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Pyrrole is an extremely weak base for an amine, with a conjugate acid pK a of −3.8. The most thermodynamically stable pyrrolium cation (C 4 H 6 N +) is formed by protonation at the 2 position. Substitution of pyrrole with alkyl substituents provides a more basic molecule—for example, tetramethylpyrrole has a conjugate acid pK a of +3.7.
PAs are metabolized in the liver through CYP450-mediated pathways. This metabolic process leads to the formation of reactive intermediates, such as pyrrolic metabolites, which can covalently bind to proteins in the liver, forming pyrrole-protein adducts. These adducts impair the function of essential liver proteins, leading to hepatotoxicity.
Pyrrolysine-containing proteins are known to include monomethylamine methyltransferase (mtmB), dimethylamine methyltransferase (mtbB), and trimethylamine methyltransferase (mttB). Homologs of pylS and pylT have also been found in an Antarctic archaeon, Methanosarcina barkeri and a Gram-positive bacterium , Desulfitobacterium hafniense .
Nicotine is a molecule containing a pyrrolidine ring attached to a ring of pyridine (other heterocyclic amine). Nicotine belongs to a group of compounds known as alkaloids, which are naturally occurring organic compounds with nitrogen in them. Pyrrole is another compound made up of molecules with a five-membered heterocyclic ring. These ...
The pyrrolidine ring structure is present in numerous natural alkaloids i.a. nicotine and hygrine. It is found in many drugs such as procyclidine and bepridil. It also forms the basis for the racetam compounds (e.g. piracetam, aniracetam). The amino acids proline and hydroxyproline are, in a structural sense, derivatives of pyrrolidine.
Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. The fusion of two benzene rings gives rise to a third ...
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Alkaloids with partial pyrrolidine structure are usually sub-categorized based on their occurrence and biogenetic origin. Hygrin and cuscohygrin were isolated from the leaves of the coca shrub, [2] while (-)-codonopsinine was isolated from the woodland vine tiger bell.