Effect of some 4-alkyl-5-dimethylamino-1-phenyl-1-penten-3-one hydrochlorides and related compounds on respiration in mouse liver mitochondria.

5-Dimethylamino-1-phenyl-1-penten-3-one hydrochloride (1a) has high inhibiting properties in mitochondria isolated from mice liver. Substitution at the 4-methylene group of 1a by different alkyl substituents lead to compounds with wide variation in respiration-inhibiting properties. No correlations were found between either the Charton steric parameter (v), Taft inductive value (f*) or fragmental constant (f) of the substituents at position 4 of the Mannich bases with inhibition of respiration. However the biological results suggested two receptor sites were present in the mitochondria which may interact with the Mannich bases namely a common receptor for all compounds and in addition a narrow hydrophobic binding area which can accommodate a n-butyl or higher alkyl groups which are present in some of the compounds.