Equilibrium and Kinetic Investigations of the Interaction of Model Platinum(II) Complex with DNA Constituents in Reference to the Antitumour Activity: Complex-Formation Reactions of [Pd(N,N-diethylethylenediamine)(H₂O)₂]²⁺ with Ligands of Biological Significance and Displacement Reactions of DNA Constituents

Table 2

Formation constants for complexes of [Pd(DEEN)(H₂ O)₂]²⁺ with peptides, dibasic acids, and DNA units at 37${}_{}{}^{°}\mathbf{C}$ and 0.16 M ionic strength.

Ligand	M L ${\text{H}}^{\text{a}}$	$\log \hspace{0.17em}\hspace{0.17em}{\beta }^{\text{b}}$	Ligand	M L ${\text{H}}^{\text{a}}$	$\log \hspace{0.17em}\hspace{0.17em}{\beta }^{\text{b}}$
Glycinamide			Cyclobutane-1,1- dicarboxylic acid
	0 1 1	7.50(0.02)		0 1 1	5.37(0.01)
	1 1 0	7.81(0.02)		0 1 2	8.17(0.01)
	1 1-1	4.16(0.01)		1 1 0	6.11(0.02)
		(${\text{pK}}^{\text{H}}$= 3.65)		1 1 1	7.76(0.05)
Glycylglycine			Succinic acid
	0 1 1	7.77(0.01)		0 1 1	5.24(0.02)
	0 1 2	10.81(0.01)		0 1 2	9.17(0.03)
	1 1 0	7.71(0.01)		1 1 0	4.21(0.00)
	1 1-1	2.61(0.08)		1 1 1	9.16(0.01)
Aspargine			Malonic acid
	0 1 1	8.35(0.01)		0 1 1	5.01(0.02)
	0 1 2	10.51(0.03)		0 1 2	7.65(0.03)
	1 1 0	9.30(0.02)		1 1 0	5.68(0.02)
	1 1-1	$-$0.50(0.04)		1 1 1	8.15(0.06)
		(${\text{pK}}^{\text{H}}$= 9.80)
Glycylleucine			Adipic Acid
	0 1 1	7.91(0.01)		0 1 1	5.25(0.03)
	1 1 0	7.35(0.03)		0 1 2	9.14(0.04)
	1 1-1	1.98(0.08)		1 1 0	3.98(0.00)
		(${\text{pK}}^{\text{H}}$= 5.37)		1 1 1	8.26(0.00)
Glutamine			Oxalic acid
	0 1 1	8.77(0.01)		0 1 1	3.76(0.02)
	0 1 2	10.78(0.02)		0 1 2	5.37(0.03)
	1 1 0	9.40(0.02)		1 1 0	5.84(0.07)
	1 1-1	$-$1.40(0.05)		1 1 1	8.06(0.07)
		(${\text{pK}}^{\text{H}}$=10.80)
Inosine			Fumaric acid
	0 1 1	8.43(0.02)		0 1 1	4.27(0.04)
	1 1 0	7.38(0.03)		0 1 2	6.63(0.04)
	1 2 0	10.64(0.05)		1 1 0	4.23(0.04)
	1 1 1	11.89(0.05)		1 1 1	7.74(0.06)
Inosine-$5^{\prime }$-monophosphate			Cytidine-$5^{\prime }$-monophosphate
	0 1 1	8.83(0.02)		0 1 1	6.12(0.02)
	0 1 2	15.07(0.03)		0 1 2	10.42(0.03)
	1 1 0	8.18(0.03)		1 1 0	5.59(0.07)
	1 2 0	13.35(0.04)		1 2 0	8.37(0.09)
	1 1 1	13.93(0.04)		1 1 1	10.66(0.05)
Adenine			Uridine-$5^{\prime }$-monophosphate
	0 1 1	9.29(0.03)		0 1 1	9.23(0.01)
	0 1 2	13.32(0.04)		0 1 2	15.12(0.02)
	1 1 0	9.17(0.11)		1 1 0	9.14(0.01)
	1 2 0	13.77(0.02)		1 2 0	13.82(0.02)
	1 1 1	18.36(0.02)		1 1 1	15.15(0.04)
Cytosine			Uracil
	0 1 1	4.45(0.02)		0 1 1	8.98(0.01)
	1 1 0	5.68(0.03)		1 1 0	8.33(0.04)
	1 2 0	8.51(0.04)		1 2 0	13.70(0.08)
Guanosine			Guanosine-$5^{\prime }$-monophosphate
	0 1 1	8.91(0.01)		0 1 1	9.18(0.02)
	0 1 2	11.01(0.02)		0 1 2	15.12(0.03)
	1 1 0	10.18(0.06)		1 1 0	9.03(0.06)
	1 2 0	18.88(0.06)		1 2 0	13.44(0.19)
				1 1 1	15.06(0.01)
Adenosine			Thymidine
	0 1 1	3.40(0.01)		0 1 1	9.28(0.04)
	1 1 0	2.74(0.04)		1 1 0	8.05(0.08)
	1 2 0	5.15(0.00)		1 2 0	13.22(0.04)

${}_{}{}^a\text{M}$, L and H are the stoichiometric coefficients corresponding to Pd(DEEN), ligands,and ${\text{H}}^{+}$, respectively; the coefficient –1 refers to a proton loss. ${}_{}{}^{\text{b}}\log \hspace{0.17em}\hspace{0.17em}\beta$ of Pd(DEEN)- ligands. Standard deviations are given in parentheses; sum of square of residuals are less than $5e^{-7}$ , $\text{p}{\text{K}}^{\text{H}}=\log \hspace{0.17em}\hspace{0.17em}\hspace{0.17em}{\beta }_{110}-\log \hspace{0.17em}\hspace{0.17em}\hspace{0.17em}{\beta }_{11\text{-}1}.$