiber and matrix. Water uptake tests were performed at room temperature for soaking times of 24, 50, 168, 240, 330, 480, 550, 600, and 750 h. The addition of boron compounds increases water gain from 4.4 % to 6.1 %, according to sorption results. The tensile elongation at break values of the composites increased slightly after short-term water absorption. SEM images showed that alkali-treated flax fibers and boron compounds dispersed uniformly in the PLA matrix. After 750 h of immersion, the addition of boron fillers to PLA/flax composite increased Young's Modulus and flexural modulus by about 50 % and 72 %, respectively, in comparison to the control composite sample. The addition of boric acid: borax combines into the PLA/flax composite slowed the rate of decline in tensile and flexural strength after various immersion times. Finally, using MINITAB software, the experimental results were subjected to a one-way analysis of variance (ANOVA). [ABSTRACT FROM AUTHOR]

Positively charged amino acids in the DNA polymerase domain are important for interaction with DNA. Two potential residues in the palm domain of Pca -Pol, a DNA polymerase from Pyrobaculum calidifontis , were identified and mutated to arginine in order to improve the properties of this enzyme. The mutant proteins were heterologously produced in Escherichia coli. Biochemical characterization revealed that there was no significant difference in pH, metal ion, buffer preferences, 3′ − 5′ exonuclease activity and error rate of the wild-type and the mutant enzymes. However, the specific activity, processivity and extension rate of the mutant enzymes increased significantly. Specific activity of one of the mutants (G522R-E555R) was nearly 9-fold higher than that of the wild-type enzyme. These properties make G522R-E555R mutant enzyme a potential candidate for commercial applications. [ABSTRACT FROM AUTHOR]

In the current study, native and different fatty acid-esterified waxy maize starches (octanoate, myristoate, and stearoate), followed by an OSA-potato starch (as an industrial emulsifier) were used to prepare sunflower oil-in-water (O/W) emulsion. The effect of emulsifier type and concentration were evaluated on properties of emulsions in terms of mean droplet size, droplet size distribution, and creaming index. To prepare the emulsion, the emulsifier to oil ratios of 1.25 and 0.5 for octanoate and industrial emulsifier (control) were considered as the selected formulations based on the lowest creaming index (2.63 and 0 %, respectively). The influence of various pHs and ionic strengths on droplet size, span and zeta potential value was similar for both produced emulsions. Therefore, the fatty acid-esterified starch could be suggested as a promising environmentally friendly alternative to industrial emulsifiers for fabrication of emulsions with similar stability. [Display omitted] • Waxy maize starch was esterified by different types of fatty acid chlorides (FACs). • The esterified starches were used to stabilize emulsions at various concentrations. • Octanoate could stabilize oil-in-water emulsions successfully. • Both octanoate and industrial emulsions had the same trend under condition stresses. • The rheological behavior of emulsion resultant was similar to industrial one. [ABSTRACT FROM AUTHOR]

According to the 12 principles of green chemistry, surface functionalization was performed using glutaric anhydride under solvent-free and catalyst-free conditions. FTIR spectra and DS analyses demonstrated the functionalization of HCl-hydrolyzed cellulose. The influence of two parameters, i.e., the glutaric anhydride concentration and the reaction time, on the functionalization of HCl-hydrolyzed cellulose was investigated. Protocol efficiency was studied by a degree of substitution (DS). It was found that higher concentrations of glutaric anhydride cause an enhancement of DS to 0.75 and 0.87 for GA3–12 and GA9–12, respectively. In addition, the longer reaction time increased zeta potential from −12.2 ± 1.7 for G9–6 to −34.57 ± 2.2 for GA9–12. Morphology analysis by SEM showed a decrease in fiber length for the functionalized cellulose. DSC profiles confirmed dehydration at a range of 17 to 134 °C. A glass transition was revealed at −30 to −20 °C for all studied samples. The fusion, the depolymerization of cellulose chains, the cleavage of glycosidic linkages, and the decomposition of the crystalline parts of cellulose occur at 195 to 374 °C. Therefore, an efficient and greener process was developed to functionalize the HCl-hydrolyzed cellulose by glutaric anhydride, a safe and non-toxic anhydride, in the absence of the solvent and catalyst. [ABSTRACT FROM AUTHOR]

