14 C-标记腈菌唑的合成及其在小麦幼苗上的吸收与传导确证

以14C标记碳酸钡(Ba14CO3)为起始物,采用4步反应合成14C-1,2,4-三唑,总强度为5.813 1 mci,比强为15.53 μci/mg, 纯度大于99%,放化收率84.21%。在此基础上,参照文献报道的有关腈菌唑合成的方法,以4-氯苯乙腈为原料,经取代、缩合等3步反应合成了14C-腈菌唑,其总强度为0.556 6 mci,比强为2.53 μci/mg,纯度大于96%,放化收率85.4%。应用同位素示踪技术研究了14C-腈菌唑在2~3叶期小麦幼苗上的吸收、分布和传导。结果表明,根部给药后6~120 h,小麦根部放射性物质分布比例由59.88%下降为 24.87%;在幼苗茎基部和叶片中,放射性物质分布比例分别由14.18%、1.19%上升为 19.47%和33.75%;14C-腈菌唑被小麦幼苗吸收后向顶传导的速度很快,在叶片中的分布和积累与根部给药时间呈正相关,放射强度由2.94×10-6 μci上升为322.72×10-6 μci。放射性自显影表明,根部给药后120 h,14C-腈菌唑可以内吸传导到整个小麦植株。

Synthesis of 14C-Labelled Myclobutanil and the Corroboration of its Uptake and Translocation in Wheat Seedling

Based on the original material of 14C-labelled Ba14CO3,14C-labelled 1,2,4-triazol was synthesized by means of 4 steps reaction,which radioactive strength,specific activity,radiochemical purity and radiochemical yield were 5.813 1 mci,15.534 7 μci/mg,more than 99% and 84.21%,respectively.According to the methods reported to synthesize myclobatanil,14C-labelled myclobutanil was made from 4-chlorophenylacetonitrile through substitution and condensation.Its radioactive strength,specific activity,radiochemical purity and radiochemical yield was 0.556 6 mci,2.53 μci/mg,more than 96% and 85.4%,respectively.The uptake,translocation and distribution of myclobutanil in wheat seedling at 2~3 leaves stage were studied by radioactive trace experiment.The result showed that radioactivity in the treated wheat roots dropped from 59.88% to 24.87%,and the accumulation of radioactivity in the stem base and leaves respectively increased from 14.18% and 1.19% to 19.47% and 33.75% after dipping the roots into 14C-myclobutanil solution for 6~120 h.14C-myclobutanil could be absorbed and translocated upwards to the top of wheat seedling readily.The distribution and accumulation of 14C-myclobutanil in wheat leaves were positively correlated with treatment time of dipping the root into the chemical solution,with a steady increase in radioactivity from 2.94×10-6 μci at 6 h to 322.72×10-6 μci at 120 h.Autoradiograph experiment indicated that 14C-myclobutanil could be absorbed and distributed in whole seedling at 120 h after treating the roots.