New amide and diterpene alkaloids with anticholinesterase activity from Delphinium cyphoplectrum roots

BACKGROUND

The cholinergic hypothesis posits a robust correlation between the onset of Alzheimer's disease and a pronounced deficit in acetylcholine, a pivotal neurotransmitter crucial for the central cholinergic nervous system's function, pivotal for memory and learning. Diterpene alkaloids exhibit intricate and distinctive chemical structures that facilitate their passage through the blood-brain barrier. Moreover, their potent pharmacological attributes render them promising candidates for addressing central nervous system disorders.

OBJECTIVES

This investigation aims to scrutinize the alkaloidal composition of Delphinium cyphoplectrum (Ranunculaceae) roots, further exploring their anticholinesterase inhibitory activity and mode of inhibition.

METHOD

Innovative chromatography techniques were repetitively employed to purify the alkaloids. Acetylcholinesterase (AChE) inhibition assays were conducted using Ellman's tests. The mode of inhibition was meticulously characterized through Michaelis-Menten, and Lineweaver-Burk plots. Conducting molecular docking studies, we employed the AUTO DOCK 4.2 software package.

RESULTS

Eight alkaloids were identified including five C19-diterpene alkaloids (6,14,16,18-tetramethoxy-1,7,8-trihydroxy-4-methylaconitane (1), 6,16,18-trimethoxy-1,7,8,14-tetrahydroxy-4-methylaconitane (2), 6,8,16,18-tetramethoxy-1,7,14-trihydroxy-4-methylaconitane (3), 6,14,16-trimethoxy-1,7,8,18-tetrahydroxy-4-methylaconitane (4), and 14-O-acetyl-8,16-dimethoxy-1,6,7,18-tetrahydroxy-4-methylaconitane (5)), an epoxy C18-diterpene alkaloid (6,8,16-trimethoxy-1,7,14-trihydroxy-3,4-epoxyaconitane (6)), a known (pyrrolidin-2-one (7) and an undescribed amide alkaloid (1-(2'-hydroxylethylamine)-3,5,5,-trimethyl-1,5-dihydro-2H-pyrrol-2-one (8). All diterpene alkaloids underwent assessment for acetylcholinesterase (AChE) inhibition assay and displayed noteworthy AChE activity, surpassing that of the reference drug (with IC50 values of 13.7, 21.8, 23.4, 28.2, 40.4, and 23.9 for compounds 1-6, respectively, in comparison to 98.4 for Rivastigmine). Analysis of Michaelis-Menten and Lineweaver-Burk plots represents an uncompetitive mode of inhibition for compound 1 on AChE. Notably, computational docking simulations indicated that all diterpene alkaloids were accommodated within the same enzymatic cleft as the reference ligand, and displaying superior free binding energy values (from - 10.32 to -8.59 Kcal.mol-1) in contrast to Rivastigmine (-6.31 Kcal.mol-1).

CONCLUSION

The phytochemical analysis conducted on the roots of Delphinium cyphoplectrum yielded the identification of eight alkaloidal compounds including one C18-diterpene, five C19-diterpene, one pyrrolidine and one amide alkaloids. AChE inhibition assay and molecular simulations unveiled remarkable significant potency attributed to the C19-diterpene alkaloids by the order of 1 > 2 > 3,6 > 4 > 5. Presence of hydroxyl group on C-1, C-7, C-8, C-14, and C-18 increased the effect. The best in vitro activity was recorded for compound 1 able to bind to Asp72 in the narrow region of PAS, while interacting by pi-sigma with Phe330 at the hydrophobic region of the gorge involving the acyl and choline binding site. This observation underscores the substantial promise of this category of natural products in the realm of drug discovery for Alzheimer's Disease, offering a compelling avenue for further research and therapeutic development.

Effect of melatonin on steroidogenesis-related enzymes expression and testosterone synthesis following CoCl2-induced hypoxia in TM3 Leydig cells

Objectives

This study examined the effects of melatonin treatment on steroidogenesis dysfunction and testosterone impairment, following CoCl2-induced hypoxia in TM3 Leydig cells.

