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

Abstract

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.

Steroids: reactions and partial synthesis

“…The role of C-2 in the brassinosteroid receptor interaction has been explored. 124 The biological activity of 6a-carbabrassinolide 52, which was prepared by the ring expansion of a 6-ketone with trimethylsilyldiazomethane, has been assessed. 125 [26-2 H 3 ]-Brassinosteroids have been prepared.…”