Fractional elution

Separation of chloroformic fraction of raw material by a polyamide sorbent with the following individual fractions elution and crystallization allowed to study lignans of burdock with IR-, mass- and NMR spectroscopy. In result, aixtiin, arctigenin, lappaols were identified. Sepai ation of essential oils was provided by the method two of State Phaiiuacopeias of the Ukraine. Essential oils were analyzed by the means of gas chromatography. 

Bromonaphthalene [580-13-2] M 207.1, m 59 . Purified by fractional elution from a chromatographic column. Crystd from EtOH. 

The product, isolated as above, is dissolved in pentane solution and chromatographed on 100 g of alumina. The initial fraction eluted with pentane, yields 1.02 g (48%) of 2,2-dimethyl-5a-cholestan-3-one mp 111-113°, after crystallization from ether-methanol. The subsequent fraction, eluted with pentane and pentane-benzene (9 1) gives 0.12 g (6%) of 2a-methyl-5a-cholestan-3-one mp 119-120°, after crystallization from methanol-ether. 

In an attempt to isolate a factor responsible for stimulating hepatocyte growth. Nelson et al. (31) used a PolyHEA column to fractionate an extract of liver by size. The active fraction eluted at a position corresponding to approximately 200 Da the actual molecular weight (electrospray mass spectrometry ES-MS) was 215 Da. The compound of interest proved to be glycerophosphorylethano-lamine. 

Preswelled Sephacryl S-1000 was prepared in a K26/100 column (88 X 2.6 cm). Equilibration with 0.005 M NaOH containing 0.002% NaN3 at a flow rate of 0.67 ml/min was achieved after 20 hr. Sample solutions were applied with a 5-ml injection loop. The mass and iodine-complexing potential of separated glucan components was determined off-line for each of the subsequently eluted 5-ml fractions. Based on the determined mass of carbohydrate for each of the fractions, elution profiles such as Fig. 16.1 were constructed. 

Twenty grams of the resulting oily substances were mixed with 20 grams of silicic acid (Mal-linckrodt Chemical Co.),applied to a column 40 cm in length and 4.5 cm in diameter filled with silicic acid,and eluted with a be nzene-ecetone-methanol mixture. The initial eluate which eluted with a 1 1 0 mixture was discarded and the active fractions eluted with 1 3 0 and 1 3 0.3 mixtures were collected and concentrated to dryness in vacuo. 11 g of this crude substance was then dissolved in a small amount of ethyl acetate and applied to the same silicic acid column as above. After discarding the initial eluates by the 1 1 and 2 1 benzene-acetone mixtures, aclacinomycin 8 fractions were first eluted with the above mixtures of 1 3 and 1 5 ratio, and aclacinomycin A fractions were then eluted with the 1 5 0.5 and 1 5 1 benzene-acetone-methanol mixtures. The eluates were dried over anhydrous sodium sulfate and concentrated to dryness in vacuo. 4,8 g of crude aclacinomycin A and 3.5 g of aclacinomycin 8 were obtained as yellow powder. 

Preparation of cholesta-5,7-diene-ia,3/3-diol a solution of 500 mg of the 1,4-cyclized adduct of cholesta-5,7-dien-3/3-ol-ia,2a-epoxideand 4-phenyl-1,2,4-triazoline-3,5-dione in 40 ml of tetrahydrofuran is added dropwise under agitation to a solution of 600 mg of lithium aluminum hydride in 30 ml of THF. Then, the reaction mixture liquid Is gently refluxed and boiled for 1 hour and cooled, and a saturated aqueous solution of sodium sulfate is added to the reaction mixture to decompose excessive lithium aluminum hydride. The organic solvent layer is separated and dried, and the solvent Is distilled. The residue Is purified by chromatography using a column packed with silica gel. Fractions eluted with ether-hexane (7 3 v/v) are collected, and recrystallization from the methanol gives 400 mg of cholesta-5,7-diene-la, 3/3-diol. 

