Search

The extraction condition of curcumin from Curcuma longa L was optimized through four factors and three levels orthogonal experiment based on the results of single factor tests. Under the optimal conditions: the concentration of ethanol 80%, extraction temperature 70°C, the ratio of liquid to material 20, and extraction time 3 h, a crude extract with the yield of curcumin 56.8 mg/g could be obtained. The isolation and purification of curcuminoids from the crude extract was performed on high performance counter current chromatography employing an optimized solvent system n‐hexane/ethyl acetate/methanol/water (2/3/3/1, v/v/v/v). From 97 mg crude sample (in which the purity of curmumin was 68.56%), 67 mg curmumin, 18 mg demethoxycurcumin, and 9.7 mg bisdemethoxycurcumin with a high‐performance liquid chromatography purity of 98.26, 97.39, and 98.67%, respectively, were obtained within 70 min. The antioxidant activities and cytotoxicity of purified curcumin was comparable to that of the commercial product, indicating that the biological activity of curcumin could be maintained by this method. [ABSTRACT FROM AUTHOR]

A novel method for Fmoc/ tBu solution-phase peptide synthesis and the development of a new benzyl-type group-assisted purification (GAP) protecting group is reported. This GAP protecting group is utilized in place of a polymer support, facilitating C→N Fmoc peptide synthesis without chromatography or recrystallization. The GAP group can be added and removed in high yield, and was used to synthesize over 1 gram of the immunostimulant, thymopentin, in high overall yield (83 %) and purity (99 %). [ABSTRACT FROM AUTHOR]

The interest of pharmaceutical companies for complementary high-performance chromatographic tools to assess a product's purity or enhance this purity is on the rise. The high-throughput capability and economic benefits of supercritical fluid chromatography, but also the 'green' aspect of CO2 as the principal solvent, render supercritical fluid chromatography very attractive for a wide range of pharmaceutical applications. The recent reintroduction of new robust instruments dedicated to supercritical fluid chromatography and the progress in stationary phase technology have also greatly benefited supercritical fluid chromatography. Additionally, it was shown several times that supercritical fluid chromatography could be orthogonal to reversed-phase high-performance liquid chromatography and could efficiently compete with it. Supercritical fluid chromatography is an adequate tool for small molecules of pharmaceutical interest: synthetic intermediates, active pharmaceutical ingredients, impurities, or degradation products. In this review, we first discuss about general chromatographic conditions for supercritical fluid chromatography analysis to better suit compounds of pharmaceutical interest. We also discuss about the use of achiral and chiral supercritical fluid chromatography for analytical purposes and the recent applications in these areas. The use of preparative supercritical fluid chromatography by pharmaceutical companies is also covered. [ABSTRACT FROM AUTHOR]

An improved and efficient synthesis of (+)-cloprostenol has been accomplished in nine steps and 26% overall yield from commercially available (-)-Corey lactone 4-phenylbenzoate alcohol 1. The present route avoids tedious purifications and requires only one column chromatography operation, which reduces the generation of waste and is suitable for . Chirality 27:392-396, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Herein, we report a short, three-step synthesis of d-[1-14C]-serine (4) in high enantiomeric purity. Starting from [14C]-KCN and 2-(benzyloxy)acetaldehyde, Strecker reaction using ( R)-1-phenylethylamine as the chiral auxiliary gave two diastereomeric aminonitriles 1 and 2 in the ratio of 4:3, which were conveniently separated and purified chromatographically. Following hydrolysis and subsequent hydrogenolysis, the purified major diastereomer 1, was smoothly converted to d-[1-14C]-serine (4) in an enantiomeric excess of >99%, thus circumventing time intensive chiral HPLC enantiomeric resolution. [ABSTRACT FROM AUTHOR]

