Mimicking natural phytohormones. 26-Hydroxycholestan-22-one derivatives as plant growth promoters

- 26-Hydroxycholestan-22-one derivatives were synthesized from the steroidal sapogenin diosgenin.
- The new cholestane derivatives act as phytohormones.
- Plant growth promotion was measured in Mexican rice cultivars.
- All the compounds show excellent activity compared to homobrassinolide.

26-Hydroxycholestan-22-one derivatives with oxygenated functions in the rings A and/or B were successfully synthesized from diosgenin. After the modifications of rings A and B, the spiroketal side chain was selectively opened through a Lewis acid mediated acetolysis to afford the cholestane derivatives. These compounds incorporate pharmacophores, which mimic the activity of natural phytohormones and show high growth promoting activity in Mexican rice cultivars using the rice lamina inclination test.

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