Cold-insoluble fraction

To a stirred — 78 C solution of 5.85 mL (62.5 mmol) of 3-methoxy-l-prnpene in 25 mL of THf- are added 43.1 mL (50 mmol) of 1.16 M. vcc-butyllithium in cyclohexane over a 20-25 min period. The mixture is stirred at — 78 °C for an additional 10 min, and diisopinocampheyl(methoxy)borane [50 mmol prepared from (+ )-a-pinene] in 50 mL of THF is added. This mixture is stirred for 1 h, then 8.17 mL (66.5 mmol) of boron trifluoride diethyl etherate complex are added dropwise to give a solution of diisopiuocampheyl[(Z)-3-inethoxy-2-propenyl]borane. Immediately. 2.8 mL (50 mmol) of acetaldehyde are added and the mixture is stirred for 3 h at — 78 rC and then allowed to warm to r.t. All volatile components are removed in vacuo, then the residue is dissolved in pentane. The insoluble fraction is washed with additional pentane. The combined pentane extracts are cooled to 0 JC and treated with 3.0 mL (50 mmol) of ethanolamine. The mixture is stirred for 2 h at 0rC and is then seeded with a crystal of the diisopinocampheylborane-ethanolaminc complex. The resulting crystals arc filtered and washed with cold pentane. The filtrate is carefully distilled yield 5.6 g (57%) d.r. (synjanti) >99 1 (2/ ,37 )-isomer 90% ee bp 119-120 C/745 Torr. 

The first application of natural-abundance solid state 15NNMR was on the complex solids from the reaction of hydrogen cyanide and ammonia. Signals in the solid state spectrum of the cold water soluble fraction are attributed to the NH4 salt, amine-, urea-, peptide-, nitrile-, and pyrrole-like nitrogens. The spectrum of the cold water insoluble fraction shows two broad resonances indicating a diversity of nitrogen functionality, possibly including crosslinked aromatics and purine-like compounds (3). 

Gum arable is easily dissolved, even in cold water, although warm water is preferable. However, the natural product contains an insoluble fraction and the properties of the solution depend on the preparation conditions. For this reason, solutions (150-300 g/1) are prepared by specialized laboratories, stabilized by sulfuring and supplied ready for use. These preparations are checked to ensure that their purity complies with the Enologi-cal Codex standard (optical rotation) and that they have the expected protective effect in wine. Preparations should not affect turbidity, nor should they increase a wine s capacity to foul filter surfaces to any great extent. 

Abbreviations alk. alkaloids (cyclopenin + cyclopenol) CH cycloheximide dpm decompositions per minute, cf. 2. P cyclopium Penicillium cyclopium p. i. after inocu-lation of cultures prot. TOA-insoluble fraction of homogenate (protein) TCA trichloroacetic acid L-Phe L-phenylalanine for brevity labelled L Phe stands for radioactively labelled phenylalanine (U- C-L-Phe) and cold L-Phe stands for unlabelled phenylalanine. 

Fig. 1. Release of cysteine-linked ADP-ribose by mercuric ion. The acid insoluble fraction of rat liver (15) was dissolved in 98% ice cold formic acid and radiolabeled mono-ADP-ribosylated protein was added. The solution was diluted with five volumes of ice cold H2O and precipitated by addition of 100% (w/v) ice cold trichloroacetic acid to a final concentration of 20% (w/v). The sample was held on ice for 10 min and subjected to centrifugation. The precipitate was resuspended in ice cold, 98% formic acid and stored at -20° C for subsequent use. To release cysteine-linked ADP-ribose, the sample in ice cold 98% formic acid was diluted with an equal volume of ice cold H2O or a freshly prepared solution of 20 mM mercuric acetate and the resulting solution was incubat at 37°C 10 min. The samples were then placed on ice, 5 volumes of ice cold H2O were added followed by 100% (w/v) trichloroacetic acid to a final concentration of 20%. After 10 min on ice, the samples were collected by centrifugation and the supernatant was removed. A sample was taken to determine released radiolabeled mono-ADP-ribose. The pellet containing the remaining protein-bound mono-ADP-ribose was dissolved in 250 mM ammonium acetate, 10 EDTA and 6 M guanidine before sampling for radioactivity. ( ) presence, (O) absence of mercuric ion. Panel A shows a time course at 10 mM mercuric ion and Panel B shows a 10 min incubation at the indicated concentrations of mercuric ion.

