Glycocholate structure

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,... 

The structures of the salts of glycocholic acid and taurocholic acid are ... 

There are only a limited number of studies comparing the systematic changes in the structure of enhancers and their influence on the oral mucosal membranes. For example, for insulin absorption in rats, it was shown that sodium glycocholate, laureth-9, sodium laurate, and sodium lauryl sulphate were approximately equipotent. Several non-ionic surfactants having a Ci2 hydrophobic tail were much less effective.P 24]... 

A. This compound is the bile salt glycocholic acid. During its synthesis, the ring structure of cholesterol is hydroxylated and reduced, and the side chain is oxidized and conjugated with... 

Fig. 2. Solution structure of dysprosium glycocholate, 1 1 complex — the dysprosium ion is the large sphere at the bisector of the carboxyl group the hydrophilic side of the molecule faces the observer. (Modified from ref. 14, courtesy of Dr. Stephen Barnes.)...

Recently, the side chain structure of glycocholate monomers was resolved by NMR employing the paramagnetic lanthanide, dysprosium [14]. Dysprosium chloride interacted with 0.5 mM sodium glycocholate in to form a 1 1 salt... 

Primary bile acids generally exist in bile in the form of conjugates with glycine or taurine through a peptide bond. These water-soluble conjugates, by virtue of their surface active properties, solubilize lipophilic substances in the gut, forming micelles in the process. The structures of two such compounds, glycocholic (XIII) and taurocholic (XIV) acids, are shown in Fig. 8. 

Figure 5 (a and b) Chemical structure of the sodium salt of several bile acids 1 cholic acid, 2 chenodeoxycholate, 3 deoxychoUc acid, 4 glycocholic acid, 5 taurochoUc acid, and 6 tauro deoxychoUc acid, (c) Structures of micelles from choUc acid derivatives, proposed by Small and coworkers. Two or four molecules assemble because of hydrophobic interactions between the cholesterol groups. The hydroxyl groups (black dots on cholesterol) and the carboxylic acids side group shield the hydrophobic domain from water. (Refs. 22-24 for cmcs and Ref. 16 for aggregation numbers.) (Reproduced with permission from Ref. 21. Indian Academy of Sciences, 2004.)... 

Figure 13.19 Structure of sodium glycocholate. The hydrophobic tail of sodium glycocholate dissolves in ingested fats, stabilizing them on the aqueous medium of the digestive system.

FIGURE 8.8 Structures of steroids, (a) The steroid ring system, (b) Cholesterol, (c) A bile salt, glycocholate (choloylglycine)... 

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