Template:Affinities and estrogenic potencies of estrogen esters and ethers at the estrogen receptors

Affinities and estrogenic potencies of estrogen esters and ethers at the estrogen receptors
EstrogenOther namesRBATooltip Relative binding affinity (%)aREP (%)b
ERERαERβ
EstradiolE2100100100
Estradiol 3-sulfateE2S; E2-3S?0.020.04
Estradiol 3-glucuronideE2-3G?0.020.09
Estradiol 17β-glucuronideE2-17G?0.0020.0002
Estradiol benzoateEB; Estradiol 3-benzoate101.10.52
Estradiol 17β-acetateE2-17A31–4524?
Estradiol diacetateEDA; Estradiol 3,17β-diacetate?0.79?
Estradiol propionateEP; Estradiol 17β-propionate19–262.6?
Estradiol valerateEV; Estradiol 17β-valerate2–110.04–21?
Estradiol cypionateEC; Estradiol 17β-cypionate?c4.0?
Estradiol palmitateEstradiol 17β-palmitate0??
Estradiol stearateEstradiol 17β-stearate0??
EstroneE1; 17-Ketoestradiol115.3–3814
Estrone sulfateE1S; Estrone 3-sulfate20.0040.002
Estrone glucuronideE1G; Estrone 3-glucuronide?<0.0010.0006
EthinylestradiolEE; 17α-Ethynylestradiol10017–150129
MestranolEE 3-methyl ether11.3–8.20.16
QuinestrolEE 3-cyclopentyl ether?0.37?
Footnotes: a = Relative binding affinities (RBAs) were determined via in-vitro displacement of labeled estradiol from estrogen receptors (ERs) generally of rodent uterine cytosol. Estrogen esters are variably hydrolyzed into estrogens in these systems (shorter ester chain length -> greater rate of hydrolysis) and the ER RBAs of the esters decrease strongly when hydrolysis is prevented.[1][2] b = Relative estrogenic potencies (REPs) were calculated from half-maximal effective concentrations (EC50) that were determined via in-vitro β‐galactosidase (β-gal) and green fluorescent protein (GFP) production assays in yeast expressing human ERα and human ERβ. Both mammalian cells and yeast have the capacity to hydrolyze estrogen esters.[3] c = The affinities of estradiol cypionate for the ERs are similar to those of estradiol valerate and estradiol benzoate (figure).[4] Sources: Affinities: [1][2][5][6][7] Estrogenic potencies: [8][9][10][11] Additional: [4][3][12]