State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.
Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China.
Molecules. 2018 Mar 28;23(4):778. doi: 10.3390/molecules23040778.
To develop a new pesticide with phloem mobility, a series of new amino acid-fipronil conjugates were designed and synthesized based on derivatization at the 3-position of the pyrazole ring of fipronil. Experiments using a seedling system showed that all tested conjugates were phloem mobile except for the isoleucine-fipronil conjugate, and that the serine-fipronil conjugate () exhibited the highest concentration in phloem sap (52.00 ± 5.80 μM). According to prediction with log values and uptake experiments with oocytes, the phloem loading process of conjugate involved both passive diffusion and an active carrier system (). In particular, compared with for a previously reported glycinergic-fipronil conjugate (GlyF), passive diffusion played a more important role for conjugate in the enhancement of phloem mobility. This study suggests that associating a nutrient at a different position of an existing pesticide structure could still be effective in obtaining phloem-mobile derivatives, but the distinct physicochemical properties of resultant conjugates may lead to different phloem loading mechanisms.
为开发具有韧皮部内流动性的新型农药，基于氟虫腈吡唑环 3 位的衍生化，设计并合成了一系列新型氨基酸-氟虫腈缀合物。采用幼苗系统的实验表明，除异亮氨酸-氟虫腈缀合物外，所有测试的缀合物均具有韧皮部内流动性，而丝氨酸-氟虫腈缀合物（）在韧皮部汁液中的浓度最高（52.00±5.80 μM）。根据 log 值预测和用卵母细胞进行的摄取实验，缀合物的韧皮部装载过程既涉及被动扩散，也涉及主动载体系统（）。特别是与先前报道的甘氨酰基-氟虫腈缀合物（GlyF）相比，对于提高韧皮部流动性的缀合物，被动扩散在增强过程中起着更为重要的作用。本研究表明，在现有农药结构的不同位置结合一种养分，仍可能有效地获得具有韧皮部内流动性的衍生物，但由此产生的缀合物的显著物理化学性质可能导致不同的韧皮部装载机制。
