Approaches to High-Performance Preparative Chromatography of Proteins

2009 ◽  
pp. 217-254 ◽  
Author(s):  
Yan Sun ◽  
Fu-Feng Liu ◽  
Qing-Hong Shi
Keyword(s):  
High Performance ◽  
Preparative Chromatography

scholarly journals ISOLATION AND IDENTIFICATION OF EUPHORBIA TRIODONTA PLANT POLYPHENOLS BY CHROMATO-MASS SPECTROMETRY

2020 ◽  
pp. 105-114
Author(s):  
Zhamollitdin Fazlitdinovich Ziyavitdinov ◽  
Rahima Abdulla ◽  
Yuliya Igorevna Oshchepkova ◽  
Nodira Gulyamzhanovna Abdulladzhanova ◽  
Shavkat Ismailovich Salikhov
Keyword(s):  
High Performance ◽  
Preparative Chromatography ◽  
Isolation And Identification ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Polyphenolic Composition ◽  
Ferghana Valley ◽  
The Republic ◽  
Matrix Detector ◽  
First Time

The aim of this work is to study the composition of polyphenols contained in plants of Euphorbia triodontus Prokh., growing throughout the Republic of Uzbekistan, in particular the Ferghana Valley region, using a high-performance liquid chromatograph with a diode-matrix detector (HPLC-DAD) and a tandem chromato-mass spectrometer (HPLC – Q-TOF-MS/MS). The roots of the plant Euphorbia triodontus Prokh., growing on the territory of Uzbekistan, collected in the period after flowering, studied the polyphenolic composition. For the first time from this type of Euphorbia, the method of stepwise hydrophobic chromatography was used to isolate polyphenolic fractions. By HPLC, as a result of semi-preparative chromatography, 6 individual compounds were isolated from the fraction eluted with a 20% methanol solution in the amount of: E-20-1 – 7 mg, E-20-2 – 22 mg, E-20-3 – 14.2 mg, E-20-4 – 41 mg, E-20-5 – 11.4 mg and E-20-6 – 32 mg. As a result of mass spectrometric analyzes, it was established that the polyphenols isolated in an individual state consist of gallic acid and glucose linked by an ester bond: O-galloyl-β-D-glucose. The structure of individual compounds was determined: E-20-1 – 1-O-meta-trigalloyl-β-D-glucopyranosyl-(4-O-β-D)-1-O-meta-trigalloyl-β-D-glucose, E-20-2 – 1-O-meta-trihalloyl-β-D-glucose, E-20-3 – 1-O-meta-tetragalloyl-β-D-glucose, E-20-4 – 1-O-meta-trigalloyl-4-O-haloyl-β-D-glucose, E-20-5 – 2,3,6-tri-O-galloyl-β-D-glucose and E-20-6 – 1,2,3,4,6-penta-O-galloyl-β-D-glucose.

scholarly journals STRUCTURE OF POLYPHENOLS OF LEAVES TANNING SUMAC RHUS CORIARIA L.

2020 ◽  
pp. 133-140
Author(s):  
Zhamollitdin Fazlitdinovich Ziyavitdinov ◽  
Yuliya Igorevna Oshchepkova ◽  
Nodira Gulyamzhanovna Abdulladzhanova ◽  
Shavkat Ismailovich Salikhov
Keyword(s):  
High Performance ◽  
Structural Characteristics ◽  
Preparative Chromatography ◽  
Individual State ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Rhus Coriaria ◽  
The Individual ◽  
Matrix Detector ◽  
First Time

