Abstract:
To improve the bioactivities of phenazine-1-carboxylic acid (shenqinmycin), 22 phenazine-1-carboxylate derivatives containing acetophenone structural fragments
3a -
3c and
6a -
6s , which have not been reported in literatures were synthesized by bromination reaction and nucleophilic substitution using phenazine-1-carboxylic acid and different substituted acetophenone as raw materials. And their structures were confirmed by
1H NMR,
13C NMR and high resolution mass spectrometry. The fungicidal activities of the target compounds against 6 plant pathogens and the acaricidal activities of adult mite of
Tetranychus cinnatarinus were determined by mycelial growth rate method and agar moisturizing leaf soaking method, respectively. The results of fungicidal activity assay showed that most of the target compounds had certain inhibitory activities against
Rhizoctonia solani. At the concentration of 0.2 mmol/L, the inhibition rates of compounds
6b and
6e against
R. solani were 56.05% and 65.37%, respectively, which were lower than that of the control compound phenazine-1-carboxylic acid (86.83%). The results of acaricidal activity determination showed that: at 1 mmol/L, the corrected mortality rates of compounds
6k and
6m were 87.88% and 90.82%, respectively, and the LC
50 values of compounds
6k and
6m against adult mite of
T. cinnatarinus were 0.25 mmol/L and 0.19 mmol/L, respectively. The new compounds synthesized in this work not only had certain fungicidal activities, but also had better acaricidal activities. It provided a new idea for the further structural modification of phenazine-1-carboxylic acid.