ECDYSTEROID XYLOSIDES FROM LIMNANTHES DOUGLASII

Bioassay/RIA-guided phytochemical examination of seeds of members of t he genus Limnanthes demonstrates the presence of moderate to high leve ls of phytoecdysteroids. Limnanthes douglasii has afforded two novel e cdysteroid glyco sides: limnantheoside A [20-hydroxyecdysone-3-beta-D- xylopyranoside] and limnantheoside B [ponasterone A-3-beta-D-xylopyran oside], together with 20-hydroxyecdysone and ponasterone A. HPLC/RIA d ata support the additional presence of small amounts of ecdysone and a n analogous ecdysone glycoside. The levels of ecdysteroids in individu al seeds and plants of L. douglasii are very variable. The HPLC behavi our of ecdysteroid glycosides, including these two new xylosides, in b oth RP- and NP-systems using different mobile phases is also discussed . Copyright (C) 1997 Elsevier Science Ltd