scholarly journals Facile Bioinspired Preparation of Fluorinase@Fluoridated Hydroxyapatite Nanoflowers for the Biosynthesis of 5′-Fluorodeoxy Adenosine

2020 ◽  
Vol 12 (1) ◽  
pp. 431
Author(s):  
Ningning Li ◽  
Bingjing Hu ◽  
Anming Wang ◽  
Huimin Li ◽  
Youcheng Yin ◽  
...  

To develop an environmentally friendly biocatalyst for the efficient synthesis of organofluorine compounds, we prepared the enzyme@fluoridated hydroxyapatite nanoflowers (FHAp-NFs) using fluorinase expressed in Escherichia coli Rosetta (DE3) as the biomineralization framework. The obtained fluorinase@FHAp-NFs were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and FT-IR spectrum and used in the enzymatic synthesis of 5′-fluorodeoxy adenosin with S-adenosyl-L-methionine and fluoride as substrate. At an optimum pH of 7.5, fluorinase confined in the hybrid nanoflowers presents an approximately 2-fold higher synthetic activity than free fluorinase. Additionally, after heating at 30 °C for 8 h, the FHAp-NFs retained approximately 80.0% of the initial activity. However, free enzyme could remain only 48.2% of its initial activity. The results indicate that the fluoride and hybrid nanoflowers efficiently enhance the catalytic activity and thermal stability of fluorinase in the synthesis of 5′-fluorodeoxy adenosine, which gives a green method for producing the fluorinated organic compounds.

2020 ◽  
Vol 1 (4) ◽  
pp. 22-25
Author(s):  
Azwan Morni

This study reports a green method for the synthesis of gold nanoparticles (AuNPs) using the aqueous extract of Salix aegyptiaca extract. The effects of gold salt concentration, extract concentration and extract quantity were investigated on nanoparticles synthesis. Novel methods of ideally synthesizing AuNPs are thus thought that are formed at ambient temperatures, neutral pH, low costs and environmentally friendly fashion. AuNPs were characterized with different techniques such as UV–vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and TEM. FT-IR spectroscopy revealed that gold nanoparticles were functionalized with biomolecules that have primary carbonyl group, -OH groups and other stabilizing functional groups. TEM experiments showed that these nanoparticles are formed with various shapes and X-ray diffraction pattern showed high purity and face centered cubic structure of AuNPs. For electrochemical properties of AuNPs, a modified glassy carbon electrode using AuNPs (AuNPs/GCE) was investigated. The results show that electronic transmission rate between the modified electrode and [Fe (CN)6]3-/4- increased.


Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 305 ◽  
Author(s):  
Yan Zhang ◽  
Hui Zhang ◽  
Fang Wang ◽  
Li-Xia Wang

The ginger essential oil/β-cyclodextrin (GEO/β-CD) composite, ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) particles and ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) microsphere were prepared with the methods of inclusion, ionic gelation and spray drying. Their properties were studied by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the particle size of GEO/β-CD composite was smaller than that of β-CD and GEO/β-CD/CTS particles were loose and porous, while the microsphere obtained by spray drying had certain cohesiveness and small particle size. Besides, results also indicated that β-CD/CTS could modify properties and improve the thermal stability of GEO, which would improve its application value in food and medical industries.


Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 62 ◽  
Author(s):  
Gunugunuri K. Reddy ◽  
Torin C. Peck ◽  
Charles A. Roberts

Direct decomposition of NO into N2 and O2 (2NO→N2 + O2) is recognized as the “ideal” reaction for NOx removal because it needs no reductant. It was reported that the spinel Co3O4 is one of the most active single-element oxide catalysts for NO decomposition at higher reaction temperatures, however, activity remains low below 650 °C. The present study aims to investigate new promoters for Co3O4, specifically PdO vs. PtO. Interestingly, the PdO promoter effect on Co3O4 was much greater than the PtO effect, yielding a 4 times higher activity for direct NO decomposition at 650 °C. Also, Co3O4 catalysts with the PdO promoter exhibit higher selectivity to N2 compared to PtO/Co3O4 catalysts. Several characterization measurements, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), and in situ FT-IR, were performed to understand the effect of PdO vs. PtO on the properties of Co3O4. Structural and surface analysis measurements show that impregnation of PdO on Co3O4 leads to a greater ease of reduction of the catalysts and an increased thermal stability of surface adsorbed NOx species, which contribute to promotion of direct NO decomposition activity. In contrast, rather than remaining solely as a surface species, PtO enters the Co3O4 structure, and it promotes neither redox properties nor NO adsorption properties of Co3O4, resulting in a diminished promotional effect compared to PdO.


