Purification of Epothilones A and B with Column Chromatography on a Sephadex LH-20

2014 ◽  
Vol 904 ◽  
pp. 164-169
Author(s):  
Ji Kun Yang ◽  
Lin Zhao ◽  
Rui Cheng Sun ◽  
Yue Mao Shen ◽  
Nai Qiang Wang ◽  
...  

A simplified and efficient method was developed for the large-scale purification of the epothilone A and B from fermentation products ofSorangium cellulosumafter organic solvent extraction in this paper. Extractant from XAD-16 resin with tetrachloromethane containing epothilones was concentrated under vacuum, subjected to Sephadex LH-20 column chromatography, and eluted with several solvents. Fractions containing epothilones are pooled, concentrated, and applied to a second cycle of column chromatography with other solvents. Result showed that elution with acetone gave the best purity of epothilones [78.1% by high-performance liquid chromatography (HPLC) than that with pure methanol, pure ethanol, 70% (v/v) aqueous methanol or methanol-dichloromethane (1:1, v/v).] Then, when flow rate was 0.2 mL/min and sample amount (epoA) was 1 mg in second cycle, elution with methanol was resulted in complete separation between epothilone A and B, and further improved separately the purity of epothilone A and B to 90.27% and 77.34%. This simplified purification scheme avoided the loss of expensive epothilones in the common silica gel separation process and achieved the separation of epothilone A and B, significantly reduce the cost of the production without preparative liquid chromatography, or other equipment.

1983 ◽  
Vol 131 (1) ◽  
pp. 257-265 ◽  
Author(s):  
Metin Colpan ◽  
Jürgen Schumacher ◽  
Wolfgang Brüggemann ◽  
Heinz L. Sänger ◽  
Detlev Riesner

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 785 ◽  
Author(s):  
Miguel A. Taco-Ugsha ◽  
Cristian P. Santacruz ◽  
Patricio J. Espinoza-Montero

Photovoltaic energy presents environmental advantages; however, these advantages are limited by the cost of manufacturing solar cells and in many cases, scarce or dangerous materials are incorporated. Therefore, the use of natural dyes from mortiño (Vaccinium floribundum) as sensitizers in solar cells is proposed. The dyes were extracted by maceration in acidified methanol (HCl, citric acid and trifluoroacetic acid TFA) and were characterized by High-Performance Liquid Chromatography (HPLC), Thin-Layer Chromatography (TLC) and spectrometric methods (UV-Vis, IR and MS-MALDI). The construction and characterization of cells were in standard conditions. The study confirms that pigments in mortiño are flavonoids of the anthocyanidin group as: cyanidin-3-galactoside, and cyanidin-3-arabinoside. The efficiency of solar cells was between 0.18–0.26%; the extraction with TFA in methanol leads to the best performance. Although they have low power conversion efficiency, mortiño dyes could be an alternative to artificial sensitizers for solar cell technologies because they are harmless and abundant substances.


1986 ◽  
Vol 111 (3) ◽  
pp. 507-511 ◽  
Author(s):  
E. S. Penny ◽  
A. M. Sopwith ◽  
R. L. Patience ◽  
J. A. H. Wass ◽  
G. M. Besser ◽  
...  

ABSTRACT Four forms of circulating immunoreactive human GH-releasing factor (ir-hGRF) have been identified in each of four normal subjects, with a mean increase in total ir-hGRF of twofold over basal levels following a mixed meal. Plasma samples (200 ml) from each individual were subjected to large-scale Vycor extraction with initial purification by high-performance liquid chromatography on a reversed-phase C18 column, followed by analytical separation of the ir-hGRF components using a C3 wide-pore reversed-phase column, and subsequent radioimmunoassay of the fractions. The mean recovery of total ir-hGRF from the plasma (fasted and non-fasted) was 76±16% (2×s.e.m.). Analytical separation of the ir-hGRF revealed four components which co-eluted with synthetic hGRF-37, hGRF-40 and hGRF-44, and a peak eluting between hGRF-40 and -44 which may represent hGRF-42. The hGRF-40 was shown to be the predominant circulating molecular form in the fasted state in each subject, and in three out of four subjects following a mixed meal. The hGRF-44 showed the greatest percentage increase over basal in all four individuals. J. Endocr. (1986) 111, 507–511


2019 ◽  
Vol 15 (3) ◽  
pp. 277-293 ◽  
Author(s):  
Sevinc Kurbanoglu ◽  
Ozer Karsavurdan ◽  
Sibel A. Ozkan

Introduction: Ultra-Performance Liquid Chromatographic (UPLC) method enables analyst to establish an analysis at higher pressure than High Performance Liquid Chromatographic (HPLC) method towards liquid chromatographic methods. UPLC method provides the opportunity to study a higher pressure compared to HPLC, and therefore smaller column in terms of particle size and internal diameter are generally used in drug analysis. The UPLC method has attracted gradually due to its advantages such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. In this review, the recent selected studies related to the UPLC method and its method validation are summarized. The drug analyses and the results of the studies which were investigated by UPLC method, with certain parameters from literature are presented. Background: Quantitative determination of drug active substances by High-Performance Liquid Chromatography (HPLC) from Liquid Chromatography (LC) methods has been carried out since the 1970's with the use of standard analytical LC methods. In today's conditions, rapid and very fast even ultra-fast, flow rates are achieved compared to conventional HPLC due to shortening analysis times, increasing method efficiency and resolution, reducing sample volume (and hence injection volume), reducing waste mobile phase. Using smaller particles, the speed and peak capacity are expanding to new limit and this technology is named as Ultra Performance Liquid Chromatography. In recent years, as a general trend in liquid chromatography, ultra-performance liquid chromatography has taken the place of HPLC methods. The time of analysis was for several minutes, now with a total analysis time of around 1-2 minutes. The benefits of transferring HPLC to UPLC are much better understood when considering the thousands of analyzes performed for each active substance, in order to reduce the cost of analytical laboratories where relevant analysis of drug active substances are performed without lowering the cost of research and development activities. Methods: The German Chemist Friedrich Ferdinand Runge, proposed the use of reactive impregnated filter paper for the identification of dyestuffs in 1855 and at that time the first chromatographic method in which a liquid mobile phase was used, was reviewed. Christian Friedrich Chönbein, who reported that the substances were dragged at different speeds in the filter paper due to capillary effect, was followed by the Russian botanist Mikhail S. Tswet, who planted studies on color pigment in 1906. Tswet observes the color separations of many plant pigments, such as chlorophyll and xanthophyll when he passes the plant pigment extract isolated from plant through the powder CaCO3 that he filled in the glass column. This method based on color separation gives the name of "chromatographie" chromatography by using the words "chroma" meaning "Latin" and "graphein" meaning writing. Results and Conclusion: Because the UPLC method can be run smoothly at higher pressures than the HPLC method, it offers the possibility of analyzing using much smaller column sizes and column diameters. Moreover, UPLC method has advantages, such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. The use of the UPLC method especially analyses in biological samples such as human plasma, brain sample, rat plasma, etc. increasingly time-consuming due to the fact that the analysis time is very short compared to the HPLC, because of the small amount of waste analytes and the considerable savings in their cost.


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