Antioxidant Activity of Various Extracts and Organic Fractions of Ziziphus jujuba

Antioxidant effectiveness of indigenous medicinal plant Ziziphus jujuba shoots extracts and fractions with different polarity solvents (n–hexane, ethylacetate, methanol, chloroform) was assessed for total phenolics content (TPC), total flavonoid contents (TFC), DPPH radical scavenging activity and percentage inhibition of peroxidation in linoleic acid system. The shoots extracts and fractions contained appreciable levels of total phenolic contents 310-823 GAE (mg/100g Dry plant matter) and total flavonoid contents 210-650 CE (mg/100g of Dry plant matter). The Ziziphus jujuba extracts and various organic fractions also exhibited good DPPH 50% inhibition (IC50) ranges from 23.1µg/mL to 52.5 µg/ml and Inhibition of Peroxidation in Linoleic Acid  20.1 to 70.1%., respectively. Of the Ziziphus jujuba shoots extracts and fractions tested, 100% methanolic extract and 100% chloroform fraction exhibited the maximum antioxidant activity, the results of the present investigation demonstrated significant (p< 0.05) variations in the antioxidant activity. The results of the present comprehensive analysis demonstrated that Ziziphus jujuba shoots extracts and organic fractions are a viable source of natural antioxidants and might be exploited for functional foods and nutraceutical application

Synthesis and DPPH scavenging assay of reserpine analogues, computational studies and in silico docking studies in AChE and BChE responsible for Alzheimer's disease

A doença de Alzheimer (DA) é uma doença neurodegenerativado sistema nervoso central, em rápido crescimento, e antioxidantes ajudam a suprimir o estresse oxidativo causado por radicais livres, responsávies pela DA. Avaliou-se, biologicamente, série de derivados sintéticos de indol selecionados para identificar novos antioxidantes. A maioria dos compostos avaliados apresentou de significativa a boa propriedade antioxidante (valor de IC50 399,07140.0 ± 50 µM). Eftuaram-se estudos de Teoria do Funcional de Densidade (DFT) com os compostos e os seus correspondentes radicais livres. As diferenças de energia entre os compostos protótipos e os radicais livres correspondentes proporcionaram boa justificativa para a tendência encontrada nos seus valores de IC50. O ancoramento in silico dos compostos com a acetilcolinesterase (AChE) e com a butirilcolinesterase (BChE), que contribuem para a DA, foi, também, realizado para prever o seu potencial anti-DA.Alzheimer's disease (AD) is a fast growing neurodegenerative disorder of the central nervous system and anti-oxidants can be used to help suppress the oxidative stress caused by the free radicals that are responsible for AD. A series of selected synthetic indole derivatives were biologically evaluated to identify potent new antioxidants. Most of the evaluated compounds showed significant to modest antioxidant properties (IC50 value 399.07 140.0±50 µM). Density Functional Theory (DFT) studies were carried out on the compounds and their corresponding free radicals. Differences in the energy of the parent compounds and their corresponding free radicals provided a good justification for the trend found in their IC50 values. In silico, docking of compounds into the proteins acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are well known for contributing in AD disease, was also performed to predict anti-AD potential

In situ immobilization of CuO on SiO\u3csub\u3e2\u3c/sub\u3e/graphite matrix, modified with benzimidazolium-1-acatate ionic liquid: Application as catechol sensor

© 2017 Carbon ceramic material (SiO2/C) was prepared using the sol-gel technique. Copper oxide was in situ synthesized on the pores of the matrix, to ensure homogenous distribution of the electroactive species in the matrix pores. To enhance the conductivity of material, the SiO2/C/CuO was modified with benzimidazolium-1-acetate ionic liquid. The surface area (SBET 432.56 m2/g) and pore volume (0.90 cm3/g) of the material were calculated from BET analysis. SEM images showed compactness of materials, having no phase segregation within the magnification used. The structure of ionic liquid was confirmed using NMR and FTIR analysis. The electrodes as a pressed disk fabricated from SiO2/C, SiO2/C/CuO, and SiO2/C/CuO/IL materials were tested as an electrochemical sensor for catechol determination. Electrochemical impedance spectroscopy has revealed that the SiO2/C/CuO/IL-based sensor assists the charge transfer owing to electron rich density, resonance, and conductance of ionic liquid structural moiety. SiO2/C/CuO/IL electrode exhibits excellent sensitivity, linear response range and low limit of detection (LOD) of 712 μA μmol− 1 dm3 cm− 2, 0.2 mM–10 mM and 0.7 × 10− 8 mol L− 1, respectively. The sensor was also tested for the determination of catechol in real samples and gives very good results for its determination

Surface engineered mesoporous silica carriers for the controlled delivery of anticancer drug 5-fluorouracil: Computational approach for the drug-carrier interactions using density functional theory

