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.
Li
Yiping
Y
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.
Kuwano
Eiichi
E
Noriega
Fernando G
FG
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