Molecularly imprinted polymer nanoparticles-based electrochemical sensor for determination of diazinon pesticide in well water and apple fruit samples.

In this research, an electrochemical sensor based on molecularly imprinted polymer (MIP) nanoparticles for selective and sensitive determination of diazinon (DZN) pesticides was developed. The nanoparticles of diazinon imprinted polymer were synthesized by suspension polymerization and then used for modification of carbon paste electrode (CPE) composition in order to prepare the sensor. Cyclic voltammetry (CV) and square wave voltammetry (SWV) methods were applied for electrochemical measurements. The obtained results showed that the carbon paste electrode modified by MIP nanoparticles (nano-MIP-CP) has much higher adsorption ability for diazinon than the CPE based non-imprinted polymer nanoparticles (nano-NIP-CP). Under optimized extraction and analysis conditions, the proposed sensor exhibited excellent sensitivity (95.08 µA L µmol(-1)) for diazinon with two linear ranges of 2.5 × 10(-9) to 1.0 × 10(-7) mol L(-1) (R (2) = 0.9971) and 1.0 × 10(-7) to 2.0 × 10(-6) mol L(-1) (R (2) = 0.9832) and also a detection limit of 7.9 × 10(-10) mol.L(-1). The sensor was successfully applied for determination of diaznon in well water and apple fruit samples with recovery values in the range of 92.53-100.86 %. Graphical abstract Procedure for preparation of electrochemical sensor based on MIP nanoparticles for determination of diazinon.

Characterization of fructan extracted from Eremurus spectabilis tubers: a comparative study on different technical conditions.

The fructans, inulin and oligofructose, were known to possess many physiologic properties. In the present study, the Box-Behnken design was used to determine the optimum extraction conditions of fructan from Eremurus spectabilis root powder (Serish) with water extraction, direct and indirect ultrasound assisted extraction methods that gave the maximum yield. Sonication amplitude (20-100 %), sonication temperature (30-70 °C) and sonication time (5-40 min) were considered variables of direct and indirect ultrasound extractions while for conventional extraction the following variables were water to solid ratio (30-50 v/w), temperature (40-90 °C) and time (5-40 min). A second-order polynomial model was fitted to each response and the regression coefficients were determined using least square method. There was a good agreement between the experimental data and their predicted counterparts. In addition to establishing the difference of these extraction methods, the scanning electron microscopy, Fourier-transform infrared spectroscopy, zeta potential and particle size analysis have been shown to be useful tools to investigate, approximate and predict characteristics of extracted fructan. Moreover, comparison of conventional extraction, direct sonication extraction, indirect sonication extraction showed the indirect sonication extraction is a suitable method for fructan extraction.

Determination of parathion, aldicarb, and thiobencarb in tap water and bottled mineral water in Mashhad, Iran.

Water is a necessity for life. Currently, because of different contaminations in tap water, most people prefer using bottled mineral waters. Pesticides (e.g., organophophorous, carbamates, etc.) are among the most dangerous chemicals that may be found in drinking waters, which can cause long- and short-term complications. Because all people consume at least 2 L of water per day, water-quality monitoring is vital. In this study, we determined the concentration of three pesticides (aldicarb, parathion, and thiobencarb) in 13 tap-water samples collected from 13 different urban areas and 10 samples of bottled mineral water in Mashhad, a major city in northeast Iran. Samples were analyzed by gas chromatography coupled with a pulsed flame photometric detector after solid-phase extraction. Results showed that 2 of 13 tap-water samples and 2 of 10 bottled mineral water trademarks were contaminated either by parathion or by thiobencarb or both, with concentrations ranging between 0.6 and 0.8 ppb. According to the defined guideline values, determined concentrations of pesticides are below the permissible World Health Organization level for these toxic agents, and it is considered that drinking these tap waters and bottled mineral waters are safe for human consumption.

Synthesis and characterization of composite polymer, polyethylene glycol grafted flower-like cupric nano oxide for solid phase microextraction of ultra-trace levels of benzene, toluene, ethyl benzene and o-xylene in human hair and water samples.

