Juvenile hormones properties

These inhibitors would be classified as anti-juvenile hormones and could be expected to show selective action on insects as a class. Such analogs are by no means just around the corner since at least two important properties that they should possess may be difficult to build into small organic molecules suitable for pest control. These properties are the ability to withstand general metabolic inactivation while retaining the ability to inhibit irreversibly the target enzymes of the corpus allatum and the property to accumulate selectively in corpora allata, a physically small target, so as to offset dilution in the general body cavity. 

SS was a mixture of positional isomers, corresponding to attack by perbenzoic acid at various double bonds in RR. Of these, one isomer (a racemic modification) was found to be identical, in physical and biological properties, to the natural juvenile hormone. This isomer was the one resulting from reaction at the double bond first introduced into the molecule. 

The action of precocenes on the molecular level is not understood. Pratt and Bowers (1977) demonstrated the inhibition of the final steps in juvenile hormone biosynthesis, including epoxidation of farnesenic acid, following administration of precocene II to the test insects. Based on their experimental findings, members of the Bristol research group hypothesised that precocene and its derivatives are epoxidised to 3,4-epoxides having alkylating properties. The formation of these epoxides competes with the epoxidation step in JH biosynthesis, thus destroying the ability of corpora allata to synthesise JH. 

Different biological properties juvenile hormone as a pest control... 

Antifeedant Compounds Insecticidal and Nematicidal Activity Diterpenes with Juvenile Hormone Activity Diterpenes That Prevent Reproduction in Insects Trail-Marking Pheromones Diterpenes from Marine Plants Sweeteners Medicinal Properties Antitumor Compounds Sesterterpenes Biosynthesis Biological Activity References... 

Triterpenes and Steroids in Invertebrates Insects.—Terpenoid metabolism in insects will be considered separately from other invertebrates. Although insects do not possess the complete machinery required for biosynthesis of sterols from small molecules, it has been reported that a Sarcophaga bullata homogenate converts squalene into a compound with the chromatographic properties of squalene 2,3-oxide. However, this report warrants substantiation. The major insect juvenile hormone (133 R = Me) becomes labelled from [ C]acetate and also from l-[ H or... 

---