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Hyperbranched polyamidoamine (PAMAM) has a high density of surface amino groups. This feature was exploited in the surface modification of κ-carrageenan gel beads for successful protease immobilization. The optimum PAMAM pH was at 2.1 and 9.3. However, treatment of κ-carrageenan gel beads at the higher pH showed re-usability for more than seven successive times. As a result of central composite design optimization, the maximum immobilization yield was obtained by soaking 8 U for 24 h. The comparative thermodynamics studies showed an enhancement in the thermal stability at high temperature for the immobilized protease as well as increased half-life time from 24.06 min to 79.95 min. Also, the D-values increased from 165.03 min to 548.23 min for free and immobilized enzyme, respectively. Moreover, the enzyme stability enhancement for the immobilized protease catalyst was accompanied with a remarkable increase in the enthalpy and in the free energy. Immobilized protease onto Carr-PAMAM gel beads can retain 89% of its initial activity and lost only 11% after 8 weeks of storage at 4 °C. Furthermore, an effective removal of silver from used X-ray film by the immobilized protease was achieved for six repeated cycles. Unlabelled Image [ABSTRACT FROM AUTHOR]

Twelve bacterial strains were isolated from beehives of Yemen, Nigerian and Libyan honey bee. All the isolates showed dextransucrase activity with degrees of variation. Esawy-1 recorded the highest activity (10.53) and was identified morphologically and based on 16S rRNA as Enterococcus faecalis . Some isolate safety was assessed such as hemolytic activity and resistance to antibiotic. The isolate showed sensitivity to most tested antibiotic such as levofloxacin, ofloxacin, ciprofloxacin and vancomycin. Also, the hemolytic activity was negative. A 2- level Plackett–Burman design was used to determine the bioprocess parameters that affected dextransucrase productivity. Central composite design was consequently showed 6.70-fold improvement in dextransucrase productivity in compared to the basal medium. Also, the results showed a 96% correlation between sucrose concentration and the amount of dextran yield. FTIR and 1HNMR spectrum confirmed that the formed polysaccharide was dextran comparing to a standard dextran. Enterococcus faecalis Esawy KR758759 dextran showed a fibrinolytic activity matching the standard Hemoclar preparation (40%) while the anticoagulation activity was negative. Also, it recorded a promising prebiotic against Lactobacillus casie (1.82). All previous results recommended the Enterococcus faecalis dextran to be used in food and pharmaceutical fields and paid attention to the honey as a source of potential bacterial dextransucrase. [ABSTRACT FROM AUTHOR]

Previously, Bacillus subtilis HMNig-2 and Bacillus subtilis MENO2 exhibited in vitro promising probiotic characteristics. They were tolerant to pH, bile salts, pancreatic enzymes, exhibited antimicrobial activity against pathogens and had ability to form biofilm. These strains also showed the highest levansucrase production and levan yield. In this study, the impact of the two Bacillus subtilis isolates and their levans were assessed in vivo in a mouse model. A novel correlation between the probiotic properties of the strains and their yielded levans was studied in terms of their effect on gut microbiota, immune system improvement and protection from Salmonella typhimurium infection that could cause liver inflammation and hepatic infiltration. Generally, the synbiotic strain (HMNig-2 and its levan) recorded the best results in lowering the coliform count by 1.5 log while increasing Lactobacillus bacteria count in gut by almost 0.8 log. Furthermore, it achieved the highest total IgA (22.4 µg/mL), IgG (115.2 µg/mL) and lysozymes concentrations (81.6 U/mL) compared to 14.1 (µg/mL), 98.8 (µg/mL) and 64.5 (U/mL) of control, respectively indicating its beneficial role in immune system improvement. Results suggested that interaction between the probiotic strains with their levan could be used as synbiotics providing optimal liver protection against pathogen complications as shown by normal hepatic lobules and portal tracts. Levans of isolate B. subtilis HMNig-2 and B. subtilis MENO2 showed free radical scavenging activity of 48% and 40%, respectively. Results suggest the worth of studying further the possible applications of honey isolates and their products in health protection. [ABSTRACT FROM AUTHOR]

