Table 1.

The structure and function of GPER ligands.

Compound	Structure	Agonist/ Antagonist	Affinity/Efficacy Kd/IC50/EC50	Reference(s)
Endogenous Ligand
Estrogen
Estrone (E1)		Unknown	>>10 μM	[17]
Estradiol (E2)
17β-Estradiol		Agonist	3–6 nM	[17,18]
17α-Estradiol		Unknown	>10 μM	[17]
2-Methoxy-E2		Agonist	10 nM	[143]
2-Hydroxy-E2		Antagonist	0.1–1 μM	[144]
Estriol (E3)		Antagonist	>1 μM	[17,54]
Aldosterone		Agonist	None detected	[95,104,145]
Synthetic Ligands
G1		Agonist	7–11 nM	[111,112]
G15		Antagonist	20 nM	[112,119]
G36		Antagonist	~ 20 nM	[113]
GPER-L1		Agonist	100 nM	[120]
GPER-L2		Agonist	100 nM	[120]
Bisphenol A		Agonist	0.6 μM	[121,122,123,124]
Nonylphenol		Agonist	0.8 μM	[124,125,126]
Atrazine		Agonist	>10 μM	[124,127,128]
Kepone		Agonist	1.4 μM	[124]
Methoxychlor		Unknown	~10 μM	[124]
p,p′-DDT		Unknown	2.8 μM	[124]
o,p′-DDT		Agonist	7.1 μM	[17,124]
p,p′-DDE		Unknown	~10 μM	[124]
2,2′5′-PCB-4-OH		Unknown	3.8 μM	[124]
Phytoestrogens
Genistein		Agonist	133 nM	[124,129,130,131]
Daidzein		Agonist	<1 nM	[132]
Equol		Agonist	100 nM	[133]
Oleuropein		Agonist	200 nM	[134]
Hydroxytyrosol		Agonist	100 nM	[133]
Resveratrol		Agonist	300 nM	[135,136,137]
Quercetin		Agonist	1 μM	[136,138]
Tectoridin		Agonist	10 μM	[139]
Apigenin		Agonist	20–50 μM	[136,142]
Zearalenone		Unknown	0.8 μM	[124,140,141]