Materials and Methods

The TM3 cells were divided into four groups. The first group received no treatment. The MLT group was treated with a concentration of 1 mM melatonin. In the CoCl2 group, 0.2 mM CoCl2 was added to the medium to induce Hif1α overexpression. The MLT+CoCl2 group received 0.2 mM CoCl2 and 1 mM melatonin. After 24 hr treatment, the cells and supernatants were collected and used for further determination. The MTT assay was performed to estimate the decrease in cell viability throughout the CoCl2 and melatonin treatment. The mRNA and the protein levels were evaluated using Real-time PCR and Western blot analysis. The ELISA assay kit was used to detect the testosterone content.

Results

CoCl2 treatment caused Hif1α overexpression in TM3 Leydig cells. Moreover, CoCl2 treatment of these cells led to considerable downregulation of Star, Hsd3b1, and Gata4 well as Mtnr1a and Mtnr1b mRNA/protein expression coupled with testosterone content repression in the cell culture medium. Melatonin administration in cells treated with CoCl2, decreased Hif1α mRNA/protein expression, but had no significant effect on Star, Hsd3b1, Gata4, Mtnr1a mRNA/protein expression, and the testosterone level in the cell culture medium. Melatonin caused recovery of decrease in the Mtnr1b gene and protein expression.

Conclusion

There was no significant effect on steroidogenesis-related genes, proteins, and testosterone synthesis in the absence of gonadotropin treatment plus melatonin following CoCl2-induced hypoxia in TM3 Leydig cells.

Preparation of new MOF-808/chitosan composite for Cr(VI) adsorption from aqueous solution: Experimental and DFT study

In this study, a series of Zirconium-based MOF and chitosan composites (MOF-808/chitosan) were synthesized as efficient adsorbent for Cr(VI) ions elimination from aqueous solution. MOF-808/chitosan structure and morphology was characterized by FE-SEM, EDX, XRD, BET, zeta potential analysis, FT-IR, XPS techniques. The kinetic studies ascertained that Cr(VI) adsorption over MOF-808/chitosan followed pseudo-second-order kinetic model. The adsorption isotherms fitted the Langmuir isotherm model, implying on homogeneously adsorption of Cr(VI) on the surface of MOF-808/chitosan. According to the Langmuir model, the maximum capacity was obtained to be 320.0 mg/g at pH 5. Thermodynamic investigation proposed spontaneous (ΔG° < 0), disordered (ΔS° > 0) and endothermic (ΔH° > 0) for adsorption process. Besides, MOF-808/chitosan displayed an appropriate reusability for the elimination of Cr(VI) ions from their aqueous solutions for six successive cycles. DFT study of the adsorption process displayed and confirmed the role of hydrogen bonding and electrostatic attraction simultaneously.

Effect of fluoxetine treatment on neurotoxicity induced by lysolecithin in male rats

