Cholesterol butyrate

This normal substance was later identified as a cell-sphtting enzyme that decomposes proteins, fats, and carbohydrates. Its protective action is inhibited by cholesterol esters such as cholesterol succinate and cholesterol butyrate. (Hraice, the exclusion of fats in the diet is apparently well justified.) A low level of proteolytic enzymes seems to indicate a predisposition to cancer, and levels decrease in the sickly and the elderly. 

Commonly, lipids like glycerides (mono-, di-, or tri-), waxes (e.g., camauba wax, beeswax, cetyl alcohol, emulsilying wax, cholesterol, cholesterol butyrate, etc.), and vegetable oils are nsed as carriers to dissolve/disperse the drug molecules. The surfactants (e.g., polysorbates, sodium dodecyl sulfate, castor oil, bile salts, etc.) and cosurfactants (e.g., alcohols, polyethylene glycol, cranophor, poloxamer, etc.) are used to emulsify the molten lipid mixture in aqneons media The SLNs can then be lyophilized with excipients to obtain the dried powder. The list of excipients and formnlations of the marketed products is found in Mehnert and Mader and Pardeike et... 

System (6) has been described for the simultaneous determination of submicrogram amounts of 17a-deoxy and 17a-hydroxy corticosteroids [145]. Prior to analysis, the corticosteroids were treated with periodic acid in 50% aqueous dioxane, and extracted with dichloromethane. Acylation of the 3- and 17a-hydroxyl groups was carried out using 1 1 butyric anhydride and pyridine. 4- C -cholesterol was added as the tracer, and cholesterol isobutyrate as the internal standard. The column used was glass (8 ft X 5 mm) packed with 1% SE 30 or QF-1 on GasChrom Q (100-120 mesh), and was operated at 250-260°C. Argon (at a flow rate of 30 mL/min) was used as the carrier gas, and detection was by a Sr detector. It was reported that the corticoids could be determined with a precision of approximately 15% down to levels as low as 0.1-0.2 pg. 

The resolution of racemic FTC butyrate (34) was required for the synthesis of the antiviral drug emtricitabine (Emtriva) (Scheme 7.15) a nucleoside reverse transcriptase inhibitor targeted for treatment of human immunodeficiency virus (HIV) and hepatitis infections [35]. The racemic FTC butyrate ester (34) was treated with immobilized cholesterol esterase, which cleaved the required isomer to the corresponding alcohol (-) 35 with 91% and 52% conversion [36]. The product was isolated as the hydrochloride salt to give 31% yield (98% ) from the 8 kg demonstration. The esterase was immobilized by precipitation onto an accurel polypropylene support using acetone followed by cross linking with glutaralde-... 

The helper effects of DOPE and cholesterol appear to be hydrocarbon chain-specific. This is demonstrated in studies of their mixtures with a series of alkyl acyl carnitine esters (alkyl 3-acyloxy-4-trimethylammonium butyrate chloride) tested with CV-1 cell culture (monkey fibroblast) [127]. The influence of the aliphatic chain length (n - 12-18) on transfection in vitro was determined using cationic liposomes prepared from these lipids and their mixtures with the helper lipids DOPE and cholesterol (Fig. 30). Both helper lipids provided for significant transfection enhancements in an apparently chain-specific manner, with the highest effects found for short-chain lipids with diC12 0 and diC14 0 chains in 1 1 mixtures with the respective helper lipid. 

The high-value HMG-CoA reductase inhibitor Simvastatin (8) is marketed by Merck under the name Zocor. The active ingredient is obtained from a fermentation approach. It is very similar in structure to lovastatin, which has fallen from the top-sellers list. Lovastatin (9) is also a cholesterol-reducing drug that is isolated from Aspergillus terreus.51-60 It is still obtained by fermentation,61 and with the current advances in molecular biology,62 64 chemical approaches are not able to compete in a cost-effective manner.65-67 The usage of lipases allows for the manipulation of the butyric acid sidechain to access other HMG-CoA reductase inhibitors such as simvastatin.68 A number of routes to various portions of lovastatin have been reported.69... 

Since then, there have been numerous studies that investigated the effect of different types and amounts of fat, individual fatty acids and other dietary components on plasma cholesterol level. It is now realized that all saturated fatty acids do not elevate plasma cholesterol levels to the same extent. The short-chain fatty acids, butyric (C4 o), caproic (C6 o), caprylic (Cs o) the medium-chain capric (Cio o) and stearic (Ci8 o) acids,... 

Calcium Lactate 814-80-2 Cellulose Acetate Butyrate 9004-36-8 Cholesterol 57-88-5... 

Synonyms Cholesterol butanoate Cholesteryl butyrate Source Huang, Z. Kawi, S. Chiew, Y. C. 

Fig. 11.6.1. HPLC separation of cholesterol and cholesteryl ester standards. Chromatographic conditions column, Supelcosil LC-18 (250x4.6 mm I.D.) mobile phase, acetonitrile-methanol-chloroform (1 1 1, v/v/v) flow rate, 1.0 ml/min temperature, ambient detection, differential refractometer. Peaks 1, cholesterol, 2, acetate 3, propionate 4, butyrate 5, nonanoate 6, decanoate 7, arachidonate 8, laurate 9, linoleate 10, oleate 11, elaidate 12, palmitate 13, stearate. The average mass of lipid chromatographed was 20-40 ng. Reproduced from Perkins et al. (1981), with...

Before fatty acids are analyzed by GC, they must first be converted to the methyl esters. There is now a substantial body of work to confirm that acid-catalyzed transesterification is undesirable in general for the preparation of methyl esters because it can cause geometrical isomerization with an increase in the relative proportions of trans,trans isomers, and other unwanted side reactions (2,5,6). However, there appear to be no significant drawbacks to the use of base-catalyzed transesterification of lipids. For example with sodium methoxide in methanol, glycerolipids are transesterified in 10 min at 50°C. (A longer reaction time is necessary for cholesterol esters containing CLA.) Of course, with samples such as milk fat that contain a high proportion of short-chain fatty acids, it is advisable to use modified methods to minimize the loss of butyric and hexanoic adds, especially (7). 

The effect of thyroid hormones on fatty acid metabolism probably resembles the effect of the hormone on cholesterol metabolism. Fatty acid synthesis increases in hyperthyroidism and decreases in hypothyroidism. In contrast, the rate of oxidation of butyrate is accelerated in hyperthyroidism and decreased in hy-pxthyroidism. The levels of serum phospholipids are increased in hypothyroidism. The mechanism of this metabolic alteration is not known. 

The activity of hydroxymethylglutarate CoA reductase, which produces mevalonic acid—a precursor of cholesterol—was unchanged in diabetic rats. The observations made on diabetic rats contrast with those made in fasted animals in which ketosis is likely to result from activation of the hydroxymethylglutarate CoA shunt pathway, probably due to decreased activity of the hydroxymethylglutarate CoA reductase. In the presence of NADH and a specific mitochondrial dehydrogenase, acetoacetic acid is reduced to yield j8-hydroxybutyric acid, one of the ketone bodies that is excreted in the urine in ketosis. In fact, D-jS-hydroxy-butyric acid represents 50-75% of the blood content of ketone bodies. Therefore, hydroxybutyric acid metabolism assumes a particular importance. 

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