Structure-toxicity relationships for aminoalkanols: A comparison with alkanols and alkanamines

The relative toxicity (log IGC(50)(-1)) of 49 selected aliphatic amines and aminoalkanols was evaluated in the static Tetrahymena pyriformis populatio n growth impairment assay. Excess toxicity, indicated by potency greater th an predicted for non-polar narcotic alkanols, was associated with both clas ses of test chemicals. Moreover, the aminoalkanols were found to be more to xic than the corresponding alkanamines. A high quality 1-octanol/water part ition coefficient (log K-ow) dependent quantitative structure-activity rela tionship (QSAR), log IGC(50)(-1) = 0.78 (log K-ow)-1.42; r(2) = 0.934, was developed for alkanamines. This QSAR represented the amine narcosis mechani sm of toxic action. No quality QSAR was developed for the aminoalkanols. Ho wever, several structure-toxicity features were observed for this class of chemicals. Two-amino-l-hydroxy derivatives being more toxic than the corres ponding derivatives, where the amino and hydroxy moieties were separated by methylene groups. Hydrocarbon branching next to the amino moiety resulted in decreased toxicity. Aminoalkanol alters lipid metabolism in T. pyriformi s.