5-(Arylmethylene)hydantoins (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) and 5-(arylmethylene)-2-thiohydantoins (20-37) have been synthesized by condensation of aromatic aldehydes with hydantoin (1) or 2-thiohydantoin (2) in the presence of ethanolamine. A number of 5-alkyl-and 5-(arylmethyl)hydantoins (40-48) and their 2-thio analogs (50-55) were synthesized from amino acids. All of these compounds were tested for pesticidal activity.
The relationship between the structure of nineteen 2,2-dimethylchromene derivatives and their effects on aphid morphogenesis were investigated in a pink clone of the pea aphid, Acyrthosiphon pisurn (Harris). Three bioassay systems were used: (1) wing induction-the induction of winged (alate) progeny by winged adults that normally produce only wingless (apterous) daughters, (2) wing inhibition-the inhibition of production of winged progeny by wingless adults that had been crowd-induced to promote the appearance of winged progeny, ( 3 ) the effect on metamorphosis-the production of precocious adults indicating a decrease in juvenile hormone titre or the induction of supernumerary moults indicating a juvenile hormone agonist effect. Compounds demonstrating wing-promoting effects had short (52 carbon) side chains at the C6 and/or C7 positions while methylation of C5 tended to decrease this activity. Of the seven compounds inducing wing formation, three also inhibited the production of winged progeny. However, the compounds affecting metamorphosis, in particular promoting precocious adult development, were similar to those that promoted wing inhibition rather than those with wing inducing effects; they had alkoxy groups at C7 with lengths of 22 carbons.There is a stronger correlation between compounds interfering with metamorphosis (and therefore evidenced to be affecting juvenile hormone levels, a classic property of some 2,2-dimethylchromene derivatives) and the promotion of wingless forms than the induction of winged forms. This finding is in contradiction to the idea that juvenile hormones are involved i n promoting wingless forms. In addition, attempts to reduce the wing-inducing properties of Precocene were inconclusive and attempts to inhibit wing formation with these two compounds atter crowding were also unsuccessful. The precise mode of action of the 2,2-dimethylchromenes in relation to aphid wing induction remains unclear but it seems likely that the effect is not related to changes in juvenile hormone titres. o 1095 WiIey-Liss, Inc.
The cytochrome P‐450‐dependent microsomal and mitochondrial ecdysone 20‐monooxygenase systems convert ecdysone into 20‐hydroxyecdysone. The microsomal fraction of fat bodies of zero h wandering stage fleshfly larvae (Neobellieria bullata; Diptera: Sarcophagidae) has a high ecdysone 20‐ monooxygenase activity. The effects of cytochrome P‐450 inhibitors were investigated in vitro on microsomal ecdysone 20‐monooxygenase. Metyrapone, fenarimol and certain imidazole derivatives (KK‐42, KK‐110, KK‐135 and PIM) are strong inhibitors. The IC50 value of KK‐110, which is the strongest inhibitor, is 2 × 10−7 M. A triazolyl and two cyclopropylamine derivatives have low activity. The activities of different NADPH‐cytochrome c (P‐450) reductase inhibitors were also assessed; diquat dibromide is a moderate inhibitor of microsomal ecdysone 20‐monooxygenase, while paraquat dichloride has no activity.
In‐vivo experiments with cytochrome P‐450 inducers and inhibitors gave the following results: (a) fenarimol, FI‐121, precocene‐2 caused “permanent” first‐instar larvae; (b) barbital, phenobarbital and their sodium salts caused significant delay in larval development; (c) PIM, PTM, metyrapone, KK‐42, KK‐135, J‐2710, RH 5849 and colchicine caused moulting disturbances; (d) J‐2710, PIM, PTM, KK‐42, KK‐135, RH 5849 and colchicine caused lethal spiracle and mandible malformation; (e) KK‐110, fenarimol, barbital and phenobarbital caused precocious pupariation.
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