Antibacterial Cellulose Acetate Microfibers Containing Pyridine Derivative Complexes

2021 ◽  
Vol 15 (2) ◽  
pp. 217-225
Author(s):  
Ruken Esra Demirdogen ◽  
◽  
Tuncay Yeşilkaynak ◽  
Tetyana Tishakova ◽  
Fatih Mehmet Emen ◽  
...  

Pyridine (L1) and 2,4-dimethylpyridine (L2) halide complexes of the type of [ML2X2] were prepared and characterized via FT-IR and 1H NMR. The CA microfibers containing complexes were electrospun and investigated via FT-IR. The morphologies of the microfibers were investigated via FE-SEM. Antibacterial activities of the complexes and the fibers were investigated.

2018 ◽  
Vol 63 (1-2) ◽  
pp. 49-60
Author(s):  
R. Crainic ◽  
◽  
L. R. Drăgan ◽  
R. Fechete ◽  
◽  
...  

2018 ◽  
Vol 21 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Mohammad A. Ghasemzadeh ◽  
Mohammad H. Abdollahi-Basir ◽  
Zahra Elyasi

Aim and Objective: The multi-component condensation of benzil, primary amines, ammonium acetate and various aldehydes was efficiently catalyzed using cobalt oxide nanoparticles under ultrasonic irradiation. This approach describes an effective and facile method for the synthesis of some novel 1,2,4,5-tetrasubstituted imidazole derivatives with several advantages such as high yields and short reaction times and reusability of the catalyst. Moreover, the prepared heterocyclic compounds showed high antibacterial activity against some pathogenic strains. Materials and Method: The facile and efficient approaches for the preparation of Co3O4 nanoparticles were carried out by one step method. The synthesized heterogeneous nanocatalyst was characterized by spectroscopic analysis including EDX, FE-SEM, VSM, XRD and FT-IR analysis. The as-synthesized cobalt oxide nanoparticles showed paramagnetic behaviour in magnetic field. In addition, the catalytic influence of the nanocatalyst was examined in the one-pot reaction of primary amines, benzil, ammonium acetate and diverse aromatic aldehydes under ultrasonic irradiation. All of the 1,2,4,5-tetrasubstituted imidazoles were investigated and checked with m.p., 1H NMR, 13C NMR and FT-IR spectroscopy techniques. The antibacterial properties of the heterocycles were evaluated in vitro by the disk diffusion against pathogenic strains such as Escherichia coli (EC), Bacillus subtillis (BS), Staphylococcus aureus (SA), Salmonellatyphi (ST) and Shigella dysentrae (SD) species. Results: In this research cobalt oxide nanostructure was used as a robust and green catalyst in the some novel imidazoles. The average particle size measured from the FE-SEM image is found to be 20-30 nm which confirmed to the obtained results from XRD pattern. Various electron-donating and electron-withdrawing aryl aldehydes were efficiently reacted in the presence of Co3O4 nanoparticles. The role of the catalyst as a Lewis acid is promoting the reactions with the increase in the electrophilicity of the carbonyl and double band groups. To investigate the reusability of the catalyst, the model study was repeated using recovered cobalt oxide nanoparticles. The results showed that the nanocatalyst could be reused for five times with a minimal loss of its activity. Conclusion: We have developed an efficient and environmentally friendly method for the synthesis of some tetrasubstituted imidazoles via three-component reaction of benzil, primary amines, ammonium acetate and various aldehydes using Co3O4 NPs. The present approach suggests different benefits such as: excellent yields, short reaction times, simple workup procedure and recyclability of the magnetic nanocatalyst. The prepared 1,2,4,5-tetrasubstituted imidazoles revealed high antibacterial activities and can be useful in many biomedical applications.


Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 429
Author(s):  
Aurelia Cristina Nechifor ◽  
Andreia Pîrțac ◽  
Paul Constantin Albu ◽  
Alexandra Raluca Grosu ◽  
Florina Dumitru ◽  
...  

