Comparative efficacy of locally isolated fungal strains for Pb(II) removal and recovery from water

The present investigation aimed to study and compare the efficiency of non-viable fungal isolates to remove divalent lead (Pb(II)) from aqueous streams. The selected fungal isolates showed identity with Aspergillus caespitosus, Aureobasidium sp. RBSS-303 and Aspergillus flavus HF5 as confirmed using gene sequencing of ITS regions of the ribosomal DNA (rDNA). The obtained equilibrium data for Pb(II) biosorption of A. caespitosus fitted better to Langmuir isotherm with maximum sorption capacity of 351.0 mg/g and A. sp. RBSS-303 and A. flavus HF5 showed good fit to Freundlich isotherm with maximum sorption capacity of 271.5 and 346.3 mg/g respectively. The values of thermodynamic factors ascertained the nature of adsorption process is endothermic with A. caespitosus and A. flavus HF5 but exothermic with A. sp. RBSS-303. The experimental data for Pb(II) biosorption fits very well to pseudo second order kinetic model. With HCl the maximum 85.5, 75.3, 73.7% recovery of Pb(II) was obtained from A. caespitosus, A. sp. RBSS-303 and A. flavus HF5, respectively. The observed percentage loss in sorption capacity of Pb(II) was 3.9% by A. flavus HF5, 12.2% by A. caespitosus and 26.6% by A. sp. RBSS-303 after five cyclic studies of sorption and desorption. Results from the study confirmed the efficiency order of A. caespitosus > A. flavus HF5 > A. sp. RBSS-303 to remove and recover Pb(II) from aqueous solution. Finally, the fungal biosorbents can be used as soil conditioning agent after compositing into valuables fungal protein.     

Antioxidant activity and kinetics studies of eugenol and 6-bromoeugenol

In this work, we report the antioxidant and free radical scavenging activity of 6-bromoeugenol and eugenol. EC₅₀, the concentration providing 50% inhibition, is calculated and the antioxidant activity index (AAI) is evaluated. The antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging method. EC₅₀ values of 6-bromoeugenol, ascorbic acid and eugenol were 34.270 μg/mL, 54.888 μg/mL and 130.485 μg/mL, respectively. 6-Bromoeugenol showed higher AAI value (1.122) followed by ascorbic acid (0.700), then by eugenol (0.295). We also investigate the kinetics of DPPH radical scavenging activity of our products to determine the useful parameter TEC₅₀ to evaluate their antiradical efficiency (ARE). Our results have shown high ARE. This study has provided the following ARE ( × 10^? 3) order for the tested antioxidants: ascorbic acid (70.119)>6-bromoeugenol (34.842) > eugenol (21.313). Finally, we classify ascorbic acid and eugenol as fast kinetics reaction (TEC₅₀ 8.82 and 11.38 min, respectively) and 6-bromoeugenol as medium kinetics reaction (TEC₅₀ 39.24 min).     

A Novel Distachionate from Breynia distachia Treats Inflammations by Modulating COX-2 and Inflammatory Cytokines in Rat Liver Tissue

Breynia distachia is a plant of genus Breynia belonging to family Phyllanthaceae. This study was conducted to isolate and examine the anti-inflammatory attributes of the roots of Breynia distachia. Methanol extract from roots were prepared by simple maceration. For phytochemical studies, isolation, purification, structure elucidation, metal analysis, total phenolic content, and solubility test were done by chromatographic and spectroscopic techniques. Anti-inflammatory activity was evaluated by cotton pallet edema model and carrageenan paw edema model, and antioxidant potential was evaluated by DPPH, FRAP, and ABTS antioxidants assays. Metal analysis of BD.Me revealed the presence of Na > Mg > K > Mn > Fe = Zn in respective order. Four phytochemicals such as gallic acid, quercetin, sinapic acid, and p-coumaric acid are found in Breynia distachia. Quercetin is present in relatively larger quantity, and shows antioxidant activity by reducing the ferric iron to ferrous iron. Novel distachionate shows high antioxidant activity in ABTS assay by reducing reactive oxygen species. Quantitative or qualitative analysis performed by HPLC indicates the ascending peaks or presence of secondary products (metabolites) respectively. Histopathology analysis of liver, spleen, heart, and kidney was done, revealing mild inflammations in spleen and liver, and no cytotoxicity in heart and kidney. Oral administration of BD.Me and ditachionate significantly inhibits the carrageenan and cotton pellet-induced paw edema in 1st and 2nd h with (ns = p > 0.05) than control. After 3rd, 4th, 5th, and 6th h, BD.Me and ditachionate showed inhibition of paw edema in a highly significant (*** = p < 0.001) manner as compared to control. In cotton-pellet edema model, distachionate shows a %inhibition of 57.3% at a dose level of 5 mg/kg. Docking values obtained from distachionate-COX-2 complex suggest a potent inhibitor evaluated for this protein. The distachionate shows effective anti-inflammatory activity. Methanol extracts of roots showed significant lipoxygenase inhibitory activity by IC₅₀ values of 155.7 ± 0.55 and 132.9 ± 0.33 μg/mL. Data from various in vitro and in vivo models suggest that novel distachionate isolated from Breynia distachia shows strong antioxidant and anti-inflammatory activities; it should be further studied for the exploration of its medicinal potential.     

