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81.
Leyla Yurttaş Aslıhan Kubilay Asaf Evrim Evren İpek Kısacık Hülya Karaca Gençer 《Phosphorus, sulfur, and silicon and the related elements》2020,195(9):767-773
AbstractSome new 3,4,5-trisubstituted 1,2,4-triazole derivatives were synthesized and studied for their antimicrobial activity. The lead compounds were obtained starting from 8-hydroxyquinoline and ethyl 2-chloroacetate. The obtained ester compound (1) first reacted with hydrazine hydrate (2) then with phenyl isothiocyanate (3). Ring closure by KOH led to 3-mercapto-1,2,4-triazole derivative (4). Lastly, it reacted with 2-chloro-N-(substituted (benzo)/thiazole)acetamide derivatives to obtain the final compounds (5a–j). The structural elucidation of the compounds was performed by 1H NMR and 13C NMR spectroscopy and high resolution mass spectrometry techniques and elemental analysis. The synthesized compounds were investigated for their antimicrobial activities against seven bacteria and four fungi. As a result of the activity studies, it was observed that compounds N-(6-nitrobenzothiazol-2-yl)-2-[[4-phenyl-5-((quinolin-8-yloxy)methyl)-4H-1,2,4-triazol-3-yl]thio]acetamide (5a) and N-(6-fluorobenzothiazol-2-yl)-2-[[4-phenyl-5-((quinolin-8-yloxy)methyl)-4H-1,2,4-triazol-3-yl]thio]acetamide (5d) were the most active molecules. Also, the antifungal activity of the compounds was found to be higher than their antibacterial activity although lower than the standard drug’s potential. Additionally, the physicochemical properties of the compounds were calculated which were evaluated to be at a suitable range for oral administration. 相似文献
82.
Structure and physico‐chemical properties of a photocatalyst, especially surface area and absorption ability, were correlated to catalytic activities in photodegradation of dye pollutants in water. In this investigation photocatalytic degradation of azo dye Direct yellow 12 (Chrysophenine G) in water was studied. Titanium(IV) oxide was supported on Clinoptilolite (CP) (Iranian Natural Zeolite) using solid‐state dispersion (SSD) method. The results show that the TiO2/Clinoptilolite (SSD) is an active photocatalyst. The maximum effect of photo degradation was observed at 10 wt.% TiO2, 90 wt.% Clinoptilolite. A first order reaction with k = 0.0108 min?1 was observed. The effects of some parameters such as pH, amount of photocatalyst, initial concentration of dye were examined. 相似文献
83.
Mohammadreza Shokouhimehr Mehdi Shahedi Asl Babak Mazinani 《Research on Chemical Intermediates》2018,44(3):1617-1626
In this study, mesoporous silica materials with tuned pores and surface areas were successfully synthesized by adjusting the amount of applied hexane and controlling the hydrothermal temperature. The synthesized silica materials were then functionalized by an amine group to produce solid base catalysts and be applicable as efficient heterogeneous base catalysts for the Henry reaction. The mesoporous silica catalysts possessing large-pores and surface area expose their active catalytic sites and thereby improve contacts with reactants fulfilling the reactions expeditiously in comparison with solid base catalysts possessing small-pores and surface area. The results indicated that the yield of the products is significantly dependent on the structure of the applied solid base catalysts. The modulated large-pore solid base catalysts presented high catalytic activity in Henry reactions and could be reused for five consecutive cycles. 相似文献
84.
In the present work, a on-chip electromembrane extraction (CEME) was designed and employed for simultaneous extraction of mefenamic acid (MEF) and diclofenac (DIC), as acidic model analytes, and betaxolol (BET), as a basic model analyte, followed by HPLC-UV. The CEME consists of two polymethyl methacrylate (PMMA) parts which each part consists of two separated microfluidic channels. A polypropylene sheet membrane impregnated with an organic solvent was sandwiched between the parts. One of the parts was used as the flow path for the sample solution and the other one as holder for the acceptor phases. The separated microfluidic channels of the sample solution part were connected to each other using a small piece of a capillary tube and the sample solution was pumped through them by means of a micro-syringe pump. However, the acceptor phases of the acidic and basic analytes were separately kept stagnant in the two microfluidic channels during the extraction process. A d.c. potential was applied for migration of the analytes from sample solution through the organic membrane into the acceptor phases. All effective variables on the extraction efficiency of the analytes were optimized. Under the optimized conditions, preconcentration factors higher than 15 were achieved and the calibration curves were linear in the range of 10–500 μg L−1 (r2 > 0.9982). RSD% values (n = 4) and LODs were less than 7.1% and 5.0 μg L−1. The results demonstrated that CEME could efficiently be used for the simultaneous analysis of acidic and basic analytes in biological samples. 相似文献
85.
A simple method is proposed for the determination and speciation of Mn(II) and Mn(VII) in waters utilizing a macroporous resin, Amberlite XAD-7HP. The batch method was employed and flame atomic absorption spectrometry was used in all determinations. Amberlite XAD-7HP resin was shown to retain Mn(VII) between pH 4 and 12. If the solution contains only one of the species, either Mn(II) or Mn(VII), the resin behaves selectively depending on the pH of the solution. The elution from the sorbent was realized using K2C2O4 in HNO3. The efficiency of the method was checked via spike recovery experiments. The proposed method was successfully applied to industrial wastewater samples and quantitative recoveries (≥96.0%) confirmed the accuracy of the method. 相似文献
86.
87.
Yılmaz Turgut Murat Azizoglu Aslı Erdogan Nevin Arslan Halil Hosgoren 《Tetrahedron: Asymmetry》2013,24(13-14):853-859
In order to find the most effective catalyst for the enantioselective reduction of a prochiral ketone, a series of novel β-hydroxyamide derivatives of salicylic acid and chiral amino alcohols were synthesized. Different substituted prochiral ketones have been reduced in high yield (up to 99%) and the corresponding secondary alcohols are formed with good enantiomeric excess (up to 86%). The mechanism of this type of catalyst can be explained by considering the reaction mechanism for the CBS catalyst. 相似文献
88.
Kamran Asemi Mehdi Akhlaghi Manouchehr Salehi Seyed Kasra Hosseini Zad 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(8):1063-1074
Finite Element Method based on Rayleigh–Ritz energy formulation is applied to obtain the elastic behavior of functionally
graded thick truncated cone. The cone has finite length, and it is subjected to axisymmetric hydrostatic internal pressure.
The inner surface of the cone is pure ceramic and the outer surface is pure metal, and the material composition varying continuously
along its thickness. Using this method, the effects of semi-vertex angle of the cone and the power law exponent on distribution
of different types of displacements and stresses are considered. 相似文献
89.
90.
J. Rafiei J. Sabbaghzadeh I. Mashayekhe Asl S. Sh. Kazemi 《Optics Communications》2010,283(18):3469-3474
A study of the thermo-mechanical analysis in edge-pumped composite Yb:YAG disk laser is presented. A three-dimensional model of disk and cooling system was created in ANSYS software. Heat load density applied on active medium was 14.6% of power absorption density. Temperature, stress and strain analysis showed a uniform distribution in the upper surface and maximum in the center. Finally, optimum heat exchanger coefficient and temperature of cooling system were obtained by comparing with different analyses and results. 相似文献