Background The phycobiliprotein C-phycocyanin (C- PC) is used in cosmetics, diagnostics and foods and also as a nutraceutical or biopharmaceutical. It is produced in the cyanobacterium Arthrospira platensis grown phototrophically in open cultures. C- PC may alternatively be produced heterotrophically in the unicellular rhodophyte Galdieria sulphuraria at higher productivities and under improved hygienic standards if it can be purified as efficiently as C- PC from A. platensis. Results Ammonium sulfate fractionation, aqueous two-phase extraction, tangential flow ultrafiltration and anion exchange chromatography were evaluated with respect to the purification of C- PC from G. sulphuraria extracts. Galdieria sulphuraria C- PC showed similar properties to those described for cyanobacterial C- PC with respect to separation by all methodologies. The presence of micelles in G. sulphuraria extracts influenced the different procedures. Only chromatography was able to separate C- PC from a second phycobiliprotein, allophycocyanin. Conclusion C- PC from heterotrophic G. sulphuraria shows similar properties to cyanobacterial C- PC and can be purified to the same standards, despite initial C- PC concentrations being low and impurity concentrations high in G. sulphuraria extracts. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

All therapeutic antibodies that are currently approved or under development are IgGs, with IgG1 and IgG2 being the most prevalent subclasses. The present study investigates the effect of antibody subclass on its chromatographic properties. To this end, two sets of antibodies with identical variable domains and differing subclasses (IgG1 and IgG2) were compared by using purification methods that are most commonly used in industrial antibody manufacturing processes. Each antibody was examined using Protein A chromatography, cation-exchange chromatography, hydrophobic interaction chromatography and salt-induced precipitation studies. The results of these experiments show that the variable region of an antibody has a greater influence on its chromatographic behaviour than antibody subclass. [ABSTRACT FROM AUTHOR]

HSP65–MUC1 is a fusion protein between BCG (Bacille Calmette–Guerin)-derived HSP65 (heat-shock protein 65) and human MUC1 (mucin 1) VNTR (variable number of tandem repeats)-domain peptides that has shown antitumour efficacy. China's Food and Drug Administration has recently approved a Phase I clinical trial using HSP65–MUC1 for the treatment of MUC1-positive breast cancer. In order to produce sufficient quantities of clinical-grade HSP65–MUC1, we established a pilot-scale purification scheme comprising two steps of column chromatography: HIC (hydrophobic-interaction chromatography) and IEX (ion-exchange chromatography). The pH values of the buffers used in homogenization and HIC were adjusted to pH 9.0 to maintain protein stability and prevent protein degradation. Using this manufacturing process, we obtained clinical-grade HSP65–MUC1 with a yield of 400 mg per 70 g of wet cell pellet and >96% purity. [ABSTRACT FROM AUTHOR]

The cytochrome P450 (Cyt-P450) proteins from the fat body and midgut of the cotton bollworm, Helicoverpa armigera, were respectively partially purified by a set of purification procedures including differential centrifugation, solubilization of CHAPS, protein precipitation by PEG precipitation and DE-32 column chromatography. The Cyt-P450 was detected by methods of CO difference spectrum and SDS-PAGE. Fraction of detergent solubilized microsomes from the fat body of H. armigera was purified more than 17-fold. Three protein bands were detected by SDS-PAGE with molecular masses of 70 600, 63 300 and 571 200Da. It is possible that the proteins with molecular mass of 63 300 and 571 200Da were the isozymes of Cyt-P450. [ABSTRACT FROM AUTHOR]

In our search for bioactive compounds from the whole plantof Picria felterraeLour., three new phenylethanoid glycosides, picfeosides A-C (1-3), along with five known phenylethanoid glycosides, namely wiedemannioside (4), acteoside (5), acteoside isomer (6), cis-acteoside isomer (7), and cis-acteoside (8), were isolated using several chromatographic purification steps, including semipreparation HPLC on RP-18. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis.(Managing editor: Wei WANG) [ABSTRACT FROM AUTHOR]

