Phytoecdysteroids in the genus Agapanthus (Alliaceae)

Bioassay/RIA-based analysis of seeds of 15 species, subspecies and varieties of Agapanthus revealed the presence of phytoecdysteroids in most 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. inapertus. Phytoecdysteroid levels were almost undetectable in samples of A. coddii, A. caulescens ssp. angustifolius, A. minor var. alba and A. praecox ssp. orientalis. RF-HPLC separation coupled with monitoring by RIA and bioassay revealed that the samples contain significantly different ecdysteroid profiles. The major phytoecdysteroid in several of the extracts has been identified as 20-hydroxyecdysone on the basis of chromatographic evidence. It is concluded that ecdysteroid levels and profiles vary considerably in seeds of the genus Agapanthus, even between seed samples of the same species. (C) 1997 Elsevier Science Ltd.