ChemInform Abstract: Reverse Phase Flash Chromatography: A Convenient Method for the Large Scale Separation of Polar Compounds.

ChemInform ◽  
2010 ◽  
Vol 23 (4) ◽  
pp. no-no
Author(s):  
I. A. O'NEIL
Keyword(s):  
Convenient Method ◽  
Large Scale ◽  
Polar Compounds ◽  
Flash Chromatography ◽  
Reverse Phase ◽  
Scale Separation

scholarly journals Efficient Flow Synthesis of Human Antimicrobial Peptides

2020 ◽  
Vol 73 (4) ◽  
pp. 380
Author(s):  
John S. Albin ◽  
Bradley L. Pentelute
Keyword(s):  
Natural Products ◽  
Immune Responses ◽  
Antimicrobial Peptides ◽  
Large Scale ◽  
Flow Chemistry ◽  
Flash Chromatography ◽  
Reverse Phase ◽  
Vast Array ◽  
Host Immune Responses ◽  
Therapeutic Development

Organisms from all kingdoms of life have evolved a vast array of peptidic natural products to defend against microbes. These are known collectively as antimicrobial peptides (AMPs) or host defence peptides, reflecting their abilities not only to directly kill microbes, but also to modulate host immune responses. Despite decades of investigation, AMPs have yet to live up to their promise as lead therapeutics, a reality that reflects, in part, our incomplete understanding of these diverse agents in their various physiological contexts. Towards improving our understanding of AMP biology and the ways in which this can be best leveraged for therapeutic development, we are interested in large-scale comparisons of the antimicrobial and immunological activities of human AMPs, an undertaking that requires an efficient workflow for AMP synthesis and subsequent characterization. We describe here the application of flow chemistry and reverse-phase flash chromatography to the generation of 43AMPs, approaches that, when combined, significantly expedite synthesis and purification, potentially facilitating more systematic approaches to downstream testing and engineering.

Large-scale separation of alkaloids from Corydalis decumbens by pH-zone-refining counter-current chromatography

2006 ◽  
Vol 1115 (1-2) ◽  
pp. 267-270 ◽  
Author(s):  
Xiao Wang ◽  
Yanling Geng ◽  
Fuwei Li ◽  
Xingang Shi ◽  
Jianhua Liu
Keyword(s):  
Large Scale ◽  
Zone Refining ◽  
Scale Separation ◽  
Counter Current

SPECIAL REVIEWS

PEDIATRICS ◽  
1948 ◽  
Vol 2 (4) ◽  
pp. 489-497
Author(s):  
CHARLES A. JANEWAY
Keyword(s):  
Plasma Proteins ◽  
Chemical Structure ◽  
Large Scale ◽  
Blood Donors ◽  
Red Cross ◽  
American Red Cross ◽  
Scale Separation ◽  
Medical Progress ◽  
Scientific Curiosity ◽  
Free People

This brief review of some of the recent accessions to our knowledge of the chemical structure, physiologic functions, and therapeutic applications of the plasma proteins serves to emphasize three important elements in medical progress—scientific curiosity, the humanitarian impulse, and effective social organization. We have had the privilege of summarizing the work of hundreds of investigators, whose studies are giving us new tools for the investigation and treatment of disease. Their work has only been possible because the magnificent response of a free people to the call for blood donors by a voluntary philanthropic agency, the American Red Cross, was coupled with a technical triumph, the development of practical methods for the large-scale separation of the plasma proteins, itself the culmination of highly theoretical and seemingly impractical investigations by protein chemists in various countries for many years.

scholarly journals Separation and Purification of Two Flavone Glucuronides fromErigeron multiradiatus(Lindl.) Benth with Macroporous Resins

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Zhi-feng Zhang ◽  
Yuan Liu ◽  
Pei Luo ◽  
Hao Zhang
Keyword(s):  
Large Scale ◽  
Raw Materials ◽  
Sorption Isotherms ◽  
Preparative Separation ◽  
Separation And Purification ◽  
Bioactive Constituents ◽  
Simple Method ◽  
Scale Separation ◽  
Adsorption And Desorption ◽  
Macroporous Resins

