Interaction of chiral bis-distamycin derivatives with DNAs: electronic circular dichroism study

• Published in: Tetrahedron: asymmetry 2006-04, Vol.17 (7), p.1049-1055
• Main Authors: Palivec, Lukáš, Valík, Martin, Král, Vladimír, Urbanová, Marie
• Format: Article
• Language: English
• ISSN: 0957-4166; 1362-511X
• DOI: 10.1016/j.tetasy.2006.04.001

(4 R,9 R)- and (4 S,9 S)-enantiomers of bis-distamycine derivatives linked by Trögers base scaffold show mirror opposite ECD spectra. After addition of DNA the new diastereomeric complexes providing different asymmetrical ECD are formed. The new diastereomeric complexes of two oligo- N-methylpyrrole peptides, linked by a methano[1,5]-diazocin scaffold with DNA, were prepared. The specificity of the binding modes of (4 S,9 S)- and (4 R,9 R)-bis-distamycins derivative with ct-DNA explains the observed optical activity of the racemic mixture of distamycin if DNA is present. The bis-distamycin derivative possesses a clear sequence selectivity for A-T rich sequences of DNA, although a nonspecific binding mode with low affinity was also seen for G-C rich sequences. The reversibility of ECD spectra at 5 °C after heating to 90 °C was established.