scholarly journals Isolation, Characterization, and Pharmaceutical Applications of an Exopolysaccharide from Aerococcus Uriaeequi

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 337 ◽  
Author(s):  
Chunlei Wang ◽  
Qiuping Fan ◽  
Xiaofei Zhang ◽  
Xiaoping Lu ◽  
Yanrui Xu ◽  
...  
Keyword(s):  
Free Radical ◽  
Marine Bacteria ◽  
High Performance ◽  
Safety Assessment ◽  
Biological Function ◽  
Gel Filtration ◽  
Sodium Hyaluronate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Flocculating Rate

Many marine bacteria secrete exopolysaccharides (EPSs), which are made up of a substantial component of the macro-molecules surrounding cells. Recently, the wide demand for EPSs for food, cosmetics, pharmaceutical and other applications has led to great interest in them. In this study, an EPS produced by marine bacteria Aerococcus uriaeequi HZ strains (EPS-A) was isolated and purified to examine its structure and biological function. The molecular weight of EPS-A analyzed by high-performance liquid gel filtration chromatography (HPGFC) is found to have a number average of 2.22 × 105 and weight average of 2.84 × 105, respectively. High-performance liquid chromatography (HPLC) and Fourier-transform–infrared (FT–IR) analysis indicate that EPS-A was a polysaccharide composed of glucose and a little mannose. In addition, the flocculating rate of sewage of EPS-A was 79.90%. The hygroscopicity studies showed that hygroscopicity of EPS-A was higher than chitosan but lower than that of sodium hyaluronate. The moisture retention of EPS-A showed similar retention activity to both chitosan and sodium hyaluronate. EPS-A also can scavenge free radicals including both OH• free radical and O2•− free radical and the activity to O2•− free radical is similar to vitamin C. Safety assessment on mice indicated that the EPS-A is safe for external use and oral administration. EPS-A has great potential for applications in medicine due to its characteristics mentioned above.

Thermal Spraying of High Performance Thermoplastics

1998 ◽  
Author(s):  
E. Lugscheider ◽  
C. Herbst ◽  
A. Fischer
Keyword(s):  
High Performance ◽  
Elevated Temperatures ◽  
Thermal Spraying ◽  
Paper Coatings ◽  
Thermally Sprayed Coatings ◽  
Ft Ir ◽  
Ir Analysis ◽  
Thermally Sprayed ◽  
Sprayed Coatings ◽  
Wipe Tests

Abstract Thermally sprayed coatings of high performance thermoplastics are of interest espacially for the chemical industry for anti-corrosion applications at elevated temperatures. In this paper coatings of polyetherether-keton (PEEK) and polyphenylen-sulphide (PPS) have been produced by simple flamespraying. They have been investigated by optical metallography, FT-IR analysis and DSC-analysis. Among the coating properties also the "in-flight" particles have been studied by wipe-tests and FT-IR analysis in order to assess possible decomposition effects during spraying.

scholarly journals PHYTOCHEMICAL PROFILING, FREE-RADICAL SCAVENGING AND ANTI-INFLAMMATORY ACTIVITIES OF MELIOSMA SIMPLICIFOLIA (L.)

2020 ◽  
pp. 62-68
Author(s):  
S. PAVITHR ◽  
T. SEKAR
Keyword(s):  
Free Radical ◽  
Methanol Extract ◽  
Inflammatory Activity ◽  
Scavenging Activity ◽  
Paw Edema ◽  
Stem Extract ◽  
Ft Ir ◽  
Ir Analysis ◽  
Anti Inflammatory ◽  
Dpph Scavenging

Objective: In the current research, to determine the stem extract of Meliosma simplicifolia (L.) for total phenol, tannin, total flavonoid, antioxidant activity, anti-inflammatory and identify the phytoconstituents utilizing GC-MS and FT-IR. Methods: The ability of the plant extract to act as hydrogen/electrons donor or scavenger of radicals was determined by in vitro antioxidant assays using 2,2-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, reducing power assay, superoxide radical (O2•) scavenging activity. The anti-inflammatory activity was evaluated using carrageenan and formalin-induced paw edema models using Wistar albino rats. The GC-MS and FT-IR analysis of the methanolic stem extract of M. simplicifolia was revealed the presence of phytochemicals. Results: Quantitative studies of estimated phenol, flavonoid and tannin, as for the methanol extract of stem showed the highest content of phenolic compounds (39.83±3.62GAE mg/100). Antioxidant activities were concluded the estimation M. simplicifolia stem for as followed the studies. In stem the methanol extract showed the highest DPPH scavenging activity (124.3µg/ml). The anti-inflammatory activity has shown in high doses of methanolic extract 250 mg/kg of significant value (p<0.05) inhibition of paw edema, on 6th hour, respectively. The FT-IR analysis has confirmed their characteristic peak values and functional groups. Conclusion: M. simplicifolia has an effective of anti-inflammatory activity and constitutes a potential source for the development of new treatments.

