The biological activity of two symmetric amine derivatives of the cis-syn-cis triquinane system

N-benzyl-3,11-azatricyclo[6.3.0.0]undecane and N-octyl-3,11-azatricyclo[6.3.0.0]undecane, two triquinane compounds containing an endocyclic nitrogen atom and differing side-chains, were synthesized by thermal 2 + 2 cycloreversion from the symmetric cage compound pentacyclo[5.4.0.0.0.0]undecane-8,11-dione. The conformation of the cyclic system showed close similarity with the conformation of the hydrate of 4-methyltricyclo[6.3.0.0]undeca-3,11-dione. Both N-benzyl-3,11-azatricyclo[6.3.0.0]undecane and N-octyl-3,11-azatricyclo[6.3.0.0]undecane showed similar suppressant activity on the Ca2+ action potential of guinea-pig papillary muscle--the benzyl (aromatic) derivative fully suppressed the action potential (AP) whilst the aliphatic (octyl) derivative suppressed the AP to about 50% at the same dosages. Similarly, both these compounds (irreversibly) suppressed the chronotropy of spontaneously contracting guinea-pig atria by approximately 30% at concentrations of 1 x 10(-5) M or more.