Scutellarein-7-O-β-D-glucuronide (SG) and apigenin-7-O-β-D-glucuronide (AG) are two major bioactive constituents with known pharmacological effects inErigeron multiradiatus. In this study, a simple method for preparative separation of the two flavone glucuronides was established with macroporous resins. The performance and adsorption characteristics of eight macroporous resins including AB-8, HPD100, HPD450, HPD600, D100, D101, D141, and D160 have been evaluated. The results confirmed that D141 resin offered the best adsorption and desorption capacities and the highest desorption ratio for the two glucuronides among the tested resins. Sorption isotherms were constructed for D141 resin under optimal ethanol conditions and fitted well to the Freundlich and Langmuir models (R2>0.95). Dynamic adsorption and desorption tests was performed on column packed with D141 resin. After one-run treatment with D141 resin, the two-constituent content in the final product was increased from 2.14% and 1.34 % in the crude extract ofErigeron multiradiatusto 24.63% and 18.42% in the final products with the recoveries of 82.5% and 85.4%, respectively. The preparative separation of SG and AG can be easily and effectively achieved via adsorption and desorption on D141 resin, and the method developed can be referenced for large-scale separation and purification of flavone glucuronides from herbal raw materials.

scholarly journals Turbulent viscosity and magnetic Prandtl number from simulations of isotropically forced turbulence

2020 ◽  
Vol 636 ◽  
pp. A93 ◽  
Author(s):  
P. J. Käpylä ◽  
M. Rheinhardt ◽  
A. Brandenburg ◽  
M. J. Käpylä
Keyword(s):  
Magnetic Fields ◽  
Prandtl Number ◽  
Large Scale ◽  
Turbulent Viscosity ◽  
Scale Dependence ◽  
Scale Separation ◽  
Separation Ratio ◽  
Magnetic Prandtl Number ◽  
Magnetic Diffusivity ◽  
Forced Turbulence

Context. Turbulent diffusion of large-scale flows and magnetic fields plays a major role in many astrophysical systems, such as stellar convection zones and accretion discs. Aims. Our goal is to compute turbulent viscosity and magnetic diffusivity which are relevant for diffusing large-scale flows and magnetic fields, respectively. We also aim to compute their ratio, which is the turbulent magnetic Prandtl number, Pmt, for isotropically forced homogeneous turbulence. Methods. We used simulations of forced turbulence in fully periodic cubes composed of isothermal gas with an imposed large-scale sinusoidal shear flow. Turbulent viscosity was computed either from the resulting Reynolds stress or from the decay rate of the large-scale flow. Turbulent magnetic diffusivity was computed using the test-field method for a microphysical magnetic Prandtl number of unity. The scale dependence of the coefficients was studied by varying the wavenumber of the imposed sinusoidal shear and test fields. Results. We find that turbulent viscosity and magnetic diffusivity are in general of the same order of magnitude. Furthermore, the turbulent viscosity depends on the fluid Reynolds number (Re) and scale separation ratio of turbulence. The scale dependence of the turbulent viscosity is found to be well approximated by a Lorentzian. These results are similar to those obtained earlier for the turbulent magnetic diffusivity. The results for the turbulent transport coefficients appear to converge at sufficiently high values of Re and the scale separation ratio. However, a weak trend is found even at the largest values of Re, suggesting that the turbulence is not in the fully developed regime. The turbulent magnetic Prandtl number converges to a value that is slightly below unity for large Re. For small Re we find values between 0.5 and 0.6 but the data are insufficient to draw conclusions regarding asymptotics. We demonstrate that our results are independent of the correlation time of the forcing function. Conclusions. The turbulent magnetic diffusivity is, in general, consistently higher than the turbulent viscosity, which is in qualitative agreement with analytic theories. However, the actual value of Pmt found from the simulations (≈0.9−0.95) at large Re and large scale separation ratio is higher than any of the analytic predictions (0.4−0.8).

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