In this research, poly (ethylene glycol)-poly (ethylene glycol) grafted flower-like cupric oxidenano particles (PEG-PEG-g-CuO NPs) as a novel fiber coating of solid-phase microextraction (SPME) were synthesized by using sol-gel technology. This fiber was successfully applied to extract and determine the ultra-trace levels of benzene, toluene, ethyl benzene and o-xylene in human hair using head space-solid-phase microextraction (HS-SPME) coupled to gas chromatography-flame ionization detector. Characterization and chemical composition of the nano particle was performed by Fourier transform infrared spectroscopy (FT-IR), energy dispersion spectroscopy (EDS) and back scatter analysis (BSA). These methods confirmed the successful fabrication of PEG-g-CuO NPs. The surface morphology of the fibers were inspected by scanning electron microscopy. The scanning electron microscopy (SEM) revealed many "crack-like" features and highly porous structure on the surface of fiber. The synthesized nanocomposites were used for preconcentration and extraction of benzene, toluene, ethyl benzene and o-xylene (BTEX). The effects of operating parameters such as: desorption temperature and time, extraction temperature, extraction time, stirring speed and salt effect were investigated and optimized. Under the optimal conditions, the method detection limits and the limits of quantification were between 0.00025-50.00000pgmL(-1) and 0.00200-200.00000pgmL(-1), respectively. Linearity was observed over a range 0.00200-200000.00000pgmL(-1). The relative standard deviations for one fiber (repeatability; n=5) were obtained from 3.30 up to 5.01% and between fibers or batch to batch (n=3; reproducibility) in the range of 3.63-6.21%. The developed method was successfully applied to simultaneous determination of BTEX in human hairs, tap water and distillate water.

Preparation, characterization and molecular modeling of PEGylated human growth hormone with agonist activity.

In this study, site-specific PEGylated human growth hormone (hGH) was prepared by microbial transglutaminase, modeled and characterized. To this end, the effects of different reaction parameters including reaction media, PEG:protein ratios, reaction time and pH value were investigated. PEG-hGH was purified by size exclusion chromatography method and analyzed by SDS-PAGE, BCA, peptide mapping, ESI and MALDI-TOF-TOF mass spectroscopy methods. Biophysical and biological properties of PEG-hGH were evaluated. Molecular simulation was utilized to provide molecular insight into the protein-receptor interaction. The optimum conditions that were obtained for PEGylation were phosphate buffer with pH of 7.4, 48 h of stirring and PEG:protein ratio of 40:1. By this method, mono-PEG-hGH with high reaction yield was obtained and PEGylation site was at Gln-40 residue. The circular dichroism and fluorescence spectrum indicated that PEGylation did not change the secondary structure while tertiary structure was altered. Upon enzymatic PEGylation, agonistic activity of hGH was preserved; however, Somavert(®), which is prepared by chemical PEGylation, is an antagonist form of protein. These data were confirmed by the total energy of affinity obtained by computational protein-receptor interaction. In conclusion, PEGylation of hGH was led to prepare a novel form of hormone with an agonist activity which merits further investigations.

Preparation, evaluation and application of diazinon imprinted polymers as the sorbent in molecularly imprinted solid-phase extraction and liquid chromatography analysis in cucumber and aqueous samples.

A series of diazinon imprinted polymers (MIPs) were prepared and evaluated in the binding study in comparison with a non-imprinted polymer (NIP). The optimised MIP was evaluated as a sorbent, for extraction and preconcentration of diazinon from aqueous media and cucumber tissue. The HPLC-UV method was calibrated, in the range of 0.025-10 mg/kg. The results indicated that the optimised MIP had an excellent affinity for diazinon. The molecularly imprinted solid-phase extraction (MISPE) procedure was optimised with a recovery of 77-98%, in aqueous solution, and a recovery of 82-110%, in cucumber. The intra-day variation and inter-day variation values were less than 8.26% and 9.7%, respectively. Our data showed that, the MIP enabled the extraction of trace amounts of diazinon successfully from aqueous solution and cucumber, demonstrating the potential of MISPE for rapid, sensitive and cost-effective sample analysis.

