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In view of the feed/foods inevitably contaminated by toxic and carcinogenic aflatoxin B1 (AFB1), efficient mesoporous metformin-chitosan/silica­cobalt ferrite nanospheres (Mt-CS/CFS NSs) was prepared to remove AFB1 from aqueous/non-aqueous media. The morphological, functional, and structural characteristics and adsorption properties of C/N-enriched CS/CFS were investigated systematically. The interactive operating variables (temperature (5.0-35 °C); time (10-100 min); AFB1 dose (50-100 µg/mL); and Mt-CS/CFS dosage (0.5-3.5 mg) were optimized via the Box-Behnken design (BBD), which demonstrated good agreement between the experimental data and proposed model. The adsorption efficiency in artificially contaminated cow's milk as well as aqueous environment reached over 91.0 % in a wide pH range (3.0-9.0), without significant change in the nutritional value of milk. Freundlich isotherm and second-order adsorption kinetics were regarded as the most suitable models to fit the adsorption results, and the adsorption rate is dominated by the intra-particle diffusion and boundary layer diffusion. Thermodynamic analyses proved that the process was spontaneous and exothermic. The adsorption mechanism could be explained as physisorption via hydrogen bonding, n-π interaction, and hydrophobic/hydrophilic interactions. The porous Mt-CS/CFS NS derived from chitosan nanoparticles is therefore outstanding adsorbent, offering great adsorptive performance and recycabilities, which impedes economic losses in the food industry.

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Currently, the use of magnetic physical adsorbents for detoxification is widely applied in the food industry; however, the fabrication of high-efficiency low-cost absorbents without damaging the nutritional quality of food is a major challenge. Herein, a simple, green, efficient, and cost-effective method for the magnetic solid-phase extraction of aflatoxin B1 (AFB1) from edible oils and aqueous matrices was developed using a dopamine-loaded biomass chitosan-iron-cobalt spinel oxide nanocomposite (DC/CFOS NC). The characterization, physicochemical processes, mechanism, and reusability of DC/CFOS were systematically evaluated in detail. It was found that the adsorption characteristic of DC/CFOS NC was accurately represented by the pseudo-second-order kinetics (k2 = 0.199 g mg-1 min-1) and Freundlich isotherm models (Kf = 1.139 (mg g-1) (L mg-1), R2 = 0.991)), and its adsorptive process is feasible, spontaneous, and exothermic. Benefiting from its high specific surface area, microporous structure, and polar/non-polar active sites, the as-prepared DC/CFOS exhibited an excellent adsorption performance for AFB1 (50.0 µg mL-1), as measured using the Freundlich isotherm model. The mechanistic studies demonstrated that the synergistic effects of the surface complexation and electrostatic interactions between the functional groups of DC/CFOS NC and AFB1 were the dominant adsorption pathways. Besides, DC/CFOS exhibited negligible impacts on the nutritional quality of the oil after the removal process and storage. Thus, DC/CFOS NC showed sufficient efficacy and safety in the removal of AFB1 from contaminated edible oil.

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BACKGROUND AND OBJECTIVE: Multi-walled Carbon Nano Tubes (MWCNTs) as an important element of nanosciences have a remarkable absorption in the region of NIR window (650-900 nm) which can overcome the limitations of deep treatment in photothermal therapy. To disperse MWCNTs in water, it is proposed to attach carboxylated functional group (-COOH) to MWCNTs in order to increase dispersivity in water. MATERIALS AND METHODS: A stable suspension of MWCNTs-COOH with different concentrations (from 2.5 to 500 µg/ml) was prepared. Then, they were compared for their ability to increase temperature in the presence of 810 nm laser irradiation and through a wide range of radiation time (from 20 to 600 s) and three laser powers (1.5, 2 and 2.5 w). The temperature rise was recorded real time every 20 seconds by a precise thermometer. RESULTS: Absorption spectrum of MWCNTs-COOH suspension was remarkably higher than water in a wavelength range of 200 to 1100 nm. For example, using the concentrations of 2.5 and 80 µg/ml of MWCNTs-COOH suspension caused a temperature elevation 2.35 and 9.23 times compared to water, respectively, upon 10 min laser irradiation and 2.5 w. Moreover, this predominance can be observed for 1.5 and 2 w radiation powers, too. Our findings show that the maximum of temperature increase was obtained at 80 µg/ml concentration of MWCNT-COOH suspension for three powers and through all periods of exposure time. Our results show that the minimum required parameters for a 5°C temperature increase (a 5°C temperature increase causes cell death) were achieved through 2.5 w, 28 µg/ml concentration and 20 second irradiation time in which both concentration and radiation times were relatively low. CONCLUSION: Our results showed that MWCNTs-COOH can be considered as a potent photothermal agent in targeted therapies. New strategies must be developed to minimize the concentration, irradiation time and radiation power used in experiments.

