TABLE 2.

Structure–Activity Relationships for the P2Y₁ Receptor

Modifications	Examples	Effects on potencya
Base modifications
2-Thioether	2-MeSATP	↑
	2-Hexylthio ATP	↑
8-Substitution	8-Br-ATP	↓ or no change
	8-(6-Aminohexylamino) ATP	↓
N6	N6-methyl ATP	No change
Ribose modifications
Deoxy	2′-Deoxy ATP	↓
	3′-Deoxy ATP	↓
	2′-,3′-Dideoxy ATP	↓
Other substitutions	3′-Amino, 3′-deoxy ATP	↑
	Adenosine 3′-phosphate 5′-phosphosulfate	↑, partial agonist
	3′-Benzylamino 3′-deoxy ATP	↓
Phosphate substitutions
Thiophosphate	ATPγS	↑
Methylene bridge	αβMeATP	↓
	βγMeATP	↓
Imino bridge	AppNHp	No change
Diphosphates
	ADP	↑ or similar potency
	ADPβS	↑
	2-Thioether diphosphates	↑
Monophosphates
	AMP	Inactive
	2-(5-Hexenylthio) AMP	↑

^aRelative to ATP.