Ecdysones and synthetic analogs: Molting hormone activity and inhibitive effects on insect growth, metamorphosis and reproduction.

Five ecdysones and 19 ecdysone analogs were assessed for molting hormone activity in the house fly assay. When these 5B-steroids were further tested in the house fly, the confused flour beetle, the yellow fever mosquito, and the German cockroach, many of the compounds inhibited growth, development and/or reproduction. The relationship of structure to both the molting hormone and inhibitive activity of these compounds is discussed. In previous studies (1, 2), we showed that a synthetic analog of the insect steroid mclting hormones (gcdysones), when ingested, inhibited growth and metamorphosis and was also a female chemosterilant for certain insects. This report concerns the effect of structure on both the inhibitive effects and molting hormone activity of certain ecdysones and a number of synthetic ecdysone analogs and derivatives. EXPERIMENTAL AND RESULTS Compounds The ecdysones tested (Fig i) were either received as gifts, isolated from plants and/or insects, or purchased from a comercial source. Where necessary, the ecdysones were purified by adsorption chromatography and/or recrystallization. The purity of these compounds was assessed by melting point determination, thinlayer chromatography, and spectroscopic (UV, IR, NMR and Mass) analyses. The synthesis and properties of the synthetic ecdysone analogs (Fig 2) are reported in a companion paper in this issue of Steroids. Synthetic analogs I, V, and XVII were extracted from treated diets and analyzed by chromatography and spectroscopy to assess their stability. Less than 5% hydrolysis and/or decomposition was found to occur with these steroids. 1 0 6 S T E R O I D S 16:1 • R ' NO HO 0 FT ] cH2°" 0 H QH-*~0 • . 0