Molecular weight water-soluble

Minimization of the elastic behavior of the fluid at high deformation rates that are present when high molecular weight water-soluble polymers are used to obtain cost-efficient viscosities at low shear rates. 

UF solutions are clear water solutions. They contain only very low molecular-weight, water-soluble UF reaction products plus unreacted urea. Various combinations of UF solutions are found. They contain a maximum of 55% unreacted urea with the remainder as one or more of methylolureas, methylolurea ethers, MDU, DMTU, or triazone, a cycHcal oligomer. AAPFCO has defined this class of compounds as urea—formaldehyde products (water- s oluble). 

Gottlieb and Geller (34) reported further to have obtained an enzyme preparation from mushroom spawn, which they claim to catalyze a reaction between native lignin and oxygen. They believe that this enzyme is different from other phenol oxidases heretofore studied. It was later reported that the enzyme acts on low molecular weight water soluble compounds closely related to native lignin. The nature of these compounds was, however, not determined (35). 

The enzyme p-ethylphenol methylene hydroxylase (EPMH), which is very similar to PCMH, can also be obtained from a special Pseudomonas putida strain. This enzyme catalyzes the oxidation of p-alkylphenols with alkyl chains from C2 to C8 to the optically active p-hydroxybenzylic alcohols. We used this enzyme in the same way as PCMH for continuous electroenzymatie oxidation of p-ethylphenol in the electrochemical enzyme membrane reactor with PEG-ferrocene 3 (MW 20 000) as high molecular weight water soluble mediator. During a five day experiment using a 16 mM concentration of p-ethylphenol, we obtained a turnover of the starting material of more than 90% to yield the (f )-l-(4 -hydroxyphenyl)ethanol with 93% optical purity and 99% enantiomeric excess (glc at a j -CD-phase) (Figure 14). The (S)-enantiomer was obtained by electroenzymatie oxidation using PCMH as production enzyme. 

Figure 3.4 Radar plot to demonstrate the physicochemical characteristics of Lipitor. The simple plot demonstrates that two parameters fall within the optimal zone (logP and PSA), while three others slightly exceed the boundaries molecular weight, water solubility and number of rotatable bonds.

In recent years, several procedures have been developed for handling high molecular weight, water-soluble biomolecules. Several of these procedures are here briefly described. [See the Chapman (1993) and Watson (1985) references for a thorough discussion of these techniques. The Harrison (1992) reference presents a thorough treatment of chemical ionizations.]... 

The low-molecular-weight water-soluble fraction of LCP flour was found by thin layer chromatographic methods to contain several flavonoid components. To establish the role of flavonoids in the production of yellow color in biscuits, these components were extracted from LCP and glandless cottonseed flours with 85Z aqueous isopropyl alcohol (which is a better solvent for flavonoids than water). Before removal of the flavonoids, the flours had been treated with petroleum ether to extract residual lipids that could interfere with flavonoid isolation. Extraction of the residual lipids did not significantly alter the color of biscuits prepared with the extracted flours (Figure 7). 

The resins A, B, and C all apparently occur in relatively narrow molecular weight ranges if one neglects the very low molecular weight water-soluble components. The ranges are A (2500), B (4000), and C (8000). The initial polymerizations were designed to produce relative molecular weight differences of this type. 

Uptake by organism Molecular weight Water solubility Log K Not appropriate... 

Hemodialysis is more efficient than peritoneal dialysis and has been well studied. It assists in correction of fluid and electrolyte imbalance and may also enhance removal of toxic metabolites (eg, formate in methanol poisoning, oxalate and glycolate in ethylene glycol poisoning). The efficiency of both peritoneal dialysis and hemodialysis is a function of the molecular weight, water solubility, protein binding, endogenous clearance, and distribution in the body of the specific toxin. 

Clapp, C. E. (1957). High Molecular Weight Water-Soluble Muck Isolation and Determination of Constituent Sugars of a Borate Complex-Forming Polysaccharide Employing Electrophoretic Techniques. Ph.D. dissertation, Cornell University. 

Other studies (Robinson et al, 1970 Gronberg et al, 1971 Morgan, 1972, 1973 Church and Flint, 1973 Stanley and Flint, 1974) also examined the water-soluble fraction from 14C-metribuzin-treated plants. Size-exclusion chromatography (SEC) of the water-soluble fractions indicated molecular weights for the radioactive residues from 300 to 800 atomic mass units (AMU). Stanley and Flint (1974) showed that many of the SEC fractions from metribuzin-treated alfalfa had a peptidic component. This was in accord with the short-term studies of Falb and Smith (1987), who used SEC to show many high molecular weight water-soluble metabolites of both peptidic and glucosidic nature. 

It has long been known that the basic "brothy" flavor of cooked meat is due to the interaction of low molecular weight, water-soluble constituents of muscle. The species specific flavor compounds are... 

Special honors are also due to S. Jacobi, who like Irwin Blank was not a clinician but a Ph.D. scientist. He discovered the famous natural moisturizing factor, made up of low molecular weight, water-soluble substances, dominantly amino acids, which are chiefly responsible for the ability of the stratum corneum to absorb water and to hold onto it in the face of a hostile dry environment.8 He went on to show that an extract of the natural moisturizing factor could ameliorate dry skin. 

Equation (6.134) indicates that the physicochemical properties of drug, solvent, and polymer influence the overall release kinetics. The main key property governing swelling and erosion is the molecular weight of the polymer. Low-molecular-weight water-soluble polymers may provide synchronized swelling and erosion processes (e.g., polyethylene oxide < 2 x 106). However, those properties cannot be easily... 

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