Isoarnottinin 4′-glucoside, a glycosylated coumarin from Prangos uloptera, with biological activity

Coumarins are a well-known group of natural products distributed in the plant kingdom especially in the family Apiaceae with various biological activities. Isoarnottinin 4′-glucoside is a simple glycosylated coumarin found previously in a few genera of Apiaceae, and its biological activities have not been previously described in details. In the present paper, the compound was isolated from Prangos uloptera (Apiaceae) leaves using HPLC techniques. Antimicrobial, phytotoxic and cytotoxic activities of the compound were evaluated by disk diffusion, lettuce assay and MTT method. Our results indicated that the compound has high antibacterial effect against Erwinia carotovora, a common plant pathogen with MIC value of 100 μg/ml. The compound also exhibited significant phytotoxic activity against lettuce and modest cytotoxic activity against HeLa cell line with IC₅₀ of 0.84 mg/ml. It could be concluded that isoarnottinin 4′-glucoside may play phytoalexin or allelopathic role for plant and may be a candidate for an antibacterial agent or a bioherbicide.     

Isoarnottinin 4'-glucoside, a glycosylated coumarin from Prangos uloptera, with biological activity

Coumarins are a well-known group of natural products distributed in the plant kingdom especially in the family Apiaceae with various biological activities. Isoarnottinin 4'-glucoside is a simple glycosylated coumarin found previously in a few genera of Apiaceae, and its biological activities have not been previously described in details. In the present paper, the compound was isolated from Prangos uloptera (Apiaceae) leaves using HPLC techniques. Antimicrobial, phytotoxic and cytotoxic activities of the compound were evaluated by disk diffusion, lettuce assay and MTT method. Our results indicated that the compound has high antibacterial effect against Erwinia carotovora, a common plant pathogen with MIC value of 100 microg/mL. The compound also exhibited significant phytotoxic activity against lettuce and modest cytotoxic activity against HeLa cell line with IC50 of 0 .84 mg/mL. It could be concluded that isoamottinin 4'-glucoside may play phytoalexin or allelopathic role for plant and may be a candidate for an antibacterial agent or a bioherbicide.     

Biochemical characterization of an extracellular polyextremophilic α-amylase from the halophilic archaeon Halorubrum xinjiangense

An extracellular haloalkaliphilic thermostable α-amylase producing archaeon was isolated from the saltwater Lake Urmia and identified as Halorubrum xinjiangense on the basis of morphological, biochemical, and molecular properties. The enzyme was purified to an electrophoretically homogenous state by 80 % cold ethanol precipitation, followed by affinity chromatography. The concentrated pure amylase was eluted as a single peak on fast protein liquid chromatography. The molecular mass of the purified enzyme was about 60 kDa, with a pI value of 4.5. Maximum amylase activity was at 4 M NaCl or 4.5 M KCl, 70 °C, and pH 8.5. The K _m and V _max of the enzyme were determined as 3.8 mg ml^?1 and 12.4 U mg^?1, respectively. The pure amylase was stable in the presence of SDS, detergents, and organic solvents. In addition, the enzyme (20 U) hydrolyzed 69 % of the wheat starch after a 2-h incubation at 70 °C in an aqueous/hexadecane two-phase system.     

Adsorption Properties of Tetracycline onto Graphene Oxide: Equilibrium,Kinetic and Thermodynamic Studies

Graphene oxide (GO) nanoparticle is a high potential effective absorbent. Tetracycline (TC) is a broad-spectrum antibiotic produced, indicated for use against many bacterial infections. In the present research, a systematic study of the adsorption and release process of tetracycline on GO was performed by varying pH, sorption time and temperature. The results of our studies showed that tetracycline strongly loads on the GO surface via π–π interaction and cation–π bonding. Investigation of TC adsorption kinetics showed that the equilibrium was reached within 15 min following the pseudo-second-order model with observed rate constants of k₂ = 0.2742–0.5362 g/mg min (at different temperatures). The sorption data has interpreted by the Langmuir model with the maximum adsorption of 323 mg/g (298 K). The mean energy of adsorption was determined 1.83 kJ/mol (298 K) based on the Dubinin–Radushkevich (D–R) adsorption isotherm. Moreover, the thermodynamic parameters such as ΔH°, ΔS° and ΔG° values for the adsorption were estimated which indicated the endothermic and spontaneous nature of the sorption process. The electrochemistry approved an ideal reaction for the adsorption under electrodic process. Simulation of GO and TC was done by LAMMPS. Force studies in z direction showed that tetracycline comes close to GO sheet by C₈ direction. Then it goes far and turns and again comes close from amine group to the GO sheet.     