A series of 1,2,3-triazoles coupled diaryl sulfone containing compounds were synthesized by the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction in benign solvents under ultrasound irradiation. In situ formation of azides from α-bromoketones together with the CuAAC reaction in one pot allowed safe handling and good availability of azides for the development of a small library of compounds. The sonication reduced reaction time and increased yields compared to otherwise same conditions. All synthesized compounds were evaluated for antibacterial, antifungal and antioxidant activities. Compounds 3b, 6b and 9e-9g were found to be the most potent antifungal agents with minimal inhibitory concentration (MIC) at 25 µg/mL; moreover other compounds revealed good to moderate antimicrobial activity. Compound 8e showed an excellent antioxidant activity using a DPPH free radical scavenging assay. [ABSTRACT FROM AUTHOR]

Abstract: Phytase production by Penicillium purpurogenum GE1 isolated from soil around bean root nodules was investigated by solid state fermentation (SSF) using mixed substrates consisted of corn cob and corn bran. The SSF conditions were optimized by using one-variable–at-a-time strategy. The optimum conditions for phytase production were at 27°C, pH 8 and 66% moisture content. The study of different carbon and nitrogen sources revealed that glucose and peptone registered the highest enzyme productivity (92±5.6U/g ds, 125±4.9U/g ds). Among different surfactants, maximum phytase productivity was observed with Tween 80 at 0.001 concentrations (170±4.2U/gds). A Box–Behnken design was employed to investigate the optimization of the most significant variables affecting the enzyme production. Maximal phytase production was detected after the addition of (g/5gds): 0.75 glucose, 0.375 peptone and 0, 01 tween 80. This result represented an improvement in phytase production of 2.6 folds when compared to that previously obtained using the basal medium under the same cultivation conditions. The generated model was found to be very adequate for phytase production (90% accuracy) as the experimental value was 444±3.5U/gds compared to 401U/gds for the predicted value. In brief, the production of phytase using corn cob and corn bran is a novel and cheap way for the production of this important enzyme and opens a new way for researchers to discover and explore this arena. [Copyright &y& Elsevier]

Abstract: A sequential optimization strategy, based on statistical experimental designs, was employed to enhance the production of invertase by Lactobacillus brevis Mm-6 isolated from breast milk. First, a 2-level Plackett–Burman design was applied to screen the bioprocess parameters that significantly influence the invertase production. The second optimization step was performed using fractional factorial design in order to optimize the amounts of variables have the highest positive significant effect on the invertase production. A maximal enzyme activity of 1399U/ml was more than five folds the activity obtained using the basal medium. Invertase was immobilized onto grafted alginate beads to improve the enzyme''s stability. Immobilization process increased the operational temperature from 30 to 60°C compared to the free enzyme. The reusability test proved the durability of the grafted alginate beads for 15 cycles with retention of 100% of the immobilized enzyme activity to be more convenient for industrial uses. [Copyright &y& Elsevier]

Abstract: In the present work, 1-(5-methyl-2-phenyl-1H-imidazol-4-yl)ethanone 1 was prepared and used as a precursor for the synthesis of new thiazole, arylidiene and coumarin derivatives. The antimicrobial, antioxidant, anti-hemolytic, and cytotoxic activities of new compounds have been screened. Compound 12 showed an excellent antibacterial activity for all the tested bacteria with minimal inhibitory concentration (MIC) ranged between 21.9 and 43.8 μg/mL. While, compounds 2, 8 and 10a were the best antioxidant reagents using the DPPH method. Compounds 6a and 10b proved to exhibit potent antioxidative activity as reflected in the ability to inhibit lipid per-oxidation in rat brain and kidney homogenates and rate erythrocyte hemolysis. Compounds 6a proved to have the highest cytotoxic activity (81.9%) followed by 2, 6c, 7b and 12 using in vitro Ehrlich ascites assay. The details synthetic methods, spectroscopic data and biological results are recorded. [Copyright &y& Elsevier]

Abstract: Reaction of aryloxyacetic acid hydrazides 1a,b with α-haloketones such as hydrazonoyl chlorides 2a,b; phenacyl bromides 6a,b; and 2-chloro-N-(1,3-thiazol-2-yl)acetamide 10 led to the formation N-(4-halophenyl)-2-[2-(aryloxyacetyl)hydrazinylidene]propanehydrazonoyl chloride 3a–d; (ethene-1,2-diyl)bis-2-(naphthalen-2-yloxy)acetohydrazides 9a,b; and 2-[(2-aryloxyacetyl)hydrazinyl)]-N-(1,3-thiazol-2-yl)acetamides 11a,b; respectively. The nucleophilic substitution reaction of 3a–d with thiophenol and sodium benzenesulfinate furnished the corresponding hydrazinylidenepropanehydrazonothioates 4a–d and sulfones 5a–d, respectively. The antimicrobial activities of the synthesized compounds were evaluated. The obtained data indicated that the majority of the tested compounds exhibited antibacterial activity while all those compounds showed antifungal activity. Sulfone 5d showed greater effect with all tested organism than well known antibacterial and antifungal agents with minimal inhibitory concentration (MIC) ranged between 4.125 and 16.5 μg/mL. [Copyright &y& Elsevier]

