Lipidic ketones

Processes fats, carbohydrates, proteins from diet synthesizes and distributes lipids, ketone bodies, and glucose for other tissues converts excess nitrogen to urea. 

To deduce the location of the double bond within the lipid backbone, the mixture (500 ng) was subjected to consecutive bisthiomethylation of the alkene85 and O-methyloxime formation (Equation 3). GC—MS study of the fragmentation of these derivatives (e.g., see 31, derived from 24) allowed simultaneous determination of the cleavage site (between C24 and C25) and of which portion contained the original ketone (i.e., the odd versus even mass fragments of 17 3 and 426 for 31). All of the monounsaturated lipid ketones had the alkene in the same downstream location in other words, they varied in the number of methylene units between the ketone and alkene functional groups but were constant in their -octyl terminal alkyl moiety. The four most major components (24, 25, 27, and 28) were prepared by chemical synthesis and used to confirm their identity in the natural pheromone and their pheromonal activity both alone and in admixtures. 

Virtually aU forms of DM result from a decrease in the circulating concentration of insulin (insuUn deficiency) and a decrease in the response of peripheral tissues to insulin (insulin resistance). These abnormalities lead to alterations in the metabolism of carbohydrates, lipids, ketones, and amino adds the central feature of the syndrome is hyperglycemia. 

Oxidation of olefins to ketones by palladium chloride and an inorganic (cupric ions) or organic (benzoquinone) co-oxidizer is an effective method which has been applied for a long time. It was used in the regioselective preparation of a lipidic ketone, from an olefinic azide, without disturbance of the latter group (Fig. 35) 38... 

Quazepam (88) has a highly fluorinated sidechain so as to make this tranquilizer resistant to dealkylation. It also incorporates a lipid-solubilizing 2-thione moiety. The synthesis begins with bi aryl ketone derivative by ] -al kylation with 2,2,2-trifluoroethyltriclate to give 86. 

In this chapter, we have examined the use of cells and enzymes to chemically transform lipids. We have had to be selective and have predominantly focused attention on the transformation of sterols and steroids. We first explained why these compounds were commercially important and why they only occur in low concentrations in natural systems. We pointed out that a very large number of reaction types are possible, but those which have found greatest use include stereospedfic hydroxylations, alcohol/ketone interconversion, hydrolysis, conjugation and isomerisation. 

Precursor and derived lipids These include fatty acids, glycerol, steroids, other alcohols, fatty aldehydes, and ketone bodies (Chapter 22), hydrocarbons, hpid-soluble vitamins, and hormones. 

Inherited aldolase A deficiency and pyruvate kinase deficiency in erythrocytes cause hemolytic anemia. The exercise capacity of patients with muscle phos-phofiaictokinase deficiency is low, particularly on high-carbohydrate diets. By providing an alternative lipid fuel, eg, during starvation, when blood free fatty acids and ketone bodies are increased, work capacity is improved. 

Simple lipids such as CE, WE, EFA, cholesterol, alcohols, ketones, TG, DG, and MG are usually separated on silica gel plates. Depending on the complexity of the lipid material and the variety of lipid classes present in a single sample, either single-or multiple-solvent systems can be used (Figure 12.4a). Although benzene [45] or... 

Ketosis is a pathologic state produced by an excess of ketone bodies in the organism. However, ketosis may be regarded as a lipid metabolism pathology with a certain reserve, since excessive biosynthesis of ketone bodies in the liver is sequent upon an intensive hepatic oxidation not only of fatty acids, but also of keto-genic amino acids. The breakdown of the carbon frameworks of these amino acids leads to the formation of acetyl-CoA and acetoacetyl-CoA, which are used in... 

The formation of lipid components in an aqueous phase at temperatures from 370 to 620 K was studied by Rushdie and Simoneit (2001), who heated aqueous solutions of oxalic acid in a steel vessel for 2 days the yield of oxidized compounds reached a maximum (5.5% based on oxalic acid) between 420 and 520 K. A broad spectrum of compounds was obtained, from n-alkanes to the corresponding alcohols, aldehydes and ketones. At higher temperatures, i.e., above 520-570 K, cracking reactions competed with the synthetic reactions. 

Oxidative damage to membrane polyunsaturated fatty acids leads to the formation of numerous lipid peroxidation products, some of which can be measured as index of oxidative stress, including hydrocarbons, aldehydes, alcohols, ketones, and short carboxylic acids. 

Patel, M. S., Johnson, C. A., Rajan, R. etal. The metabolism of ketone bodies in developing human brain development of ketone-body-utilizing enzymes and ketone bodies as precursors for lipid synthesis. /. Neurochem. 25 905-908, 1975. 

Following their use in the behavioral trials, sub-sets of the experimental females (n = 8) and experimental newly-emerged males (n = 8) were immediately sacrificed with an overdose of brevital sodium and their skin lipids were extracted with hexane overnight (LeMaster and Mason 2002). After removal of the animals, the extracts were returned to Western Oregon University where the methyl ketones composing the female sexual attractiveness pheromone were isolated using column chromatography (described in LeMaster and Mason 2002). 

Raven, A. M., van Bergen, P. F., Stott, A. W., Dudd, S. N., and Evershed, R. P. (1997). Formation of long-chain ketones in archaeological pottery vessels by pyrolysis of acyl lipids. Journal of Analytical and Applied Pyrolysis 40 267-285. 

For instance, 2-methylpropene reacted with acetic acid at 18°C in the presence of Al-bentonite to form the ester product (75). Ion-exchanged bentonites are also efficient catalysts for formation of ketals from aldehydes or ketones. Cyclohexanone reacted with methanol in the presence of Al-bentonite at room temperature to give 33% yield of dimethyl ketal after 30 min of reaction time. On addition of the same clay to the mixture of cyclohexanone and trimethyl orthoformate at room-temperature, the exothermic reaction caused the liquid to boil and resulted in an almost quantitative yield of the dimethyl ketal in 5 min. When Na- instead of Al-bentonite is used, the same reaction did not take place (75). Solomon and Hawthorne (37) suggest that elimination reactions may have been involved in the geochemical transformation of lipid and other organic sediments into petroleum deposits. 

Because of its wide range and diversity of synthetic functions, the liver may be considered to be the body s factory, taking raw materials and producing many compounds some of which are exported for use in other tissues. This section describes the syntheses of proteins, lipids and lipoproteins, ketones, urea and haem. Not all of these pathways are unique to the liver, but all illustrate important points of hepatic function. 

Ketone bodies are produced in the liver by partial oxidation of long-chain fatty acids arising from the triacylglyc-erol stored in adipose tissue, so that the question arises, why should one lipid fuel be converted into another There are several reasons. 

Male red-sided garter snakes court larger females more than small ones. Even the skin lipid extracts from large females elicit courtship from more males than those from small females. Larger females possess more unsaturated methyl ketones, while small females have more saturated methyl ketones (LeMaster and Mason, 2002). 

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