97478-05-2Relevant academic research and scientific papers
Quaternary salts of 4,3′ and 4,4′ bis-pyridinium monooximes. Part 2: Synthesis and biological activity
Srinivas Rao, Chennamaneni,Venkateswarlu, Vobalaboina,Achaiah, Garlapati
, p. 2134 - 2138 (2006)
In continuation of our investigations of unsymmetrical bisquaternary monooximes, we synthesized four new series of compounds bridged by hexyl, heptyl, octyl and nonyl groups. All eight monooximes viz., dibromides of 1-(4-hydroxyiminomethylpyridinium)6-(3/4-carbamoylpyridinium)hexane, 1-(4-hydroxyiminomethylpyridinium)-7-(3/4-carbamoylpyridinium)heptane, 1-(4-hydroxyiminomethylpyridinium)-8-(3/4-carbamoylpyridinium)octane, 1-(4-hydroxyiminomethylpyridinium)-9-(3/4-carbamoylpyridinium)nonane as well as the corresponding bis-oximes were synthesized and characterized by spectral data. Their ability to reactivate tetraethylpyrophosphate (TEPP) inhibited mouse total brain cholinesterase was investigated and compared with the conventional oxime 2-pyridinealdoxime chloride (2-PAM). Mouse brain homogenate was used as the source of acetylcholinesterase. Among all the compounds, tested the compound with the hexylene bridge (6b) and a 3-carbamoyl group on the second pyridine ring was found to be the most active acetylcholinesterase reactivator (72%) which is greater than that of 2-PAM (56%). However, the activity was reversed; as the chain length increased from a heptylene to a nonylene bridge, they potentiated the inhibitory effect of TEPP rather than reactivation. It is interesting to note that compound 6b with a carbamoyl group at the 3rd position of the pyridine ring showed dose dependent reactivation whereas the corresponding compound 6a with the carbamoyl group present at the 4th position of the pyridine ring showed reactivation at lower concentration (30 μM) and potentiation of TEPP inhibition at higher concentrations (100 and 300 μM).
NAD(P)+-NAD(P)H Models. 53. Proximity Effect of Intramolecular Heteroatom on Reaction Rate
Ohno, Atsuyoshi,Goto, Takehito,Kobayashi, Hisami,Oka, Shinzaburo
, p. 698 - 704 (1985)
NAD(P)H-model compounds that have a sulfur or oxygen substituent in the molecule have been synthesized and kinetics for the reduction of both substituted and unsubstituted α,α,α-trifluoroacetophenones with these model compounds are studied.Reduction with the heteroatom-containing model compounds proceeds at a slower rate than the reduction with a model without any heteroatom substituents.Furthermore, the dependency of the kinetic isotope effect on the electron-deficiency of the substrate differs.Kinetic parameters reveal tha the retardation caused by the heteroatom is due to the loss of entropy in the initial electron-transfer process.The enthalpic term favors the reduction with the heteroatom-containing model.