Proteomics screening of molecular targets of granulocyte colony stimulating factor in the mouse brain and PC12 cell line.

AIMS: Granulocyte colony stimulating factor (G-CSF), a new neuroprotective agent, binds to its specific receptors in the brain. In this study we hypothesized that at least a part of G-CSF's neuroprotective effect may be mediated through its interaction with other proteins in the brain. MAIN METHODS: Using an immunoprecipitation (IP) kit, at first the antibody of G-CSF was covalently crosslinked to protein A/G agarose. Then the mouse brain or PC12 cell lysate mixed with G-CSF was added to the agarose beads plus antibody. After immunoaffinity isolation of target proteins, gel electrophoresis was performed and protein bands were identified using MALDI-TOF/TOF and MASCOT software. KEY FINDINGS: Our data show that G-CSF physically binds to cellular proteins like sodium/potassium-transporting ATPase, beta actin, aldehyde dehydrogenase, regucalcin and glutathione-s-transferase. These proteins are involved in membrane transportation, cell structure, signal transduction, enzymes involve in calcium related cell signaling and redox homeostasis. SIGNIFICANCE: Interaction of G-CSF with these proteins can explain some of its pharmacological effects in the CNS.

Photochemical behavior of sethoxydim in the presence of vegetable oils.

The photodecomposition of herbicides may be affected by adding vegetable oils to the spray tank. In this study nine vegetable oils were compared to assess the photodecomposition of sethoxydim under natural light conditions. The experiment was conducted as completely randomized factorial design with three replicates at the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013. Each herbicidal solution (with and without vegetable oil) was exposed to sunshine with time intervals of 0, 5, 10, 20, 30, 60, 120, and 240 min. The results revealed that the half-life value was increased by adding castor bean and cottonseed oils to 1.39- and 1.18-fold, respectively, compared to nonvegetable oil. These values for turnip, olive, corn, soybean, sunflower, canola, and sesame oils were decreased down to 4.74-, 2.38-, 1.81-, 1.75-, 1.52-, 1.28-, and 1.11-fold, respectively. A positive relationship existed between the half-life of sethoxydim in the presence of vegetable oils and their viscosity. However, a negative relationship was monitored between unsaturated/saturated fatty acids ratio and the monounsaturated value with half-life. A positive relationship also existed between saturated fatty acids, polyunsaturated fatty acids, palmitic acid, and linoleic acid with half-life. This study revealed that the amount of fatty acids in vegetable oils is a determining factor in preventing or facilitating the photodecomposition of sethoxydim.

Fractionation of Eremurus spectabilis fructans by ethanol: Box-Behnken design and principal component analysis.

The fructans, inulin and oligofructose, are known to exert many food and pharmaceutical applications and are widely used in functional foods throughout the world for their nutritional and techno-functional properties. In the present study, the Box-Behnken design was used to determine the optimal conditions for fructan precipitation from Eremurus spectabilis root powder (Serish) by adding ethanol that gave the maximum yield. Ethanol-to-syrup (E/S) ratio (2:1-15:1), precipitation temperature (30-60°C) and syrup concentration (10-40°B) were considered variables of fructan precipitation. The most compatible model among mean, linear and quadratic expressions was fitted to each response and the regression coefficients were determined using least square method. There was a good agreement between the experimental data and their predicted counterparts. The optimum conditions for fractionating fructan composition of Serish by ethanol were estimated to be E/S ratio of 8.56, temperature of 23.51°C and initial syrup concentration of 40°B. Precipitation under these optimized conditions achieved the best yield (85.81%), average chain length (12.92) and purity (80.18%). In addition, principal component analysis (PCA) allowed discriminating among precipitated fructan specialties.

Method Validation for the One-Month Stability Study of trans-Resveratrol in Human Plasma.

