Based on the GC-MS direct comparison with synthetic candidates, a new brassinolide-related steroidal lactone detected in the pollen and anthers of Japanese cedar (Cryptomeria japonica) was identified as (22R,24S)-2α, 3α, 22-trihydroxy-24-methyl-B-homo-7-oxa-5α-cholestan-6,23-dione, being the first brassinolide catabolite with 23-oxo function in the side chain and termed as cryptolide, and furthermore, the first occurrence of 28-homobrassinolide in plants was also demonstrated by this work.