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A series of N-[2-oxo-2-(4-substitutedphenyl)ethyl]piperazinyl quinolones(1a-e,2a-e and 3a-c) and N-[2-hydroxyimino-2-(4-substitutedphenyl)ethyl]piperazinyl quinolones(1f-j,2f-j and 3d-f) were evaluated for antituberculosis activity against Mycobacterium tuberculosis H37R, using the BACTEC 460 radiometric system and BACTEC 12B medium. Active compounds were also screened by serial dilution to assess toxicity to a VERO cell line. Nine compounds were efficient antimycobacterial agents showing MIC values ranging from 0.78 to 6.25 micrograms/ml. Generally, ciprofloxacin derivatives were more active than norfloxacin and enoxacin derivatives and the oxime analogues were less active than corresponding ketones. The most selective and less toxic compound 1a was tested for efficacy in vitro in TB-infected macrophage model (EC90 = 3.68 micrograms/ml, EC99 = 9.18 micrograms/ml).

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Dihydropyridine having substituted imidazole at 4-position in conjunction with various C3, C5 diesters have calcium channel antagonist activity. In this paper a group of dialkyl, dicycloalkyl and diaryl ester analogues of nifedipine, in which the ortho-nitro phenyl group at position 4 replaced by 2-methyl-4(5)-chloro-5(4)-imidazolyl substituent, were synthesized and evaluated as calcium channel antagonists using the high K+ contraction of guinea-pig ileal longitudinal smooth muscle (GPILSM). The results for the symmetrical ester series showed that increasing the length chain in C3 and C5 ester substituents increased activity. When increasing of the length or lipophilicity accompany with increasing the hindrance, the activity decreased. In asymmetrical diester series, the results showed when R1 is methyl or ethyl, increasing of the lipophilic property in R substituent increases the activity if this high lipophilicity don't accompany with steric hindrance. Our results demonstrate that in symmetrical and asymmetrical series aromatic compounds were more active than aliphatic compounds. In symmetrical diesters compounds, the most active compound was diphenylethyl ester derivative, that it was more active than the reference drug nifedipine. These structure activity data indicate that the 2-methyl-4(5)chloro-5(4)-imidazolyl moiety is bioisoester of 2-nitrophenyl and 2-chlorophenyl moieties.

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A series of N-substituted-piperazinyl-quinolones were synthesized and evaluated for in vitro antibacterial activity. Compounds with a 2-(2,4-dichlorophenyl)-2-oxoethyl group attached to the piperazine ring (5a-c) had similar antibacterial activity to the reference drugs, ciprofloxacin, norfloxacin and enoxacin against both Gram-positive and Gram-negative bacteria. The oximes 6a-c and 6g-i were almost less active than corresponding ketones against the tested microorganisms, however the 2,4-difluorophenyl analogues (6g-i) were more active than 2,4-dichlorophenyl derivatives (6a-c). If the hydrogen of oxime is replaced with a benzyl group (6d-f & 6j-l), in-vitro antibacterial activity was decreased against both Gram-positive and Gram-negative bacteria. Generally ciprofloxacin derivatives were more active than norfloxacin and enoxacin derivatives.

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