Synthesis and biological activity of three new 5α-hydroxy spirostanic brassinosteroid analogues

Abstract

Three new spirostanic brassinosteroid analogues have been synthesized for the first time from diosgenin: (25R)-2α,3α-epoxy-5α-hydroxyspirostan-6-one (3), (25R)-2β,3α,5α-trihydroxyspirostan-6-one (5) and (25R)-2β-methoxy-3α,5α-dihydroxyspirostan-6-one (6). In the radish hypocotyl elongation and cotyledon expansion bioassay compound 3 showed plant growth promoting activity whereas 6 was shown to be phytotoxic.