After having been dried over sodium suifate and evaporated under vacuum, this extract gives as a solid residue 14.7 g of crude 7-cyanoacetylamino-cephalosporanic acid which is purified by chromatography on 30 times its own weight of silica gel. The fractions eluted with chloroform plus acetone (7 3) furnish a product which crystallizes from acetone plus ether in the form of needles melting at 168° to 170°C with decomposition. 

The mycelium (56 g dry weight) was filtered off and the steroidal material was extracted with methylene chloride, the methylene extracts evaporated to dryness, and the resulting residue chromatographed over a Florisil column. The column was packed with 200 g of Florisil and was developed with five 400-ml fractions each of methylene chloride, Skelly-solve 8-acetone mixtures of 9 1, 8 2, 7 3, 1 1, and methanol. The fraction eluted with Skellysolve 8-acetone (7 3) weighed 1.545 g and on recrystallization from acetone gave, in three crops, 928 mg of product of MP 210° to 235°C. The sample prepared for analysis melted at 245° to 247°C. 

A solution of 2.7 grams of chromic acid in 20 cc of water and 50 cc of acetic acid was added to the stirred solution of the above oil in 100 cc of acetic acid, maintaining the temperature below 20°C. After 90 minutes standing, 50 cc of methanol were added and the mixture concentrated under vacuum (20 mm). The residue was extracted with ether, washed to neutral and evaporated to dryness. The residual semicrystalline product (7 grams) was chromatographed over alumina and the fractions eluted with ether yielded 3.2 grams of A -19-norandrosten-3,17-dione having a MP of 163° to 167°C. 

A solution of 9-phenyl-9//-purine-6-carbonitrile (0.2 g. 0.9 mmol) and N,.V-dielhylprop-l-ynamine (0.2 g, 1.8 mmol) in xylene (3 mL) was refluxed for 18 h. After cooling, the mixture was poured into excess H20, and extracted with CHC13. The extract was washed with H20, dried (Na2S04), and concentrated to dryness. The residue was chromatographed (silica gel, CHCl, then benzene/ EtOAc 20 1). The fraction eluted with benzene/ EtOAc gave the product [yield 194 mg (65 %)] as pale yellow needles after recrystallization (benz-cnc/petroleum ether) mp 157— 158 C. 

Cu(OAc), H20 (0.75 g, 3.7 mmol) was added to a refluxing solution of metal-free 1,4,8,11.15,18,22,25-octa(propyloxy)phthalocyanine (0.1 g, 0.1 mmol) in BuOH (5 mL). The solution was maintained at reflux for 0.5 h, cooled, and chromatographed (silica gel, CH2C12 and Et20). The green-blue fraction eluted first was crystallized from a slowly evaporating solution in CH2Cl2/py yield 0.086 g (81 %). 

Purification of luciferin (Rudie etal., 1976). The luciferin fractions from the DEAE-cellulose chromatography of luciferase were combined and concentrated in a freeze-dryer. The concentrated solution was saturated with ammonium sulfate, and extracted with methyl acetate. The methyl acetate layer was dried with anhydrous sodium sulfate, concentrated to a small volume, then applied on a column of silica gel (2 x 18 cm). The luciferin adsorbed on the column was eluted with methyl acetate. Peak fractions of luciferin were combined, flash evaporated, and the residue was extracted with methanol. The methanol extract was concentrated (1 ml), then chromatographed on a column of SephadexLH-20 (2 x 80 cm) usingmethanol asthe solvent. The luciferin fractions eluted were combined and flash evaporated. The residue was... 

HPLC on a Cl 8-silica column, with 27% (v/v) acetonitrile (pH 2.6 with H3PO4). The active fraction eluted is concentrated, and the panal in the residue is extracted with ethyl acetate. After evaporating ethyl acetate, panal is redissolved in 30% methanol, and stored at -30°C. 