Demyelination disorder is an unusual pathologic event, which occurs in the central nervous system (CNS). Multiple sclerosis (MS) is an inflammatory demyelinating disease that affects the CNS, and it is the leading cause of disability in young adults. Lysolecithin (LPC) is one of the best toxin-induced demyelination models. In this study, a suitable model is created, and the effect of fluoxetine treatment is examined on this model. In this case, it was assumed that daily fluoxetine treatment had increased the endogenous remyelination in the LPC model. This study was focused on investigating the influence of the fluoxetine dose of 5 or 10 mg/kg per day for 1 and 4 weeks on LPC-induced neurotoxicity in the corpus callosum region. It was performed as a demyelinating model in male Wistar rats. After 3 days, fluoxetine was injected intraperitoneally (5 or 10 mg/kg per day) for 1 and 4 weeks in each group. After completing the treatment course, the corpus callosum was removed to examine the gene expression and histological analysis was performed. The results of the histopathological study of hematoxylin and eosin staining of the corpus callosum showed that in 1 and 4-week treatment groups, fluoxetine has reduced the level of inflammation at the LPC injection site (5 and 10 mg/kg per day). Fluoxetine treatment in the luxol fast blue (LFB) staining of the corpus callosum has been led to an increase in myelination capacity in all doses and times. The results of the genetic study showed that the fluoxetine has significantly reduced the expression level of tumor necrosis factor-α, nuclear factor κβ, and induced nitric oxide synthase in comparison with the untreated LPC group. Also, the fluoxetine treatment has enhanced the expression level of the forkhead box P3 (FOXP3) gene in comparison with the untreated group. Fluoxetine has increased the expression level of myelination and neurotrophic genes such as myelin basic protein (MBP), oligodendrocyte transcription factor 2 (OLIG2), and brain-derived neurotrophic factor (BDNF). The outcomes demonstrated that fluoxetine reduces inflammation and strengthens the endogenous myelination in the LPC-induced demyelination model; however, supplementary studies are required for specifying the details of its mechanisms.

An innovative, highly stable Ag/ZIF-67@GO nanocomposite with exceptional peroxymonosulfate (PMS) activation efficacy, for the destruction of chemical and microbiological contaminants under visible light

In this work, Ag nanoparticles were loaded on ZIF-67 covered by graphene oxide (Ag/ZIF-67@GO), and its catalytic performance was studied for the heterogeneous activation of peroxymonosulfate (PMS) under visible-light. The catalyst surface morphology and structure were analyzed by FT-IR, XRD, XPS, DRS, FE-SEM, EDX, TEM, BET, ICP-AES and TGA analysis. The efficacy of PMS activation by the Ag/ZIF-67@GO under visible light was assessed by phenol degradation and E. coli inactivation. Phenol was completely degraded within 30 min by HO^•, SO₄^•- and O₂^•- generated through the photocatalytic PMS activation. In addition, total E. coli inactivation was attained in 15 min that confirmed the highly efficient catalytic activation of PMS by the as-made nanocomposite under visible light. The reaction mechanism was elucidated and the importance of the generated reactive species followed the order of: HO^• > SO₄^•- > O₂^•- > h⁺, implying a radical-pathway dominated process.

The effect of different concentrations of cerium oxide during pregnancy on ovarian follicle development in neonatal mice

OBJECTIVES

Cerium is a member of the rare metals group and widely used in drug delivery, gene therapy, molecular imaging and medicine. In this study, we investigated the effect of different doses of Cerium (IV) oxide (CeO₂ ) during pregnancy on neonatal mice ovaries, as well as its effect on blood biochemical parameters.

METHODS

Thirty pregnant NMRI mice were divided into five groups: Control and 4 groups treated with CeO₂ (10, 25, 80, 250 mg/kg.bw i.p) at the GD7 and GD14. The ovarian histological of neonatal (2 and 6 day-olds), as well as blood serum of neonates at 15-dpp were analyzed.

RESULTS

Count of ovarian primordial follicles in neonates at 2 dpp showed a significant decrease in the groups treated with 80 and 250 mg/kg.bw doses of CeO₂ . There was also a significant decrease in ovarian primordial and primary follicles in neonates at 6-dpp at 250 mg/kg.bw doses of CeO₂ in the control (P < 0.05). There was no significant difference in serum levels of malondialdehyde and total antioxidant capacity between the experimental and control groups.

CONCLUSIONS

Our results suggest that the effects of CeO₂ on the ovarian tissue of neonatal mice during pregnancy may be dose-dependent.

Evaluation of biomarkers in liver following Solanum melongena green calyx administration in diabetic rats

Background

Solanum melongena green calyx (SMGC) has antioxidant properties. Diabetes mellitus (DM) increases oxidative stress and causes cellular damages in liver. This study attempts to show the protective effects of SMGC against morphometric, inflammatory, oxidative, and apoptotic changes in liver following DM induction.

