Identification of Brassinolide, Castasterone, Typhasterol, and Teasterone from the Pollen of Lilium elegans

Endogenous brassinosteroids in the pollen of Lilium elegans were investigated. Four biogenetically-related brassinosteroids, i.e., teasterone (4), typhasterol (3), castasterone (2), and brassinolide (1), were identified by GC-MS or GC-SIM, suggesting the presence of the biosynthetic pathway, teasterone (4)→typhasterol (3)→castasterone (2)→brassinolide (1) in the pollen.