STICK INSECT (CARAUSIUS-MOROSUS PHASMATODEA, LONCHODIDAE) BRAIN EXTRACT CONTAINS MULTIPLE FRACTIONS WITH ALLATOSTATIC ACTIVITY

A first attempt to purify inhibitors of juvenile hormone biosynthesis from extracts of brains of the Indian stick insect, Carausius morosus, is reported here. A heterologous bioassay in the cricket, Gryllus bim aculatus, was used throughout the study. Separation of a prepurified e xtract using C-18 reversed-phase high performance liquid chromatograph y (RP-HPLC) resulted in a broad zone with biological activity. Upon re -chromatography of each of six active regions on a wide-pore C-18 colu mn, the material separated in distinct peaks of biologically active fr actions. Introducing a third purification step (C-8 column) resulted i n a total of 18 absorbance peaks with allatostatic activity. It remain s to be seen whether all these fractions contain authentic allatostati ns which are active in stick insects, or whether other functions can b e attributed to them.