B Dayal

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Initial experiments were conducted to determine whether or not the aging process alters the ability of young, mature, or aged male Fischer 344 rats (5- to 6-, 15- to 16-, and 25- to 26-months-old, respectively) to respond to thermal nociceptive stimuli. Using the tail-flick analgesiometric assay, 25- to 26-month-old rats responded significantly faster to(More)
We measured the turnover and absorption of sitosterol and cholesterol, along with plasma sterol and lipoprotein concentrations, in one control and two subjects with sitosterolemia with xanthomatosis. All individuals consumed the same diet which contained approximately 500 mg/day of cholesterol and 250 mg/day of sitosterol. Sterol absorption was measured by(More)
Plasma and fecal sterols of patients who exhibited tendon xanthomas with normal plasma cholesterol levels were studied. Plasma levels were (mg/dl mean +/- SD): cholesterol 232 +/- 36; cholestanol 5.9 +/- 2.1 (normal less than 0.6); sitosterol 18 +/- 5.6 (normal less than 1.0); campesterol 11 +/- 3.3 (normal less than 1.0). Other sterols such as sitostanol(More)
This paper describes three simple and short methods for the conversion of cholic acid into cholylaldehyde with protected hydroxyl groups. The first method involves lithium aluminum hydride reduction of the tetrahydropyranyl ether of methyl cholate and oxidation of the resulting primary alcohol with pyridinium chlorochromate. The second method employs(More)
An efficient and convenient procedure for the hydrolysis of bile acid methyl esters is described. This is achieved by the addition of aqueous lithium hydroxide in methanol/dioxane (or tetrahydrofuran) at room temperature. Under these conditions, the formates as well as the acetate derivatives were also hydrolyzed, and the desired bile acids were isolated in(More)
This paper describes an operationally simple, rapid hydrogenation of unsaturated sterols and bile alcohols in a domestic microwave oven. This has been achieved by the addition of catalytic amounts of Pd/C in methylene chloride/propylene glycol solvents in the presence of ammonium formate followed by microwave irradiation. It is suggested that this(More)
An improved method for the preparation of bile acid methyl esters is described. This is achieved by the addition of catalytic amounts of p-toluenesulfonic acid in a solution of bile acid in methanol. Advantages of this procedure over conventional methods include (1) use of a mild solid acid catalyst which prevents the formation of undesirable byproducts,(More)
The absolute configuration of the C27 pentahydroxy bile alcohol present in bile and feces of two patients with cerebrotendinous xanthomatosis (CTX) was determined by circular dichroism (CD) spectroscopy. Under anhydrous conditions CD spectra of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 23, 25-pentol in the presence of Eu (fod) 3[tris (1, 1, 1, 2, 2, 3,(More)
A rapid and easily performed procedure for the synthesis of 5 beta-cholestane-3 alpha, 7 beta, 12 alpha, 25-tetrol by means of an efficient homologation sequence of the intermediate, 3 alpha, 7 beta, 12 alpha-triformyloxy-24-oxo-25-diazo-25-homo-5 beta-cholane is described. The reaction sequence involved treating the intermediate, alpha-diazoketone in(More)