The F1 complex of the ATP synthase of Streptomyces lividans was isolated and purified. The procedure involved the solubilization of F1 from membranes with buffer of low ionic strength in the presence of EDTA, ion-exchange chromatography and gel filtration. The purified F1 complex from S. lividans (SLF1) consists of five subunits α, β, γ, δ and ε with molecular masses of 58000, 50000, 36000, 28000 and 13000, respectively and exhibits immunological cross-reactivity with the F1 portion purified from Escherichia coli (ECF1). The enzymatic properties of SLF1 were determined by the use of microtiter-plate-based assay and compared with data obtained for ECF1. ATPase activity of SLF1 (specific activity: 20–30 U/mg) was only observed in the presence of high concentrations of Ca2+ (to mM). Stimulation of the ATPase activity by Mg2+ was not detectable; quite to the contrary, Mg2+ inhibited the Ca2+-stimulated activity of SLF1. SLF1 was re-bound to F1-stripped membranes of S. lividans, but not to F1-stripped membrane vesicles of E. coli. In contrast, ECF1 could be cross-reconstituted with F1-stripped membranes of S. lividans; however, a structural but not a functional reconstitution of the hybrid F1Fo complex was observed. [ABSTRACT FROM AUTHOR]

Reports on the purification and characterization of brain pyridoxal kinase from sheep brain. Use of ammonium sulphate fractionation, diethylaminoethanol-cellulose chromatography, affinity chromatography and Sephadex G-100 gel filtration; Molecular mass of the native enzyme.

A protein, which facilitates assembly ora nucleosome-like structure in vitro, was previously partially purified from mouse FM3A cells [Ishimi, Y. et al. (1983) J. Biochem, (Tokyo) 94, 735-744]. The protein has been purified to approximately 80% from FM3A cells by using histone-Sepharose column chromatography. It sedimented at 4.6 S and had a molecular mass of 53kDa. A preincubation of core histones with the 53-kDa peptide before DNA addition was necessary for the nucleosome assembly. The 53-kDa peptide bound to core histones and formed a 12-S complex. This complex contained stoichiometrical amounts of the 53-kDa peptide and core histones, and the core histones in this complex were composed of equal amounts of H2A, H2B, H3 and H4 histones. The nucleosomes were assembled by adding pBR322 DNA to the 12-S complex. When mononucleosome DNA and core histones were mixed in the presence of the 53-kDa peptide, formation of a 10.5-S complex was observed. The complex contained DNA and core histones in equal amounts, while no 53-kDa peptide was detected in the complex. From above results it is suggested that the 53-kDa peptide facilitates nucleosome assembly by mediating formation of histone octamer and transferring it to DNA. Rat antibody against the 53-kDa peptide did not bind to nucleoplasmin from Xenopus eggs. The relationship between the 53-kDa peptide and nucleoplasmin is discussed. [ABSTRACT FROM AUTHOR]

The results reported in the present paper and N-terminal sequence homologies established by other authors strongly support the assumption that the gastric protease previously called bovine pepsin I or bovine pepsin B belongs to the aspartate protease group and corresponds to gastricsin (or pepsin C) (EC 3.4.23.3) from other species. Bovine gastricsin was prepared from commercial extracts of adult bovine veils by a procedure involving DEAE-cellulose chromatography, gel filtration on Sephacryl S-200 and a further DEAE-cellulose chromatography. The preparation thus obtained was shown to be free of chymosin and bovine pepsin A by immunodiffusion, selective inactivation in urea and isoelectric focusing. Us molecular weight was estimated by gel filtration to be 32800. Bovine gastricsin displayed microheterogeneity on isoelectric focusing with pi values of the components ranging from 3.5 to 4.0. Chromatography of bovine gastricsin on hydroxyapatite separated three fractions, none of them being homogeneous by isoelectric focusing. Concanavalin-A—Sepharose 4B bound bovine gastricsin to some extent, but without any significant fractionation. Proteolytic activity could be detected directly on the isoelectric focusing gel for all the components of gastricsin and its fractions from hydroxyapatite and concanavalin-A—Sepharose 4B. Bovine gastricsin and its fractions from hydroxyapatite have similar amino acid compositions, different from those of bovine chymosin and pepsin A but obviously related to those of human, simian and porcine gastricsins. Bovine gastricsin which is inactivated by reaction with diazoacetyl-DL-norleucine methyl ester and with 1,2-epoxy-(p-nitrophenoxy)propane in a 1:1 and 1:2 stoichiometry, respectively, is able to hydrolyse a synthetic hexapeptide, Leu-Ser-Phe(NO2)-Nle-Ala-Leu-OMe, used as reference substrate for aspartate proteases, and exhibits a low activity towards N-acetyl-L-phenylalanyl-L-diiodotyrosine. Its specific clotting activity with χ-casein as substrate is only half of that of chymosin and pepsin A. [ABSTRACT FROM AUTHOR]

