Table 3. Inhibitory activities and/or binding dissociation constants of 5-iodotubercidin against the kinases and the number of electrostatic interactions.

Kinase	IC50 (µM)	K d † (µM)	4-Aminopyrrolopyrimidine	Ribose	I atom
CK2a1	10.9†		3 hydrogen bonds	None	1 hydrogen bond
CK1g2	0.4†		3 hydrogen bonds	3 hydrogen bonds	1 hydrogen bond
ERK1	1.2‡		3 hydrogen bonds	3 hydrogen bonds	1 hydrogen bond
ERK2	0.9‡		3 hydrogen bonds	3 hydrogen bonds	1 hydrogen bond
Haspin	0.009§	0.006¶	3 hydrogen bonds	3 hydrogen bonds	1 hydrogen bond, 1 halogen–π interaction
CLK1		0.007¶	3 hydrogen bonds	3 hydrogen bonds	1 hydrogen bond, 1 halogen–π interaction

^†Massillon et al. (1994 ▸).

^‡Kinoshita et al. (2008 ▸).

^§Balzano et al. (2011 ▸).

^¶Heroven et al. (2018 ▸).