The juvenile hormone—I. Methods of purification and isolation

Abstract

Methods for the purification and isolation of juvenile hormone from Hyalophora cecropia are described. Ether extraction, low temperature precipitation, thin layer chromatography, and gas liquid chromatography were utilized. JH activity was followed by means of the Tenebrio bioassay. An apparent gain in activity of approximately five-fold was obtained during the course of purification. This was interpreted to be largely the result of a loss of inhibitors during the low temperature precipitation procedure. The final active material, indicated to be a single compound by preliminary gas liquid chromatographic analysis, represented 0·0045–0·0051 per cent of the crude oil used as starting material. The juvenile hormone activity was increased from 25 Tenebrio Units per μl for the crude oil to ⋍2·6×10 6 Tenebrio Units per μl for the final active substance. This represents an approximate 1·05×10 5-fold purification.