Chromatography on DEAE-cellulose and gel filtration on Sephadex revealed that pyrazon dioxygenase from pyrazon-degrading bacteria consists of three different enzyme components. No component alone oxidizes the phenyl moiety of pyrazon, only when the three components are combined can oxidation be detected. Following electron paramagnetic resonance and ultraviolet measurements the protein nature of the three components was determined: component A1 (molecular weight about 180000, red-brown in colour) is an iron-sulphur protein. The existence of approximately two moles of iron and two moles of inorganic sulphur per mole of protein was demonstrated. This enzyme component was purified to homogeneity in disc elcctrophoresis. Component A2 is a yellow protein of a molecular weight of about 67000. FAD was shown to be the prosthetic group of this protein. Component B (molecular weight about 12000, brown in colour) is a protein of the ferredoxin type, which was purified to homogeneity, as demonstrated by disc electrophoresis. A hypothetical scheme for the cooperation of the three components is proposed: component A2 accepts as cosubstrate NADH and functions as a ferredoxin reductase. The ferredoxin, component B, has the function of an electron carrier. The conversion of the substrates is effected by component A1, the terminal dioxygenase. [ABSTRACT FROM AUTHOR]

Poly(ADP-ribose) polymerase with a high specific activity was obtained from Ehrlich ascites tumor cells by extraction of nuclei with 175 mM potassium phosphate, followed by chromatography on DNA-agarose. Electrophoretic analysis indicated that the preparation contained two proteins, one of which was shown to catalyze the synthesis of poly( ADP-ribose). As expected from results obtained by other workers, the synthesis was inhibited by nicotinamide and thymidine. and stimulated by DNA. Addition of histones gave inhibition of the synthesis, unless DNA was present in the reaction mixture. [ABSTRACT FROM AUTHOR]

32P-labelled N-formyl methionyl transfer RNA from Escherichia coli strain CA265 was purified by chromatography on a column DEAE Sephadex followed by chromatography on benzoylated DEAE cellulose. Nucleotides from ribonuclease T1 and pancreatic ribonuclease digests of tRNAF were separated and their sequences determined. tRNAF consists of 77 nucleotides of which pCG is 5′-terminal and CAACCOH is 3′-terminal. [ABSTRACT FROM AUTHOR]

ABSTRACT This work demonstrates that self-disproportionation of enantiomers via achiral chromatography can be recommended as inexpensive and general method for optical purifica- tion of enantiomerically enriched compounds. In particular, the advantage of this approach over conventional recrystallization is that it can be used for both crystalline as well as liquid com- pounds. Chirality, 25:365-368, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Review: [117 refs. [ABSTRACT FROM AUTHOR]

Review: 79 refs. [ABSTRACT FROM AUTHOR]

Review: [54 refs. [ABSTRACT FROM AUTHOR]

Review: report on a synthetic strategy that allows the separation of enantiomerically ure planar chiral rotaxanes; 10 refs. [ABSTRACT FROM AUTHOR]

BSTRACT A comparison of the effectiveness of two procedures, ammonium sulfate fractionation and concanavalin A affinity (Con A) chromatography, for the purification of β-conglycinin from soy flour was made. In addition, the effect of toasting on the effectiveness of these two procedures for purifying β-conglycinin was studied. Results indicated that Con A affinity chromatography was less effective than the ammonium sulfate fractionation for the purification of β-conglycinin. The ammonium sulfate fractionation produced nearly homogeneous β-conglycinin; however, the yield from this procedure was very low (4.1%). Toasting the soy flour decreased the purification effectiveness of both procedures. [ABSTRACT FROM AUTHOR]

Review: 75 refs. [ABSTRACT FROM AUTHOR]

Review: 192 refs. [ABSTRACT FROM AUTHOR]

Review: 22 refs. [ABSTRACT FROM AUTHOR]

Review: 157 refs. [ABSTRACT FROM AUTHOR]

Review: 29 refs. [ABSTRACT FROM AUTHOR]