precipitation procedure
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Author(s):  
Nehad Yousf ◽  
Amir Elzwawy ◽  
Emtinan Ouda ◽  
S. A. Mansour ◽  
El Shazly M. Duraia

Abstract In the present contribution, the 3D hollow structure of manganese cobalt oxide/carbon nanotubes (MnCo2O4/CNTs) nanocomposite was successfully synthesized through a co-precipitation procedure followed by post-heat treatment. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Based on the obtained results, the surface of carbon nanotubes was coated uniformly in radial directions by manganese oxide (MnO2) nanosheets forming a flower-shaped structure. In the next step, cobalt oxide precursor was introduced to form MnCo2O4/CNTs nanocomposite. The XRD data confirms the formation of MnCo2O4/CNTs. The estimated values of the strain and the crystallite size based on the Williamson-Hall (W-H) method are calculated as 5.326×10-4 and 16 nm respectively. The fingerprint area of FTIR suggests the successful incorporation of MnO2 and cobalt oxide onto CNTs’ surfaces. The flower-shaped structure in the nanoscale is verified by the FESEM and TEM devices. Furthermore, the magnetic specifications revealed the paramagnetic with a small ferromagnetic component of the aforementioned MnCo2O4/CNTs nanocomposite.


2021 ◽  
Vol 1 (4) ◽  
pp. 320-324
Author(s):  
Mahesh P Jadhav ◽  
Swati G Swami

Tyrosinase has an important role in melanin formation, is responsible for the production of colour pigments of skin, hair, and eye. In the presents study, tyrosinase was isolated from Mushrooms, isolation of enzyme was done by acetone precipitation procedure and precipitation of enzyme was done with ammonium sulphate precipitation method. Plants selected for extraction were Azadirachta indica (Neem), Manikara zapota (Chiku), Annona squamosa (Sitaphal), and Hibiscus Rosa-sinesis (China rose). For phytochemical screening Alkaloids-Mayer’s Test, Flavonoids (Shinoda Test, Alkaline Reagent Test), sugar (Benedict’s reagent Test), Glycosides (Borntrager's Test), Phenolic compounds Test (Ferric chloride Test, Gelatin Test, Lead Acetate Test). Mushroom tyrosinase inhibitory assay was determined by the spectroscopic method. The study shows the tyrosinase inhibitory activity of selected medicinal plants.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 515
Author(s):  
Wei-Sheng Chen ◽  
Shota Mesaki ◽  
Cheng-Han Lee

Tin anode slime is a by-product of the tin electrolytic refining process. This study investigated a route to separate Sn, Sb, Bi, and Cu from tin anode slime after leaching with hydrochloric acid. In the solvent extraction process with tributyl phosphate, Sb and Sn were extracted into the organic phase. Bi and Cu were unextracted and remained in the liquid phase. In the stripping experiment, Sb and Sn were stripped and separated with HCl and HNO3. Bi and Cu in the aqueous phase were also separated with chemical precipitation procedure by controlling pH value. The purities of Sn, Sb, Cu solution and the Bi-containing solid were 96.25%, 83.65%, 97.51%, and 92.1%. The recovery rates of Sn, Sb, Cu, and Bi were 76.2%, 67.1%, and 96.2% and 92.4%.


Bioanalysis ◽  
2020 ◽  
Vol 12 (21) ◽  
pp. 1509-1519
Author(s):  
Weiping Wang ◽  
Pengyan Li ◽  
Mengna Fang ◽  
Xiaoting Li ◽  
Yu Zhang ◽  
...  

Aim: Nimodipine and 3-n-butylphthalide are co-administered to treat vascular dementia, but the pharmacokinetic interaction between the two drugs is still unknown. Therefore, a robust, high-throughput and economical supercritical fluid chromatography–ESI-MS/MS method has been initially developed to simultaneously determine nimodipine and 3-n-butylphthalide in beagle plasma, in order to study the safety of co-administration. Materials & methods: After a simple protein precipitation procedure, isocratic elution with mobile phase of CO2 and methanol (containing 0.3% formic acid and 2 mM ammonium acetate) was applied to minimize run time and facilitate sensitive and high-throughput bioanalysis. The method was fully validated according to US FDA Guidance. The validated method was then successfully applied in a pharmacokinetic interaction study. Results: The results indicated there is no significant pharmacokinetic interaction between the two drugs.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paolo Passaretti ◽  
Inam Khan ◽  
Timothy R. Dafforn ◽  
Pola Goldberg Oppenheimer

Abstract M13 bacteriophage is a well-established versatile nano-building block, which can be employed to produce novel self-assembled functional materials and devices. Sufficient production and scalability of the M13, often require a large quantity of the virus and thus, improved propagation methods characterised by high capacity and degree of purity are essential. Currently, the ‘gold-standard’ is represented by infecting Escherichia coli cultures, followed by precipitation with polyethylene glycol (PEG). However, this is considerably flawed by the accumulation of contaminant PEG inside the freshly produced stocks, potentially hampering the reactivity of the individual M13 filaments. Our study demonstrates the effectiveness of implementing an isoelectric precipitation procedure to reduce the residual PEG along with FT-IR spectroscopy as a rapid, convenient and effective analytic validation method to detect the presence of this contaminant in freshly prepared M13 stocks.


