Novel fluorescent conjugate containing glucose and NBD and its carrier-mediated uptake by tobacco cells

et al. 2016

Environ Sci Pollut Res

Self Cite

Producing quality food in sufficient quantity while using less agrochemical inputs will be one of the great challenges of the twenty-first century. One way of achieving this goal is to greatly reduce the doses of plant protection compounds by improving the targeting of pests to eradicate. Therefore, we developed a vectorization strategy to confer phloem mobility to fenpiclonil, a contact fungicide from the phenylpyrrole family used as a model molecule. It consists in coupling the antifungal compound to an amino acid or a sugar, so that the resulting conjugates are handled by active nutrient transport systems. The method of click chemistry was used to synthesize three conjugates combining fenpiclonil to glucose or glutamic acid with a spacer containing a triazole ring. Systemicity tests with the Ricinus model have shown that the amino acid promoiety was clearly more favorable to phloem mobility than that of glucose. In addition, the transport of the amino acid conjugate is carrier mediated since the derivative of the L series was about five times more concentrated in the phloem sap than its counterpart of the D series. The systemicity of the L-derivative is pH dependent and almost completely inhibited by the protonophore carbonyl cyanide 3-chlorophenylhydrazone (CCCP). These data suggest that the phloem transport of the L-derivative is governed by a stereospecific amino acid carrier system energized by the proton motive force.

Section: Synthesis Of Glucose and Amino Acid Conjugatesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Vectorization of agrochemicals: amino acid carriers are more efficient than sugar carriers to translocate phenylpyrrole conjugates in the Ricinus system

Marhadour

et al. 2016

Environ Sci Pollut Res

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“…The second component is a roughly linear component at higher concentrations, indicating the existence of passive diffusion (Figure B). Upon cotreatment with 50 μM CCCP, which is widely utilized in studies of transmembrane transport to dissipate the proton motive force, ,, the saturable component of 2-NBDGTF uptake appeared to be apparently inhibited (Figure b). To study the pH effect of incubation medium on 2-NBDGTF uptake, the disks were incubated with different pH buffer solution (pH ranging from 4.0 to 8.0).…”

Section: Resultsmentioning

confidence: 99%

A Novel Fluorescent Conjugate Applicable To Visualize the Translocation of Glucose–Fipronil

Wang

Wen

et al. 2014

J. Agric. Food Chem.

The ability to visualize the movement of glycosyl insecticides contributes to learning their translocation and distribution in plants. In our present work, a novel fluorescent glucose-fipronil conjugate N-[3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazol-5-yl]-1-(2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-β-D-glucopyranosyl)-1H-1,2,3-triazole-4-methanamine (2-NBDGTF), was obtained via click chemistry. Disk uptake experiments showed that an active carrier-mediated system was involved in the 2-NBDGTF uptake process. Meanwhile, 2-NBDGTF exhibited comparable phloem mobility with GTF in castor bean seedlings. Visualization of 2-NBDGTF uptake and transport experiment showed that this fluorescent glucose-fipronil conjugate could be loaded into sieve tubes after transiting through epidermal cells and mesophyll cells and then translocate from cotyledon to hypocotyl via phloem in castor bean seedlings. The results above determined that it is a promising fluorescence tagging approach for revealing the activities of glycosyl insecticides and 2-NBDGTF is a reasonable and feasible fluorescent surrogate of GTF for tracing the distribution of glucose-fipronil conjugates.

“…31 The uptake of IPNG into tobacco cells involves an active transport process. 32 Specifically, GTF can be mediated by sugar carrier systems during its phloem loading. The glucose conjugates (2-GTF, 3-GTF, 4-GTF, and 6-GTF) are isomers of GTF and have very similar properties with each other (Table 1).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Glucose Positions Affect the Phloem Mobility of Glucose–Fipronil Conjugates

Wang

Mao

et al. 2014

J. Agric. Food Chem.

In our previous work, a glucose-fipronil (GTF) conjugate at the C-1 position was synthesized via click chemistry and a glucose moiety converted a non-phloem-mobile insecticide fipronil into a moderately phloem-mobile insecticide. In the present paper, fipronil was introduced into the C-2, C-3, C-4, and C-6 positions of glucose via click chemistry to obtain four new conjugates and to evaluate the effects of the different glucose isomers on phloem mobility. The phloem mobility of the four new synthetic conjugates and GTF was tested using the Ricinus seedling system. The results confirmed that conjugation of glucose at different positions has a significant influence on the phloem mobility of GTF conjugates.