The aim of this work is to study the composition and structural characteristics of the polyphenols of the tanning sumac Rhus coriaria L. of the Anacardiaceae family, growing in Uzbekistan, using a high-performance liquid chromatograph with a diode-matrix detector (HPLC-DAD) and a tandem temple mass-spectrometer (HPLC– Q-TOF-MS / MS). The phenolic compounds of the aerial part (leaves) of Rhus coriaria L. plants of the Anacardiaceae family were studied. For the first time, polyphenol fractions were isolated from tanning sumac leaves using stepwise hydrophobic chromatography. By HPLC, as a result of semi-preparative chromatography from the fraction eluted with 30% ethanol, 9 individual compounds were obtained, in the amount of: R-1 – 0.5 mg, R-2 – 0.8 mg, R-3 – 2.3 mg, R-4 – 12.6 mg, R-5 – 34.5 mg, R-6 – 15 mg, R-7 – 8 mg, R-8 – 7.1 mg, R-9 – 45.5 mg As a result of mass spectrometric analyzes and NMR spectroscopy for individual polyphenols, it was established that the polyphenols isolated in the individual state consist of gallic acid and glucose, interconnected by an ester bond: mono-, di-, tri-, tetra-, penta- , hexa-, hepta-, octa- and non-O-galloyl-β-D-glucose.

Purification and analysis of the purity of NADH.

1976 ◽  
Vol 22 (8) ◽  
pp. 1322-1329 ◽  
Author(s):  
S A Margolis ◽  
B F Howell ◽  
R Schaffer
Keyword(s):  
High Performance ◽  
Adenine Nucleotides ◽  
Rapid Assessment ◽  
Deae Cellulose ◽  
Adenosine Monophosphate ◽  
High Performance Liquid Chromatographic ◽  
Preparative Chromatography ◽  
Analytical Technique ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract We developed an analytical reverse-phase high-performance liquid chromatographic procedure for rapid assessment of the purity of NADH. The method completely separates adenosine monophosphate and adenosine diphosphoribose from NADH. By use of this analytical technique we found that preparative chromatography on DEAE-cellulose gives NADH that is free from adenine nucleotides as well as other impurities that commonly are present in NADH. The absorbance ratio at 260 and 340 nm of the purified NADH in 1.8 mmol/liter ammonium carbonate is 2.261 +/- 0.002 (+/- 1 SD).

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

1970 ◽  
Vol 28 ◽  
pp. 360-361
Author(s):  
John W. Coleman
Keyword(s):  
Boundary Conditions ◽  
High Performance ◽  
Force Fields ◽  
Optical Design ◽  
Direct Conversion ◽  
Design Engineering ◽  
Design Data ◽  
Scalar Potentials ◽  
Geometric Elements ◽  
At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

Prospects for convergent beam electron diffraction with a 200kV cold field-emission transmission electron microscope

1991 ◽  
Vol 49 ◽  
pp. 466-467
Author(s):  
J W Steeds ◽  
R Vincent
Keyword(s):  
Field Emission ◽  
High Performance ◽  
Small Diameter ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Special Modification ◽  
Convergent Beam

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.

Current State of Biological High-Resolution Scanning Electron Microscopy

1988 ◽  
Vol 46 ◽  
pp. 180-181 ◽  
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Performance ◽  
Low Voltage ◽  
Backscattered Electrons ◽  
Lens Position ◽  
Low Voltage Operation ◽  
Signal Collection ◽  
Probe Size ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

A new generation of high performance field emission scanning electron microscopes (FSEM) is now commercially available (JEOL 890, Hitachi S 900, ISI OS 130-F) characterized by an "in lens" position of the specimen where probe diameters are reduced and signal collection improved. Additionally, low voltage operation is extended to 1 kV. Compared to the first generation of FSEM (JE0L JSM 30, Hitachi S 800), which utilized a specimen position below the final lens, specimen size had to be reduced but useful magnification could be impressively increased in both low (1-4 kV) and high (5-40 kV) voltage operation, i.e. from 50,000 to 200,000 and 250,000 to 1,000,000 x respectively.At high accelerating voltage and magnification, contrasts on biological specimens are well characterized1 and are produced by the entering probe electrons in the outmost surface layer within -vl nm depth. Backscattered electrons produce only a background signal. Under these conditions (FIG. 1) image quality is similar to conventional TEM (FIG. 2) and only limited at magnifications >1,000,000 x by probe size (0.5 nm) or non-localization effects (%0.5 nm).

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

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