FIGURE 7 The kinetics of a hardening of epoxy resin ED-22 curve 1, composites K-1 curve 2, K-2 curve 3, K-3 curve 4 and K-4 curve 5, hardened by PEPA on a cold, where n-the maintenance of insoluble fractions. 

The total amount of radioactivity incorporated into the cells and its distribution in cold acid soluble and insoluble fractions were determined by liquid scintillation counting. The acid soluble metabolites were separated by chromatography on... 

After polymerization, a fraction of the polymer remains in solution in heptane. The insoluble polymer is extracted 2 hours by boiling heptane in a Kumagawa. The heptane insoluble fraction is expressed (in percent) as the ratio of the insoluble polymer to the whole polymer (including cold and hot heptane soluble). 2 hour Kumagawa extraction is equivalent on a powder to 24 hour Soxhlet extraction. 

Fraction I cold water-soluble nitrogen (CWSN) Fraction II cold water-insoluble nitrogen (CWIN), which is hot water-soluble Fraction III hot water-insoluble nitrogen (HWIN). 

Figure 3 Size fractionation of EDTA-soluble polyuronides from Rutgers and transgenic fruit juice processed by cold- and hot-break methods. Pectin from processed juice was extracted as ethanol-insoluble solids and size fractionated on a Sepharose CL4B column. Under the same chromatographic conditions, elution of the branched dextrans with average molecular mass 2000, 500, 252, 151, 40 and 17.7 kD-peaked in fraction number 46, 50, 54, 62, 67 and 72, respectively. Modified from Thakur et al. [23].

Instant tea produced as described above will dissolve completely in hot water but not in cold water, as the caffeine-polyphenol complexes are insoluble under those conditions. Since virtually all instant tea manufacture in the U.S. is for iced tea preparation, process modification is required. This initial extract may be cooled to 5 to 10°C and the cold water insoluble material or cream be allowed to precipitate. Under these conditions, 20 to 35% of the extract solids may be separated by centrifugation. The supernatant solids will reconstitute in cold water after concentration and drying.105 It is also possible to process the cream to make a portion of it compatible with the product and thereby retain the caffeine and some polyphenolic components that are present in this fraction.106 Commercial use of the enzyme Tannase, which removes gallic acid from gallated tea polyphenols107 and reduces cream formation108 can be used to reduce cream losses and manufacture instant teas retaining more of the natural polyphenol content. 

The structure and roles of membrane microdomains (rafts) in cell membranes are under intensive study but many aspects are still unresolved. Unlike in synthetic bilayers (Fig. 2-2), no way has been found to directly visualize rafts in biomembranes [22]. Many investigators operationally define raft components as those membrane lipids and proteins (a) that remain insoluble after extraction with cold 1% Triton X-100 detergent, (b) that are recovered as a low density band that can be isolated by flotation centrifugation and (c) whose presence in this fraction should be reduced by cholesterol depletion. 

In entrainer sublimation, an entrainer gas is blown into the vaporisation chamber of a sublimer in order to increase the vapour flowrate to the condensing equipment, thereby increasing the yield. Air is the most commonly used entrainer, though superheated steam can be employed for substances such as anthracene that are relatively insoluble in water. If steam is used, the vapour may be cooled and condensed by direct contact with a spray of cold water. Although the recovery of the sublimate is efficient, the product is wet. The use of an entrainer gas in a sublimation process also provides the heat needed for sublimation and an efficient means of temperature control. If necessary, it may also provide dilution for the fractional condensation at the desublimation stage. Entrainer sublimation, whether by gas flow over a static bed of solid particles or through a fluidised bed, is ideally suited to continuous operation. 

Hemicelluloses are quite difficult to extract from cell walls of softwoods (9,10) and are usually destroyed or depolymerized during the chemical pulping of these raw materials. However, other hemicelluloses, primarily xylans, can be extracted by cold, dilute sodium hydroxide from grasses and many hardwoods in very high yields (9,77). These xylans are deacetylated in an alkaline medium and are for the most part insoluble (hemicellulose A). A partially water soluble fraction (hemicellulose B) has also been... 

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