Methods

For DM induction, the streptozotocin (60 mg/kg) was injected intraperitoneally. After the preparation of the SMGC extract, phytochemical content was analyzed. Sixty-four rats were categorized into 8 groups (n = 8); control, diabetic, SMGC, and diabetic + SMGC. SMGC administration was applied orally with doses of 100, 300, 500 mg/kg for 4 weeks. The assays of nitrite oxide, lipid peroxidation (LP), and Ferric Reducing Ability of Plasma (FRAP) were conducted for sample analysis. P53, Bcl2, and Bax genes expression, inflammatory cytokines, enzymes, and morphological features were measured. Apoptotic cell index, body weight, and levels of glucose and insulin were also analyzed. A one-way ANOVA test was used for statistical analysis.

Result

According to the phytochemical analysis, the SMGC is rich in Tannins and Saponins. Antioxidant values, p53 and Bax genes expression, inflammatory cytokines, enzymes, body weight, serum glucose, and morphometrical features were increased significantly (except insulin and FRAP levels and Bcl2 gene expression which were decreased) in diabetic group compared to the control group (P < 0.05). Also, evaluated parameters were reduced significantly (except insulin and FRAP levels and Bcl2 gene expression which were increased) in SMGC and diabetic + SMGC groups in comparison with the diabetic group (P < 0.05).

Conclusion

These findings revealed that the SMGC attenuates blood glucose levels in diabetic animals and also eliminates destructive effects of DM on liver through antioxidant features.

Evaluation of male infertility treatment following Rhus coriaria extract administration on rats exposed to morphine

Morphine is the most common analgesic drug that is widely used in post-operative interventions. This drug causes free radical accumulation leading to spermatogenesis failure. Antioxidant agents like Sumach (Rhus coriaria) neutralize cellular free radicals. In this study, the properties of antioxidative, modulative of inflammatory cytokines, and apoptotic genes following Sumach extract administration on morphine-induced fertility destruction in male Wistar rats was evaluated. Sixty-four animals were grouped (n = 8) including; 1: control, 2: morphine, 3-5: Sumach (200, 400, 800 mg/kg), and 6-8: morphine + Sumach. Hydroalcoholic extract of Sumach seeds was prepared. Treatments with Sumach extract were applied orally and intraperitoneally daily for 8 weeks. The P53, Bcl2 and caspase-3 genes expression were measured by real-time PCR. Cytokines involved in inflammation were evaluated by ELISA. Sperm parameters, total antioxidant capacity (TAC), testosterone, and germinal layer height (GLH) were assessed. All parameters (investigated in this study) in Morphine group reduced significantly than the control group (P ˂ 0.01) (except P53 and caspase-3 genes expression and inflammatory cytokine which were improved). All factors in Sumach and Sumach + Morphine groups were significantly enhanced compared to the Morphine group (P ˂ 0.01) (except P53 and caspase-3 genes expression and inflammatory cytokine which were declined). Morphine disrupted the physiological function of male fertility system. Besides, all doses of Sumach showed no therapeutic changes compared to the control group. Sumach with anti-infertility features compensates the toxic effect of Morphine administration.

Solvent Parameters Effects on the Second-Order Rate Constants of the Reaction of 2-Chloro-3,5-Dinitropyridine with Aniline in Aqueous Solutions of Alcohols

Aromatic nucleophilic substitution reaction kinetics of 2-chloro-3,5-dinitropyridine with aniline was studied in aqueous solutions of methanol, ethanol, and 2-propanol at room temperature. The obtained results for aqueous solutions indicate that the second-order rate constants are in order of 2-propano > ethano > methanol with a maximum at water mole fraction of 0.9. The influence of solvent parameters including normalized polarity (ETN), dipolarity/polarisability (π*), and hydrogen bond donor acidity (α) on the second-order rate constants were investigated and multiple regressions gave much better results with regard to single parameter regressions. Dipolarity/polarisability and hydrogen bond donor acidity of media demonstrate opposite effects on the reaction rate. The dipolarity/polarisability of media has a positive effect regarding to zwitterionic character of the reaction intermediate and the hydrogen bond donor acidity shows a negative effect because of hydrogen-bonding interactions between aniline and solvent molecules.

