Juvenile Hormone Activity of Isomers of Farnesol

Abstract

SINCE the juvenile hormone of insects was first extracted from the abdomens of male cecropia moths¹, its presence or the presence of juvenile hormone-like activity has been demonstrated in other insects², in invertebrates³, in bacteria, yeast, and higher plants⁴, in certain organs of mammals⁵, and in the fæces of the beetle Tenebrio molitor⁶. Recently, the active constituents of the fæces of T. molitor were isolated and identified as two related acyclic sesquiterpenes, farnesol (I) and farnesal⁷, and the activity of one of them, farnesol, was examined in detail on the assassin bug, Rhodnius prolixus⁸. Although the juvenile hormone activity of farnesol was demonstrated, its unit activity was far less than those of partially purified extracts of cecropia moths, and therefore it is not likely that farnesol is the true juvenile hormone of insects^8,9. Nevertheless, interest is centred on these terpenes as possible precursors of the juvenile hormone.