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

Abstract

Six monosaccharide derivatives of rotenone were designed and synthesized to assess whether rotenone could become phloem mobile by the addition of a monosaccharide group. Phloem mobility experiments showed that only D-glucose conjugates exhibit phloem transport properties in castor bean (Ricinus communis L.) seedlings. Two D-glucose conjugates, 2-O-β-D-glucopyranosyldemethylrotenone and 6'-O-β-D-glucopyranosyldalpanol, had significantly obtained systemicity compared with that of rotenone, and 6'-O-β-D-glucopyranosyldalpanol was more mobile than 2-O-β-D-glucopyranosyldemethylrotenone. Coupling with a monosaccharide core is a reasonable method for conferring phloem mobility on insecticides, but phloem mobility is also affected by the parent molecule and the position of the monosaccharide.

The influence of steric configuration of phenazine‐1‐carboxylic acid‐amino acid conjugates on fungicidal activity and systemicity

“…In the last few decades, with experimental assays on many of the known phloem mobile xenobiotics, the Kleier mathematical model was established based on the physicochemical properties of xenobiotics and the intermediate permeability hypothesis with the acid trap mechanism for weak acids, and then widely applied to predict the phloem mobility of xenobiotics . The application of the model is in broad agreement with many of the known phloem mobile herbicides, fungicides and insecticides, except for a few xenobiotics whose transport is carrier‐mediated …”

“…[34][35][36] The application of the model is in broad agreement with many of the known phloem mobile herbicides, fungicides and insecticides, except for a few xenobiotics whose transport is carrier-mediated. 6,13,14,37 We used the Kleier model to predict the phloem mobility of test compounds. The log K ow and pK a were calculated with the ALOGPS 2.1 program and ACD log Dv 6.00 software, respectively.…”

“…1,2 To date, the number of fungicides that have ambimobility activity (both phloem mobile and xylem mobile) in plants is very limited, exemplified by fungicides such as metalaxyl, 3 or phosethyl-Al. 4 Successful attempts have been made to achieve this goal by changing the physicochemical properties of molecular structures 1,5 or introducing a small molecule which is endogenous and can bi-directionally transport in plant, 6 such as an amino acid, [7][8][9][10][11] or a sugar [12][13][14] onto the non-phloem mobile agrochemicals. For example, to fit the Kleier prediction model widely employed to predict whether xenobiotics are capable of phloem transport ability based on their physical and chemical properties (log K ow and pKa, respectively), an acidic derivative of the fungicide fenpiclonil, N-carboxymethyl-3cyano-4-(2,3-dichlorophenyl)pyrrole, showing moderate phloem mobility was designed and synthesized, and it was found to exhibit high phloem mobility using the castor bean system.…”

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 linker length of glucose–fipronil conjugates has a major effect on the rate of bioactivation by β‐glucosidase

“…The introduction of carboxyl group, amino acids, or glycosyl group is an efficient strategy to confer phloem mobility to pesticides with no or weak mobility. Our group has previously synthesized a series of phloem mobile sugar–pesticide conjugates, but this modification is typically accompanied by the reduction in biological efficacy . The existence of the β‐glucosidase‐based two‐component plant defense system has prompted an exploration of the feasibility of exploiting endogenous β‐glucosidase activity to hydrolyze glucose–pesticide conjugates, thereby supplementing the plants' native chemical defenses with a phloem mobile pesticide.…”