MxNi100−x (M = Ag, and Co) nanoparticles supported on CeO2 nanorods derived from Ce–metal organic frameworks as an effective catalyst for reduction of organic pollutants: Langmuir–Hinshelwood kinetics and mechanism

Ag_xNi_100−x and Co_xNi_100−x bimetallic nanoparticles supported on CeO₂ nanorods showed remarkable catalytic activity in a reduction reaction.

Investigating the role of MoS2/reduced graphene oxide as cocatalyst on Cu2O activity in catalytic and photocatalytic reactions

Synergistic effect of MoS₂/rGO as cocatalyst on Cu₂O catalytic and photocatalytic activity.

The Incomplete Superficial Palmar Arch

Introduction:

Superficial palmar arch (SPA) is dominant vascular structure in palm of hand. In present study we described a case of Ulnar / Radiopalmar pattern of incomplete SPA in an Iranian cadaver. When the SPA is complete, the superficial palmer branches of the radial artery contribute to the ulnar artery. In incomplete type of SPA, there was no anastomosis between the ulnar and radial arteries (UA, RA).

Case Report:

In the present case, the brachial artery divided into RA and UA at the cubital fossa. There was no anastomosis between radial and ulnar arteries (RA, UA) in the palm of the hand. UA gave three palmar digital arteries; proper palmar digital artery and two common palmar digital arteries. RA gave proper palmar digital artery and arteria princeps pollicis.

Conclusion:

Knowledge of anatomical variation of SPA is important for the hand surgical interventions and this is a very rare variation which can be easily tested clinically by Allen's test

Persistent median artery in the carpal tunnel and anastomosis with superficial palmar arch

Persistent median artery (PMA) in present cadaver originated from the brachial artery and anastomosed with the superficial palmar arch (SPA). As the PMA may be the cause of carpal tunnel syndrome and SPA is the main source of arterial supply, knowledge of which are important for the hand surgical interventions.

Synthesis of the visible-light-driven Ag3VO4/Ag3PO4/Ag photocatalysts with enhanced photocatalytic activity

A novel Ag₃VO₄/Ag₃PO₄/Ag photocatalyst is reported with enhanced photocatalytic activity.

Protective effect of quercetin on skeletal and neural tube teratogenicity induced by cyclophosphamide in rat fetuses

Cyclophosphamide (CP) is a drug commonly used to treat neoplastic disease and some autoimmune diseases. It is also a well-known and well-studied teratogen causing a variety of birth defects in fetuses of pregnant women treated with the drug. There are many reports that show the adverse effects of CP can be decreased by use of antioxidant drugs. It appears that, quercetin has antioxidant effect. The aim of this study was prevention or decrease of teratogenicity of CP in fetuses of rats by quercetin. This study was performed on 35 pregnant rats divided into six groups. Control group was received normal saline (5 mL kg(-1), intraperitoneally) and 2-6 groups received a single dose of CP (15 mg kg(-1)), a single dose of quercetin (75 or 200 mg kg(-1)), CP plus quercetin (75 or 200 mg kg(-1)) intraperitoneally at 9(th) day of gestation, respectively. Fetuses were collected at 20(th) day of gestation and after determination of weight and crown rump length were stained by alizarin red - alcian blue method and skeletal system were examined by stereomicroscope. The results showed that the cleft palate, exencephaly, spina bifida and omphalocele incidence were 55.56%, 27.77%, 33.34% and 11.11%, in fetuses of rat that received only CP, respectively. However, it decreased to 16.00%, 16.00%, 16.00% and 8.00% by quercetin (75 mg kg(-1)) and so to 12.90%, 12.90%, 6.45% and 3.28% by quercetin (200 mg kg(-1)), respectively. On the basis of results, quercetin significantly can decrease teratogenicity induced by CP.

