Selective inhibitors of monoamine oxidase (MAO). 5. 1-Substituted phenoxathiin inhibitors containing no nitrogen that inhibit MAO A by binding it to a hydrophobic site.

It is believed that a monoamine oxidase (MAO) inhibitor specific for MAO A, which is reversibly bound to this enzyme and displaceable by tyramine, will be an antidepressant which will not cause a rise in blood pressure when tyramine-containing foods are ingested. Some linear tricyclic compounds with a larger and a smaller group forming the central ring and with a lipophilic group ortho to the larger group (here mostly the SO2 function of phenoxathiin 10,10-dioxide) are reported to have the sought properties. Potency appears to require short length and relatively small cross section for the substituent.

Selective inhibitors of monoamine oxidase. 4. SAR of tricyclic N-methylcarboxamides and congeners binding at the tricyclics' hydrophilic binding site.

Linear [6.6.6] tricyclic moieties whose center ring is made of two atoms of differing size (here primarily thioxanth-9-ones and phenoxathiins) monosubstituted meta to the sulfur by C(O)NHMe include potent and selective inhibitors of monoamine oxidase A.

Selective inhibitors of monoamine oxidase. 3. Structure-activity relationship of tricyclics bearing imidazoline, oxadiazole, or tetrazole groups.

Inhibition of monoamine oxidase A (MAO A) is believed to cause antidepressant and possibly antianxiety effects. The previous paper had developed structure-activity relationships (SAR) for in vitro MAO A inhibition by tricyclic N-arylamides. It is shown in this paper that the same in vitro SAR can be carried over to tricyclics whose potentially toxic amide function is replaced by an appropriately substituted imidazoline, a 1,2,4- or 1,3,4-oxadiazole, or an alkylated tetrazole moiety.

Selective inhibitors of monoamine oxidase. 2. Arylamide SAR.

Monoamine oxidase (MAO) exists in two forms distinguishable by substrate specificity. Inhibition of MAO A is believed to be responsible for the antidepressant activity of MAO inhibitors. A group of N-arylacetamides are highly specific inhibitors of MAO A, some with IC50 values in the 10-100 nM range.