Introduction: Drug delivery systems are the topmost priority to increase drug safety and efficacy. In this study, hybrid porous silicates SBA-15 and its derivatives SBA@N and SBA@3N were synthesized and loaded with an anticancer drug, 5-fluorouracil. The drug release was studied in a simulated physiological environment.Method: These materials were characterized for their textural and physio-chemical properties by scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), small-angle X-ray diffraction (SAX), and nitrogen adsorption/desorption techniques. The surface electrostatics of the materials was measured by zeta potential.Results: The drug loading efficiency of the prepared hybrid materials was about 10%. In vitro drug release profiles were obtained in simulated fluids. Slow drug release kinetics was observed for SBA@3N, which released 7.5% of the entrapped drug in simulated intestinal fluid (SIF, pH 7.2) and 33% in simulated body fluid (SBF, pH 7.2) for 72 h. The material SBA@N presented an initial burst release of 13% in simulated intestinal fluid and 32.6% in simulated gastric fluid (SGF, pH 1.2), while about 70% of the drug was released within the next 72 h. Density functional theory (DFT) calculations have also supported the slow drug release from the SBA@3N material. The release mechanism of the drug from the prepared carriers was studied by first-order, second-order, Korsmeyer–Peppas, Hixson–Crowell, and Higuchi kinetic models. The drug release from these carriers follows Fickian diffusion and zero-order kinetics in SGF and SBF, whereas first-order, non-Fickian diffusion, and case-II transport were observed in SIF.Discussion: Based on these findings, the proposed synthesized hybrid materials may be suggested as a potential drug delivery system for anti-cancer drugs such as 5-fluorouracil

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Effect of zeolite surface modification with ionic liquid [APTMS] [Ac] on gas separation performance of mixed matrix membranes

© 2018 Elsevier B.V. This study focuses on using a (3-aminopropyl)trimethoxysilane and acetate ion based ionic liquid to modify zeolite 4A as a filler in a polysulfone (PSf) membrane for CO2/CH4 and CO2/N2 separation, aiming at improving the polymer-filler interaction and separation performance of the mixed matrix membrane (MMM). The ionic liquid was covalently attached onto the zeolite surface. Zeolite modification was confirmed through FTIR analysis of pristine and modified filler. N2 sorption isotherms were used to characterize the porous structure, which showed decrease in surface area and pore volume after surface modification of zeolite. The crystal structure of zeolite 4A remained unaffected after modification with ionic liquid, as shown by XRD and SEM. Moreover, the synthesized PSf-based MMMs were tested in the separation of CO2 from CH4. Experiments were conducted at different temperatures and feed conditions, and pure and mixed gas permeability/selectivity data was reported. This modification of zeolites with methoxy groups containing cation and acetate anion based ionic liquid, resulted in an improved separation performance, as the modified filler enhanced the MMMs selectivity of CO2/CH4 by 37% and for CO2/N2 by 43% at 30 wt% filler loading as compared to pristine filler MMMs. The 3-(trimethoxysilyl)propan-1-aminium acetate coating acts as a selecting film which notably improves the selectivity at marginal expense of CO2 permeance.status: publishe

Supported protic ionic liquid membrane based on 3-(trimethoxysilyl) propan-1-aminium acetate for the highly selective separation of CO2

© 2017 Elsevier B.V. The ability to tailor ionic liquids can result in very high separation efficiency for CO2/CH4 and CO2/N2. In this study, a new protic ionic liquid was synthesized with high CO2 absorption capacity employing (3-aminopropyl) trimethoxysilane and acetic acid, both of these have been reported to exhibit high affinity for CO2. The synthesized ionic liquid was characterized by FTIR and the supported ionic liquid membrane was tested to determine the separation of CO2 from CH4. Experiments were conducted at different temperatures and feed conditions, and pure and mixed gas permeability/selectivity data were reported. This combination of silyl ether functionalized cation and acetate ion dramatically improved the membrane separation performance as the SILM displayed CO2 permeance of 23 GPU combined with CO2/CH4 selectivity of 41. The synthesized SILM was stable upto 10 bar as no leaching of ionic liquid was observed and the permeance increased from 23 to 31 GPU as the temperature was raised from 25 °C to 65 °C, while the selectivity slightly decreased from 41 to 35 over the same temperature range. The exceptionally high selectivity of CO2/CH4 makes [APTMS][Ac] a promising room temperature ionic liquid for CO2 separation without facilitated transport. A synergistic effect of methoxy groups from [APTMS] part of the ionic liquid caused the enhanced permeability of CO2 as supported by theoretical calculations.status: publishe

Synergy of high permeability and selectivity of superbase/choline chloride/urea solution impregnated membranes for CO₂ capture

A new generation of solvents called ternary deep eutectic solvents have emerged as a promising candidate to replace ionic liquids (IL) in CO2 capturing due to its inherent advantages of both, superbase and deep eutectic solvents (DES). In this work, the binary and ternary DES were synthesized to investigate the effect of superbase on the performance of DES based membrane systems for acid gas capture. The reline DES system was chosen as binary DES and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was used as superbase. The ternary DES was prepared by mixing DBU in reline DES system in different molar ratios. The permeability and selectivity of the synthesized membrane for CO2, CH4, and N2 were investigated in pure and mixed gas experiments. Moreover, the effect of the DES molar ratio, operating conditions of feed on the DES based supported liquid membranes (SLMs) performance was studied comprehensively. These novel ternary DES SLMs showed significant permeability and selectivity values up to 38.12 Barrer and 58.65 respectively. These values were found to be significantly higher than the permeability and selectivity value of binary DES-SLM i.e. 31 Barrer and 51.67 respectively. The improved gas performance results of ternary DES can be attributed to the basicity and fast reaction kinetics of the superbase/DBU. The ternary DES can potentially alternate the ILs and commonly used binary DESs in CO2 capturing process due to their high affinity towards CO2 gas.</p