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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.
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 ...
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.
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.
A number of domain organizations of PylRS is known: pylS itself consists of an N-terminal tRNA-binding domain and a C-terminal synthase domain, but other organizations consist of two domains in separate proteins or a protein made up of a lone C-terminal domain. The CTD probably originated from PheRS.
In brewing, proteins rich in proline combine with polyphenols to produce haze (turbidity). [25] L-Proline is an osmoprotectant and therefore is used in many pharmaceutical and biotechnological applications. The growth medium used in plant tissue culture may be supplemented with proline. This can increase growth, perhaps because it helps the ...
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Catuabines, found in catuaba, an infusion or dry extract made from Erythroxylum vaccinifolium; Scopine; Synthetic analogs of tropane alkaloids also exist, such as the phenyltropanes. They are not considered to be alkaloids per definition.