The bromodomain-containing protein 9, a component of the SWI/SNF chromatin remodeling complex, functions as an 'epigenetic reader' selectively recognizing acetyl-lysine marks. It regulates chromatin structure and gene expression by recruitment of acetylated transcriptional regulators and by modulating the function of remodeling complexes. Recent data suggests that BRD9 plays an important role in regulating cellular growth and it has been suggested to drive progression of several malignant diseases such as cervical cancer, and acute myeloid leukemia. Its role in tumorigenesis suggests that selective BRD9 inhibitors may have therapeutic value in cancer therapy. Currently, there has been increasing interest in developing small molecules that can specifically target BRD9 or the closely related bromodomain protein BRD7. Available chemical probes will help to clarify biological functions of BRD9 and its potential for cancer therapy. Since the report of the first BRD9 inhibitor LP99 in 2015, numerous inhibitors have been developed. In this review, we summarized the biological roles of BRD9, structural details and the progress made in the development of BRD9 inhibitors. [ABSTRACT FROM AUTHOR]

Alpha-synuclein (α-SN) is the central protein in synucleinopathies including Parkinson's disease. Nevertheless, the molecular mechanisms through which α-SN leads to neuronal death remain unclear. To elucidate the relationship between α-SN and apoptosis, some indicators of the intrinsic and extrinsic apoptotic cell death were assessed in normal and a stable HEK293T cell line expressing firefly luciferase after transfection with the wild-type (WT) and A53T mutant α-SN. Opposite to WT-α-SN, overexpression of A53T-α-SN resulted in enhanced expression of almost two fold for RIPK1 (93.0 %), FADD (45 %), Caspase-8, and Casp-9 activity (52.0 %) in measured time. Transfection of both WT-α-SN and A53T-α-SN showed an increase in the Casp-3/Procasp-3 ratio (WT: 60.5 %; A53T: 41.0 %), Casp-3 activity (WT: 65.0 %; A53T: 20.5 %), and a decrease in luciferase activity (WT: 50 %; A53T: 34.8 %). Overexpression of A53T-α-SN brought about with more cell death percentage compared to WT-α-SN within 36 h. No significant alteration in cytochrome c and reactive oxygen species release into cytosol were observed for both WT-α-SN and A53T-α-SN. Altogether, these findings highlight the link between disease related mutants of α-SN (like A53T-α-SN) in triggering of RIPK1-dependent extrinsic apoptotic pathway in cell death during neurodegeneration. [ABSTRACT FROM AUTHOR]

Aminopropyl functionalized PEGylated mesoporous silica nanoparticles [H 2 N-Pr@PEGylated SBA-15] were synthesized and evaluated as a promising biocompatible additive to study the activity and thermal reversibility and stability of human carbonic anhydrase II (HCA II). For this purpose, the additive was prepared by covalent amino propyl functionalization of mesoporous silica nanoparticles (MSNs) bearing PEG moiety as linker. The MSNs was fully characterized using different techniques including transmission electron microscopy, N 2 adsorption–desorption measurements, thermal gravimetric analysis, Fourier transform infrared spectroscopy and dynamic light scattering. The average particle size of [H 2 N-Pr@PEGylated SBA-15] was about 80 nm and showed high loading capacity for HCA II at pH 7.75 as a target protein. The efficiency of [H 2 N-Pr@PEGylated SBA-15] in improving reversibility of HCA II was investigated by various techniques including UV–vis, 1,8-Anilinonaphtalene Sulfonate (ANS) fluorescence, circular dichroism (CD), and differential scanning calorimetry. Our results showed that [H 2 N-Pr@PEGylated SBA-15] can increase the protein thermal reversibility and stability. Herein, kinetic studies were applied to confirm the ability of [H 2 N-Pr@PEGylated SBA-15] in increasing the activity of HCA II at high temperatures. Together our results present the [H 2 N-Pr@PEGylated SBA-15] as a water-dispersible and efficient additive for improving the activity, and thermal reversibility and stability of enzyme. [ABSTRACT FROM AUTHOR]

