Synthesis, bioactivities and phloem uptake of dipeptide-chlorantraniliprole derivatives

Shijie Zheng,Xiaomin Lin,Chen Zhao,Hanxiang Wu,Hanhong Xu

doi:10.1186/s13065-020-00673-7

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.

Highlights

With increasing demand for food and environmental safety, the use of pesticides is subjected to stringent restrictions
Phloem mobility in R. communis Phloem mobilities of all dipeptide conjugates were studied in R. communis, which is an ideal model to investigate the phloem mobility of xenobiotics [10, 12, 32]
When R. communis cotyledons were treated with dipeptide methyl ester conjugates 4a– k, the concentrations of tested compound in phloem sap were close to the limit of detection, and only corresponding dipeptide conjugates 5a–k were detected by High-performance liquid chromatography (HPLC)

Summary

Introduction

With increasing demand for food and environmental safety, the use of pesticides is subjected to stringent restrictions. It has been demonstrated that coupling existing nonphloem mobile pesticide structures with endogenous substances, such as amino acids and saccharides, was Dipeptides and tripeptides can be transported into plant cells through peptide transporters, which were first discovered in Arabidopsis plants [16] as a H+-coupled transporter for oligopeptides [17, 18]. Similar facilitator transporters, such as oligopeptide transporter (PepT1 and PepT2), were found in mammals to drive the uptake of di- and tri-peptides [19, 20].

Methods

Results

Conclusion