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21.
Amir Khojastehnezhad Abolghasem Davoodnia Mehdi Bakavoli Niloofar Tavakoli‐Hoseini Mohsen Zeinali‐Dastmalbaf 《中国化学》2011,29(2):297-302
A simple, efficient and green method for the synthesis of 14‐aryl‐14H‐dibenzo[a,j]xanthenes by a one‐pot condensation reaction of β‐naphthol and aryl aldehydes using silica gel‐supported polyphosphoric acid (PPA/SiO2), an effective and reusable catalyst, under solvent‐free conditions is described. The present methodology offers several advantages, such as a simple procedure with an easy work‐up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents. 相似文献
22.
23.
Abolghasem Jouyban Masoumeh Abbasi Elaheh Rahimpour Mohammad Barzegar-Jalali Jalil Vaez-Gharamaleki 《Physics and Chemistry of Liquids》2018,56(5):619-626
The solubility of deferiprone (DFP) in five organic solvents including ethyl acetate, chloroform, acetonitrile, 1,4-dioxane and dichloromethane was investigated by the flask-shake method under atmospheric pressure at temperatures ranging from 293.15 to 313.15 K. In general, the solubility (mol L–1) obeyed the following order from high to low in different mono-solvents: dichloromethane > chloroform > acetonitrile > 1,4-dioxane > ethyl acetate. The solubility of DFP in the mono-solvents increased with a rise of temperature. The solubility data were successfully correlated with the van’t Hoff equation. The generated data in this work and the previously published data were used to calculate the thermodynamic parameters of the system using the modified van’t Hoff equation, and the derived thermodynamic properties were correlated using Abraham solvation parameters. 相似文献
24.
The processes of lactic acid production include two key stages, which are (a) fermentation and (b) product recovery. In this
study, free cell of Bifidobacterium longum was used to produce lactic acid from cheese whey. The produced lactic acid was then separated and purified from the fermentation
broth using combination of nanofiltration and reverse osmosis membranes. Nanofiltration membrane with a molecular weight cutoff
of 100–400 Da was used to separate lactic acid from lactose and cells in the cheese whey fermentation broth in the first step.
The obtained permeate from the above nanofiltration is mainly composed of lactic acid and water, which was then concentrated
with a reverse osmosis membrane in the second step. Among the tested nanofiltration membranes, HL membrane from GE Osmonics
has the highest lactose retention (97 ± 1%). In the reverse osmosis process, the ADF membrane could retain 100% of lactic
acid to obtain permeate with water only. The effect of membrane and pressure on permeate flux and retention of lactose/lactic
acid was also reported in this paper. 相似文献
25.
The equilibrium solubility of acetaminophen in methanol + water binary mixtures at 298.15 K was determined and correlated with the Jouyban–Acree model. Preferential solvation parameters by methanol (δx1,3) were derived from their thermodynamic solution properties by means of the inverse Kirkwood–Buff integrals method. δx1,3 values are negative in water-rich mixtures but positive in compositions from 0.32 in mole fraction of methanol to pure methanol. It is conjecturable that in the former case, the hydrophobic hydration around non-polar groups plays a relevant role in the solvation. The higher solvation by methanol in mixtures of similar cosolvent compositions and methanol-rich mixtures could be explained in terms of the higher basic behavior of this cosolvent. 相似文献
26.
27.
Jos B. de Araújo-Neto Maria M. C. da Silva Cícera D. de M. Oliveira-Tintino Iêda M. Begnini Ricardo A. Rebelo Luiz E. da Silva Sandro L. Mireski Michele C. Nasato Maria I. L. Krautler Jaime Ribeiro-Filho Abolghasem Siyadatpanah Polrat Wilairatana Henrique D. M. Coutinho Saulo R. Tintino 《Molecules (Basel, Switzerland)》2021,26(23)
The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains. 相似文献
28.
Banafsheh Vahdani Alviri Mehrdad Pourayoubi Abolghasem Farhadipour Manpreet Kaur Jerry P. Jasinski 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(10):1424-1433
The asymmetric unit of O,O′‐dimethyl [(2,3,4,5,6‐pentafluorophenyl)hydrazinyl]phosphonate, C8H8F5N2O3P, is composed of two symmetry‐independent molecules with significant differences in the orientations of the C6F5 and OMe groups. In the crystal structure, a one‐dimensional assembly is mediated from classical N—H…O hydrogen bonds, which includes R22(8), D(2) and some higher‐order graph‐set motifs. By also considering weak C—H…O=P and C—H…O—C intermolecular interactions, a two‐dimensional network extends along the ab plane. The strengths of the hydrogen bonds were evaluated using quantum chemical calculations with the GAUSSIAN09 software package at the B3LYP/6‐311G(d,p) level of theory. The LP(O) to σ*(NH) and σ*(CH) charge‐transfer interactions were examined according to second‐order perturbation theory in natural bond orbital (NBO) methodology. The hydrogen‐bonded clusters of molecules, including N—H…O and C—H…O interactions, were constructed as input files for the calculations and the strengths of the hydrogen bonds are as follows: N—H…O [R22(8)] > N—H…O [D(2)] > C—H…O. The decomposed fingerprint plots show that the contribution portions of the F…H/H…F contacts in both molecules are the largest. 相似文献
29.
Abolghasem Davoodnia Mehdi Bakavoli Mehdi Soleimany Niloofar Tavakoli-Hoseini 《Monatshefte für Chemie / Chemical Monthly》2009,47(3):355-358
Abstract A new route to the synthesis of 2-arylthieno[2,3-d]pyrimidin-4(3H)-ones has been developed through heterocyclization of 2-amino-4,5-dimethylthiophene-3-carboxamide
with aromatic aldehydes in boiling glacial acetic acid followed by air oxidation. The unoxidized intermediates, 2-aryl-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones, are isolated when the reactions are carried out either at room temperature or under a nitrogen atmosphere.
Graphical Abstract
相似文献
30.
Behruz Feriduni Mir Ali Farajzadeh Mohammad Barzegar Shahram Sadeghvand Maryam Khoubnasabjafari Abolghasem Jouyban 《Journal of the Iranian Chemical Society》2018,15(11):2503-2510
A simple, sensitive, and rapid analytical method has been developed and validated for the extraction and quantification of valproic acid and its main metabolite (3-heptanone) in human plasma. Initially, the proteins of plasma were precipitated with trifluoroacetic acid. Then a very small volume of a water-immiscible extractant and acetonitrile was mixed and rapidly injected into the pre-treated plasma sample. For further turbidity (dispersion of the extractant into sample solution), the cloudy solution was vortexed. After centrifugation, the settled phase was injected into gas chromatography-flame ionization detection. The effective parameters, such as type and volume of extraction and disperser solvents, vortex time, and pH were studied and optimized. The limits of detection of valproic acid and 3-heptanone were obtained, 0.065 and 0.015 mg L?1, respectively. An acceptable precision was obtained for a concentration of 2 mg L?1 of each analyte (relative standard deviation?≤?8%). The average absolute recoveries (n?=?3) of valproic acid and 3-heptanone were 52?±?2 and 42?±?1%, respectively. The validated method has been successfully used in analysis of the analytes in human plasma samples. 相似文献