Terpenoids with Insect Juvenile Hormone Activity

3 Terpenoids with Insect Juvenile Hormone Activity 

At the same time, however, the juvenile hormone activity exhibited specifically in the hemipteran bug Pyrrhocoris apterus L. [749] by two constituents of the balsam fir [Ahies halsamea (L) Miller), namely, juvabione (syn. methyl todomatuate), CII, [750] and its dehydroderivative [751], shows that this type of activity, in some insects at least, can reside in sesquiterpenoids arising [137] via the usual biogenetic pathway involving departure of the pyrophosphate function of famesyl pyrophosphate. Actually the isolation from the pulp of 

As would have been expected a priori, juvabione is a structurally specific agent as has been conclusively proven by the demonstration that synthetic racemic juvabione has one half the potency of the naturally occurring optically active compound [753]. 

In the earlier review it was emphasised that, in marked contrast to their role in the development of our understanding of biogenesis and molecular rearrangements, the terpenoids had played little or no part in the evolution of theories of drug action as then established. The advances of the ensuing 6 years necessitate some revision of this statement since, although the terpenoids as a whole have made little contribution to the increased sophistication of our cur- 

despite these studies and others, the terpenoids would not appear to have played as significant a role in studies of drug action as they could reasonably have been expected to do. Thus, although apparently well suited to such 

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More epoxides (1) with juvenile hormone activity (Vol. 2, p. 7) have been made by epoxidizing the Wittig products of citronellal (2), and some of these substances also increase silk production.Reduction of the double bond sometimes increases the activity against Oncopeltus fasciatus. Insecticidal activity is also reported for certain terpenoid cyclopropanes [e.g. (3), made from limonene and ethyl diazoacetate] and for isobornyl thiocyanoethyl ether (made from cam-phene and ethylene chlorohydrin followed by treatment with potassium thiocyanate). The insect-repelling activity shown by thujic acid amides (4) is... 

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