Sephadex chromatography

A solution of a 3-azidopyridine4(0.5-1.0 g) in a mixture of MeOH (75 mL) and dioxane (75 mL) containing NaOMc (2.5-3.0 g, large excess) was irradiated under N2 with a 400-W high-pressure Hg lamp equipped with a Pyrex filter until TLC indicated that the reaction was complete (1 - 2 h). The solvents were removed under reduced pressure, the residue was treated with ice-water (10-20 mL) and the mixture was extracted with hexane. The extract was washed with H20, dried and evaporated in vacuo to leave the product, which was further purified by chromatography (Sephadex, benzene). All the diazepines were oils. 

Dextran which is a linear a-l,6-linked glucose pol)nner produced by Leuconostoc mesenter-oides is also used in affinity chromatography. Sephadex (cross-linked by glyceryl bridges) and... 

An aliquot of Ac-AKEAAHAEAAEAA-NH, in H,0 was placed in a preweighed 1.5-mL microcentrifuge tube and lyophilized to dryness. The dried powder (15 mg, 11.7 pmol) was dissolved in dry DMSO (100 pL) and 29 pM bis(p-nitrophenyl) ester of iron(III) mesoporphyrin IX in DMSO (100 pL) was added, followed by DIPEA (45 pL, 22 equiv). The soln was warmed to 40 °C until HPLC indicated no further reaction (ca. 3h). It was then diluted to 1.0 mL with 50 mM NaOAc, pH 6, and purified by sequential ion-exchange chromatography (Sephadex CM50 50 mM NaOAc, pH 6), RP-HPLC (Vydac... 

Smith et al. (1989, 1991) exposed Lemna minor to 5lCr(VI) in the form of chromate and demonstrated that extracts showed Cr associated with complexes of about 2000 D and > 100000 D. Aqueous extracts were subjected to gel permeation chromatography (Sephadex G50) and both 51Cr and protein activity were followed. Although the Cr fractions corresponded to protein fractions, the authors were unable to demonstrate that these were Cr-induced proteins, since the protein profiles for Cr-treated and untreated plants were the same. Clearly more work is required on the chemical identification of metal complexes in such extracts. 

The accumulation of the acyl intermediate (PVIm-Ac ) was established unequivocally by studying the acylation and deacylation behaviors of the polymer separately. Overberger and Glowaky (60) allowed polyvinylimidazole 1 to react with loi -chain acyl substrates SJJ" 15 and separated the partially acylated polymer by utilizing gel permeation chromatography (Sephadex LH-20). Table 4—3 gives first-order rate coie stants for acylation (kobs) and deacylation (ka) reactions, is larger than kobs fot... 

Low-pressure exclusion chromatography Sephadex LH-20 RP-HPLC Nova-Pak CIS Absorbance at 214 nm and Alcaide-Hidalgo... 

Figure 4. Separation by gel permeation chromatography (Sephadex G 25) of exocellular nickel and organic carbon after fungal groioth (isolate 458, 10 fig Ni/mL)...

By means of streptomycin sulfate treatment, Sephadex G-25 filtration, DEAE-Sepharose CL-6B chromatography, Sephadex G-150 filtration, and hydroxyapatite chromatography we succeeded in isolating and purifying two NADPH-dependent oxidoreductases from enzyme extracts of Saccharomvces cerevisiae. which catalyze the enantioselective reduction of 3-oxoacid esters to (S)- and (R)-3-hydroxyacid esters (11). 

P. polycolor Ammonium sulfate (1) — Hydroxyapapite chromatography Sephadex C150 (IV) CM Sephafiex (11) 9,270 N2... 

Fig. 7. Gel chromatography (Sephadex G-50 Superfine) of serum from a gastrinoma patient. The chromatogram shows the elution of gastrin peptides as measured using a conventional radioimmunoassay directed against bioactive carboxyamidated gastrins or using a processing-independent radioimmunoassay specific for sequence 55-66 of human progastrin.

After rota-evaporation of the ether the crude product was purified by column chromatography (sephadex LH-20 Rf(5)= 0.25) with chloroform/ethyl formate/methanol (100 10 1) as eluant. The 1.1.6c-fraction was concentrated and the residue recrystallized from methanol yielding 18.6 mg (12.5%) of 1.1,6c, mp 163 - 165 °C. 

Solutions of 150 mg (ca. 3 x 10 mol) of 1.1.6b in 150 mL of an anhydrous mixture of cyclohexane/benzene (80/20) were irradiated (pyrex cuvette, Hg high-pressure lamp as an external light source) until the educts 1.1.6b were no longer detectable by TLC. After rota-evaporation of the solvent the crude products were purified by column chromatography (sephadex LH-20) with chloroform/methanol (see table) as eluant. 

The samples were fractionated by gel chromatography (Sephadex LH 20) in 1,4-dioxan. The fractions were characterized as follows ... 

Starfish (Styracaster caroli) were collected at a depth of 2000 m between the islands of Thio and Lifou (New Caledonia). Polar (aqueous and acetone) extracts of the starfish yielded three unique polyhydroxylated steroidal amines with an unusual 20-epicholanic skeleton, carolisterols A and B (39-41). The separation was achieved by column chromatography (Sephadex LH-20), droplet counter current chromatography, and reversed-phase HPLC (34). 

Brassinosteroids are extracted preferably by methanol or meihanol/ethylacetate, partitioned between water and chloroform as well as 80% methanol and n-hexane. The purification is carried out by successive chromatographic methods such as silica gel column chromatography, Sephadex LH-20 chromatography, ion exchange chromatography and preparative HPLC. Concerning the... 

Figure 15.7 Distribution of iodine-bound proteins in the cytosol of human liver. The protein in the cytosol of human liver was separated by gel chromatography (Sephadex G-2000) the protein was directly monitored by UV detector at 280 nm. The chromatogram of protein is shown in the protein elution curve iodine-associated proteins are shown in the curve of the iodine in the eluted fraction.

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