Binding constants (log K_s)^a,b and parameters^c calculated from the fluorescence titrations of 15a–c, 16a, 16c, 17a, 21a and 21b with double-stranded (ds-) polynucleotides at pH = 7.0 (buffer sodium cacodylate, I = 0.05 mol dm⁻³).

Compd	ctDNA		p(dAdT)2
	log Ks	I/I0c	log Ks	I/I0c
15a	6.5	3.4	5.5	7.2
15b	5.6	11.4	5.9	15.4
15c	6.2	7.6	6.0	9.5
16a	NDd	NDd	5.4	2.2
16c	6.4	63.1	5.9	71.5
17a	NDd	NDd	6.6	2.0
21a	NDd	NDd	5.3	4.9
21b	NDd	NDd	NDd	NDd

^aAccuracy of n ± 20%, consequently log K_s values vary in the same order of magnitude.

^bProcessing of titration data by means of the Scatchard equation⁶³ gave values of ratio n [bound compound]/[polynucleotide] from 0.1–0.4, for easier comparison all data were recalculated for fixed n = 0.2.; correlation coefficients were >0.99 for most of the calculated K_s.

^c I ₀ – starting fluorescence intensity of 15a–c, 16a, 16c, 17a, 21a and 21b; I – fluorescence intensity of 15a–c, 16a, 16c, 17a, 21a and 21b/polynucleotide complex calculated using the Scatchard equation.

^dNot determined; fluorescence changes of the studied compound with polynucleotides were too small/linear for accurate calculation of binding constants.