Purification and Partial Characterization of Peroxidases from Three Food Waste By-Products: Broad Bean Pods,Pea Pods,and Artichoke Stems

Applied Biochemistry and Biotechnology - In this study, peroxidases (PODs) from three waste by-products: broad bean pods (BBP), pea pods (PP), and artichoke stems (ARS) were purified and their...     

A biomimetic principle for the chemical modification of metal surfaces: synthesis of tripodal catecholates as analogues of siderophores and mussel adhesion proteins

By following a biomimetic design principle, tetravalent scaffolds based on an adamantyl and trisalkylmethyl core structure have been synthesized. These scaffolds have been coupled to three catecholamines, thus resembling the characteristic tripodal recognition motif of many natural metal binders, such as mussel adhesion proteins and siderophores, for example, enterobactin. Besides this tripodal recognition element, our scaffolds provide a fourth position for the conjugation of effector molecules. These effectors can be conjugated through biocompatible conjugation techniques to the scaffold and can be used to tailor the properties of different metal surfaces for a range of applications, for example, in implant engineering. Herein, we describe the synthesis of several tripodal metal binders and their immobilization on TiO(2) surfaces by using a simple dip-coating procedure. Furthermore, we demonstrate the conjugation of our surface binders to the dye eosin Y as an effector molecule by peptide coupling. The resulting surfaces have been analyzed by using ellipsometry, time-of-flight secondary ion mass spectrometry, IR spectroscopy, and contact-angle measurements to confirm the specific loading on TiO(2) films and nanoparticles with our trivalent surface binders. As a proof of concept, we have demonstrated the functionalization of TiO(2) nanoparticles with the eosin Y dye.     

Lie group analysis for thermophoretic and radiative augmentation of heat and mass transfer in a Brinkman-Darcy flow over a flat surface with heat generation

A boundary layer analysis is presented to investigate numerically the effects of radiation,thermophoresis and the dimensionless heat generation or absorption on hydromagnetic flow with heat and mass transfer over a flat surface in a porous medium.The boundary layer equations are transformed to non-linear ordinary differential equations using scaling group of transformations and they are solved numerically by using the fourth order Runge-Kutta method with shooting technique for some values of physical parameters.Comparisons with previously published work are performed and the results are found to be in very good agreement.Many results are obtained and a representative set is displayed graphically to illustrate the influence of the various parameters on the dimensionless velocity,temperature and concentration profiles as well as the local skin-friction coefficient,wall heat transfer,particle deposition rate and wall thermophoretic deposition velocity.The results show that the magnetic field induces acceleration of the flow,rather than deceleration(as in classical magnetohydrodynamics(MHD) boundary layer flow) but to reduce temperature and increase concentration of particles in boundary layer.Also,there is a strong dependency of the concentration in the boundary layer on both the Schmidt number and mass transfer parameter.     

Synthèses et applications des oxophosphonates en chimie organique

Synthesis and affliations of oxophosphonates in organic chemistry. This work devoted to oxophosphonates deals with three different series of compounds: the α-ketophosphonates, the β-ketophosphonates and finally the γ- and δ-ketophosphonates which were considered as one series of compounds. For each type of products, the various synthetic methods as well as their reactivity were presented. In the last part, we have developed different methods of reduction, nucleophilic addition and substitution reactions. Particular attention was focused on sulfur and nitrogen containing derivatives as well as fluorinated and chlorinated compounds.     

Left annihilator of generalized derivations on Lie ideals in prime rings

Let \(R\) be a prime ring, \(L\) a noncentral Lie ideal of \(R\), \(F\) a generalized derivation with associated nonzero derivation \(d\) of \(R\). If \(a\in R\) such that \(a(d(u)^{l_1} F(u)^{l_2} d(u)^{l_3} F(u)^{l_4} \ldots F(u)^{l_k})^{n}=0\) for all \(u\in L\), where \(l_1,l_2,\ldots ,l_k\) are fixed non negative integers not all are zero and \(n\) is a fixed integer, then either \(a=0\) or \(R\) satisfies \(s_4\), the standard identity in four variables.     

The role of Ga substitution on magnetic and electromagnetic properties of nano-sized W-type hexagonal ferrites

A series of nano-sized single phase W-type SrGa_xZn₂Fe_16?xO₂₇ (x = 0.0, 0.1, 0.2, 0.3, 0.4) hexaferrites prepared by sol gel technique and sintered at 950 °C have been investigated. The thermal decomposition behavior of nitrate–citrate gel of as prepared powder was investigated by means of DTA/TGA analysis. The sintered powders were characterized by FTIR, XRD, SEM, VSM and vector network analyzer (VNA). X-ray diffraction patterns for pure and substituted W-type hexaferrites show the single phase structure with no impurity phase. The lattice parameters (a and c) decrease with the increase of Ga contents (x). The grain size estimated from SEM images is in the range of 139–76 nm which confirms the nanocrystalline nature of the investigated samples. The saturation magnetization (M_s) decreases whereas coercivity (H_c) increases with the increase of Ga contents (x). The values of H_c for all of the investigated samples lie in the range of few hundred oersteds which is one of the necessary conditions for EM materials. The microwave absorption property is enhanced in the frequency (with respect to ?20 dB) from 0.5 to 13 GHz, and the bandwidth reaches 0.899 GHz. The attenuation peak value is ?32 dB at the matching thickness of 3.4 mm.