Cholate

The structure of cholic acid helps us understand how bile salts such as sodium tauro cholate promote the transport of lipids through a water rich environment The bot tom face of the molecule bears all of the polar groups and the top face is exclusively hydrocarbon like Bile salts emulsify fats by forming micelles m which the fats are on the inside and the bile salts are on the outside The hydrophobic face of the bile salt associates with the fat that is inside the micelle the hydrophilic face is m contact with water on the outside... 

Sodiiun dodecylsulfate, cetyltrimethylam-monium chloride, sodium cholate, -cyclodextrin dansylated amino acids and polycyclic aromatic hydrocarbons > 45-fold 1% in water the greatest enhancement of fluorescence is that of sodium cholate on pyrene [263]... 

The most prevalent steroid in animal cells is cholesterol (Figure 25.30). Plants contain no cholesterol, but they do contain other steroids very similar to cholesterol in structure (see page 256). Cholesterol serves as a crucial component of cell membranes and as a precursor to bile acids (e.g., cholate, glycocholate,... 

Bile acids, which exist mainly as bile salts, are polar carboxylic acid derivatives of cholesterol that are important in the digestion of food, especially the solubilization of ingested fats. The Na and salts of glycocholic acid and tauro-cholic acid are the principal bile salts (Ligure 25.41). Glycocholate and tauro-cholate are conjugates of cholic acid with glycine and taurine, respectively. 

It has been reported that the percolation of conductance of water/AOT/n-heptane microemulsions is assisted by sodium cholate and retarded by sodium salicylate [282]. 

A new cholesterol flow injection analysis biosensor has also been described as an application of the H2O2 ECL sensor56. In that work, the luminol electrochemiluminescence, previously studied in aqueous media, was implemented in Veronal buffer added of 0.3% triton X-100 (v/v), 0.3% PEG and 0.4% cholate to enable the solubilisation of the cholesterol and then its efficient oxidation catalyzed by the immobilized cholesterol oxidase. The ECL reaction occurred thus in a micellar medium and the performances of the H2O2 ECL sensor were investigated. 

Indeed a limited number of monomeric [Mn(dioxolene)2] complexes have been structurally characterized (M = Ni dioxolene = 3, 6-di-terf-butyl-l,2-benzosemiquinone, n = 0 51a dioxolene = A AT -bis, 3-dihydroxybenzoyl)-l,7-diazaheptane, n = 2 51b dioxolene = 1,2-cate-cholate, n = 2 51c M = Pd, Pt dioxolene = 3,5-di-terf-butyl- 1,2-benzo-semiquinone, n = 052), likely due to the fact that Ni(II) in the presence of... 

Thawed microsomal preparations (500-700 mg protein) from little skates were digested with sodium cholate (1 mg/mg protein) in 10 mM potassium phosphate buffer (pH 7.7) to make a final concentration of 10 mg protein/ml, in the presence of 0.1 mM EDTA,... 

The elution profile of cytochrome P-448 (absorption at 418 nm) and epoxide hydratase activity from a sodium cholate-solubi-lized hepatic microsomal preparation (from DBA-treated male skates) applied to a DEAE-cellulose column and eluted with Buffer II is shown in Fig. 3. The void volume of the column contained significant amounts of epoxide hydratase activity. Fractions 40-70 (Fig. 3) were combined, and concentrated. The carbon monoxide difference spectrum, which had an absorption maximum at 448 nm in the induced state, is shown in Fig. 4. This form of the cytochrome (i.e.,... 

Very similar results to those described in Fig. 3-6 were obtained when sodium cholate solubilized hepatic microsomes from DBA-treated female little skates were subjected to chromatography on DEAE-cellulose as described above (data not shown). Also not shown are the results obtained with hepatic microsomes from untreated male and female little skates. With untreated animals, 80-90% of the cytochrome P-450 eluted from the DEAE-cellulose column only at higher ionic strength (i.e., with the KC1 gradient). However, in all preparations studied, an appreciable amount of cytochrome P-450 (10-20%), having its absorption maximum in the carbon monoxide-ligated and reduced state at 450 nm, was eluted from the column with buffer II, as was observed with cytochrome P-448 of hepatic microsomes from DBA-treated skates. The further purification of the various forms of cytochrome P-450 from control and DBA-pretreated little skate livers is currently in progress in our laboratory. 

The reconstituted system consisted of Cytochrome P-488 (0.2 nmol), NADPH-Cytochrome c reductase (1500 units) and sodium cholate (1.25 mg). It was preincubated for 30 min at 31°. The final reaction mixture (which was incubated at 31° for 20 min) com tained the preincubated system described above, excess NADPH and t4C-BP (100 nmol 4.1 mCi/mmol) in a final volume of 1 mL 0.5M HEPES buffer, pH 7.6. Rate of BP metabolism was 665 pmol/min/nmol Cytochrome P-488. Abbreviations used for metabolites are described in legend to Figure 2. 

Stabilization in water (surface tension 72 mN/m) can be achieved through the use of surfactants [77] such as SDBS [78] or sodium cholate [79], or long chain polymers such as polyvinyl alcohol. While this allows a non-toxic and easily removed solvent to be used, the presence of the surfactant or polymer molecules can be detrimental to the subsequent applications [80]. 

Hayakawa E, Yamamoto A, Shoji Y, Lee VH (1989) Effect of sodium glyco-cholate and polyoxyethylene-9-lauryl ether on the hydrolysis of varying concentrations of insulin in the nasal homogenates of the albino rabbit. Life Sci 45 167— 174. 

Impurity profiling by MEKC was demonstrated for the first time in 1990 for the separation of diltiazem and its impurities. MEKC employing the bile salt, sodium cholate, as the micellar phase provided satisfactory separation of diltiazem and its impurities within 15 Salicylamide and 12 of its impurities were separated within 6 min by MEKC with a... 

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