Fig. 8. Preparative isolation of hexon antigen of EDS-76 by hydrophobic-interaction chromatography on Butyl-PG column (2x5 cm) (A) application of the allantoic fluid diluted (1 5) by 50 mM potassium acetate, pH 4,130 ml (B)0.01 mol/1 potassium acetate, pH 5.5 (C) 0.01 mol/1 potassium bicarbonate pH 8.0, 10% isopropanol (D) 0.01 mol/1 potassium carbonate pH 9.6, 10% isopropanol. EDS-0 — components of alantoic fluid eluted with buffer A, EDS-1 — desorbed hexon fraction eluted with buffer C, EDS-2 — fraction desorbed with buffer D [56]...

Crude polysaccharide fraction (GL-2) was prepared from the leaves of P. ginseng by hot water extraction, ethanol precipitation and dialysis, and GL-2 was fractionated by Cetavlon precipitation and weakly acidic polysaccharide fraction (GL-4) was obtained[3]. GL-4IIb2 was purified from GL-4 by DEAE-Sepharose CL-6B as described previousely [3]. In order to remove the color-materials, GL-4IIb2 was further purified by Q-Sepharose (C1 form), and the major fraction, eluted with 0.3 M NaCl, was repurifled by gel filtration on Bio-gel P-30 column to obtain purified active polysaccharide, GL-4IIb2. ... 

Heat and reflux a 5-g portion of soil sample with 50 mL of methanol-phosphate buffer (pH 7)-water (15 7 28, v/v/v) solvent mixture in a round-bottom flask for 1 h. After cooling, transfer a 10-mL portion of the supernatant to a test-tube and mix with 11 mL of 0.02M H3PO4 solution. Load this solution on to a silica-based SPE cartridge (Analytichem International Clin-Elut 1020) at a flow rate of 1-2 drops per second. Discard this fraction. Elute the analytes with 30 mL of dichloromethane. Concentrate the eluate to dryness with air in a water-bath at a temperature of 40 °C (do not use vacuum). Dissolve the residues in 5mL of HPLC injection solution [900 mL of water - - 50 mL of phosphate buffer (pH 7) 4-50 mL of ACN 4-4 g of TBABr]. Pinal analysis is performed using liquid chromatography/ultraviolet detection (LC/UV) with a three-column switching system. 

Pass the solution derived from Section 6.2.2 through a Cig cartridge (conditioned prior to use successively with 5mL of acetonitrile and 10 mL of water), then elute interfering substances with 15 mL of acetonitrile-water (3 17, v/v) and discard the eluate. Elute imibenconazole-debenzyl with 20 mL of acetonitrile-water (2 3, v/v) and collect the eluate in a 100-mL separatory funnel (imibenconazole-debenzyl fraction). Elute imibenconazole with 20 mL of acetonitrile-water (17 3, v/v) and collect the eluate in a 100-mL separatory funnel (imibenconazole fraction). Add 30 mL of 20% sodium chloride aqueous solution and 40 mL of ethyl acetate to each separatory funnel and shake the funnel with a mechanical shaker for 5 min. Collect the ethyl acetate extract, dry the extract with anhydrous sodium sulfate and transfer into a 100-mL round-bottom flask. Concentrate the ethyl acetate extract to near dryness by rotary evaporation and dry with a stream of nitrogen. Dissolve the residue of each fraction in acetone for gas chromatographic determination as in Section 6.3. 

Use of radioligands in the chemical purification of receptors. Here, the bound radioligand allows the receptors to be tracked through the various purification steps — for example, in the fractions eluting from separation columns. In such experiments, it is important for the radioligand to be irreversibly bound to the receptor. 

The total volume Vt occupied by the eluent within the column is the sum of the interstitial or void volume Vq, which is equal to the volume of the mobile phase, and the volume Vp within the pores. Different molecular weight fractions elute at a certain retention time corresponding to retention volume Vr ... 

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