The separation, concentration and transport of the amino acids through membranes have been continuously developed due to the multitude of interest amino acids of interest and the sources from which they must be recovered. At the same time, the types of membranes used in the sepa-ration of the amino acids are the most diverse: liquids, ion exchangers, inorganic, polymeric or composites. This paper addresses the recuperative separation of three amino acids (alanine, phe-nylalanine, and methionine) using membranes from cellulosic derivatives in polypropylene ma-trix. The microfiltration membranes (polypropylene hollow fibers) were impregnated with solu-tions of some cellulosic derivatives: cellulose acetate, 2-hydroxyethyl-cellulose, methyl 2-hydroxyethyl-celluloseand sodium carboxymethyl-cellulose. The obtained membranes were characterized in terms of the separation performance of the amino acids considered (retention, flux, and selectivity) and from a morphological and structural point of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) and thermal gravimetric analyzer (TGA). The re-sults obtained show that phenylalanine has the highest fluxes through all four types of mem-branes, followed by methionine and alanine. Of the four kinds of membrane, the most suitable for recuperative separation of the considered amino acids are those based on cellulose acetate and methyl 2-hydroxyethyl-cellulose.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Buzuayehu Abebe ◽  
H. C. Ananda Murthy ◽  
Enyew Amare Zereffa

AbstractZinc oxide (ZnO) is a fascinating semiconductor material with many applications such as adsorption, photocatalysis, sensor, and antibacterial activities. By using a poly (vinyl alcohol) (PVA) polymer as a capping agent and metal oxides (iron and manganese) as a couple, the porous PVA-aided Zn/Fe/Mn ternary oxide nanocomposite material (PTMO-NCM) was synthesized. The thermal, optical, crystallinity, chemical bonding, porosity, morphological, charge transfer properties of the synthesized materials were confirmed by DTG/DSC, UV–Vis-DRS, XRD, FT-IR, BET, SEM-EDAX/TEM-HRTEM-SAED, and CV/EIS/amperometric analytical techniques, respectively. The PTMO-NCM showed an enhanced surface area and charge transfer capability, compared to ZnO. Using the XRD pattern and TEM image analysis, the crystalline size of the materials was confirmed to be in the nanometer range. The porosity and superior charge transfer capabilities of the PTMO-NCM were confirmed from the BET, HRTEM (IFFT)/SAED, and CV/EIS analysis. The adsorption kinetics (adsorption reaction/adsorption diffusion) and adsorption isotherm test confirmed the presence of a chemisorption type of adsorbate/methylene blue dye-adsorbent/PTMO-NCM interaction. The photocatalytic performance was tested on the Congo red and Acid Orange-8 dyes. The superior ascorbic acid sensing capability of the material was understood from CV and amperometric analysis. The noble antibacterial activities of the material were also confirmed on both gram-negative and gram-positive bacteria.


2010 ◽  
Vol 93-94 ◽  
pp. 13-16
Author(s):  
Khalil J. Asali

Reactions of the labile complex (Me3tach)M(CO)3 (Me3tach = 1,3,5-trimethyl-1,3,5-triazacyclohexane; M = W, Mo) with bis(phenylthio)alkanes ( = PhS(CH2)nSPh), (2:3 molar ratio) in CH2Cl2 as solvent (at 35 oC M = W, 0 oC M = Mo) afforded in good yields bimetallic tricarbonyl complexes triply- bridged by bis(phenylthio)alkanes of the type [M(CO)3]2(μ-PhS-(CH2)n-SPh)3 [n = 3 (a), 4 (b), 5 (c), 6 (d); M = W (1), Mo (2)]. These new triply-bridged complexes were characterized by 1H NMR, FT-IR and elemental analysis. Additionally, it has been observed that the thermodynamic stability of some of these new complexes in chlorinated hydrocarbons depends mainly on the nature of the metal center and varies in the order W >> Mo.


