Synthesis, bioactivities and phloem uptake of dipeptide-chlorantraniliprole derivatives

Abstract

Phloem systemicity is a desirable property for insecticides to control sucking insects. However, the development of phloem systemic insecticides is challenging. One possible strategy is to link existed insecticides with endogenous substances so that the resulting conjugates can be transported by specific transporters into the phloem. In this study, novel dipeptide promoieties were introduced into chlorantraniliprole, which is an efficient and broad-spectrum anthranilic diamide insecticide without phloem mobility. Twenty-two new dipeptide-chlorantraniliprole conjugates have been synthesized. Systemic tests showed that all conjugates exhibited phloem mobility in Ricinus communis. In particular, compound 4g with alanyl-alanine dipeptide fragment was able to accumulate in phloem sap (114.49 ± 11.10 μM) in the form of its hydrolysis product 5g. Results of bioassay showed that conjugates 4g and 5g were able to exhibit comparable insecticidal activity against Plutella xylostella L. and Spodoptera exigua compared to its parent compound chlorantraniliprole. This work demonstrated that the dipeptide structures were able to contribute to the improvement of the uptake and phloem mobility of chlorantraniliprole, and two phloem mobile conjugates with satisfactory in vivo insecticidal effect was obtained as new candidates for high-efficient insecticides.

Dipeptide Conjugates: An Important Class of Therapeutic Agents

“…Conjugating dipeptide structures with existing pesticides is expected to be another potential strategy to obtain new candidates for phloemmobile pesticides, which could enhance the efficiency and reduce the consumption of pesticides. 3 Such conjugates of peptides or amino acids display wide structural heterogeneity due to variable amino acid sequences and are also effective against a broad spectrum of infections, ranging from Gram-positive to Gram-negative bacteria and fungal to protozoal and viral infections. The structural reliability of such conjugates allows them to take on different amphiphilic conformations responsible for the particular activity.…”