N-Acetylcysteine (NAC) loaded PLGA nanoparticles were prepared by electrospray method. The influence of independent parameters such as concentration, flow rate and nozzle to collector distance was studied on particle size and size distribution of generated nanoparticles using a Box–Behnken experimental design. Smallest size was found to be obtained at minimum value for both flow rate and concentration of polymer, regardless of collecting distance value in the ranges studied. Additionally, the minimum value of size distribution was observed at lowest values of both concentration of polymer and collecting distance, regardless of flow rate value. In total, a sample with minimum size and polydispersity was predicted to have flow rate, polymer concentration and collecting distance values of 0.06 (ml/h), 0.5 (%w/w) and 9.28 (cm), respectively. The experimentally prepared nanoparticles with lowest size and size distribution values, had a size of 122 (nm) and size distribution of 24. Zeta potential, drug loading and encapsulation efficiency of optimized nanoparticles were −6.58, 5% and 54.5%, respectively. [ABSTRACT FROM AUTHOR]

Paenibacillus polymyxa ATCC 21830 was used for the production of curdlan gum for first time. A Box–Behnken experimental design was applied to optimize six variables of batch fermentation culture each at three levels. Statistical analyses were employed to investigate the direct and interactive effects of variables on curdlan production. Optimum cultural conditions were temperature (50 °C), pH (7), fermentation time (96 h), glucose (100 g/L), yeast extract (3 g/L) and agitation speed (150 rpm). The yield of curdlan production was 6.89 g/L at optimum condition medium. Response surface methodology (RSM) and artificial neural network (ANN) were used to model cultural conditions of curdlan production. The maximum yield of curdlan production were predicted to be 6.68 and 6.85 g/L by RSM and ANN at optimum condition. The prediction capabilities of RSM and ANN were then statistically compared. The results showed that the ANN model is much more accurate in prediction as compared to the RSM. The infrared (IR) and NMR spectra, the thermogram of DSC and pattern of X-ray diffraction for the curdlan of the present study were almost identical to those of the commercial curdlan sample. The average molecular weight of the purified curdlan was determined to be 170 kDa by gel permeation chromatography. [ABSTRACT FROM AUTHOR]

The purpose of this work was to develop and characterize chitosan–alginate beads for the extended delivery of cefpodoxime proxetil (CFP), to understand the impact of formulation and process parameters on the critical quality attributes (CQAs) using a quality-by-design approach. For this, a study was performed with various formulation and process parameters to determine their impact on CQAs of beads, which were determined to be time for 80% of the drug released ( T 80% ), particle size, and encapsulation efficiency. The beads of CFP were optimized using a three-factor, three-level Box–Behnken design. A formulation comprising of 4.38% (w/v) alginate, 1.39% (w/v) chitosan and 6.82% (w/v) calcium chloride was found to fulfill requisites of an optimum formulation. In vitro release studies showed that the drug is released from the optimized formulation over a period of 24 h in a sustained release manner, primarily by non-Fickian diffusion. The optimized formulation was characterized by DSC, FTIR, XRD and SEM analysis. Antimicrobial studies revealed that the release of the drug over 24 h periods was above the minimum concentration required for inhibition of microbial growth. This research highlights the level of understanding that can be accomplished through a well designed study based on the approach of QbD. [ABSTRACT FROM AUTHOR]

Co-precipitation method was adopted to synthesize ternary heterostructure catalysts La/CS-CoSe NSs (lanthanum/chitosan‑cobalt selenide nanostructures) without the use of a surfactant. During synthesis, a fixed amount (3 wt%) of CS was doped with 2 and 4 wt% La to control the growth, recombination rate and stability of CoSe NSs. The doped samples served to enhance the surface area, porosity and active sites for catalytic degradation of rhodamine B dye and antibacterial potential against Staphylococcus aureus (S. aureus). Additionally, the synthesized catalysts were examined for morphological, structural and optical characteristics to assess the influence of dopants to CoSe. XRD spectra verified the hexagonal and cubic structure of CoSe, whereas the porosity of the undoped sample (CoSe) increased from 45 to 60 % upon incorporation of dopants (La and Cs). Among the samples analyzed during this study, 4 % La/CS-CoSe exhibited significant bactericidal behavior as well as the highest catalytic reduction of rhodamine B dye in a neutral environment. Molecular docking analysis was employed to elucidate the underlying mechanism behind the bactericidal activity exhibited by CS-CoSe and La/CS-CoSe NSs against DHFR S. aureus and DNA gyrase S. aureus. [ABSTRACT FROM AUTHOR]

