A Comparative Study between Conventional and Advanced Extraction Techniques: Pharmaceutical and Cosmetic Properties of Plant Extracts

This study aimed to compare the influence of extraction methods on the pharmaceutical and cosmetic properties of medicinal and aromatic plants (MAPs). For this purpose, the dried plant materials were extracted using advanced (microwave (MAE), ultrasonic (UAE), and homogenizer (HAE) assisted extractions) and conventional techniques (maceration, percolation, decoction, infusion, and Soxhlet). The tyrosinase, elastase, α-amylase, butyryl, and acetylcholinesterase inhibition were tested by using L-3,4 dihydroxy-phenylalanine, N-Succinyl-Ala-Ala-p-nitroanilide, butyryl, and acetylcholine as respective substrates. Antioxidant activities were studied by ABTS, DPPH, and FRAP. In terms of extraction yield, advanced extraction techniques showed the highest values (MAE > UAE > HAE). Chemical profiles were dependent on the phenolic compounds tested, whereas the antioxidant activities were always higher, mainly in infusion and decoction as a conventional technique. In relation to the pharmaceutical and cosmetic properties, the highest inhibitory activities against α-amylase and acetylcholinesterase were observed for Soxhlet and macerated extracts, whereas the highest activity against tyrosinase was obtained with MAE > maceration > Soxhlet. Elastase and butyrylcholinesterase inhibitory activities were in the order of Soxhlet > maceration > percolation, with no activities recorded for the other tested methods. In conclusion, advanced methods afford an extract with high yield, while conventional methods might be an adequate approach for minimal changes in the biological properties of the extract.     

Gamma irradiation induced preparation of poly(acrylamide–itaconic acid)/zirconium hydrous oxide for removal of Cs-134 radionuclide and methylene blue

Adsorption experiments were carried out to investigate the removal of Cs-134 radionuclide and methylene blue (MB) from aqueous solution using poly(acrylamide–itaconic acid)/N,N′-methelyenediacrylamide/zirconium hydrous oxide composite [poly(AM–IA)/DAM/Zr(OH)₄] as an adsorbent. The effects of initial pH value, initial concentration of Cs or MB, adsorbent dose, contact time and temperature on adsorption were investigated. Characterization of the prepared composite was carried out using FT-IR, XRD, TGA, DTA, and SEM. The adsorption behaviors showed that the adsorption kinetics and isotherms were in good agreement with the pseudo-second-order and the Langmuir models indicating the chemosorption mechanism. Thermodynamic studies were carried out and it was found that the process was spontaneous exothermic in nature. Discussion of the results of the adsorption behavior showed that the prepared composite can be used as a promising adsorbent for removal of Cs-134 or MB.     

A green and efficient synthesis of isoxazol-5(4<Emphasis Type="Italic">H</Emphasis>)-one derivatives in water and a DFT study

A series of 4-arylmethylene-3-methylisoxazol-5(4H)-one derivatives are obtained via treating ethyl acetoacetate, hydroxylamine hydrochloride and variety of aromatic aldehyde compounds in the presence of antimony trichloride as an efficient catalyst in aqueous media. Mild conditions, safe, short reaction times, commercially available catalyst, environmentally friendly, no uses of organic solvent and high yields are remarkable advantages to this process. (Z)-4-(3-hydroxybenzylidene)-3-methylisoxazol-5(4H)-one, (HBIM), is characterized by theoretical (density functional theory) and experimental (IR, ¹H NMR, CV and UV). The structural parameters, vibrational frequencies, molecular electrostatic potential, frontier molecular orbital analysis (HOMO–LUMO), thermodynamic properties and nonlinear optical properties are found and discussed. UV–Vis spectra are recorded in two organic solvents. Thermal stability of HBIM is studied by thermogravimetric analysis. The molecule orbital contributions are studied using the total and partial density of states (TDOS and PDOS).     

Phenolic compounds from Eucalyptus gomphocephala with potential cytotoxic and antioxidant activities

Two new phenolic compounds, 2,4,6-trihydroxy-5-methyl-acetophenone 2-O-beta-D-glucopyranoside (3), and benzyl alcohol 7-O-(3',4',6'-tri-O-galloyl)-beta-D-glucopyranoside (8), together with eight known phenolic compounds, were isolated from the 70% aqueous acetone extract of Eucalyptus gomphocephala DC. (Myrtaceae). The isolated compounds were elucidated based on their 1H, 13C, DQF-COSY, selective 1D-TOCSY, HSQC, and HMBC NMR spectroscopic and ESI-MS data. The antioxidant effect of the phenolic compounds was tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical and super oxide anion radical scavenging assays. The cytotoxicity of the isolated compounds was evaluated using HeLa cell line.     

1-motivic sheaves and the Albanese functor

Using sheaf theoretic methods, we define functors and . The functor extends the one in [L. Barbieri-Viale, B. Kahn, On the derived category of 1-motives, I. Prépublication Mathématique de l’IHÉS (M/07/22), June 2007, 144 pages] to non-necessarily geometric motives. These functors are then used to define higher Néron-Severi groups and higher Albanese sheaves.     

Comparison of radiation detector performance for different metal contacts on CdZnTe deposited by electroless deposition method

A comparative study of four different metals gold (Au), platinum (Pt), ruthenium (Ru) and rhodium (Rh) deposited on CdZnTe(CZT) by the electroless deposition method has been carried out. Two of these materials, Ru and Rh, have been deposited for the first time by this method. In contrast to the Pt deposition, the deposition of Ru and Rh were not carried out under the optimal conditions. The metals deposited on the samples were identified by Total reflection X‐ray Fluorescence (TXRF). Rutherford Backscattering Spectrometry (RBS) analyses show that Au forms the thickest layer (∼160 nm) for the experimental conditions of this work. Current‐voltage measurements show that Pt forms a more linear ohmic contact with the lowest leakage current. A ⁵⁷Co gamma ray spectrum gave a better detector performance with a FWHM 11 keV at 122 keV. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Determination of Cd and Zn by isotope dilution-thermal ionisation mass spectrometry using a sequential analysis procedure

Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) was used to examine the certified Cd and Zn content of 4 Certified Reference Materials (CRMs); 2 soils: GBW07401 and GBW07405, 1 plant CRM060 and an animal tissue SRM1566a. The CRMs were chosen to be of contrasting origin and Cd:Zn content. Three digestion procedures were compared: (i) an open tube aqua regia procedure (ii) microwave digestion using Teflon bombs and (iii) hydrofluoric acid (HF) digestion using PTFE bombs. The Cd and Zn levels obtained using ID-TIMS all fell within the published certified range for the CRMs. This was the case regardless of the digestion procedure used, although HF digestion tended to yield marginally higher levels than the other procedures and in one instance, Cd in GBW07401, was significantly different (P<0.05) from the certified range. A filament loading procedure was developed, to allow sequential analysis of Cd and Zn on the same single filament during thermal ionisation mass spectrometry analysis. The sequential analysis technique was evaluated to ensure that Zn did not fractionate during Cd analysis and there was no inter-element interference. No marked difference in the precision and accuracy of the isotope ratio measurements were obtained from sequential element analyses on the same filament when compared to individual element analyses for a range of standard solutions or for sample digests. The most efficient procedure in terms of costs and productivity for future work of this kind would be a combination of microwave digestion and sequential analysis of Cd and Zn on the same filament.