Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.In this paper,to discover the new bactericide candidates,we designed,prepared a...Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.In this paper,to discover the new bactericide candidates,we designed,prepared a new type of1,2,3,4-tetrahydro-β-carboline(THC)derivatives and evaluated the in vitro and in vivo bioactivities against the Xanthomonas oryzae pv.oryzae(Xoo),Xanthomonas axonopodis pv.citri(Xac),and Pseudomonas syringae pv.actinidiae(Psa).The in vitro bioassay results exhibited that most title molecules possessed good activity toward the three plant pathogenic bacteria,the compound A17 showed the most active against Xoo and Xac with EC50 values of 7.27 and 4.89 mg mL^(-1)respectively,and compound A8 exhibited the best inhibitory activity against Psa with EC50value of 4.87 mg mL^(-1).Pot experiments showed that compound A17 exhibited excellent in vivo antibacterial activities to manage rice bacterial leaf blight and citrus bacterial canker,with protective efficiencies of 52.67 and 79.79%at 200 mgmL^(-1),respectively.Meanwhile,compound A8 showed good control efficiency(84.31%)against kiwifruit bacterial canker at 200 mg mL^(-1).Antibacterial mechanism suggested that these compounds could interfere with the balance of the redox system,damage the cell membrane,and induce the apoptosis of Xoo cells.Taken together,our study revealed that tetrahydro-β-carboline derivatives could be a promising candidate model for novel broadspectrum bactericides.展开更多
Sucrose phosphorylase(SPase)can transfer the glucosyl group of sucrose to different compounds and has been widely used in industry.To overcome the low thermostability of the sucrose phosphorylase from Leuconostoc mese...Sucrose phosphorylase(SPase)can transfer the glucosyl group of sucrose to different compounds and has been widely used in industry.To overcome the low thermostability of the sucrose phosphorylase from Leuconostoc mesenteroides ATCC 12291(LmSP),a method named PROSS was used to construct mutants with increased thermostability.All variants were screened by measuring their residual activities after heating at 50℃.Then,a single point mutant and a combined mutant with improved thermostability and activity were obtained.The half-lives of mutants at 50℃ were approximately twice as high as those of the wild type.In addition,2-O-α-d-glucosylglycerol(αGG)was synthesized by the wild type and the two improved variants,and the reaction conditions were optimized.Under the conditions of glycerol concentration of 3.2 mol/L,sucrose concentration of 1.2 mol/L,and enzyme concentration of 40 U/mL at 37℃ for 60 h,the yield ofαGG reached the maximum,and the sucrose conversion rate of the wild type,the mutant V23L and the combined mutant V23L/S424R were 62.3%,70.7%and 76.3%,respectively.In this study,SPase mutants with higher activity and stability were obtained,and achieved high-level production ofαGG.展开更多
基金the supports from National Natural Science Foundation of China(21877021,32160661,and 32202359)the Guizhou Provincial S&T Project China(2018[4007])+2 种基金the the Guizhou Province China[Qianjiaohe KY number(2020)004]the Program of Introducing Talents of Discipline to Universities of China(D20023,111 Program)the Guizhou University(GZU)Found for Newly Enrolled Talent China(202229)。
文摘Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.In this paper,to discover the new bactericide candidates,we designed,prepared a new type of1,2,3,4-tetrahydro-β-carboline(THC)derivatives and evaluated the in vitro and in vivo bioactivities against the Xanthomonas oryzae pv.oryzae(Xoo),Xanthomonas axonopodis pv.citri(Xac),and Pseudomonas syringae pv.actinidiae(Psa).The in vitro bioassay results exhibited that most title molecules possessed good activity toward the three plant pathogenic bacteria,the compound A17 showed the most active against Xoo and Xac with EC50 values of 7.27 and 4.89 mg mL^(-1)respectively,and compound A8 exhibited the best inhibitory activity against Psa with EC50value of 4.87 mg mL^(-1).Pot experiments showed that compound A17 exhibited excellent in vivo antibacterial activities to manage rice bacterial leaf blight and citrus bacterial canker,with protective efficiencies of 52.67 and 79.79%at 200 mgmL^(-1),respectively.Meanwhile,compound A8 showed good control efficiency(84.31%)against kiwifruit bacterial canker at 200 mg mL^(-1).Antibacterial mechanism suggested that these compounds could interfere with the balance of the redox system,damage the cell membrane,and induce the apoptosis of Xoo cells.Taken together,our study revealed that tetrahydro-β-carboline derivatives could be a promising candidate model for novel broadspectrum bactericides.
基金This study was funded by the Key Research and Development Program of China(2021YFC2100102-03)the National Natural Science Foundation of China(32001064).The computational results used in this article were obtained using Interdisciplinary Center for Modern Technologies facilities,NCU,Torun,Poland.
文摘Sucrose phosphorylase(SPase)can transfer the glucosyl group of sucrose to different compounds and has been widely used in industry.To overcome the low thermostability of the sucrose phosphorylase from Leuconostoc mesenteroides ATCC 12291(LmSP),a method named PROSS was used to construct mutants with increased thermostability.All variants were screened by measuring their residual activities after heating at 50℃.Then,a single point mutant and a combined mutant with improved thermostability and activity were obtained.The half-lives of mutants at 50℃ were approximately twice as high as those of the wild type.In addition,2-O-α-d-glucosylglycerol(αGG)was synthesized by the wild type and the two improved variants,and the reaction conditions were optimized.Under the conditions of glycerol concentration of 3.2 mol/L,sucrose concentration of 1.2 mol/L,and enzyme concentration of 40 U/mL at 37℃ for 60 h,the yield ofαGG reached the maximum,and the sucrose conversion rate of the wild type,the mutant V23L and the combined mutant V23L/S424R were 62.3%,70.7%and 76.3%,respectively.In this study,SPase mutants with higher activity and stability were obtained,and achieved high-level production ofαGG.