Synthesis of Cu-doped NiO composited with cellulose nanocrystals (CNC) was carried out by co-precipitation method. The aim of this study is to investigate the catalytic, antibacterial and molecular docking studies of prepared samples. XRD patterns confirmed rhombohedral structure of synthesized nanostructures with gradual increase in crystallite size with doping. The morphology as well as interlayer spacing was evaluated with HRTEM while functional groups presence in dopant-free and doped nanostructures was confirmed using FTIR spectra. Both CNC/NiO composite and Cu-doped CNC/NiO showed higher catalytic potential compared to dopant-free NiO, while Cu-doped CNC/NiO nanostructures exhibited significant potential for use in industrial dye degradation applications. Besides this, CNC/NiO composite showed good antibacterial activity against Escherichia coli (E. coli) bacteria and its bacterial activity increased with Cu doping. Furthermore, molecular docking predictions against dihydrofolate reductase and DNA gyrase enzyme confirmed interaction of NiO NPs, CNC/NiO and Cu-doped CNC/NiO inside active pockets and showed good agreement with in vitro bactericidal activity. [ABSTRACT FROM AUTHOR]

New chitosan Schiff base (CS-NB) and its CS-NB-NiFe nanocomposite have been prepared and characterized by FTIR spectroscopy, XRD, SEM and DSC. FT-IR spectra and XRD patterns revealed the preparation of chitosan Schiff base CS-NB and its CS-NB-NiFe nanocomposite. DSC demonstrated the endo and exothermic correspondence the evaporation of solvent and decomposition of pyranose ring, respectively. Antibacterial activities was evaluated for the as-prepared compounds against two Gram-positive (Staphylococcus aureus and Bacillus cereus) and two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and the results shows that the antibacterial activities of the compounds are found to be stronger than that of chitosan. The order of antibacterial effect according to inhibitory zone around is as follows: S. aureus > E. coli > B. cereus > P. aeruginosa. In addition, the removal of methyl green (MG) dye using CS-NB and its CS-NB-NiFe nanocomposite were analyzed and results showed that the compounds can be effectively used to remove of MG from aqueous solution. Results show that the percentage removal of MG by nanocomposite is higher than Schiff base. [ABSTRACT FROM AUTHOR]

Differential scanning calorimetry has many advantages over other techniques to study the thermal stability of proteins due to its direct measurement of thermodynamic parameters. Most proteins undergo irreversible thermal denaturation causing their thermogram to be scan rate dependent. We modeled reversible and irreversible protein thermograms at varying scan rates. The complete Lumry-Eyring model was used to model the irreversible thermograms at various values of T 1/2 (temperature at which equilibrium constant equals unity) and T * (temperature at which rate constant equals 1 min −1 ). Our results have shown that the thermal effects of two processes are integrated with decreasing the T * relative to T 1/2 . It is also shown that the shape of second derivatives of thermograms under different conditions have specific pattern which can be used to judge and estimate the correct model for protein denaturation. [ABSTRACT FROM AUTHOR]

The aim of this study is to develop a simple and applicable HPLC method for the detection of cefpodoxime acid (CFA) in rabbit plasma after oral administration of cefpodoxime proxetil (CFP) loaded chitosan–alginate (CH-ALG) beads formulation. CFP is a prodrug that is deesterified in vivo to its active metabolite CFA to exhibit antibiotic activity. Chromatographic separation of CFA and internal standard (IS) was achieved by a RP18(C18), Phenomenax®100, (250 × 4.6 mm) with the mobile phase consisting of (0.02 mol/l (20 mM) ammonium acetate solution and acetonitrile (92:8, v/v, pH = 4.6) at a flow rate of 1.0 ml/min. The method was validated according to the requirements of US-FDA guidelines for bioanalytical method validation. The linear regression analysis for the calibration plots showed good linear relationship (R 2 = 0.9905) in the working concentration range of 0.5–50 μg/ml. The limits of detection and quantification (S/N = 3) were 0.069 and 0.136 μg/ml. Plasma CFA levels were successfully determined in rabbit with satisfactory precision and accuracy. The analyte was found to be stable after a number of stability studies. The proposed HPLC method was successfully applied to pharmacokinetic study in rabbits for CFP loaded CH-ALG beads and marketed immediate release (IR) tablets. All pharmacokinetic parameters were assessed. [ABSTRACT FROM AUTHOR]