2020 ◽  
Author(s):  
Henry P Wood ◽  
Nicola J Baxter ◽  
Clare R Trevitt ◽  
F Aaron Cruz-Navarrete ◽  
Andrea M Hounslow ◽  
...  

<p>Manipulation of enzyme behaviour represents a sustainable technology that can be harnessed to enhance the production of valuable metabolites and chemical precursors. b-glucose 1,6-bisphosphate (bG16BP) is a native reaction intermediate in the catalytic cycle of b-phosphoglucomutase (bPGM) that has been proposed as a treatment for human congenital disorder of glycosylation involving phosphomannomutase 2 (PMM2). Studies of both bPGM and PMM2 could benefit from a green and high-yielding method for bG16BP production. Three strategies have been reported previously for the synthesis of bG16BP; however, each of these methods either delivers low yields or uses chemicals and procedures with significant environmental impacts. Herein, through combined use of NMR spectroscopy, kinetic assays and site-directed mutagenesis, we report the efficient enzymatic synthesis of anomer-specific bG16BP using a variant of bPGM. Further purification, employing a simple environmentally considerate precipitation procedure requiring only a standard biochemical toolset, results in a product with high purity and yield. Moreover, this synthesis strategy illustrates how manipulation of the catalytic magnesium coordination of an enzyme can be utilised to generate large quantities of a valuable metabolite.</p>


Author(s):  
Henry P Wood ◽  
Nicola J Baxter ◽  
Clare R Trevitt ◽  
F Aaron Cruz-Navarrete ◽  
Andrea M Hounslow ◽  
...  

<p>Manipulation of enzyme behaviour represents a sustainable technology that can be harnessed to enhance the production of valuable metabolites and chemical precursors. b-glucose 1,6-bisphosphate (bG16BP) is a native reaction intermediate in the catalytic cycle of b-phosphoglucomutase (bPGM) that has been proposed as a treatment for human congenital disorder of glycosylation involving phosphomannomutase 2 (PMM2). Studies of both bPGM and PMM2 could benefit from a green and high-yielding method for bG16BP production. Three strategies have been reported previously for the synthesis of bG16BP; however, each of these methods either delivers low yields or uses chemicals and procedures with significant environmental impacts. Herein, through combined use of NMR spectroscopy, kinetic assays and site-directed mutagenesis, we report the efficient enzymatic synthesis of anomer-specific bG16BP using a variant of bPGM. Further purification, employing a simple environmentally considerate precipitation procedure requiring only a standard biochemical toolset, results in a product with high purity and yield. Moreover, this synthesis strategy illustrates how manipulation of the catalytic magnesium coordination of an enzyme can be utilised to generate large quantities of a valuable metabolite.</p>


2020 ◽  
Author(s):  
Henry P Wood ◽  
Nicola J Baxter ◽  
Clare R Trevitt ◽  
F Aaron Cruz-Navarrete ◽  
Andrea M Hounslow ◽  
...  

<p>Manipulation of enzyme behaviour represents a sustainable technology that can be harnessed to enhance the production of valuable metabolites and chemical precursors. b-glucose 1,6-bisphosphate (bG16BP) is a native reaction intermediate in the catalytic cycle of b-phosphoglucomutase (bPGM) that has been proposed as a treatment for human congenital disorder of glycosylation involving phosphomannomutase 2 (PMM2). Studies of both bPGM and PMM2 could benefit from a green and high-yielding method for bG16BP production. Three strategies have been reported previously for the synthesis of bG16BP; however, each of these methods either delivers low yields or uses chemicals and procedures with significant environmental impacts. Herein, through combined use of NMR spectroscopy, kinetic assays and site-directed mutagenesis, we report the efficient enzymatic synthesis of anomer-specific bG16BP using a variant of bPGM. Further purification, employing a simple environmentally considerate precipitation procedure requiring only a standard biochemical toolset, results in a product with high purity and yield. Moreover, this synthesis strategy illustrates how manipulation of the catalytic magnesium coordination of an enzyme can be utilised to generate large quantities of a valuable metabolite.</p>


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