BACKGROUND: trans-Resveratrol (t-Res) is a natural phenolic compound with various biological activities such as antioxidant, anticancer, cancer chemopreventive, cardioprotective, and neuroprotective. OBJECTIVES: There is no comprehensive study about the stability of t-Res in human plasma. With respect to extensive use of t-Res in clinical trials and pharmacokinetic studies, in this study, we aimed to measure the plasma stability of t-Res at different conditions of lighting, pH, and temperature, and in the presence of routine antioxidant agents (BHT and VIT C). MATERIALS AND METHODS: t-Res stability in human plasma was evaluated at different conditions of lighting, pH and temperature, and in the presence of routine antioxidant agents (BHT and VIT C), and quantitatively determined using HPLC-UV method at 306 nm. RESULTS: Our findings revealed that t-Res was quite stable in different temperatures ranging from -70 °C to 25 °C, and acidic pH conditions in plasma for a month, when protected from light, but it was unstable in alkali pH and in lighting conditions. CONCLUSIONS: In lighting conditions, most of t-Res was isomerized to the other isomer cis-resveratrol. t-Res is unstable in alkali pH and when exposed to light. t-Res was quite stable at other conditions, and several freeze-thaw cycles did not have any effect on its stability.

Detection of sonoluminescence signals in a gel phantom in the presence of Protoporphyrin IX conjugated to gold nanoparticles.

The particles in a liquid decrease the ultrasonic intensity threshold required for cavitation onset. In this study, a new nanoconjugate composed of Protoporphyrin IX and gold nanoparticles (Au-PpIX) was used as a nucleation site for cavitation. The nonradiative relaxation time of Protoporphyrin IX in the presence of gold nanoparticles is longer than the similar time without gold nanoparticles. The acoustic cavitation activity was investigated via recording of the integrated sonoluminescence signal in the wavelength range of 220-700nm in a gel phantom by a cooled charge coupled device (CCD) at different intensities of 1MHz ultrasound. In order to confirm these results, a chemical dosimetric method was utilized, too. The recorded sonoluminescence signal in the gel phantom containing Au-PpIX was higher than the other phantoms. These records have been confirmed by the chemical dosimetric data. Therefore, we anticipate that a new nanoconjugate composed of Protoporphyrin IX and gold nanoparticles can act as an efficient sonoluminescence agent and could be introduced as a novel sonosensitizer for sonodynamic therapy.

Antioxidant activity of leaves and fruits of cultivated conifers in iran.

BACKGROUND: Use of antioxidants is a means of reducing rancidity of fats and oils in food stuffs. The commercial synthetic antioxidants in food industry have been suspected to cause negative health effects. Therefore as alternatives, there is a strong need in finding new effective and safe antioxidants from natural sources to prevent deterioration of foods, drugs and cosmetics. OBJECTIVES: IN ORDER TO INVESTIGATE THE ANTIOXIDANT ACTIVITY FROM NATURAL SOURCES AS ALTERNATIVES OF COMMERCIAL ANTIOXIDANTS, THE ANTIOXIDANT ACTIVITY OF THE EXTRACTS OF LEAVES AND FRUITS OF SIX DIFFERENT SPECIES OF IRANIAN COMMON CONIFERS: Cupressus arizonica, Pinus halepensis, Pinus nigra, Pinus brutia var. elderica, Pinus wallichiana and Cedrus deodara were investigated in the current study. MATERIALS AND METHODS: The leaves and fruits of these plants were collected from different areas of the country. Methanol extracts of leaves and fruits of Iranian common conifers (six species) were prepared. Antioxidant activity of the samples was measured using ferric thiocyante (FTC) and thiobarbituric acid (TBA) tests. RESULTS: The results of the study, using the two methods, showed that all methanol extracts of leaves and fruits of the six species possessed antioxidant activity. The antioxidant activity of the samples was compared with the antioxidant activities of butylatedhydroxytoluene (BHT), as a synthetic antioxidant and α-tocopherol as a natural antioxidant. Methanol extractions of Pinus spp. leaves and fruits showed the highest antioxidant activity (quite higher than α- tocopherol). Among the extracts examined, the leaves of P. halpensis methanol extract showed the lowest activity. CONCLUSIONS: At this stage it can be concluded that methanol extracts of these plants can be considered as strong antioxidant agents. However more investigation is necessary in order to evaluate the antioxidant activity of the components separate from each extracted sample using several different antioxidant methods.