A survey of aflatoxins in sesame seeds imported into Khorasan Province, Iran

Sesame seed is one of the main nutrient substances which is used in the food industries of Khorasan Razavi, Iran. Because it is likely that stored sesame seeds are contaminated with mycotoxins, the levels of aflatoxins (AF) in five lots of imported sesame seeds before their distribution to the market were studied during one year. A total of 269 sub-samples were obtained from a total of 9,321 tons of sesame seeds from five importing companies. Aflatoxins at >1 μg/kg were found in 50 % of all samples, but at low levels in most cases, which is illustrated by mean AFB₁ and total AF levels of 1.25?±?3.70 and 1.43?±?4.38 μg/kg, respectively. A few (1.9 %) samples exceeded the National Iranian Standard maximum accepted level for AFB₁ (5 μg/kg) or total AF (15 μg/kg); the maximum total AF level found in one sample was 48 μg/kg. The results indicate that the risk of a violative AF contamination in imported sesame seeds is not negligible but is currently relatively low.     

Transplantation of miR-219 overexpressed human endometrial stem cells encapsulated in fibrin hydrogel in spinal cord injury

Oligodendrocyte (OL) loss and demyelination occur after spinal cord injury (SCI). Stimulation of remyelination through transplantation of myelinating cells may be effective in improving function. For the repair strategy to be successful, the selection of a suitable cell and maintaining cell growth when cells are injected directly to the site of injury is important. In addition to selecting the type of cell, fibrin hydrogel was used as a suitable tissue engineering scaffold for this purpose. To test the relationship between myelination and functional improvement, the human endometrial stem cells (hEnSCs) were differentiated toward oligodendrocyte progenitor cells (OPCs) using overexpression of miR-219. Adult female Wistar rats were used to induce SCI by using a compression model and were randomly assigned to the following four experimental groups: SCI, Vehicle, hEnSC, and OPC. Ten days after injury, miR-219 overexpressed hEnSC-derived OPCs encapsulated in fibrin hydrogel, as an injectable scaffold, were injected to the injury site. In this study, with a focus on promoting functional recovery after SCI, the Basso-Beattie-Bresnahan test was performed to evaluate the recovery of motor function every week for 10 weeks and the histological assay was then performed. Results showed that the rate of motor function recovery was significantly higher in OPC group compared to SCI and vehicle groups but no marked differences were found between OPC and hEnSC groups, although, the rate of myelination in the OPC group was significantly higher than the other groups. These results demonstrated that remyelination was not the cause of recovery of motor function.     

Green synthesis of strontium nanoparticles self‐assembled in the presence of carboxymethyl cellulose: an in vivo imaging study

Carboxymethyl cellulose (CMC) is one of the main derivatives of cellulose and is used as a drug carrier for hydrophobic and hydrophilic drugs, imaging in vivo, and biological applications. Encapsulation is a technology in which target compounds are coated with wall compounds to form microcapsules. This study reports a new chemical processing wet method for precipitation and encapsulation of strontium nanoparticles (Sr NPs) within CMC structures using a sonochemical method. Preparation parameters such as microwave power and irradiation time as well as morphology and particle size of Sr NPs were also investigated. Products were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and atomic force microscopy. In this study, CMC was used as a biological stabilizer in a retentive phase to encapsulate Sr NPs. For the first time, Sr NPs were synthesized using CMC in a cost‐effective, simple, fast, micellation‐assisted, ultrasound method. Sr NPs were encapsulated in green capping agent structures of either 1%, 2% or 3% weight to provide an efficient optical nanostructure with a high yield at wavelengths 200–700 nm for use in in vivo imaging studies.     

Margollus bokanicus n. sp. from Iran,the Fourth Species of a Rare Nematode Genus (Dorylaimida,Tylencholaimellidae)

Margollus bokanicus n. sp., collected from natural habitats in Khorasaneh district, Bokan, West Azarbaijan province, Iran, is described. Morphological and morphometric data are provided as well as drawings and light microscopy illustrations. The new species is characterized by a medium size body length (0.60 to 0.73 mm), labial and postlabial sclerotizations, lip region 7-μm wide, offset by constriction and long neck (167 to 207 μm), long pharyngeal basal bulb (27 to 36 μm) or 16% to 17% of total neck length, female genital system monodelphic–opisthodelphic, anterior branch reduced to a uterine sac (26–29 μm) or 1.1 to 1.3 times the body diameter, long posterior uterus (25–28 μm) or 1.1 to 1.3 times the body diameter, V = 40 to 47, cylindroid female tail (17 to 24 μm, c = 31 to 38, c’ = 1.1 to 1.4), and males unknown. This taxon is easily distinguishable from other Margollus species by its smaller general size and more posterior vulva. A compendium of Margollus species is also presented.     

Bioassay-guided separation of an alpha-amylase inhibitor anthocyanin from Vaccinium arctostaphylos berries

Vaccinium arctostaphylos is a traditional medicinal plant in Iran used for the treatment of diabetes mellitus. In our search for antidiabetic compounds from natural sources, we found that the extract obtained from V. arctostaphylos berries showed an inhibitory effect on pancreatic alpha-amylase in vitro [IC50 = 1.91 (1.89-1.94) mg/mL]. The activity-guided purification of the extract led to the isolation of malvidin-3-O-beta-glucoside as an a-amylase inhibitor. The compound demonstrated a dose-dependent enzyme inihibitory activity [IC50 = 0.329 (0.316-0.342) mM].