Probing solvent–solvent and solute–solvent interactions in surfactant binary mixtures: solvatochromic parameters, preferential solvation, and quantum theory of atoms in molecules analysis

The behaviour of solvatochromic absorbance probes within binary mixtures of TX-100/organic solvents.

Probing the effects of the ester functional group, alkyl side chain length and anions on the bulk nanostructure of ionic liquids: a computational study

The effects of ester addition on nanostructural properties of biodegradable ILs.

An efficient system for selection and culture of Schwann cells from adult rat peripheral nerves

Schwann cells (SCs), the supporting cells of the peripheral nerves, are indispensable for regenerating the peripheral and central nervous system. Copious preparation of these cells in a well-defined manner is to be a privileged position. SCs cultivation is overwhelmed by contaminating fibroblasts which are often outgrowing as the predominant cell type in an in vitro culture. This study introduces a technically simple and efficient procedure for SCs isolation and enrichment based on implementing recombinant and defined supplements. Collected adult rat sciatic nerves were cultured for 10 days as in vitro predegeneration. After dissociation and plating, the medium changed to knockout serum replacement supplemented DMDM/F12 medium containing various growth factors. The whole procedure took 3 weeks and SCs purity was then evaluated through implementing specific cytoplasmic and membranous markers. The viability of enriched SCs were evaluated by MTT assay. Within 10 days, over 99 % homogenous SCs were achieved and confirmed through immunofluorescence staining and flow-cytometry for P75(NTR) and S100 markers, respectively. MTT data revealed that the viability and metabolic activities of purified SCs were increased in expansion medium. This study provides a technically easy and efficient method with the benefits of not utilizing bovine serum or other animal products for SCs isolation and enrichment.

Electrodeposited multi-walled carbon nanotubes on Ag-loaded TiO2 nanotubes/Ti plates as a new photocatalyst for dye degradation

MWCNTs/Ag/TiO₂NTs plates were synthesized via electrochemical reduction of functionalized multiwalled carbon nanotubes (MWCNTs) on Ag/TiO₂NTs.

Adenocarcinoma cells isolated from patients in the presence of cerium and transferrin in vitro

AIM

Cerium as a trace element in the periodic table is a member of the lanthanide group. Cerium ionic radius and its binding properties are similar to ferric ions, which may be bound to transferrin. So it can be considered as a competitive element to iron and can interfere with iron absorption. The aim of this study was to investigate the inhibitory effect of Cerium in presence of transferrin on gastric adenocarcinoma cells in vitro.

METHODS

The adenocarcinoma cells were obtained from patients after a pathological confirmation, then they were cultured in DMEM environment and cytotoxic effect of different concentrations of cerium were measured (0.1, 1, 10 and 100 µM) in the presence and absence of transferrin, on periods 24 and 48 hours by MTT and LDH cytotoxic assay.

RESULTS

The results of MTT and LDH measurements showed that Cerium itself has a cytotoxic effect on cancer cells isolated from the patient as well as it increases significantly in the presence of transferrin carrying a mortality rate of cancer cells (P <.05).

CONCLUSION

Cerium is competitive element in the mechanism of iron absorption and can interfere and inhibit the growth of adenocarcinoma cancer cells; also, the use of Cerium and transferrin simultaneously may cause a greater inhibitory effect.

A novel p–n junction Ag3PO4/BiPO4-based stabilized Pickering emulsion for highly efficient photocatalysis

This study demonstrates a new kind of photocatalytic system via utilization of the superior specific properties inherent in Pickering emulsions.

All trans retinoic acid modulates peripheral nerve fibroblasts viability and apoptosis

OBJECTIVE

Following peripheral nerve injury, residing fibroblasts start to proliferate and accumulate at the injury site and may participate in neuroma tissue evolution. Retinoic acid has been shown to regulate many cellular processes and to display anti-proliferative and anti-fibrotic properties. The aim of this study was to investigate the impact of all trans retinoic acid (ATRA) on rat peripheral nerve fibroblasts.