Inter-individual Variability of Coumarin 7-hydroxylation (CYP2A6 activity) in an Iranian Population.

OBJECTIVE(S): Coumarin hydroxylase (CYP2A6) is a polymorphic enzyme, and during the last decade has received a lot of attention because it is the principle human nicotine C-oxidase, which activates a number of procarcinogens, and metabolizes drugs. MATERIALS AND METHODS: 150 healthy Iranian volunteers, (96 male, 54 female) aged 19 to 63 years old, were given 5 mg coumarin orally after an overnight fast. Urine samples were collected before drug administration and 2, 4 and 8 h after that. The extent and rate of the formation of 7-OH-coumarin (7OHC) was determined by the urinary excretion of the metabolite as measured by the fluorometric method. RESULTS: The proportion of 7OHC excreted during the first 2 hr compared to the 7OHC excretion at 8 h was the constant and stable individual characteristic for the rate of the formation of 7OHC (2 hr coumarin test). The total amount of 7OHC formed was 32.7±12.4% (mean±SD) of the given dose. On average, 66.0% of 7OHC formed was excreted in 2 hr. No clear-cut polymorphism in the rate of 7OHC formation was found. The total amounts of 7OHC excreted were significantly lower in females. Also, the rate and amount of coumarin metabolism in Iranian population were lower than Turkish and Finnish populations. CONCLUSION: Because of the importance of enzyme activity in drug metabolism, caution should be exercised in prescribing compounds metabolized by CYP2A6 enzyme in Iranian population.

Sonodynamic Therapy Using Protoporphyrin IX Conjugated to Gold Nanoparticles: An In Vivo Study on a Colon Tumor Model.

OBJECTIVES: Sonodynamic therapy is a physical treatment which utilizes ultrasound waves with an appropriate sensitizer such as protoporphyrin IX (PpIX). The activation of sensitizer depends on cavitation, and therefore, high intensity ultrasound is an important necessity. Beside, high intensity ultrasound can induce side effects on the healthy tissues which have surrounded tumor. The particles in a liquid decrease the ultrasonic intensity threshold needed for onset of cavitation. The non-radiative relaxation time of PpIX in the presence of gold nanoparticles (GNP) is longer than the similar time without GNP. MATERIALS AND METHODS: This study was conducted on colon carcinoma tumor in BALB/c mice. The tumors were induced by subcutaneous injection of CT26 cells. Ultrasound irradiation were performed on tumors 24 hr after the injection of PpIX into GNPs. Antitumor effects were estimated by measuring tumor relative volume, doubling time and time being five times of the tumors and by calculating the average survival time of tumor-bearing mice after treatment. RESULTS: There is no inhibitory effect in control group. Ultrasound irradiation alone showed a slight antitumor effect which was enhanced by ultrasound plus PpIX (SDT). The synergistic inhibitory effect was significant when ultrasound plus PpIX was conjugated to GNPs. CONCLUSION: Our experiments suggested a significant synergistic effect of ultrasound combined with Au-PpIX that reduced tumor relative volume and increased average animal survival fraction. This effect was obviously stronger than ultrasound alone and synergistic effect of ultrasound combined with PpIX.

Nicotine content of domestic cigarettes, imported cigarettes and pipe tobacco in iran.

