186970-30-9Relevant academic research and scientific papers
Monoamine oxidase inhibition by C4-substituted phthalonitriles
Manley-King, Clarina I.,Bergh, Jacobus J.,Petzer, Jacobus P.
experimental part, p. 114 - 124 (2012/03/27)
It was recently reported that a series of C5-substituted phthalimides are remarkably potent reversible inhibitors of recombinant human monoamine oxidase (MAO) B. Modeling studies suggested that the phthalimide ring forms numerous polar interactions with the polar region of the MAO-B substrate cavity while the C5 side chain extends to, and interacts via Van der Waals interactions with the hydrophobic regions of the enzyme entrance cavity. Interactions with both cavities appear to be requirements for high affinity binding. In the present study we have examined an analogs series of C4-substituted phthalonitriles as potential human MAO inhibitors. The phthalonitriles were found to be highly potent reversible MAO-B inhibitors with most analogs exhibiting IC50 values in the low nM range. The phthalonitriles also interacted with human MAO-A, although with lower binding affinities compared to MAO-B. Modeling studies suggest that the high binding affinities of the phthalonitriles to MAO-B may depend, at least in part, on the formation of polar interactions between the nitrile functional groups and the enzyme substrate cavity. Examination of a homologs series of benzonitriles established that the phthalonitrile moiety is more optimal for MAO-B inhibition than the corresponding benzonitrile moiety, and that C3-substituted benzonitriles are better MAO-B inhibitors than C4-substituted benzonitriles. Since elimination of the nitrile functional group yielded compounds with only moderate MAO-B inhibition potencies, it may be concluded that this functional group is privileged for MAO-B inhibition.
1-Aryl-2-pyridyl-3,4-dihydronaphthalenes: Photofluorogenic ligands for the estrogen receptor
Scribner, Andrew W.,Haroutounian, Serkos A.,Carlson, Kathryn E.,Katzenellenbogen, John A.
, p. 1043 - 1057 (2007/10/03)
Three 1,2-substituted-3,4-dihydronaphthalenes that are pyridine analogs of the antiestrogen desmethylnafoxidine were prepared and evaluated as fluorescent ligands for the estrogen receptor. These compounds represent a class of fluorescent probes that we term 'photofluorogenic', denoting their ability to exist initially as a high affinity though weakly fluorescent stilbazole form which can be photocyclized-oxidized to a highly fluorescent though low affinity azaphenanthrenoid form. These probes also contain an aziridine function that provides a means for their permanent, covalent attachment to the receptor. The three dihydronaphthalene systems were prepared by efficient routes from α-(2-, 3-, and 4-pyridyl)acetophenone precursors. They demonstrate high apparent affinity for the estrogen receptor and show time-dependent irreversible inactivation, consistent with their covalent attachment to the receptor via the aziridine function. Each system is converted into an azaphenanthrene by photocyclization-oxidation of the cis-stilbazole unit. The absorbance and fluorescence emission spectra of the dihydronaphthalene precursors and azaphenanthrene products have been characterized, and they display marked sensitivity to both solvent polarity and pH. The azaphenanthrenoids derived from the 2- and 4-pyridyl isomers exhibit intense emission at wavelengths that exceed 500 nm under certain conditions and appear to be well suited as fluorescent probes for the estrogen receptor.
