1,5-Disubstituted imidazoles inhibit juvenile hormone biosynthesis by the corpora allata of the mosquito Aedes aegypti.
We investigated the effect of fifteen 1,5-disubstituted imidazoles (1,5-dis) on juvenile hormone III (JH III) and methyl farnesoate (MF) biosynthesis by the corpora allata (CA) of the mosquito Aedes aegypti in vitro. Four compounds (TH-35, TH-83, TH-62 and TH-28) significantly decreased JH biosynthesis in the CA dissected from 3-day old sugar-fed females. The decrease of JH synthesis was not always associated with increased MF. TH-30 and TH-83 increased MF levels, while TH-85 and TH-61 significantly decreased MF levels. Five compounds (TH-26, TH-60, TH-83, TH-35 and TH-30) significantly inhibited JH biosynthesis in the CA dissected from females 15 h after a blood meal. Four 1,5-dis (TH-30, TH-26, TH-28 and TH-66) caused MF increases in CA from blood-fed females. 1,5-Disubstituted imidazoles had higher inhibitory activity on JH synthesis when substituted at position 5 by a 3-benzyloxyphenyl group and at position 1 by a benzyl group (such as TH-35). Inhibition of JH and MF biosynthesis by TH-35 was age-dependent and influenced by nutritional status; inhibition differed when evaluated in the CA dissected from sugar-fed females at different days after emergence and in the CA dissected from females at different hours after a blood meal. Inhibition was always higher when the CA was more active. The addition of TH-35 significantly reduced the stimulatory effect of Aedes-allatotropin and farnesoic acid on JH synthesis. This is the first report of an inhibitory effect of 1,5-disubstituted imidazoles on JH synthesis in Diptera.
Department of Biochemistry and Molecular Biophysics and Center for Insect Science, University of Arizona, Biological Sciences West 513, P.O. Box 210088, Tucson, AZ 85721-0088, USA.
Yiping
Y
Li
Eiichi
E
Kuwano
Fernando G
FG
Noriega
D000330:Aedes / Q000187:drug effects / Q000378:metabolism*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001769:Blood / Q000378:metabolism; D003335:Corpora Allata / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D005231:Fatty Acids, Unsaturated / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000494:pharmacology; D005260:Female; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology*; D007301:Insect Hormones / Q000494:pharmacology; D007605:Juvenile Hormones / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D009479:Neuropeptides / Q000494:pharmacology; D012717:Sesquiterpenes / Q000037:antagonists & inhibitors / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000502:physiology; D013997:Time Factors
D005231:Fatty Acids, Unsaturated; D007093:Imidazoles; D007301:Insect Hormones; D007605:Juvenile Hormones; D009479:Neuropeptides; D012717:Sesquiterpenes; C032429:methyl farnesoate; C050669:allatotropin; C007702:farnesoic acid; C036585:juvenile hormone III