Collect. Czech. Chem. Commun. 2002, 67, 19-29

A Brassinosteroid Derivative Useful to Provide More Information About the Importance of the C2 Group in the Brassinosteroid-Receptor Interaction

Carme Brosa*, Marc Amorós, Esther Vázquez and Maria Piqué

Institut Químic de Sarrià, CETS, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain


Synthesis and biological activity evaluation in the rice lamina inclination test of (22R,23R)-22,23-dihydroxy-5α-stigmasta-2,6-dione (6) and its (22S,23S)-diastereoisomer 7 is described. The activity of such compounds is discussed in terms of their ability to form hydrogen bonds by means of GRID maps. The activity elicited by 6 reinforces our idea that an oxygenated function at C3 in a brassinosteroid is more important for biological activity than that at C2. The results also suggest that the 2α-OH of brassinosteroids could act as an acceptor in the putative hydrogen bonding interactions in the brassinosteroid-receptor complex.

Keywords: Steroids; Brassinosteroids; Plant growth regulators; Structure-activity relationship; Phytohormones; Rice lamina inclination test; GRID map; H-bonds.

References: 9 live references.