Bioinorganic Chemistry and Applications

Research Article

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 1

Formation constants for complexes of [Pd(DEEN)(H₂O)₂ ]²⁺ with amino acids at 37

{}^{°}C

and 0.16 M ionic strength.


Ligand	ML $H^{a}$	$\log β^{b}$	Ligand	M L $H^{a}$	$\log β^{b}$

OH^-	1 0 $-$ 1	$-$ 5.11(0.01)	Glycine	0 1 1	9.20(0.02)
	1 0 $-$ 2	$-$ 14.80(0.02)		0 1 2	11.20(0.03)
	2 0 $-$ 2	$-$ 7.20(0.04)		1 1 0	10.33(0.02)
Alanine	0 1 1	9.27(0.01)	β-Phenylalanine	0 1 1	9.12(0.01)
	0 1 2	12.17(0.02)		0 1 2	11.01(0.03)
	1 1 0	10.16(0.02)		1 1 0	9.86(0.02)
γ-Aminobutyric acid	0 1 1	9.63(0.00)	β-Alanine	0 1 1	9.70(0.02)
	0 1 2	13.10(0.02)		0 1 2	13.20(0.03)
	1 1 0	7.61(0.02)		1 1 0	9.50(0.02)
Valine	0 1 1	9.01(0.01)	Proline	0 1 1	10.06(0.01)
	0 1 2	11.48(0.02)		0 1 2	11.81(0.05)
	1 1 0	9.90(0.03)		1 1 0	10.51(0.10)
Iso-Leucine	0 1 1	9.46(0.01)	Histamine	0 1 1	9.34(0.01)
	0 1 2	11.74(0.02)		0 1 2	15.20(0.02)
	1 1 0	10.40(0.02)		1 1 0	12.85(0.08)
Histidine	0 1 1	8.84(0.01)	Ethanolamine	0 1 1	9.16(0.01)
	0 1 2	14.74(0.02)		1 1 0	6.99(0.02)
	0 1 3	16.81(0.06)		1 2 0	12.00(0.04)
	1 1 0	13.37(0.01)		1 1 -1	2.01(0.04)
	1 1 1	16.32(0.03)			( ${pK}^{H}$ = 4.98)
Serine	0 1 1	8.59(0.01)	Threonine	0 1 1	8.79(0.01)
	0 1 2	10.95(0.02)		0 1 2	10.85(0.02)
	1 1 0	10.01(0.01)		1 1 0	9.98(0.07)
	1 1-1	2.04(0.02)		1 1-1	2.10(0.08)
		( ${pK}^{H}$ = 7.97)			( ${pK}^{H}$ = 7.88)
Ornithine	0 1 1	9.81(0.02)	Lysine	0 1 1	9.90(0.02)
	0 1 2	18.16(0.02)		0 1 2	18.80(0.03)
	0 1 3	20.01(0.03)		0 1 3	21.00(0.03)
	1 1 0	12.90(0.05)		1 1 0	10.12(0.05)
	1 1 1	20.10(0.04)		1 1 1	18.70(0.02)
Aspartic acid	0 1 1	9.31(0.02)	Glutamic acid	0 1 1	9.34(0.02)
	0 1 2	12.79(0.03)		0 1 2	13.15(0.03)
	0 1 3	14.50(0.03)		0 1 3	15.73(0.05)
	1 1 0	8.53(0.03)		1 1 0	8.70(0.03)
	1 1 1	11.92(0.04)		1 1 1	11.87(0.02)
S-methylcysteine methyl ester	0 1 1	8.51(0.02)	Methionine	0 1 1	8.76(0.02)
	0 1 2	10.40(0.02)		0 1 2	11.00(0.03)
	1 1 0	9.51(0.01)		1 1 0	9.32(0.04)
Hydroxyproline	0 1 1	9.20(0.01)	Methylamine	0 1 1	9.32(0.01)
	0 1 2	11.00(0.02)		1 1 0	7.11(0.06)
	1 1 0	9.91(0.03)		1 2 0	12.53(0.04)
Cysteine	0 1 1	10.00(0.01)
	0 1 2	18.21(0.02)
	0 1 3	19.62(0.02)
	1 1 0	14.11(0.03)
		18.20(0.04)

{}^{a}M

, L, and H are the stoichiometric coefficients corresponding to Pd(DEEN), amino acid, and

H^{+}

, respectively; the coefficient –1, refers to a proton loss.

{}^{b}\log β

of Pd(DEEN)-amino acids. Standard deviations are given in parentheses; sum of square of residuals are less than 5E-7,

{pK}_{}^{H} = \log β_{110} - \log β_{11 - 1} .