Synthesis of a Series of Monosaccharide–Fipronil Conjugates and Their Phloem Mobility

Abstract

To test the effect of adding different monosaccharide groups to a non-phloem-mobile insecticide on the phloem mobility of the insecticide, a series of conjugates of different monosaccharides and fipronil were synthesized using the trichloroacetimidate method. Phloem mobility tests in castor bean ( Ricinus communis L.) seedlings indicated that the phloem mobility of these conjugates varied markedly. L-Rhamnose-fipronil and D-fucose-fipronil displayed the highest phloem mobility among all of the tested conjugates. Conjugating hexose, pentose, or deoxysugar to fipronil through an O-glycosidic linkage can confer phloem mobility to fipronil in R. communis L. effectively, while the -OH orientation of the monosaccharide substantially affected the phloem mobility of the conjugates.

Vectorizing agrochemicals: enhancing bioavailability via carrier‐mediated transport

“…Glucose and amino acid promoieties were introduced into insecticides to develop phloem‐targeted proinsecticides (Table ). The resulting derivatives included glycinyl fipronil conjugate, sugar‐fipronil conjugates, D‐glucose‐rotenone conjugates, glycinergic‐fipronil conjugate, and amino acid‐chlorantraniliprole conjugates . Despite their parent compounds lack of mobility in the phloem, several of the above mentioned insecticide conjugates had good phloem systemicity .…”

“…The resulting derivatives included glycinyl fipronil conjugate, sugar‐fipronil conjugates, D‐glucose‐rotenone conjugates, glycinergic‐fipronil conjugate, and amino acid‐chlorantraniliprole conjugates . Despite their parent compounds lack of mobility in the phloem, several of the above mentioned insecticide conjugates had good phloem systemicity . The vacuolar sequestration of sugar and glutathione conjugates via ABC transporters which occurs in planta during the final detoxification process of agrochemicals may reduce the phloem loading of these synthetic conjugates.…”

“…62 Despite their parent compounds lack of mobility in the phloem, several of the above mentioned insecticide conjugates had good phloem systemicity. 56,62 The vacuolar sequestration of sugar and glutathione conjugates via ABC transporters which occurs in planta during the final detoxification process of agrochemicals 67 may reduce the phloem loading of these synthetic conjugates. Data from short time experiments using a fluorescent insecticide sugar conjugate indicate that the dye accumulates dramatically in epidermal cells and phloem, more specifically in sieve tubes after incubation of Ricinus cotyledons in an incubation solution containing N- 65 The fluorescence in the mesophyll cells is moderate and localized mainly at their external wileyonlinelibrary.com/journal/ps part.…”

Novel amino acid ester–chlorantraniliprole conjugates: design, synthesis, phloem accumulation and bioactivity

“…For instance, the Bonnemain group has reported several derivatives of existing herbicides modified with an α ‐amino acid fragment that exhibit good phloem mobility . In our previous work, a series of glucose–fipronil conjugates (GTF and GOF) and a glycinergic–fipronil conjugate (GlyF) that show distinctive distributions in Ricinus communis have been designed . The uptake of these conjugates was proven to be mediated by an endogenous carrier system .…”

Synthesis of Rotenone-O-monosaccharide Derivatives and Their Phloem Mobility

“…2,10 In addition, 10 kinds of fipronil-monosaccharide derivatives were synthesized in our previous work ( Figure 1). 11 Most of these derivatives have been verified as having phloem systemicity. These studies revealed that conjugating glucose or another monosaccharide can confer phloem mobility on a nonphloem-mobile insecticide.…”