Formamidines cyclase

Amidines. After the initial observation that formamidines are agonists for OA receptors in the firefly (14,15 58), these compounds have been shown to mimic OA in virtually every insect system known to contain OA receptors, including the DUMETi system (59)f the glandular lobe of the corpus cardiacum (60) and the fat body ( ) of the locust, and various CNS adenylate cyclase preparations (26-28). The structure-activity relations of amidines as octopaminergic agonists have been examined in several systems including adenylate cyclase stimulation in the firefly lantern and... 

One problem with the formamidines as pesticides is that their range of activity is limited to a relatively few insect species (25) This species selectivity appears to be directly related to the ability of the compounds to activate adenylate cyclase activity in different insects. For example, as shown in Table I, we have... 

TABLE I. Effects of Phenyliminoimidazolidines (NC-5 and NC-7), Octopamine (OCT), and a Formamidine (DDCDM) on Activating Adenylate Cyclase in Three Insect Species... 

The stimulation of the octopaminergic nervous system of invertebrates is a proven strategy for the control of important pest species. This has been achieved in the past by the use of octopamine receptor agonists such as formamidine and imidazoline derivatives. However, other potential strategies to achieve this end include the inhibition of cyclic nucleotide phosphodiesterase, inhibition of the neural reuptake of octopamine, and inhibition of octopamine N-acetyltransferase. Using the American cockroach nervous system, formamidines were found to inhibit both the uptake and acetylation of octopamine, but not with a potency comparable to their effect on octopamine receptors. The tricyclic antidepressant, desipramine, and the benzylamine, xylamine, were the most active inhibitors of these octopamine removal systems. The pharmacological profiles for uptake and N-acetylation appear to be quite similar, but differ from that of the adenylate cyclase-linked octopamine receptor. 

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