TABLE 1.

Summary of the compounds investigated in this study

All the ligands have an adenosine scaffold, with substitution on the ribose 4 position (R1), N6 (R2), and/or C2 (R3). Otsuka-3 is an exception, because it does not share this structural scaffold. The individual structures of each compound are shown in Supplemental Fig. 1. References for compound disclosure; 1, (Marumoto et al., 1974); 2, (Bridges et al., 1987); 3, (Åstrand et al., 2015); 4, (Sato et al., 2010). AZ proprietary compounds are marked # and their synthesis is described in Supplemental Figs. 1–6.

Compound number	Synonym	Ref.	R1	R2	R3
1aa	CV1808	1	H	H
2bb	R-PIA	2	CH2OH	CH(R-Me)CH2Ph	H
2cb		2	CH2OH	CH2CHPh2	H
3ab	NECA		CONHEt	H	H
3ac	CGS-21680		CONHEt	H
3ad		#	CONHEt	H
3cd	UK-432,097		CONHEt	CH2CHPh2
3ce		#	CONHEt	CH2CHPh2
3cf		#	CONHEt	CH2CHPh2
3ag		#	CONHEt	H
3cg		3	CONHEt	CH2CHPh2
3dg		#	CONHEt	CH2CH(CH3)2
3eg		#	CONHEt	CH(CH2CH3)2
3ah		#	CONHEt	H
3ch		3	CONHEt	CH2CHPh2
3dh		#	CONHEt	CH2CH(CH3)2
3eh		#	CONHEt	CH(CH2CH3)2
4	Otsuka-3	4	*