Enantioselectivity in the Interaction of Calf Thymus DNA with Acridine Derivatives Having an Amino Ester or Amino Alcohol Substituent

Unless a bulky aromatic side chain is involved, acridine derivatives 1 and 2 having an amino ester or amino alcohol substituent bind to calf thymus DNA via intercalation. The binding constants evaluated by the Scatchard analysis of the hypochromicity data indicate that (1) the substituents introduced are rather inhibitory of the binding and (2) l-enantiomers are preferred than the d-enantiomers by a factor of KL/KD = 1.1–1.4, except for the case of aspartic and glutamic esters where the optical selectivity is very low or even reversed. The present enantioselectivity is discussed in terms of a local C2 chirality of the intercalation site, steric effects of the amino ester or amino alcohol substituents, and a possible conformation-controlling effect of the CO2CH3 or CH2OH group.