Norethynodrel Metabolites
| Name | Structure | Notes |
|---|---|---|
| 17α-Ethinylestra-5(10)-ene-3β,17β-diol |
|
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| 17α-Ethinylestra-5(10)-ene-3α,17β-diol |
|
|
| 17α-Ethinyl-5β-estrane-3α,17β-diol |
|
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| 17α-Ethinyl-5α-estrane-3β,17β-diol |
|
|
| 3α-Hydroxynorethynodrel |
|
Formed by aldo-keto reductase isoforms AKR1C3, AKR1C4. |
| 3β-Hydroxynorethynodrel |
|
Formed from aldo-keto reductase isoforms AKR1C1, AKR1C2, and AKR1C3. |
| Norethindrone |
|
Norethindrone acetate, norethindrone enanthate, lynestrenol, and ethynodiol diacetate (and to a very small extent, norethynodrel) are prodrugs of norethindrone. Conversion of lynestrenol to ethynodiol to norethindrone facilitated by CYP2C9, CYP2C19, and CYP3A4. Conversion of norethynodrel to norethindrone is accomplished by either non-enzymatic or enzymatic ketosteroid isomerization. |