Bile alcohols conjugates

To diagnose CTX, advantage has been taken of the elevated cholestanol levels in plasma. If the ratio of cholestanol to cholesterol is measured by gas-liquid chromatography, a value of over 1% is obtained in patients with CTX compared with less than 0.5% for normal subjects (S2). More recently, capillary gas-liquid chromatography has been used to detect bile alcohol conjugates in the urine of CTX patients and this technique has been useful to assess the efficacy of treatment with orally administered chenodeoxycholic acid (W12). 

The fate of chlordecone in humans involves uptake by the liver, enzymatic reduction to chlordecone alcohol, conjugation with glucuronic acid, partial conversion to unidentified polar forms, and excretion of these metabolites mainly as glucuronide conjugates into bile (Fariss et al. 1980 ... 

Some toxic agents such as Pb, Hg, other heavy metals, and many organic substances are excreted in the bile as conjugates to the intestinal tract for elimination in the feces. Other common routes of elimination include the lungs for gaseous (e.g., NH3) and volatile toxicants (e.g., alcohol, sweat, tears, and saliva), as well as breast milk and eggs in females. 

Conjugated bile acids and bile alcohols were analyzed by TLC using silica gel G plates (Brinkmann Instruments, Westbury, NJ 0.25-mm thickness) with the solvent system chloroform/methanol/acetic acid/water 26 8 4 2 (v/v/vA) (5,7,9). Bile salts were made visible with a spray reagent which consisted of 10 % phosphomolybdic acid in ethanol. Detection with naphthoresorcinol (0.2 % in... 

Dayal, B. and Salen, G. (1990). Fast atom bombardment mass spectrometry (FAB-MS) studies of conjugated bile alcohols. Presented in part at the 17th International Symposium on the Chemistry of Natural... 

Bile salts with a steroid structure appear to be confined to vertebrates (76). In some evolutionarily more primitive vertebrates, the major bile salts are sulfate esters of polyhydroxy C27- and C26-steroids and/or taurine-conjugated C27-steroid acids. In other primitive vertebrates, C24 bile acids, usually cholic acid and/or allocholic acid, or mixtures of primitive bile salts (bile alcohols and C27 bile acids) and modern bile salts (C24 bile acids) occur. Most of the work concerning the structure and occurrence of primitive bile salts has been carried out in the laboratories of G. A. D. Haslewood and T. Kazuno, and Haslewood and collaborators have accumu-... 

Besides hormonal steroid conjugates (Figure 2.7), bile alcohol and bile acid conjugates can also be analyzed by shotgun steroidomics. These metabolites are often elevated in abundance in plasma as a consequence of an inborn error of bile acid biosynthesis or as a consequence... 

Even when adopting a targeted approach, the coverage of lipids in a specific class can still be restricted by the dominance of a few very abundant lipids. This may be the case for steroid analysis where cholesterol is often the most abundant steroid by two orders of magnitude. This problem can be minimized by subdivision of the steroid class according to hydropho-bicity where cholesterol and more hydrophobic steroids represent one class, and oxysterols (oxidized forms of cholesterol and its precursors) and less hydrophobic metabolites represent a second class [45]. This is an approach we adopted for the analysis of steroid sulphates and bile acid/ alcohol conjugates by shotgun steroidomics, and in our LC-ESl-MS/MS work on oxysterols and cholestenoic acids in brain [46,47], plasma [48], and cerebrospinal fluid (CSF) [49]. 

Possible structures of bile alcohol (oxysterol) conjugates found in plasma of a child with neonatal hepatitis of unknown etiology. The location of the hydroxyl groups and conjugating groups are not known however, previous studies of children have shown sulfation... 

Bile alcohols and bile acids are steroids with an isoprenoid side chain at C-17 terminated by a CH2OH or carboxy group. The steroid moiety may be hydroxy-lated at different positions, e.g., at C-3bile alcohols may be conjugated with sulfate (D 11) the bile acids, with glycine (D 10) or taurine (D 11.1). 

Myxinol is a unique tetrahydroxy bile alcohol that occurs in the bile of the hagfish, a most primitive marine cyclostome. It has not been detected in the bile of other species. The structure of myxinol recently clarified by Anderson et al. (232) bears resemblance to other bile salts but offers no promise of metabolic relationship with other known structures. It is conjugated with two moles of sulfate. The hydroxyl group at carbon 3 is, 3 the hydroxyl at carbon 16 is reminiscent of pythocholic acid. Unlike pythocholic acid, myxinol has the A/B trawy-conformation and contains other hydroxyl groups at carbons 3 and 7 rather than at carbons 3 and 12. 

The solvent systems for taurine conjugates can be used for bile alcohol sulfates (10). Improved separations were observed with the upper phas of n-amyl acetate-heptane-acetic acid-water, 85 15 103 47 (by vol.) (46). Such solvent systems should also be suitable for the bile acid 3-suIfates recently described 47). 

Ishida, H., Nakayasu, H Miyamoto, H Nukaya, H and Tsuji, K. (1998b) Study on the bile salts from sunfish, Mola mola L. I. The structures of sodium cyprinol sulfates, the sodium salt of a new bile add conjugated with taurine, and a new bile alcohol and its new sodium sulfates. Chem. Pharm. Butt., 46,12-16. 

Rhizoprionodon acutus. IV. Effects of naturally occurring bile alcohols, bile acids and their conjugates on lesion development and vascular endothelial cell injury in a rat peripheral arterial occlusion model. Biol. Phann. Bull., 22, 828-835. 

Other biomarkers of exposure include tissue concentrations of chlordecone (Bungay et al. 1981 Cannon et al. 1978 Cohn et al. 1978 Egle et al. 1978 Hewitt et al. 1986b Plaa et al. 1987 Taylor 1982, 1985) and fecal or bile concentrations of chlordecone, chlordecone alcohol, and their glucuronide conjugates (Blanke et al. 1978 Boylan et al. 1979 Cohn et al. 1978 Guzelian et al. 

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