Synthesis of novel 9R/S-acyloxy derivatives of cinchonidine and cinchonine as insecticidal agents

Abstract

Endeavor to discover biorational natural products-based insecticides, two series (27) of novel 9R/S-acyloxy derivatives of cinchonidine and cinchonine were prepared and assessed for their insecticidal activity against Mythimna separata in vivo by the leaf-dipping method at 1 mg/mL. Among all the compounds, especially derivatives 6l and 6o exhibited the best insecticidal activity with final mortality rates of 75.0% and 71.4%, respectively. Overall, a free 9-hydroxyl group is not a prerequisite for insecticidal activity and C9-substitution is well tolerated; the configuration of C8/9 position is important for insecticidal activity, and 9S-configuration is optimal; 6’-OCH₃ moiety is not necessary, removal of it is also acceptable.

Graphical Abstract

Keywords:

• Cinchonidine
• cinchonine
• quinine analogues
• acyloxy
• insecticidal activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The present research was financially supported by the National Natural Science Foundation of China [Grant No. U1604105, 31901863].