Synthesis and anti-juvenile hormone activity of ethyl 4-[(6-substituted 2,2-dimethyl-2H-chromen-7-yl)methoxy]benzoates

Abstract

Ethyl 4-[(6-substituted 2,2-dimethyl-2H-chromen-7-yl)methoxy]benzoates and their analogues were prepared and the biological activities were evaluated for both anti-juvenile hormone (anti-JH) and JH activity in silkworm larvae, Bombyx mori. Of the compounds tested, ethyl 4-[(6-methoxy-2,2-dimethyl-2H-chromen-7-yl)methoxy]-benzoate (3b) showed the most effective precocious metamorphosis-inducing activity in 3rd instar larvae and JH activity in allatectomized 4th instar larvae. Furthermore, JH I and 20-hydroxyecdysone (20-E) titers in hemolymph of 3rd instar larvae treated with 3b were measured by liquid chromatography-mass spectrometry (LC-MS) and LC-MS/MS, respectively. The results revealed that compound 3b induced precocious metamorphosis by specifically decreasing JH I in hemolymph.

Physiological Activities of Anti-Juvenile Hormone Agents Against Insects and Their Role For Devising Fourth Generation Insecticides: A Comprehensive Review

“…Among the structurally derived compounds from ETB, some KF compounds had been prepared. Furuta et al (2010) designed new anti-JH agents among which KF-38 was found to possess a dual property, strong anti-JH activity and weak JH-like activity. Hexyl (KF-13) and heptyl analogues, which induced precocious metamorphosis in B. mori at low doses, had relatively high JH activity (Fujita et al, 2008).…”

Insecticidal activity and up-regulation of juvenile hormone response genes by juvenile hormone agonists in the western flower thrips, <i>Frankliniella occidentalis</i>

“…1) were synthesized as described previously. [9][10][11]21) Other test compounds have been synthesized as described below.…”

“…1), which possesses a similar structure to retinoids, exhibited precocious metamorphosis-inducing activity against B. mori. 11) Since IGRs act on insect-specific physiological functions as the target, they are believed to be less toxic to mammals than are traditional insecticides. Although a chitin synthesis inhibitor novaluron has been utilized to control thrips in Japan, JH mimics are not currently registered to control thrips.…”

Anti-juvenile hormone activity of ethyl 4-[(7-substituted 1,4-benzodioxan-6-yl)methyl]benzoates and their effect on the juvenile hormone titer in the hemolymph of the silkworm, <i>Bombyx mori</i>

“…We attempted to design a new scaffold of anti-JH agents and found that ethyl 4-[(6-methoxy-2,2-dimethyl-2H-chromen-7-yl) methoxy] benzoate (KF-38), which was designed on the basis of the structure of retinoid analogs, exhibited anti-JH activity and weak JH-like activity. 11) In a previous report, ethyl 4-[(7-methoxy-1,4-benzodioxan-6-yl) carbonyl] benzoate (KM-03) and its derivatives were prepared, but they showed no or less insecticidal activity against the western flower thrips, Frankliniella occidentalis. 12) In this study, further research on the structure-activity relationship of KM-03 was conducted.…”