Metabolites observation

The HPLC analysis of milkweed, the food-plant source for Monarch butterflies, demonstrates that it contains a complex mixture of carotenoids including lutein, several other xanthophylls, xanthophyll epoxides, and (3-carotene, Figure 25.3b. There is a component in the leaf extract that is observed to elute near 8min, which has a typical carotenoid spectrum but is not identical to that of the lutein metabolite observed at near the same retention time in the extracts from larval tissue. 

FIGURE 7.6 Targeted metabolite screening procedure, showing a flowchart that could be followed to determine whether to report a potential metabolite observed in a sample assay. (Source Adapted from Wainhaus, S. et al., Am. Drug Dis., 2007, 2, 6. With permission.)... 

Fig. 2.9.14. APCI-FIA-MS-MS(-I-) (CID) product ion mass spectrum of selected [M + NH4B parent ion (m/z 442) of non-ionic surfactant metabolite observed in Clg-SPE eluates PPG homologue (general formula H0-(CH2-CH(CH3)-0)X-H) fragmentation behaviour under CID presented in the inset [35],...

Investigation of the in vitro metabolism of delavirdine is accomplished using mouse, rat, dog, monkey, rabbit, and human liver microsomes. The primary metabolite observed is the A-dealkylated delavirdine 26. Another primary metabohte observed is the hydroxy-lation of the pyridine ring at C-6 (compound 27). The primary metabolism is by CYP3A4 and also CYP2D6. Delavirdine reduces the activity of CYP3A4, thereby inhibiting its own metabolism. 

The ability of liver to biotransform chloramphenicol has been also demonstrated in several fish species. In pertinent studies, various metabolic pathways were determined and chloramphenicol-glucuronide, chloramphenicol-base, chloramphenicol-alcohol, and chloramphenicol-oxamate were the main metabolites observed (34, 35). Following hepatic biotransformation, a large proportion of the administered dose was excreted in the urine. 

Feeding low levels of olaquindox (2.0 and 6.0 ppm in feed) to laying hens for 21 days, resulted in residues in eggs that reached a plateau after some 10 days of medication (19). The sum of residues of the parent compound and the N" -monooxy metabolite, which was the only metabolite observed, was higher in egg white than in yolk, the amount of the metabolite accounting for 15-20% of the total residues. After cessation of the medication, the residues in both yolk and white declined below 2 ppb in about 5 days. 

Figure 5.11. Kinetic profiles for top five verapamil metabolites observed in 1 /M microsomal incubations.

There are many examples, as cited above, which have demonstrated that the EC oxidation products for a given compound often coincide with metabolites observed in biological assays (Volk et al., 1988, 1989 Getek et al., 1989 Deng and Van Berkel, 1999 Jurva et al., 2000 van Leeuwen et al., 2005). These and other EC oxidation products may also be observed in purposeful degradation or stability studies. One must recognize, however, that enzyme-catalyzed, chemical and EC oxidations are often very complex and involve different phenomena. 

In vitro reductive metabolism of 14C-nitrobenzene was significantly greater in the cecal contents of rats fed NIH-07 than that in the cecal contents of either of the groups fed the AIN-76A-based diets (Table V). Furthermore, nitrobenzene metabolism by cecal contents tended to be greatest in animals fed NIH-07, least in animals fed AIN-76A, and intermediate in those fed AIN-76A containing pectin. Metabolites of nitrobenzene produced by cecal contents of animals fed NIH-07 and AIN-76A containing pectin included aniline, nitrosobenzene, and azoxybenzene, whereas aniline was the only detectable metabolite observed in animals fed the AIN-76 A diet (Table V). 

Urinary organic acid analysis is useful for differentiating isolated carboxylase deficiencies from the biotin-responsive multiple carboxylase deficiencies. P-Hydroxyisovalerate is the most common urinary metabolite observed in isolated P-methylcrotonyl-CoA carboxylase deficiency, biotinidase deficiency, biotin holo-carboxylase synthetase deficiency, and acquired biotin deficiency. In addition to P-hydroxy-isovalerate, elevated concentrations of urinary lactate, methylcitrate, and P-hydroxypropionate are indicative of multiple carboxylase deficiency. 

B), the hydroxylamine metabolite (Scheme 10, C), the nitrones (D and E), the lactam metabolite (Scheme 10, F), the hydroxylated 0-dealkylated metabolite (G), the glucuronide of metabolite G (Scheme 10, H), the oxime metabolite (Scheme 10,1), and the keto acid metabolite (Scheme 10, J)—were characterized by high-resolution LC/MS and LC/MS/MS (Table 7-10). The authors found that the major circulating metabolite observed in vivo was generated... 

PRO in potato tubers as. highly polar in nature with concentrations of individual metabolites observed in the tubers less than 0-020 ppm. 

An assay for ethanol in blood plasma has been published and a comprehensive listing of the H NMR-detectable metabolites observed in the various ID and 2D experiments, together with their spin systems and their H chemical shifts (and shifts where available) in plasma, is given in Table 2. 

Metabolic, nutritional and toxicological aspects of 160-163 Se were studied. The transport of Se within the organism and the urine metabolites observed were different, depending on the form of Se administred. Rapid and efficient incorporation of Se into SeP in the liver and excretion into the plasma followed by the slow and steady incorporation of Se into GPx in the kidneys and excretion into the plasma described. The formation of Se-methyl-/V-acetylselenohexosa-mine in liver and its excretion via urine were reported. The mechanisms underlying the interaction between Se and mercuric ions in the bloodstream were explained by the formation of a ternary complex, [(HgSe) ], -selenoprotein P... 

When the drug candidate goes to preclinical and clinical development, the goals of drug metabolism studies are to identify unambiguously all significant metabolites observed in humans, and confirm that they are present in the animal species employed for preclinical safety evaluation. 

The photolytic half-life in water was 17.6 days, indicating a moderate rate of degradation and a potential for degradation in surface water. The two monoadds and the diadd were the primary metabolites observed. The potential movement in water would be limited due to the low water solubility of dithiopyr and its strong adsorption to soil partides and plants. 

In this work will be researched the possible metabolites (observed and predicted) for some naphthenic acids. For this aim we will use the OECD (Q)SAR Application Toolbox system. Predictions are based on biotransformation rules that, in turn, are derived from reactions found in the UM-BBD and the scientific literature. The UM-PPS most accurately predicts compounds that are similar to compoxmds with known biodegradation mechanisms, for microbes under aerobic conditions and when the compounds are the sole source of energy, carbon, nitrogen or other essential elements for these microbes. Results in the OECD (Q)SAR Application Toolbox system are presented in Table 1. 

Willingale et al. investigated the biosynthetic incorporation of the known metabolite TR-2, isolated from Aspergillus fumigatuSy into verruculogen in cultures of Penicillium raistrickii [73a]. TR-2, a minor metabolite observed in cul-... 

Unknown metabolite observed by in vivo NMR spectroscopy (or other technique). 

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