13803-16-2Relevant academic research and scientific papers
Synthetic inhibitors of cytochrome P-450 2A6: Inhibitory activity, difference spectra, mechanism of inhibition, and protein cocrystallization
Yano, Jason K.,Denton, Travis T.,Cerny, Matthew A.,Zhang, Xiaodong,Johnson, Eric F.,Cashman, John R.
, p. 6987 - 7001 (2006)
A series of 3-heteroaromatic analogues of nicotine were synthesized to delineate structural and mechanistic requirements for selectively inhibiting human cytochrome P450 (CYP) 2A6. Thiophene, substituted thiophene, furan, substituted furan, acetylene, imidazole, substituted imidazole, thiazole, pyrazole, substituted pyrazole, and aliphatic and isoxazol moieties were used to replace the N-methylpyrrolidine ring of nicotine. A number of potent inhibitors were identified, and several exhibited high selectivity for CYP2A6 relative to CYP2E1, -3A4, -2B6, -2C9, -2C19, and -2D6. The majority of these inhibitors elicited type II difference spectra indicating the formation of a coordinate covalent bond to the heme iron. The majority of inhibitors were reversible inhibitors although several mechanism-based inactivators were identified. Most of the inhibitors were also relatively metabolically stable. X-ray crystal structures of CYP2A6 cocrystallized with three furan analogues bearing methanamino side chains indicated that the amine side chain coordinated to the heme iron. The pyridyl moiety was positioned to accept a hydrogen bond from Asn297, and all three inhibitors exhibited orthogonal aromatic-aromatic interactions with protein side chains. For comparison, the cocrystal structure of 4,4′-dipyridyl disulfide was also obtained and showed that the pyridine moiety could assume a different orientation than that observed for the 3-heteroaromatic pyridines examined. For the 3-heteroromatic pyridines, N-methyl and N,N-dimethyl amino groups increased the apparent Ki and distorted helix I of the protein. Substitution of a phenyl ring for the pyridyl ring also increased the apparent Ki, which is likely to reflect the loss of the hydrogen bonding interaction with Asn297. In contrast, inhibitory potency for other P450s was increased, and the selectivity of the phenyl analogues for CYP2A6 was decreased relative to the pyridyl compounds. The results suggest that inhibitors that compliment the active site features of CYP2A6 can exhibit significant selectivity for CYP2A6 relative to other human liver drug-metabolizing P450s.
PYRIDAZINE DERIVATIVES FOR INHIBITING BETA AMYLOID PEPTIDE PRODUCTION
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Page/Page column 30, (2009/05/28)
The present invention relates to novel compounds that inhibit the production of β- amyloid peptide (1-42), processes for their preparation, to compositions containing them and to their use in the treatment of diseases characterised by elevated β-amyloid levels or β-amyloid deposits, particularly Alzheimer's disease.
SYNTHETIC COMPOUNDS AND DERIVATIVES AS MODULATORS OF SMOKING OR NICOTINE INGESTION AND LUNG CANCER
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Page/Page column 59-60, (2010/02/12)
Disclosed are nicotine-related compounds that selectively inhibit cytochrome P-450 2A6 (CYP2A6), selectively inhibit cytochrome P-450 2A13 (CYP2A13), and/or selectively modulate a nicotinic acetylcholine receptor (nAChR). Also disclosed are pharmaceutical compositions comprising a compound of the invention, as well as methods of using the pharmaceutical compositions for treating or preventing a disease or disorder associated with nicotine-ingestion, or a disease or disorder amenable to treatment by selective modulation of nAChRs.
One-step synthesis of 5-acylisothiazoles from furans
Guillard,Lamazzi,Meth-Cohn,Rees,White,Williams
, p. 1304 - 1313 (2007/10/03)
Premixed ethyl carbamate, thionyl chloride and pyridine (which generate thiazyl chloride, N≡SCl) in boiling benzene or toluene convert 2,5- and 2,3,5-substituted furans into 5-acylisothiazoles regiospecifically. The reactions are much faster and generally higher yielding in boiling chlorobenzene with more thionyl chloride and with pyridine or isoquinoline as base. Under the more vigorous conditions, even fully substituted 3-bromofurans give isothiazoles, with the displacement of bromine. Deactivated furans, with electron-withdrawing groups such as ester, cyano, benzoyl and phenylsulfonyl in the α-position, react under the more vigorous conditions to give 5-acylisothiazoles with the electronegative group in the 3-position. The 'activated' 2-methyl-5-phenyl- and 5-phenyl-2-phenylthio-furans react analogously, with the more electron-releasing group becoming part of the 5-acyl substituent, exclusively or predominantly. These results are explained by initial electrophilic attack of the furan ring to give a β-thiazyl derivative which spontaneously ring-opens and closes to the isothiazole. The X-ray structures of five of the differently substituted isothiazole compounds are reported. All have very similar patterns of bonding within their isothiazole rings that appear to be independent of the electron-withdrawing or -donating nature of the substituents. Three of the compounds (8a, 8g and 13) have loosely linked chain structures in the solid state, adjacent molecules being connected by combinations of hydrogen bonding and π-π stacking interactions.