BACKGROUND: There are many different kinds of cigarettes and tobacco available in the market. Since nicotine content of various brands of cigarettes are very variable, therefore evaluation and comparison of nicotine content of different brands of cigarettes is important. The goal of the present study was to determine and compare nicotine content of various domestic and imported cigarettes available in the area. METHODS: Fourteen popular imported brands and nine popular domestic brands of cigarettes and three available brands of tobaccos were investigated for the amounts of nicotine content. Nicotine was extracted from each cigarette and tobacco samples and was analyzed by high performance liquid chromatography (HPLC) method. FINDINGS: The amount of nicotine in each cigarette was from 6.17 to 12.65 mg (1.23 ± 0.15 percent of tobacco weight in each cigarette) in domestic cigarettes. It was between 7.17-28.86 mg (1.80 ± 0.25 percent of tobacco weight in each cigarette) for imported cigarette, and between 30.08- 50.89 mg (3.82 ± 1.11 percent) for the pipe nicotine. There was significant difference in nicotine amount between imported and domestic brands of cigarettes. There was also no significant difference in nicotine content between light and normal cigarettes in imported brands. CONCLUSION: Nicotine content of all tested cigarettes, imported and domestic brands, were higher than the international standard.

Antioxidant Activity of the Essential Oils of Different Parts of Juniperus excelsa M. Bieb. subsp. excelsa and J. excelsa M. Bieb. subsp. polycarpos (K. Koch) Takhtajan (Cupressaceae).

The essential oils of branchlets and fruits of Juniperus excelsa subsp. excelsa and Juniperus excelsa subsp. polycarpos were examined for their antioxidant activity. The compositions of the essential oils were studied by GC and GC-MS. To evaluation the antioxidants activity of the volatile oils, pure components and positive controls at different concentrations, thin-layer chromatography (TLC) screening methods, diphenylpicrylhydrazyl (DPPH) assay, deoxyribose degradation test and modified deoxyribose degradation test were employed. The results of the present study demonstrate some antioxidant activity for the tested essential oils obtained from various parts of both plants. It indicates that the use of these essential oils, in very low concentrations, may be useful as a natural preservative. However before any final conclusion, it is suggested that the antioxidant activity of these oils should also be evaluated by using lipid solvent system methods.

Can saliva replace plasma for the monitoring of methadone?

The aims of this study were to determine the relationship between saliva and plasma methadone concentrations and the influence of variability in saliva pH. Saliva and plasma samples were taken before the daily dose of methadone in 60 patients undergoing methadone maintenance treatment (MMT). Saliva pH was measured immediately after sampling, and concentrations of (RS)-, (R)-, and (S)-methadone in saliva and plasma were assayed by LC/MS. In addition, unbound (R)- and (S)-methadone concentrations were measured in plasma samples by ultrafiltration. Plasma binding and pH differences between plasma and saliva were then used to estimate methadone saliva/plasma ratios and to compare them with observed values. Saliva pH ranged from 5.1 to 7.6 (mean +/- SD, 6.7 +/- 0.5). Plasma and saliva concentrations correlated weakly [(RS)-, r = 0.14, P = 0.007, n = 44; (R)-, r = 0.10, P = 0.04, n = 43; (S)-, r = 0.22, P = 0.002, n = 43], and the mean saliva-to-plasma methadone concentration ratios were 1.1 (+/-1.3 SD), 1.5 (+/-1.5), and 0.8 (+/-0.8), for (RS)-, (R)-, and (S)-methadone, respectively. Corresponding values based on unbound concentrations of methadone in plasma were 21 (+/-20.6, n = 31), 21 (+/-19, n = 34), and 17 (+/-15, n = 36). The salivary concentration-to-dose ratios showed statistically significant but weak inverse correlations with saliva pH [(RS)-, r = 0.27, P < 0.001; (R)-, r = 0.25, P < 0.001; (S)-, r = 0.29, P < 0.001, respectively]. There were significant correlations between predicted and observed saliva/plasma ratios [(RS)-, r = 0.44, P < 0.001, n = 31; (R)-, r = 0.58, P < 0.001, n = 32; (S)-, r = 0.10, P = 0.04, n = 34], but the mean predicted saliva concentrations were about 5 times lower than the mean observed values. The poor correlations between salivary and plasma methadone concentrations observed in this study are partly related to the effect of variable saliva pH. However, saliva pH explained only 10%-36% of the total variation. As a conclusion, monitoring methadone concentrations in saliva may not be a useful alternative to plasma concentration measurements. Correction for saliva pH measured immediately after collection improves the relationship between saliva and plasma methadone concentration, but most of the variation remains unexplained.