scholarly journals Kinetics and Mechanism of Oxidation of Metformin Hydrochloride by Hexamolybdocobaltate(III) in Acidic Medium

2020 ◽  
Vol 33 (1) ◽  
pp. 15-20
Author(s):  
J.D. SAWANT ◽  
K.K. PATIL ◽  
G.S. GOKAVI
Keyword(s):  
Free Radical ◽  
Ir Spectra ◽  
Oxidation Product ◽  
Acidic Medium ◽  
High Performance ◽  
Direct Electron Transfer ◽  
Metformin Hydrochloride ◽  
Experimental Conditions ◽  
Rate Of Reaction ◽  
Ft Ir

The oxidation of metformin hydrochloride by Anderson-Evans type hexamolybdocobaltate(III) anion was investigated under pseudofirst- order condition in acidic medium at 298 K. The rate of reaction is accelerated by increase in the concentration of H+ ion. The decrease in the reaction rate with increase in the concentration of the oxidant [H6CoMo6O24]3- anion and added molybdate ion kinetically indicate existence of the prior equilibria between various forms of the oxidant. In present study, the oxidant exists in monomers [H6CoMo6O24]3- anion, [H5CoMo5O20]2- anion and dimer [H4Co2Mo10O38]6- forms between the pH 2 and 1. The active oxidant species is [H5CoMo5O20]2- anion. Under experimental conditions, the reaction involves direct electron-transfer from metformin center to oxidant anion generating free radical in rate determining step. The fast hydrolysis of formed free radical in presence of second oxidant molecule leads to formation of carbonyl imino functional group in the oxidation product. The ionic strength and solvent polarity had no significant effect on the rate of reaction. FT-IR spectra of metformin and its oxidation product sample were recorded and analyzed. The FT-IR spectra show the change in frequency of the functional groups of oxidation product than that of the pure MET. The formation of oxidation product was confirmed by high performance liquid chromatography associated with electron impact mass spectroscopy (LC/EI-MS). Thermodynamic parameters are evaluated by temperature variation kinetic data and are in support of the proposed mechanism. The probable mechanism is proposed leading to complicated rate law as a result of involvement of prior equillibria between various forms of the oxidant.

scholarly journals Development of New High-Performance Biphenyl and Terphenyl Derivatives as Versatile Photoredox Photoinitiating Systems and Their Applications in 3D Printing Photopolymerization Processes

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 827 ◽  
Author(s):  
Tomal ◽  
Pilch ◽  
Chachaj-Brekiesz ◽  
Ortyl
Keyword(s):  
Free Radical ◽  
High Performance ◽  
Theoretical Calculations ◽  
Polymer Networks ◽  
Electrochemical Analysis ◽  
Type Ii ◽  
Long Wave ◽  
Different Types ◽  
Ft Ir ◽  
Iodonium Salt

Novel 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives were proposed as photosensitizes of iodonium salt for a highly effective bimolecular photoinitiating system upon soft irradiation conditions under long-wave ultraviolet (UV-A) and visible light. Remarkably, these structures are highly versatile, allowing access to photoinitiating systems for the free-radical polymerization of acrylates, the cationic photopolymerization of epoxides, glycidyl, and vinyl ethers, the synthesis of interpenetrated polymer networks (IPNs) and the thiol-ene photopolymerization processes. Excellent polymerization profiles for all of the monomers, along with the high final conversions, were obtained. The initiation mechanisms of these bimolecular systems based on the 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives were investigated using the real-time FT-IR technique, steady-state photolysis, fluorescence experiments, theoretical calculations of molecular orbitals, and electrochemical analysis. Moreover, the 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives were investigated as a type II free-radical photoinitiator with amine. It was confirmed that the 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives, in combination with different types of additives, e.g., amine as co-initiator or in the presence of onium salt, can act as a bimolecular photoinitiating system via the photo-reduction or photo-oxidation pathways, respectively.