2021 ◽  
Vol 2 (3) ◽  
pp. 31-48
Author(s):  
محمد حسن احمد ◽  
فاضل داود خالد

تم في هذا البحث تحضير وتشخيص بعض مركبات 5،2-ثنائي المعوض-4،3،1-اوكسادايازول المشتقة من حامض الدايكلوفيناك (H1). حيث تضمن العمل تحضير الاستر المثيلي لحامض الدايكلوفيناك (H2) من مفاعلته مع الميثانول بطريقة فشر ثم تحويل الاستر المذكور الى هيدرازايد الحامض المقابل (H3) ثم مفاعلة هذا الهيدرازايد مع بعض الحوامض الكاربوكسيلية بوجود اوكسي كلوريد الفسفور للحصول على مشتقات 5,2-ثنائي المعوض-43،1- اوكسادايازول (H4-H7). ثم مفاعلة المركب (H7) مع بعض الامينات الأولية للحصول على مركبات 5,2-ثنائي المعوض-4،3،1-اوكسادايازول امين (H8-H12). وقد شخصت هذه المركبات باستخدام تقنيات FT-IR و 1H-NMR و 13C-NMR علاوة على قياس درجات الانصهار لها. أظهرت نتائج التقييم الاولية لفعاليتها البيولوجية ضد نوعين من البكتريا، الاولى (Pseudomonas aeruginosa)، والثانية (Staphylococcus aureus) بأن للمركبات المحضرة ( H4 ، H6، H11، H12) فعالية تثبيطية متوسطة غالباً ضد هذين النوعين، بينما لوحظ بأن للمركبات (H7 ، H8، H9، H10) فعالية تثبيطية جيدة ضدهما على الاغلب، وكلاهما مقارنة بالمثبط القياسي المستعمل. وقد أظهرت نتائج التقييم الاولية للفعالية البيولوجية ضد نوعين من البكتريا، الاولى (Pseudomonas aeruginosa)، والثانية (Staphylococcus aureus) بأن للمركبات المحضرة ( H4 ، H6، H11، H12) فعالية تثبيطية متوسطة غالباً ضد هذين النوعين، بينما لوحظ بأن للمركبات (H7 ، H8، H9، H10) فعالية تثبيطية جيدة ضدهما على الاغلب، وكلاهما مقارنة بالمثبط القياسي المستعمل.


2016 ◽  
Vol 17 (1) ◽  
pp. 176-187 ◽  
Author(s):  
Thanaa I. Shalaby ◽  
Marwa F. El-Kady ◽  
Abd El Halem M. Zaki ◽  
Soheir M. El-Kholy

Novel magnetic cellulose acetate (CA) nanofibers were fabricated using an electrospinning process. Co-precipitated magnetite iron oxide nanoparticles were immobilized onto CA nanofibers at different weight ratios (0.2–2.5% wt/v) with a CA concentration of 15% (wt %), applied electric voltage of 20 kV, feeding rate of 1.5 ml/h and 7 cm distance between needle tip and collector. The prepared iron oxide nanoparticles were characterized using X-ray diffraction, a transmission electron microscope, a Fourier transform infrared spectrophotometer (FT-IR) and a vibrating sample magnetometer (VSM). The magnetic nanofibers were characterized by scanning electron microscopy, FT-IR, thermogravimetric analysis and VSM. The fabricated composite nanofibers were evaluated as a sorbent matrix for lead decontamination from aqueous solution using a batch technique. The influence of solution pH, contact time and adsorbent concentration on the removal efficiency was investigated. Adsorption kinetics models and isotherms were applied to the lead decontamination process onto the fabricated composite nanofibers. The kinetics of the sorption process revealed that the pseudo-second-order model fitted relatively better than the pseudo-first-order model. On the other hand, both the Langmuir and Freundlich isotherms gave a comparable fit to the adsorption data, with a high coefficient of regression of 0.999.


Author(s):  
G. Dayana Jeyaleela ◽  
S. Irudaya Monisha ◽  
J. Rosaline Vimala ◽  
A. Anitha Immaculate

Objective: Natural products from medicinal plants, either as isolated compounds or as standardized plant extracts exhibit promising source of medicinal activity against various diseases. The aim of the present work was to make an attempt of isolation of bioactive principle and characterization of the isolated compound, from the medicinal plant Melia dubaiMethods: The extraction was done by a cold percolation method and the compound was separated and isolated by chromatography technique such as a thin layer chromatography (TLC), column chromatography and high-performance liquid chromatography (HPLC). The isolated compound was crystallized and the structural characterization of the isolated compound was made using UV-Visible, FT-IR, 1H-NMR, GC-MS and MS techniques which confirmed the structure of the isolated compound.Results: The separated and isolated compound was characterized by both physical and spectral methods like Ultraviolet-Visible spectroscopy (UV-Visible), Fourier transform infrared spectroscopy (FT-IR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), Gas chromatography-mass spectrometry (GC-MS), and Mass spectrometry(MS). Based on the studies, organizational characteristics of one bioactive principle were deciphered. The results revealed that the isolated species is 2-chlorobenzimidazole and it agreed well with the reported value and spectra for 2-chlorobenzimidazole.Conclusion: The above results obtained in this research work clearly indicated the promising occurrence of 2-chlorobenzimidazole in Media dubia plant leaves. The future scope of these studies may guide us to view the biological activity of the isolated compound.


Sign in / Sign up

Export Citation Format

Share Document