MATERIALS AND METHODS

Peripheral nerve fibroblasts and C166 cells were treated with increasing doses of ATRA (0.05 nM to 1 μM). The viability of cells was determined with 3-(4,5-dimethlthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, the number of peripheral nerve fibroblasts was counted after two days of ATRA treatment and alternatively up to the end of next week. Acridine orange/ethidium bromide double staining was implemented to morphologically visualize the possible mechanism of cell death. For apoptosis, caspase 3/7 activity was measured using Caspase-Glo 3/7 assay kit.

RESULTS

MTT assay revealed that 0.05-1 nM of ATRA reduces fibroblasts viabilities. Then, almost a plateau state was observed from 1 nM to 1 μM of ATRA exposure. Additionally, a deceleration in peripheral nerve fibroblasts growth was confirmed via cell counting. Quantification of acridine orange/ethidium bromide staining displayed highly increased number of early apoptotic cells following ATRA administration. Amplified activation of caspase 3/7 was in favor of apoptosis in ATRA treated peripheral nerve fibroblasts.

CONCLUSION

The data from the present study demonstrate that ATRA could interfere in peripheral nerve fibroblasts viabilities and induce apoptosis. Although more investigations are needed to be implemented, our in vitro results indicate that retinoic acid can probably help the regeneration of injured axon via reducing of fibroblasts growth.

Incredible antibacterial activity of noble metal functionalized magnetic core-zeolitic shell nanostructures

Functionalized magnetic core-zeolitic shell nanostructures were prepared by hydrothermal and coprecipitation methods. The products were characterized by Vibrating Sample Magnetometer (VSM), X-ray powder diffraction (XRD), Fourier Transform Infrared (FTIR) spectra, nitrogen adsorption-desorption isotherms, and Transmission Electron Microscopy (TEM). The growth of mordenite nanoparticles on the surface of silica coated nickel ferrite nanoparticles in the presence of organic templates was also confirmed. Antibacterial activity of the prepared nanostructures was investigated by the inactivation of Escherichia coli as a gram negative bacterium. A new mechanism was proposed for inactivation of E. coli over the prepared samples. In addition, the Minimum Inhibitory Concentration (MIC) and reuse ability were studied. TEM images of the destroyed cell wall after the treatment time were performed to illustrate the inactivation mechanism. According to the experimental results, the core-shell nanostructures which were modified by organic agents and then functionalized with noble metal nanoparticles were the most active. The interaction of the noble metals with the organic components on the surface of nanostructures was studied theoretically and the obtained results were used to interpret the experimental results.

Systems Designed with an Ionic Liquid and Molecular Solvents to Investigate the Kinetics of an SNAr Reaction

The microscopic features of binary solvent systems formed by molecular solvents (methanol, ethanol, 2-methylpropan-2-ol, water, pyridine, acetonitrile, 1-propanol, 2-propanol, dimethylformamide) and the ionic liquid ([bmim]BF4) as cosolvent were used to select mixed solvents with particular characteristics. Molecular-microscopic solvent parameters corresponding to these binary mixtures were utilised to study the kinetics of the nucleophilic substitution reaction between 2-chloro-3,5-dinitropyridine and aniline to investigate and compare the effects of the solvents on a model chemical reaction. For these mixtures, the solvation behaviour is dominated by both the dipolarity/polarisability and hydrogen bonding interactions of the media. In these solutions, the rate constants of the reaction decrease with the mole fraction of ionic liquid.