Alginate- polyethyleneimine gel beads modified by using 0.3 M Na+ were used for covalent immobilization of Aspergillus flavus xylanase. SEM images showed distorted structure with addition of Na+ that impaired the egg-box structure formation offered much covalent binding with xylanase. Immobilization onto (Alg+PEI/Na+) showed an enhancement in the operational stability, immobilization efficiency as well as immobilization yield. Covalent immobilization of xylanase onto (Alg+PEI/Na+) enhanced xylanase activity over a wide range of pHs (4–5.5) comparable to its free formula. As well as an increase in reaction temperature up to 60°C. However, immobilized formula of enzyme showed abroad thermal stability that it retained 79.0% of its initial activity at 70°C up to 30 min whereas, free formula completely lost its activity at this temperature. Thermodynamics studies showed an enhancement in thermal stability at high temperature for the immobilized xylanase. i.e. At 70°C the t 1/2 and D-value for free formula of enzyme increased from 24 to165 min and from 79.95to 548.23 min, respectively. Moreover, the enzyme stability enhancement for immobilized formula of xylanase was proved with a remarkable increase in enthalpy and free energy. 93% of the immobilized xylanase activity was retained over 6 weeks of storage at -4°C. [ABSTRACT FROM AUTHOR]

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2 4 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH 4.5–5.5 and the optimum operational temperature from 55 °C to a higher temperature, of 60 °C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Production of levansucrase from Bacillus subtilis by SSF technique. [•] A sequential optimization strategy for identifying the enzyme production parameters. [•] Antitumor and fibrinolytic activities for levan and quaternized levan were tested. [ABSTRACT FROM AUTHOR]

Highlights: [•] This research highlights honey isolates significance as new levan sucrase sources. [•] Levan and levansucrase were scaling up successfully. [•] LevC and its Fraction 3 revealed strong cancer chemo-preventive activity. [ABSTRACT FROM AUTHOR]

Abstract: New pyrazolyl-1,2,3-triazoles and 1,2,3-triazol-4-yl-pyrazolylthiazoles were synthesized through multi step reactions using 1-tolylyl-4-acetyl-5-methyl-1,2,3-triazole as a precursor. All the newly synthesized compounds were characterized by spectral and elemental analyses. The structure of 11b was evidenced by X-ray crystallographic study. The newly synthesized compounds were evaluated for their antimicrobial activities and also their minimum inhibitory concentration (MIC) against most of test organisms was performed. Amongst the tested compounds 5a, 5c, 11b and 11c displayed excellent antimicrobial activity. [Copyright &y& Elsevier]

Abstract: Development of efficient ocular delivery nanosystems remains a major challenge to achieve sustained therapeutic effect. The purpose of this work was to develop chitosan nanoparticles using sulfobutylether-β-cyclodextrin (SBE-β-CD) as polyanionic crosslinker and to investigate the potential of using those nanostructures as ocular drug delivery systems. Econazole nitrate (ECO) was chosen as model drug molecule. The influence of different process variables (chitosan molecular weight and the concentration of the two ionic agents) on particle size, polydispersity index, zeta potential, drug content, in vitro release and mucoadhesive properties was investigated. The results showed that the prepared nanoparticles were predominant spherical in shape having average particle diameter from 90 to 673nm with positive zeta potential values from 22 to 33mV and drug content values ranging from 13 to 45%. Drug release from optimized nanoparticles was controlled with approximately 50% of the original amount released over a 8h period. The release profile of nanoparticles followed a zero-order release kinetics. The optimized nanoparticles were tested for their use as ocular drug delivery systems on albino rabbits. The in vivo studies revealed that the prepared mucoadhesive nanoparticles had better ability in sustaining the antifungal effect of ECO than the ECO solution. Therefore, chitosan/SBE-β-CD nanoparticles developed showed a promising carrier for controlled delivery of drug to the eye. [Copyright &y& Elsevier]