PHYTOECDYSTEROIDS IN THE GENUS AGAPANTHUS (ALLIACEAE)

Bioassay/RIA-based analysis of seeds of 15 species, subspecies and var ieties of Agapanthus revealed the presence of phytoecdysteroids in mos t of them. However, the concentrations varied markedly between samples . The accumulation of phytoecdysteroids was highest in a sample of A. campanulatus ssp. patens and a sample of A. inapertus ssp. hollandii ( c. 1.5 mg ecdysone equivalents per g seed, using the DBL-1 antiserum). Moderate levels were present in a sample of A. inapertus ssp. inapert us. Phytoecdysteroid levels were almost undetectable in samples of A. coddii, A. caulescens ssp. angustifolius, A. minor var. alba and A. pr aecox ssp. orientalis. RF-HPLC separation coupled with monitoring by R IA and bioassay revealed that the samples contain significantly differ ent ecdysteroid profiles. The major phytoecdysteroid in several of the extracts has been identified as 20-hydroxyecdysone on the basis of ch romatographic evidence. It is concluded that ecdysteroid levels and pr ofiles vary considerably in seeds of the genus Agapanthus, even betwee n seed samples of the same species. (C) 1997 Elsevier Science Ltd.