2016 ◽  
Vol 1141 ◽  
pp. 190-195
Author(s):  
Hitesh Saravaia ◽  
Hariom Gupta ◽  
Vaibhav Kulshreshtha

Barium Titanate (BaTiO3) nanostructures are synthesized by the molten salt-hydroxide reaction. The crystalline phase and chemical structure of the synthesized material are analyzed using powder x-ray diffraction (XRD) and FT-IR techniques, revealing the tetragonal BaTiO3 crystalline structure. Morphology and thermal stability of the material are characterized using TEM and TG-DTG analysis. BET surface area analysis shows significant active surface available for adsorption and its surface area value is found to be 14.8427 m2 g-1. The maximum adsorption of strontium metal is found to be 56.3 for the 1.2 g L-1 BaTiO3 adsorbent dose which reveals a remarkable separation property of the BaTiO3.


2012 ◽  
Vol 535-537 ◽  
pp. 149-153 ◽  
Author(s):  
Er Yuan Li ◽  
Xiu Feng Wang ◽  
Xue Zhi Wang ◽  
Hao Wang

Polyaniline/SiO2 composites were prepared by the SiO2 particles whose surface character was modified by succinic acid. The composites were characterized by Fourier transform infrared (FT–IR) spectroscopy, X–ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM). The results demonstrated that the thermal stability of PANI had improved.


2018 ◽  
Vol 36 (2) ◽  
pp. 283-287
Author(s):  
Aseel A. Kareem

Abstract Polyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI nanofiber filler enhanced the activation energy of PI composites from 0.37 eV to 0.34 eV.


2013 ◽  
Vol 32 (4) ◽  
pp. 339-343 ◽  
Author(s):  
Siyamak Bagheriyan

AbstractSb2S3 nanoparticles were synthesized via a simple sonochemical reaction between SbCl3 and thioacetamide. The effect of different parameters such as power and time of pulsation on the morphology of the product has been investigated. The Sb2 S3 nanostructures were then added to acrylonitrile-butadiene-styrene terpolymer. The effect of Sb2 S3 nanostructures on the thermal stability of the polymeric matrix has been examined. The thermal decomposition of the nanocomposite shifts towards higher temperature in the presence of the Sb2 S3 . Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), photoluminescence (PL) spectroscopy, thermogravimetric analysis (TGA), UL-94 and limiting oxygen index (LOI) analysis.


2014 ◽  
Vol 915-916 ◽  
pp. 780-783
Author(s):  
Hong Wang ◽  
Ming Tian Li ◽  
Yue Lu ◽  
Di Liu

Pyrrole and m-toluidine copolymer (P(PY/MT)) / montmorillonite (MMT) Composites were prepared by in situ chemical polymerization of pyrrole with m-toluidine monomer in the presence of montmorillonite. The structural, morphological and thermal properties of these composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). X-ray diffraction result for P(PY/MT)-MMT illuminated the intercalation of P(PY/MT) copolymer between the clay layers. The FT-IR result showed the successful incorporation of montmorillonite clay in the prepared P(PY/MT)/MMT composite. The higher thermal stability of high MMT content rate might be attributed to its higher chain compactness due to the interfacial interaction between the P(PY/MT) and the clay.


2009 ◽  
Vol 2 ◽  
pp. BTRI.S3728 ◽  
Author(s):  
Aida Elkayar ◽  
Yehia Elshazly ◽  
Mariana Assaad

The objective of this work was to study the production of hydroxyapatite (HA) from bovine teeth. Hydroxyapatite (HA) was produced from bovine teeth powder after calcination at 1150 °C. It was discovered that the sample preparation process influences its properties, so, crystal structure and thermal stability of HA were investigated. The X-Ray diffraction analysis (XRD) results confirmed that HA has been successfully produced. Fourier transform infrared spectroscopic (FT-IR) study confirmed the presence of hydroxyl (OH) and phosphate (PO4−3) functional groups. The scanning electronic microscope (SEM) was employed to identify the surface morphology of HA, and showed the nanoporous structure throughout the matrix. The sample constituents such as Ca, P, K … etc., and their values were determined by Energy dispersive X-Ray (EDX).


2012 ◽  
Vol 217-219 ◽  
pp. 551-554
Author(s):  
Ting Xi Li ◽  
Yu Hua Zhao ◽  
Qian Li ◽  
Cheng Qian Yuan ◽  
Quan Liang Chen ◽  
...  

Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis(TGA). The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.


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