Search

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]

Traditional azole antifungal formulations suffer from poor retention in the vaginal cavity, irritation and burning of the vaginal area. In the present work, we aim at the development of a novel miconazole (MCZ) microsponges gel as an attractive dosage form for vaginal candidiasis. The proposed formula has the potential to minimize the local side effects of the drug due to the controlled release characteristic, which increases patient compliance. Moreover, the mucosal retention effect of the microsponges in addition to the bioadhesion property of Carbopol gel prolongs the retention of the dosage form in the vagina and consequently improves the therapeutic efficiency. MCZ microsponges were prepared applying Quasi emulsion method using Eudragit RS100. The effect of formulation factors, namely, drug:polymer ratio (1:1, 2:1 and 4:1), the amount of poly vinyl alcohol (PVA) (25, 50 and 75 mg) and the volume of organic solvent (2.5, 5, 10 mL) on the characteristics of MCZ microsponges has been investigated. The microsponges were optimized regarding the production yield (68.8 ± 6.4%), particle size (78.2 ± 2.1 μm), entrapment efficiency (92.9 ± 1.9%) and release rate (Q150 51.8 ± 2.5%). The selected formula was further evaluated for its, flowability, porosity and surface morphology. MCZ microsponges were incorporated into Carbopol gel, then the viscosity and bioadhesion were examined. The in vitro antifungal activity of MCZ microsponges gel was comparable to the market product. In vivo, MCZ microsponges vaginal gel was more effective than the market product (p < 0.05) in eradicating Candida infection in rats, which was supported by the histopathological findings. [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: 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]

This study aimed to investigate whether the gastroprotective effects of three types of bacterial levans are correlated with their prebiotic-associated anti-inflammatory/antioxidant potentials. Three levans designated as LevAE, LevP, and LevZ were prepared from bacterial honey isolates; purified, and characterized using TLC, NMR, and FTIR. The anti-inflammatory properties of levan preparations were assessed in LPS-stimulated RAW 264.7 cell lines, while their safety and gastroprotective potentials were assessed in Wistar rats. The three levans significantly reduced ulcer number (22.29–70.05 %) and severity (31.76–80.54 %) in the ethanol-induced gastric ulcer model compared to the control (P < 0.0001/each), with the highest effect observed in LevAE and levZ (200 mg/each) (P < 0.0001). LevZ produced the highest levels of glutathione; catalase activity, and the lowest MDA levels (P = 0.0001/each). The highest anti-inflammatory activity was observed in LevAE and levZ in terms of higher inhibitory effect on IL-1β and TNF-α production (P < 0.0001 each); COX2, PGE2, and NF-κB gene expression. The three levan preparations also proved safe with no signs of toxicity, with anti-lipidemic properties as well as promising prebiotic activity that directly correlated with their antiulcer effect. This novel study highlights the implication of prebiotic-mediated systemic immunomodulation exhibited by bacterial levans that directly correlated with their gastroprotective activity. • Three types of levans were prepared from honey bacterial isolates and characterized. • The three levans significantly reduced ulcer number/severity in gastric ulcer model. • Prepared levans inhibited the inflammatory cascade on the transcriptional level. • All levans showed promising anti-lipidemic properties with no signs of toxicity. • The gastroprotective effect of prepared levans was largely prebiotic-specific. [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]

• A new set of hydronaphthalene-sulfonamides were synthesized in a facile approach. • Some of the synthesized agents reveal potent antimicrobial properties. • The promising candidates showed high level of safety towards the human normal cells. • 2D-QSAR model described the antimicrobial properties observed. In the present work, authors successfully prepared potent antimicrobial agents of new tetrahydronaphthalene-sulfonamide derivatives, derived from new easily synthetic route of 3-methoxy-8-oxo-5,6,7,8-tetrahydronaphthalene-2-sulfonyl chloride 2. Preparation method of this compound has not been published yet, however it is available commercially expensively, which motivated us to innovate new efficient and facile method for its preparation. All the synthesized compounds were tested for in vitro antimicrobial inhibitory activities against a panel of Gram-positive, Gram-negative bacterial pathological strains and Candida Albicans. Compound 2 showed poor activity towards all of the tested pathogenic strains, but it is easily modified and converted from biologically inactive compound to highly active sulfonamide products 5a-f , or moderately active compounds 3a-k. Cytotoxic evaluation of the promising candidates 5d and 5e showed marked safety profile towards the human normal cells. QSAR study for the new compounds was carried out and was compatible with the antimicrobial results. [Display omitted] [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]

New pyranocoumarin and coumarin-sulfonamide derivatives were prepared and evaluated for their antioxidant, antimicrobial, and/or anti-inflammatory activities. Coumarin-sulfonamide compounds 8a–d demonstrated significant antioxidant activity, while 7c,d, 8c,d, and 9c,d exhibited antimicrobial activity equal to or higher than the standard antimicrobials against at least one tested microorganism. Regarding the anti-inflammatory testing, pyranocoumarins 2b, 3a,b and 5c and coumarin-sulfonamide compound 9a showed more potent antiproteinase activity than aspirin in vitro; however, five compounds were as potent as aspirin. The anti-inflammatory activity of the promising compounds was further assessed pharmacologically on formaldehyde-induced rat paw oedema and showed significant inhibition of oedema. For in vitro COX-inhibitory activity of coumarin derivatives, pyranocoumarin derivative 5a was the most selective (SI = 152) and coumarin-sulfonamide derivative 8d was most active toward COX-2 isozyme. The most active derivatives met the in silico criteria for orally active drugs; thus, they may serve as promising candidates to develop more potent and highly efficient antioxidant, antimicrobial, and/or anti-inflammatory agents. [ABSTRACT FROM AUTHOR]