No abstract

A series of substituted 3H-1,2,3,5-oxathiadiazole-2-oxides (6) was prepared and tested for antihyperglycemic activity in the db/db mouse, a model for type 2 (non-insulin dependent) diabetes mellitus. The oxathiadiazoles 6 were synthesized by a two-step sequence: treatment of a substituted acetonitrile (4) with hydroxylamine to give the corresponding amidoxime (5) and cyclization with thionyl chloride to yield 6. In terms of potency, the 2-naphthalenylmethyl group (as in compound 3) was found to be the optimal substituent in this series. Compound 3 was approximately 5 times more potent than ciglitazone (1).

The synthesis and Class III antiarrhythmic activity of a series of 4-[(methylsulfonyl)amino]benzamides and sulfonamides are described. Selected compounds show a potent Class III activity and are devoid of effects on conduction both in vitro (dog Purkinje fibers) and in vivo (anesthetized dogs). Compounds having a 2-aminobenzimidazole group were found to be the most potent, and one compound having this heterocycle (5, WAY-123,398) was selected for further characterization. Compound 5 was shown to have good oral bioavailability and a favorable hemodynamic profile to produce a 3-fold increase of the ventricular fibrillation threshold and to terminate ventricular fibrillation, restoring sinus rhythm in anesthetized dogs. Voltage-clamp studies in isolated myocytes show that 5 is a potent and specific blocker of the delayed rectifier potassium current (IK) at concentrations that cause significant prolongation of action potential duration.

An antifungal principle myriocin was isolated from Myriococcum albomyces. The structure of this compound was elucidated using spectral and analytical data of its derivatives. The chemical reactions utilized in degradation work involved ozonolysis and periodic acid, oxidation. Structure 1 was assigned to myriocin based on the available chemical data. The chemical and the physical evidence led to the stereochemical expression 28.

The synthesis and biological evaluation of a series of novel 1-(aryloxy)-2-propanolamines and several related deshydroxy analogues are described. Compounds 4-29 were prepared and investigated for their class III electrophysiological activity in isolated canine Purkinje fibers and in anesthetized open-chest dogs. None of these compounds showed any class I activity. On the basis of the in vitro data, structure-activity relationships for the series are discussed. Two compounds, N-[4-[2-hydroxy-3-[methyl(2-quinolinylmethyl)amino] propoxy]phenyl]methanesulfonamide (12,WAY-123,223) and N-[2-[[methyl[3-[4-[(methylsulfonyl)amino]phenoxy]propyl] amino]methyl]-6-quinolinyl]-methanesulfonamide (24, WAY-125,971) were identified and characterized as potent and specific class III antiarrhythmic agents in vitro and in vivo. Compound 12 was found to be orally bioavailable, to produce large increases of ventricular fibrillation threshold (VFT), and, in some instances, to restore sinus rhythm from ventricular fibrillation in anesthetized open-chest dogs at a dose of 5 mg/kg (iv). The enantiomers of 12 (i.e., 13 and 14) were synthesized and were found to exhibit similar electrophysiological effects in the Purkinje fiber screen. Compound 24, a propylamine analogue with potency and efficacy comparable to those of UK-68798 (2) and E-4031 (3), was studied in voltage-clamp experiments (isolated cat myocytes) and was found to be a potent and specific blocker of the delayed rectifier potassium current (IK).