Novestrol, also known as estradiol valerate, is a synthetic estrogen used in hormone replacement therapy (HRT) and as part of contraceptive formulations. Its chemical structure contains several functional groups:

1. Phenol group (aromatic hydroxyl): This is part of the estradiol backbone. The phenol group has an -OH (hydroxyl) group attached to a benzene ring.
2. Hydroxy group (-OH): The hydroxyl group is located at the C3 position of the steroid ring structure, part of the estradiol structure.
3. Ether group (-O-): At the C17 position, an ester bond is formed, where the ester group (-COO-) is attached to valeric acid, giving it the ester functionality.
4. Carbonyl group (C=O): The ester part of the molecule includes a carbonyl group attached to the valeric acid side chain.

These functional groups work together to provide the biological activity associated with the hormone’s effects.