3-Dehydroteasterone, a 3,6-Diketobrassinosteroid as a Possible Biosynthetic Intermediate of Brassinolide from Wheat Grain

Abstract

A new brassinosteroid, (22R,23R,24S)-22,23-dihydroxy-24-methyl-5α-cholestan-3,6-dione (6) which is termed 3-dehydroteasterone, as well as castasterone (2), typhasterol (3), teasterone (4), and 6-deoxocastasterone (5) were identified from wheat (Triticum aestivum L.) grains by GC-MS. In addition, the presence of a castasterone epimer and a pair of 6-deoxocastasterone epimers was indicated, although their structures remain undetermined. 3-Dehydroteasterone is considered to be an intermediate in the conversion of teasterone to typhasterol.