The occurrence and biological activity of ecdysterone (insect moulting hormone) was examined in a number of plant species. A simple method was developed for the semiquantitative analysis of ecdysterone in plant extracts. The procedure consists of repeated washing of an aqueous methanolic extract of the plant with petroleum ether, followed by gradient elution of the freeze-dried aqueous extract on a SepPak (CIS reverse-phase cartridge), and high-performance liquid chromatography. Crude extract was purified on Sephadex LH20 for spectral analysis. Twelve species of ferns, three species of gymnosperms, and five species of angiosperms were examined for the presence of ecdysterone. Ecdysterone was found in a number of plant species, the chemistry of which has not previously been examined with respect to phytoecdysteroids. These include four species of ferns (Aspidotis densa (Brackenr.) Lellinger., Cryptogramma crispa (L.) R.Br., Blechnum spicant (L.) Roth, Polypodium glycyrrhiza D.C. Eat); two species of gymnosperms {Taxus brevifolia Nutt., Taxus canadensis Marsh.); and two species of angiosperms (Trillium cernuum L, Trillium ovatum Pursh.). Applied ecdysterone had no effect in a cytokinin bioassay, but elicited a slight increase in elongation of mung bean epicotyls (GA₃ bioassay) and elongation of excised dwarf pea hypocotyl hooks (auxin bioassay). / Science, Faculty of / Botany, Department of / Graduate

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 88-101).