Metabolites animals

Analysis of In Vivo Fecal Metabolites by LC/MS. Besides the analysis of urinary metabolites, animal metabolism studies of course require characterization of fecal metabolic products. We have found that rapid analysis of fecal extracts can also be accomplished by LC/MS, although more extensive cleanup is required. A general procedure for the extraction and LC/MS analysis of rat fecal metabolites is given in Figure 14. This procedure can easily be completed in an afternoon to provide a preliminary indication of metabolite structures. Based on this information the appropriate derivatives can be prepared for additional characterization, if necessary. 

I, 1,1 -trichloroethane and other halogenated hydrocarbons are generally supportive and rely on the body s ability to eliminate rapidly 1,1,1-trichloroethane and its metabolites. Animal studies indicate that intravenous injection or infusion of calcium gluconate or phenylephrine are protective against acute blood pressure reduction caused by exposure to 1,1,1-trichloroethane (Herd et al. 1974). Further animal testing is needed to assess whether these compounds might be used to resuscitate individuals exposed to high concentrations of 1,1,1-trichloroethane. 

HPLC has been successfully applied to the separation of proteins, nucleic acids, polysaccharides, plant pigments, amino acids, pesticides, steroids, drugs and their metabolites, animal and plant hormones and complex lipids. 

Citric acid 77-92-9] (2-hydroxy-l,2,3-propanetricarboxylic acid), is a natural component and common metabolite of plants and animals. It is tbe most versatile and widely used organic acid in foods, beverages, and pbarmaceuticals. 

In man, the metabolic pathways of mepirizole were distinct from those in experimental animals, since hydroxylation on each of the aromatic rings did not occur in man. Compound (752) was obtained by oxidation of the 3-methyl group to the carboxylic acid (a similar process occurs with 5-methylpyrazole-3-carboxylic acid, an active metabolite of 3,5-dimethylpyrazole). However, the carboxylic acid metabolite of mepirizole had no analgesic activity and did not decrease blood glucose. 

The held of marine natural products chemistry, which encompasses the study of the chemical structures and biological activities of secondary metabolites produced by marine plants, animals, and microorganisms, began in earnest in the early 1960s. " This is in stark contrast to the study of terrestrial plant natural... 

The underlying assumption driving marine natural products chemistry research is that secondary metabolites produced by marine plants, animals, and microorganisms will be substantially different from those found in traditional terrestrial sources simply because marine life forms are very different from terrestrial life forms and the habitats which they occupy present very different physiological and ecological challenges. The expectation is that marine organisms will utilize completely unique biosynthetic pathways or exploit unique variations on well established pathways. The marine natural products chemistry research conducted to date has provided many examples that support these expectations. 

Some of these compounds could be considered as dietary additives, but various other terms, including pesticides, can also be used. They can have beneficial effects on the environment and this aspect will be discussed later. The ionophore monensin, which is an alicyclic polyether (Figure 1), is a secondary metabolite of Streptomyces and aids the prevention of coccidiosis in poultry. Monensin is used as a growth promoter in cattle and also to decrease methane production, but it is toxic to equine animals. " Its ability to act as an ionophore is dependent on its cyclic chelating effect on metal ions. ° The hormones bovine somatotropin (BST) and porcine somatotropin (PST), both of which are polypeptides, occur naturally in lactating cattle and pigs, respectively, but can also be produced synthetically using recombinant DNA methods and administered to such animals in order to increase milk yields and lean meat production. "... 

Ingested plant metabolites, drugs and other compounds are processed both by the animal and by the microbial flora of the gut. The composition and activities of the gut microflora vary greatly from one animal species to another and have been very extensively reviewed." In true ruminants (sheep, cattle and deer) and in functional ruminants, such as camels and llamas, a mixed population of bacteria,... 

Although /3-oxidation is universally important, there are some instances in which it cannot operate effectively. For example, branched-chain fatty acids with alkyl branches at odd-numbered carbons are not effective substrates for /3-oxidation. For such species, a-oxidation is a useful alternative. Consider phy-tol, a breakdown product of chlorophyll that occurs in the fat of ruminant animals such as sheep and cows and also in dairy products. Ruminants oxidize phytol to phytanic acid, and digestion of phytanic acid in dairy products is thus an important dietary consideration for humans. The methyl group at C-3 will block /3-oxidation, but, as shown in Figure 24.26, phytanic acid a-hydroxylase places an —OFI group at the a-carbon, and phytanic acid a-oxidase decar-boxylates it to yield pristanie add. The CoA ester of this metabolite can undergo /3-oxidation in the normal manner. The terminal product, isobutyryl-CoA, can be sent into the TCA cycle by conversion to succinyl-CoA. 

A thin-layer chromatography assay was developed for ffie simultaneous determination of the three major hydroxylated metabolites of antipyrine 409,410, and 411 in urine of humans and other animals (82JPP168) (Scheme 95). 

Plants contain to some extent less bioavailable forms of vitamin B6, e.g., glycosylates, or biologically inactive metabolites, e.g., e-pyridoxin-lysin-complexes. In addition, the release of vitamin B6 from foods rich in fiber is assumed to be delayed. The bioavailability of vitamin B6 from animal-derived foods is therefore overall higher than from plant-derived foods. Good dietary sources of vitamin B6 include chicken, fish, pork, beans, and pulses [1]. 

Urinary excretion of metabolites of methyl parathion is rapid and efiicient in animals (Braeckman et al. 1983 Hollingworth et al. 1967). In mice, 70-80% of the activity was excreted in the urine within... 

The available evidence suggests that excretion of methyl parathion metabolites in humans and animals following acute oral exposure is essentially the same and occurs rapidly. Excretion occurs primarily via the urine. Methyl parathion can also be excreted in breast milk, although it has been detected only in a limited number of samples from women of central Asia, for which exposure data were not available (Lederman 1996) (see also Section 3.4.2.2). A study in rats also reported excretion of methyl parathion in the milk (Golubchikov 1991 Goncharuk et al. 1990). 

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