7 alpha-Methylnorethindrone enanthate 10 beta-hydroperoxide: isolation and characterization

Area of Science:

• Organic Chemistry
• Endocrinology
• Reproductive Biology

Background:

• 7 alpha-methylnorethindrone enanthate is a progestin with contraceptive properties.
• Allylic autoxidation can modify steroid structures, potentially altering biological activity.

Purpose of the Study:

• To isolate and characterize 10 beta-Hydroperoxy-7 alpha-methylnorethindrone 17-heptanoate, a novel oxidation product.
• To synthesize and evaluate the biological activity of this hydroperoxide and its derivatives.
• To compare the long-term fertility inhibition effects of the new compounds with the parent compound.

Main Methods:

• Isolation and characterization of the hydroperoxide (II) from 7 alpha-methylnorethindrone enanthate (I).
• Synthesis of hydroperoxide (II) via esterification, deketalization, and photochemical oxygenation of a precursor.
• Reduction of hydroperoxide (II) to the corresponding alcohol (VI) and acetylation to the acetoxyperoxide (VII).
• Subcutaneous injection of compounds (II), (VI), and (VII) into rats to assess fertility inhibition.

Main Results:

• 10 beta-Hydroperoxy-7 alpha-methylnorethindrone 17-heptanoate (II) was successfully synthesized and characterized.
• Derivatives, 10 beta-alcohol (VI) and 10 beta-acetoxyperoxide (VII), were also prepared.
• None of the tested compounds (II, VI, VII) demonstrated long-term inhibition of fertility in rats after a single injection.
• The parent compound (I) was significantly more effective in inhibiting fertility than norethindrone enanthate.

Conclusions:

• The novel hydroperoxide derivative and its related compounds lack the long-term fertility inhibitory effects of the parent progestin.
• Autoxidation products of 7 alpha-methylnorethindrone enanthate may have significantly reduced contraceptive efficacy.
• Further research is needed to understand the structure-activity relationship of these modified steroids.