Isolation of Juvenile Hormone in Different Species

Abstract

Following isolation (Röller et al., 1965; Röller et al., 1969), identification (Röller et al., 1967; Dahm et al., 1968), and the first synthesis (racemic form) of the juvenile hormone [JH (Dahm et al., 1967)] of the giant silk moth, Hyalophora cecropia, we started investigating the biosynthesis of the hormone. In order to [study this question successfully, our original purification procedure for JH has been refined, and the new method has been tested for the first time in Hyalophora gloveri [(Dahm and Röller, 1970) and Table 1]. Its efficiency was determined through addition of synthetic 2-¹⁴C JH to the crude oil, and the recovery of JH in all cases was found to be 50–60 per cent. The major loss of hormone occurs during the cold precipitation, when 30 per cent of the JH remains as part of the precipitate. The hormone can be recovered, only at the cost of a substantially decreased purification factor, by a change of the ratio of solvent and its amount. Precipitation at low temperature is an essential step in the process for isolation since this procedure eliminates lipoidal material that would interfere with the final separation of JH by gas chromatography.