Continuous, On-Line Interface for Reverse-Phase Microbore High-Performance Liquid Chromatography/Diffuse Reflectance Infrared Fourier Transform Analysis

1986 ◽  
Vol 40 (5) ◽  
pp. 673-680 ◽  
Author(s):  
M. A. Castles ◽  
L. V. Azarraga ◽  
L. A. Carreira
Keyword(s):  
Fourier Transform ◽  
High Performance ◽  
Diffuse Reflectance ◽  
Diamond Powder ◽  
Reverse Phase ◽  
Liquid Chromatograph ◽  
On Line ◽  
Ft Ir ◽  
Ir Analysis ◽  
Diffuse Reflectance Infrared

An ultrasonic nebulizer with a piezo-electric transducer and a newly designed and constructed continuous on-line collection station have been adapted as an interface between a reverse-phase microbore high-performance liquid Chromatograph (RP-μHPLC) and a diffuse reflectance infrared Fourier transform spectrometer. The collection station incorporates a directional vacuum port for confinement of the nebulized material onto a small area (3 to S mm i.d.) of the diamond powder. The inherent desolvation that occurs upon nebulization of the reverse-phase eluant, along with the vacuum collection system and the diamond powder diffuse reflectance substrate, makes possible the continuous on-line collection and FT-IR analysis of the compounds separated by a RP-μHPLC without any type of initial solute extraction.

scholarly journals Evaluation of the saponin green extraction from Ziziphus spina-christi leaves using hydrothermal, microwave and Bain-Marie water bath heating methods

2019 ◽  
Vol 8 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Mahdiyeh Mohaddes-Kamranshahi ◽  
Hoda Jafarizadeh-Malmiri ◽  
Mohammad Simjoo ◽  
Abbas Jafarizad
Keyword(s):  
High Performance ◽  
Chemical Properties ◽  
Extraction Methods ◽  
Color Intensity ◽  
Heating Method ◽  
Green Extraction ◽  
Physico Chemical ◽  
Ft Ir ◽  
Ir Analysis ◽  
Water Bath Heating

Abstract Saponin as a biosurfactant was extracted from Iranian Ziziphus spina-christi leaves using three green extraction methods namely, autoclave, microwave and Bain-Marie heating methods. In this study, three solvents namely, methanol, ethanol and water were used to extract saponin. The results revealed that water, as compared to the methanol and ethanol, is a more suitable solvent to extract saponin from the Z. spina-christi leaves. The obtained results indicated that saponin extraction using autoclave provided more suitable physico-chemical properties along with a better yield. In fact, maximum foam volume (12.56 cm3), color intensity (3.24% absorbance unit [a.u.]) and turbidity (1.39% a.u.) of the extracted solutions was obtained by the autoclave heating method. The high performance liquid chromatography (HPLC) results also illustrated that the amounts of extracted saponin using autoclave, Bain-Marie and microwave heating extraction methods were 14, 8.8 and 1.3 (intensity mV), respectively. The results obtained by HPLC were reconfirmed by Fourier transform infrared (FT-IR) analysis.

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

Co-purification of bone resorbing activity and adenylate cyclase stimulating activity from human tumours associated with the humoral hypercalcaemia of malignancy

1987 ◽  
Vol 114 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Chohei Shigeno ◽  
Itsuo Yamamoto ◽  
Shegiharu Dokoh ◽  
Megumu Hino ◽  
Jun Aoki ◽  
...  
Keyword(s):  
Bone Resorption ◽  
High Performance ◽  
Basic Protein ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Protein Factor ◽  
Human Tumours ◽  
Acid Stable ◽  
Bone Resorbing Activity

Abstract. We have partially purified a tumour factor capable of stimulating both bone resorption in vitro and cAMP accumulation in osteoblastic ROS 17/2 cells from three human tumours associated with humoral hypercalcaemia of malignancy. Purification of tumour factor by sequential acid urea extraction, gel filtration and cation-exchange chromatography, reverse-phase high performance liquid chromatography followed by analytical isoelectric focussing provided a basic protein (pI > 9.3) with a molecular weight of approximately 13 000 as a major component of the final preparation which retained both the two bioactivities. Bone resorbing activity and cAMP-increasing activity in purified factor correlated with each other. cAMP-increasing activity of the factor was heat- and acid-stable, but sensitive to alkaline ambient pH. Treatment with trypsin destroyed cAMP-increasing activity of the factor. Synthetic parathyroid hormone (PTH) antagonist, human PTH-(3– 34) completely inhibited the cAMP-increasing activity of the factor. The results suggest that this protein factor, having its effects on both osteoclastic and osteoblastic functions, may be involved in development of enhanced bone resorption in some patients with humoral hypercalcaemia of malignancy.

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

2020 ◽  
Vol 71 (8) ◽  
pp. 21-26
Author(s):  
Elena-Emilia Oprescu ◽  
Cristina-Emanuela Enascuta ◽  
Elena Radu ◽  
Vasile Lavric
Keyword(s):  
Maximum Yield ◽  
Strength Distribution ◽  
Point Of View ◽  
Reaction Parameters ◽  
X Ray ◽  
Ethyl Levulinate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Biodiesel Blend ◽  
Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

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