PubMed · 7409126
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
A L Kazakov, V A Bandiukova, I I Ozymyna, M I Kokovkin-Shcherbak. 1980. [Methods for analyzing isoflavonoids].. https://pubmed.ncbi.nlm.nih.gov/7409126/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The method for endotoxin removal described in this paper is useful for separation of tightly bound endotoxin from biological products, particularly those produced in Escherichia coli in the form of inclusion bodies for which a denaturation step is required to solubilise the product. We employed guanidine hydrochloride and ammonium sulphate in combination with hydrophobic interaction chromatography (HIC). These conditions enable binding of the endotoxin to the matrix, giving unbound product in the column flow-through. This makes the method generally applicable to biological products. An endotoxin reduction of about 3.7 logs was achieved; from as much as 1,100,000 EU mg(-1) in the solubilised material to about 200 EU mg(-1) in the product purified by this method. The method was developed for a cervical dysplasia vaccine, a fusion protein comprising L2, E7 and E6 from Human Papilloma Virus type 16, because both conventional and commercially available methods of endotoxin removal were ineffective in removing the tightly bound endotoxin from this product.
A new interpretation of the band spreading data in perfusion chromatography is proposed by investigating the relative importance of axial dispersion in perfusive beds. Elution chromatography of proteins (bovine serum albumin and lysozyme) under non-retained conditions on two kinds of reversed-phase perfusive supports (POROS R1/H and POROS R2/H), which have different pore structures, were carried out to obtain the axial dispersion data. The Knox equation and some empirical correlations for dispersion coefficients in porous media were applied to correlate the experimental data. The influences of particle properties, solute molecular sizes and flow velocity on the dispersion coefficient were elucidated. Axial dispersion was recognised to be the main contributor to peak broadening in perfusion chromatography. The dependence of the height equivalent to a theoretical plate on flow-rate was found to be the result of the velocity dependence of the axial dispersion. The dispersion coefficient in a perfusive column can be well represented both by a power-law relationship and a correlation derived based on stochastic theory. Pursuant to these, it was found that pore size distribution of the perfusive particles and solute molecular size are important parameters, which influenced the dispersion results significantly.
A hybrid of exponential and Gaussian functions is developed as a model of asymmetric peak profiles. This exponential-Gaussian hybrid function (EGH) is mathematically simple, numerically stable, and its parameters are readily determined by making graphical measurements and applying simple equations. Furthermore, the statistical moments of the EGH function can be accurately approximated (within+/-0.15% error) at any level of asymmetry using formulae that are easily programmed into a computer. These features of the EGH make it very easy to implement by most chromatographers. The EGH serves as a useful alternative to the exponentially modified Gaussian (EMG) for modeling slightly asymmetric peaks since the two models produce nearly the same profile at relatively low asymmetries. The EGH also serves as an addition to the extensive list of alternative models that are sometimes better than the EMG at describing highly asymmetric peaks. A comparison between EMG and EGH curves at various asymmetries is made by analysis of toluene, phenylalanine, and pyridine on a reversed-phase liquid chromatographic system.