In screening for antioxidant and α-glucosidase inhibitors from the extracts of Hertia cheirifolia L. flowers, the petroleum ether extract showed interesting antioxidant activity and inhibitory effect on the activity of α-glucosidase. The fractionation of this extract resulted in the isolation of a compound which is characterized by NMR and ESI–MS as a nopol. The nopol exhibited potent α-glucosidase inhibitory potential with IC 50 value of 220 μM. The kinetic evaluation indicated that it acts as a non-competitive inhibitor. A molecular docking study proved that the nopol presented a strong affinity with amino acid residues of α-glucosidase. [ABSTRACT FROM AUTHOR]

Fabrication of an immobilized cross-linked chitosan-epichlorohydrine thin film (CLCETF) onto glass plate for adsorption of reactive orange 16 (RO16) dye was successfully studied using the direct casting technique. Adsorption experiments were performed as a function of contact time, initial dye concentration (25 mg/L to 350 mg/L), and pH (3–11). The adsorption isotherm followed the Langmuir model. The adsorption capacity of CLECTF for RO16 was 356.50 mg/g at 27 ± 2 °C. The kinetics closely followed the pseudo-second-order model. Results supported the potential use of an immobilized CLECTF as effective adsorbent for the treatment of reactive dye without using filtration process. [ABSTRACT FROM AUTHOR]

Aqueous solutions of reline and glyceline, the most common deep eutectic solvents, were used as a medium for Catalase reaction. By some spectroscopic methods such as UV–vis, fluorescence and circular dichroism (CD) function and structure of Catalase were investigated in aqueous solutions of reline and glyceline. These studies showed that the binding affinity of the substrate to the enzyme increased in the presence of 100 mM glyceline solution, which contrasts with reline solution that probably relates to instructive changes in secondary structure of protein. Meanwhile, enzyme remained nearly 70% and 80% active in this concentration of glyceline and reline solutions respectively. In the high concentration of DES solutions, enzyme became mainly inactive but surprisingly stayed in nearly 40% active in choline chloride solution, which is the common ion species in reline and glyceline solvents. It is proposed that the chaotropic nature of choline cation might stop the reducing trend of activity in concentrated choline chloride solutions but this instructive effect is lost in aqueous deep eutectic solvents. In this regard, the presence of various concentrations of deep eutectic solvents in the aqueous media of human cells would be an activity adjuster for this important enzyme in its different operation conditions. [ABSTRACT FROM AUTHOR]

Hydrocolloid interactions with solvent/cosolutes play a vital role in the resolution of their functional properties. Basil seed gum (BSG) is a plant-derived hydrocolloid which has been found many applications in food formulations as stabilizer, emulsifier, thickener and gelling agents. Sucrose and lactose are the most effective sugars in textural and sensorial properties of bakery and dairy products which adding them to solutions containing hydrocolloids can be helpful to approach a proper formula. In this paper, the effect of temperature (25–65 °C), sucrose (10, 20, 30 and 40%) and lactose (5, 10 and 15%) were investigated through some molecular parameters of BSG. Results revealed high flexible chain (665.35), intrinsic viscosity (11.38 dl/g) and hydrogel content (73%) of BSG, which may be attributed to some extent by its high molecular weight (1.73 × 10 6 Da). The density and intrinsic viscosity of BSG were diminished by growing temperature from 25 to 55 °C. Among five models, which were applied to estimate intrinsic viscosity, Higiro-2 was the most suitable model at varying temperatures and cosolutes concentrations. The sugars showed a significant effect on the molecular parameters of BSG such as swollen specific volume, shape function, hydration parameter, and coil dimensions. The sugars showed more impact on the [η] of BSG and its molecular parameters than that of temperature. However, lactose had a more prominent effect on the BSG dimensions than that of sucrose, which can be related to its molecular conformation and spatial orientation. It is feasible to make a proper formula by BSG and explain some phenomena in its applications in food and pharmaceutical systems. [ABSTRACT FROM AUTHOR]