Eine Methode zur qualitativen und quantitativen Bestimmung von drei Juvenilhormonen von Insekten

Abstract

A method is presented permitting the qualitative and quantitative determination of all three presently known hormones (JH1-3). The determination is based on the method of radioactive isotope dilution, whereby a very small known amount of tritium-labelled JH-1 is added to the ether extract of the particular species. The addition of radioactive JH-1 permits the isolation of all three hormones, because of their similar behaviour during the chosen work up. The quantitative determination was carried out by gas chromatography and the identification was confirmed with the help of retention-times and GC-MS combination. The method was checked by using an extract of Hyalophora cecropia. For the first time methyl 10,11-epoxy-3,7,11-trimethyl-2-trans-6-trans-dodecadienoate (JH-3) could also be identified as the juvenile hormone of Melo­lontha melolontha. In Vanessa io larvae, Tenebrio molitor larvae and adults and in Musca domestica larvae none of the three known hormones could be detected. The preparation of JH-1 labelled with tritium in the methyl group of the ester was accomplished with very high specific activity (4.34 Ci/mmol) of the tritiated acid with diazomethane.

Specificity of the juvenile hormone binding protein: The geometrical isomers of juvenile hormone I

“…Data shown as means ± SD. (15), this technique is suitable only for microanalysis. Fortunately, the selectivity of HRLC and GLC for these isomers is quite different.…”

Juvenile hormone catabolism and oviposition in the codling moth, Cydia pomonella, as functions of age, mating status, and hormone treatment

“…To determine catabolic rates, racemic JH III (Sigma, St. Louis, MO) was separated from other components on a reversed phase HPLC µporasil column (30 × 0.39 cm), developed isocratically using 2.5% (v/v) ethyl acetate, 0.02% (v/v) propan-2-ol in hexane at 0.5 ml/min. JH was quantified by spectrometry (in methanol λ max 220 nm, ε = 13 830 mol; Peter and Dahm, 1975;Trautmann et al, 1974). Racemic [10-3 H(N)]JH III (specific activity 16.4 Ci/mmol, NEN Life Science Products, Boston, MA) was diluted with non-radiolabelled JH III to a final concentration of 250 pmol/µl, 12 500 dpm/µl in ethanol.…”