MCM-41-SO3H: an efficient,reusable, heterogeneous catalyst for the one-pot,three-component synthesis of pyrano[3,2-b]pyrans

Research on Chemical Intermediates - MCM-41-SO3H, ordered mesoporous silica material MCM-41 with covalently anchored sulfonic acid groups, was used as a solid acid catalyst for the convenient,...     

Classical and quantum integrability for a class of potentials in two dimensions

A method for the construction of the second constant of motion in fourth order is carried out. Correspondingly the fourth order potential equation is obtained whose solutions directly provide the classical integrable systems. Second constant of motion is obtained for a large class of potentials. Quantum invariants are also obtained with second order quantum corrections of the order O(?²) to the corresponding classical invariants. The phase space diagrams for these cases are drawn using a mathematical computer software package in two dimensions.     

57Fe Mössbauer spectroscopic study of (25−x)MnO–xZnO–15Fe2O3–60B2O3 glasses

The ⁵⁷Fe Mössbauer technique has been used to investigate the effect of zinc oxide substitution in (25???x)MnO–xZnO–15Fe₂O₃–60B₂O₃ glass system (x?=?0, 5, 10, 15 and 20 mol% of ZnO ). Mössbauer absorption spectra for all the samples recorded at room temperature suggest the existence of the two paramagnetic quadrupole doublets. The observed variations in hyperfine parameters have been explained on the basis of cations distribution and exchange interaction at the lattice sites and it is concluded that B–B interaction increases while the metal–metal interaction decreases due to replacement of manganese oxide by zinc oxide. These results suggest that the present glass system exhibits a paramagnetic behaviour that changes towards the weak paramagnetic when manganese oxide was replaced with zinc oxide.     

Calculation of the viscosity of binary liquids at various temperatures using Jouyban-Acree model

Applicability of the Jouyban-Acree model for calculating absolute viscosity of binary liquid mixtures with respect to temperature and mixture composition is proposed. The correlation ability of the model is evaluated by employing viscosity data of 143 various aqueous and non-aqueous liquid mixtures at various temperatures collected from the literature. The results show that the model is able to correlate the data with an overall percentage deviation (PD) of 1.9+/-2.5%. In order to test the prediction capability of the model, three experimental viscosities from the highest and lowest temperatures along with the viscosities of neat liquids at all temperatures have been employed to train the model, then the viscosity values at other mixture compositions and temperatures were predicted and the overall PD obtained is 2.6+/-4.0%.     

Chemical composition and antimicrobial activity of the essential oils of Ferula latisecta and Mozaffariania insignis from Iran

The hydrodistilled oils from the aerial parts of Ferula latisecta and Mozaffariania insignis, which is endemic to Iran, were analyzed by GC and GC/MS. (Z)-Ocimenone (32.4%), (E)-ocimenone (20.3%), and cis-pinocarvone (11.4%) were the main components among the 22 constituents characterized in the oil of F. latisecta, representing 87.7% of the total components detected. Twenty-five compounds were identified in the oil of M. insignis, representing 99.0% of the total oil, with octyl acetate (41.1%), β-pinene (30.3%), and α-pinene (23.9%) as the main constituents. The essential oils were examined for their potential antimicrobial activities. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 561–563, November–December, 2006.     

Facile synthesis of highly substituted 2-pyrone derivatives via a tandem Knoevenagel condensation/lactonization reaction of β-formyl-esters and 1,3-cyclohexadiones

A mild and efficient tandem process for the synthesis of new highly substituted 2-pyrones starting from commercially available 2-arylacetic acids has been developed. The synthesis is based on the Knoevenagel condensation of 1,3-cyclohexadiones with various β-formyl-esters, followed by lactonization in the presence of nano ZnO (20 mol %). Moderate to high yields and readily available cheap starting materials are the key features of the present method.     

An evaluation of the CYP2D6 and CYP3A4 inhibition potential of metoprolol metabolites and their contribution to drug–drug and drug–herb interaction by LC‐ESI/MS/MS

The aim of the present study was to evaluate the contribution of metabolites to drug–drug interaction and drug–herb interaction using the inhibition of CYP2D6 and CYP3A4 by metoprolol (MET) and its metabolites. The peak concentrations of unbound plasma concentration of MET, α‐hydroxy metoprolol (HM), O‐desmethyl metoprolol (ODM) and N‐desisopropyl metoprolol (DIM) were 90.37 ± 2.69, 33.32 ± 1.92, 16.93 ± 1.70 and 7.96 ± 0.94 ng/mL, respectively. The metabolites identified, HM and ODM, had a ratio of metabolic area under the concentration–time curve (AUC) to parent AUC of ≥0.25 when either total or unbound concentration of metabolite was considered. In vitro CYP2D6 and CYP3A4 inhibition by MET, HM and ODM study revealed that MET, HM and ODM were not inhibitors of CYP3A4‐catalyzed midazolam metabolism and CYP2D6‐catalyzed dextromethorphan metabolism. However, DIM only met the criteria of >10% of the total drug related material and <25% of the parent using unbound concentrations. If CYP inhibition testing is solely based on metabolite exposure, DIM metabolite would probably not be considered. However, the present study has demonstrated that DIM contributes significantly to in vitro drug–drug interaction. Copyright © 2016 John Wiley & Sons, Ltd.     

Enhancement of azo dyes removal efficiency by using LDH/Tris/Pd catalyst: Kinetic studies

LDH/Tris/Pd (CaAl‐layered double hydroxide/tris (hydroxymethyl)aminomethane/palladium) was synthesized and appraised for its catalytic activity towards the degradation of two selected azo dyes. The decolorization of azo dyes, acid red 18 (AR 18) and reactive yellow 15 (RY 15), requires considerably small amounts of synthesized catalyst. Kinetic studies show that the catalytic decolorization of these azo dyes follows the first order kinetic model. The reported method is simple and applicable; in addition, the stable catalyst can efficiently decolorize model azo dyes with good recyclability. Therefore, LDH/Tris/Pd can be accepted as the possible component for the utilization in wastewater treatment.     

Green route for selective gram‐scale oxidation of sulfides using tungstate/triazine‐based ionic liquid immobilized on magnetic nanoparticles as a phase‐transfer heterogeneous catalyst

Tungstate ions were successfully loaded onto triazine‐based ionic liquid‐functionalized magnetic nanoparticles through an anion exchange process. The use of triazine core for creating ionic liquid led to the immobilization of high amounts of WO₄^2?. The resulting catalyst showed high activity and selectivity in the oxidation of sulfides to sulfoxides with H₂O₂ as a green oxidant at room temperature. In addition, due to the presence of ammonium groups in the catalyst structure, water dispersibility of the catalyst was increased. More important, the catalyst was magnetically recovered and reused for up to six runs without any marked decrease of activity and selectivity. Finally, easy gram‐scale oxidation of methylphenyl sulfide as well as fast separation of catalyst and product makes the protocol economical and industrially applicable.