A Computational Study of Cytotoxicity of Substituted Amides of Pyrazine- 2-carboxylic acids Using QSAR and DFT Based Molecular Surface Electrostatic Potential

Pyrazine derivatives are important class of compounds with diverse biological and cytotoxic activities and clinical applications. In this study, B3 p 86 / 6 - 31 (+ +) G * was used to compute and map the molecular surface electrostatic potentials of a group of substituted amides of pyrazine-2-carboxylic acids to identify common features related to their subsequent cytotoxicities. Several statistical properties including potentials extrema (Vs ,min,Vs ,max), the average of positive electrostatic potential on the surface (Vs (+)), the average of V(r) over the surface (Vs) and the Lowest Unoccupied Molecular Orbital (LUMO) and system cytotoxicities were computed. Statistically, the most significant correlation is a five -parameter equation with correlation coefficient, R² values of 0.922 and R²adj = 0.879. The obtained models allowed us to reveal cytotoxic activity of substituted amides of Pyrazine2- carboxcylic acid.

A Density Functional Theory Study of Cyclization of Citronellal

A theoretical study of the kinetics and mechanism of the cyclization of citronellal in the gas phase was performed using density functional theory methods at the B3LYP level of theory with 6-311G, 6-311G*, 6-31G**, 6-311G**, 6-311+G and 6-311 + +G basis sets at 298.15K, 433.15K, and 473.15K. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactant, transition state and products were calculated. Rate constants and activation thermodynamic parameters were calculated and showed a fairly good agreement with experimental results. The effect of solvent polarity on the reaction was studied. These calculations indicated that the reaction proceeds through an asynchronous concerted mechanism.

Assembly of CeO2-TiO2 nanoparticles prepared in room temperature ionic liquid on graphene nanosheets for photocatalytic degradation of pollutants

CeO(2)-TiO(2) nanoparticles were prepared by the sol-gel process using 2-hydroxylethylammonium formate as room-temperature ionic liquid and calcined at different temperatures (500-700°C). CeO(2)-TiO(2)-graphene nanocomposites were prepared by hydrothermal reaction of graphene oxide with CeO(2)-TiO(2) nanoparticles in aqueous solution of ethanol. The photocatalysts were characterized by X-ray diffraction, BET surface area, diffuse reflectance spectroscopy, scanning electron microscopy, and Fourier transformed infrared techniques. The results demonstrate that the room-temperature ionic liquid inhibits the anatase-rutile phase transformation. This effect was promoted by addition of CeO(2) to TiO(2). The addition of graphene to CeO(2)-TiO(2) nanoparticles enhances electron transport and therefore impedes the charge recombination of excited TiO(2). The photodegradation results of the pollutants in aqueous medium under UV irradiation revealed that CeO(2)-TiO(2)-graphene nanocomposites exhibit much higher photocatalytic activity than CeO(2)-TiO(2) and pure TiO(2). The photocatalytic activity of CeO(2)-TiO(2)-graphene nanocomposites decreases with additional increasing of the graphene content. Moreover, comparison of the photocatalytic activities of CeO(2)-TiO(2)-graphene with the other CeO(2)-TiO(2)-carbon demonstrates that CeO(2)-TiO(2)-graphene nanocomposites have the highest photocatalytic activity due to their unique structure and electronic properties. Chemical oxygen demand for solutions of the pollutants gave a good idea about mineralization of them.

Detection and Identification of Toxoplasma gondii Type One Infection in Sheep Aborted Fetuses in Qazvin Province of Iran

BACKGROUND

The aim of this study was to apply the nested-PCR and bioassay methods in detection and genotyping of Toxoplasma gondii infection in provided sheep aborted fetus samples from Qazvin Province of Iran.

METHODS

Eighteen sheep aborted fetal samples were studied by nested-PCR-RFLP, histopathological observation and microbiological assay. Bioassay in mice was carried out by inoculating the brain samples intraperitoneally.

RESULTS

The results demonstrated the frequency of 66% infected sheep aborted fetal samples with T. gondii type one. Although we could not isolate any parasite from inoculated mice even after three passages, but it was confirmed histopathologically formation of cyst like bodies in prepared mice brain sections.

CONCLUSION

The results of the performed nested-PCR and formation of brain cyst in inoculated mice exhibited that T. gondii type one infection might be considered as one of the major causative agents for abortion in ewes.