Metabolite oxygenated

For a compound which contains dimethylpyperidine substructure (shown on the left), isomeric metabolites oxygenated at positions 1, 2, and 3 can be easily distinguished without NMR by conducting a single LC-APCI-MS experiment on the TSQ Quantum. Loss of 16 is observed for oxidation at position 1 (/V-oxide), loss of 18 (H20) for aliphatic hydroxylation at position 3, while for aromatic hydroxylation at position 2 no significant in-source fragmentation is observed. 

Keywords. Plant cell culture, Secondary metabolites, Oxygen, Carbon dioxide, Ethylene, Methyl jasmonate, Artemisinin, Paclitaxel, Engineering parameters... 

FIGURE 5.13 Two basic types of biological transport are (a) transport within or between different cells or tissues and (b) transport into or out of cells. Proteins function in both of these phenomena. For example, the protein hemoglobin transports oxygen from the lungs to actively respiring tissues. Transport proteins of the other type are localized in cellular membranes, where they function in the uptake of specific nutrients, such as glucose (shown here) and amino acids, or the export of metabolites and waste products. 

All the nitrogen atoms of M were thus accounted for, together with the provisional placement of two of the oxygen atoms. An acetylation experiment, under mild conditions, showed that the metabolite has five to six acetylable groups, at least four of which would be hydroxyl. This observation led to periodic acid oxidations which... 

Nifurtimox, a nitrofuran, is a prodrug that is reduced to unstable nitroanion radicals, which react to produce highly toxic oxygen metabolites, such as superoxide and peroxide. Oxidative stress subsequently kills the parasite, which seems to lack effective enzymatic pathways to detoxify oxygen metabolites. 

Any of the collection of oxygenated metabolites of arachidonic acid that are the product of cyclooxygenase, cytochrome P450, or lipoxygenase pathways. 

Other useful sensors rely on the coupling of microorganisms and electrochemical transducers. Changes in the respiration activity of the microorganism, induced by the target analyte, result in decreased surface concentration of electroactive metabolites (e.g., oxygen), which can be detected by the transducer. 

The MS-MS data from metabolite 5 shows a base peak at m/z 437, at an increase of 16 Da over the parent drug, but, in common with Indinavir, ions at m/z 364 and 465. Of most significance is the ion at m/z 465 which indicates that the extra oxygen atom is associated with the indan ring structure. 

There are many similarities between the MS-MS spectra of the (M + H)" " ions of metabolites 2 and 3, with the molecnlar weight of the latter being 16 Da greater than the former. Ions occnr in both spectra at m/z 374 and 273, thns snggesting that this additional oxygen atom has been incorporated into the indan-ring part of the molecnle. 

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