The total synthesis of (+)-8-(3-methylbut-2-enyl)-2-phenyl-2,3-dihydrochromen-4-one and (±)-2-(4-hydroxyphenyl)-8-(3- methylbut-2-enyl)-2,3-dihydrochromen-4-one was first achieved through C-prenylation...The total synthesis of (+)-8-(3-methylbut-2-enyl)-2-phenyl-2,3-dihydrochromen-4-one and (±)-2-(4-hydroxyphenyl)-8-(3- methylbut-2-enyl)-2,3-dihydrochromen-4-one was first achieved through C-prenylation, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxyace- tophenone, with total yield of 20 and 16.3%. All structures of new compounds were confirmed by IR, 1H NMR and MS. 2009 Jin Hui Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
In this study, nano-capsules of lansiumamide B (NCLB) was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B (LB). An optimal formulation was gained by orthog...In this study, nano-capsules of lansiumamide B (NCLB) was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B (LB). An optimal formulation was gained by orthogonal experiment design based on the encapsulation efficiency (E, %) value. The optimized NCLB were spherical and uniform under transmission electron microscopy (TEM). The mean particle size, zeta potential and E, were (38.50~0.64) nm, (-70.5~0.76) mV and (95.13± 1.16)%, respectively. The release profile indicated that the accumulated release of LB in NCLB reached up to 82% within 96 h. Effects of NCLB against Bursaphelenehus xylophilus and J2 ofMeloidogyne incognita were reported in this paper. The nematicidal activity of NCLB has been remarkably increased, with LCs0 values of 2.1407 mg L-1 and 19.3608 mg L-1, respectively, at 24 h after treatment. The disease progression and the average number of root knots of Ipomoea aquatica were 1.50 and 7.25, respectively, in the treatment of NCLB, at concentration of 200 mg L-1 significantly lower than the treatment of LB and ethoprophos. Compared to control, the treatments of NCLB, LB and ethoprophos leaded the disease progression to drop 68.42, 36.84 and 26.32%, respectively, and caused the average number of root knots to fall 83.94, 78.03 and 63.66%. These results suggested that NCLB, as a novel nematicides formulation, performed more efficient and longer effective maintenance against plant parasitic nematodes.展开更多
Plant-parasitic nematodes cause substantial economic losses to global agriculture yearly.The use of nematicides is an effective way of controlling plant-parasitic nematodes.However,the long-term use of traditional org...Plant-parasitic nematodes cause substantial economic losses to global agriculture yearly.The use of nematicides is an effective way of controlling plant-parasitic nematodes.However,the long-term use of traditional organophosphorus and carbamate chemical nematicides can lead to increased nematode resistance.With the increasing awareness of the necessity for the protection of the environment and human health,highly toxic nematicides no longer meet the developmental requirements of modern agriculture.Recently,many studies have been undertaken on the isolation and nematicidal activity of natural products against plant-parasitic nematodes and Caenorhabditis elegans.As an important model nematode,C.elegans plays a vital reference role in studying plant-parasitic nematodes regarding nematicidal activity,metabolic mechanism,and modes of action and target.We reviewed the latest research progress of natural nematicidal active compounds against plantparasitic nematodes and C.elegans over the past ten years,discussed the structure-activity relationship and mechanism of action,and examined the development and application of natural nematicidal active compounds.展开更多
Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,orig...Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72 hvalue reached 3.20 mg/L in vitro and the inhibition rate was 100.00%at 40 mg/L in the matrix.The structure-activity relationship of synthesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.展开更多
A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Me...A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L. Among the tested compounds, A10 and A11 exhibited 100% inhibition rates. In addition, the molecular docking results indicated that both compound A10 and A11 interacts with amino acid residue Tyr121, Trp279, Tyr70, Trp84 and Phe330 of ACh E via hydrogen bond and p–p stacking. This investigation suggested that the chromone containing substituted pyrazole scaffold could be further optimized to explore novel, high-bioactivity nematicidal leads.展开更多
Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchufus semi...Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchufus semipenetruns in vitro and in vivo. Compounds 20, 21, 35 and 39 showed excellent lethal activities after treatment for 48 h in vitro, with LC50 values of 13.4±1.8, 11.7±2.5, 13.7±2.4 and 13.31.1 mg.L-1, respectively, which were obviously superior to fosthiazate (49.1±2.8 mg.L-1) and avermectin (26.6±2.3 mg.L-1). Compound 23. can effectively control the citrus nema- tode disease caused by T. semipenetruns at 200 mg.L-1 in vivo with (68±3)% inhibitory effect, which was even better than that of avermectin ((63±2)%). The CoMFA and CoMSIA models of three-dimensional quantitative structure-activity relationships (3D-QSARs) were established. The compound 33 was designed based on the 3D-QSAR models with more vigorous nematicidal activities in vitro (LC50:9.8±1.4 mg.L-1) and in vivo ((70±5)%). These results demonstrated that compound 33 can be considered as a potential nematicide.展开更多
To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structur...To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structure diversity of the new skeleton. Their inhibitory activities in vivo were evaluated against Meloidogyne incognita. The newly prepared compounds A6, A8, A21, A28 and A38 exhibited more than 50% inhibition at the concentration of 20 mg/L. Especially compound A6 displayed 71.4% inhibition against Meloidogyne incognita at the concentration of 20 mg/L. The nematicidal activities varied significantly depending on the types and positions of the substituents, which provided guidance for further structure modification.展开更多
Nematodes are serious constraints of crop production worldwide. However, the traditional nematicides suffer from the side-effects, including environmental and human toxicity. Herein, more than 70 novel piperazinedione...Nematodes are serious constraints of crop production worldwide. However, the traditional nematicides suffer from the side-effects, including environmental and human toxicity. Herein, more than 70 novel piperazinedione derivatives based on the natural product Barettin were synthesized and evaluated against the root-knot nematode Meloidogyne incognita(M. incognita). While most of synthesized compounds exhibited certain nematicidal activity at high concentration, the best one showed a nematicidal activity of 75% at 2.4 mmol/L.展开更多
The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel c...The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita(5.1 mmol/L), Ditylenchus destructor(3.7 mmol/L), Bursaphelenchus mucronatus(6.4 mmol/L), Bursaphelenchus B. xylophilus(2.5 mmol/L) and Aphelenchoides besseyi(3.1 mmol/L),respectively. A brief investigation on the structure–activity relationships(SAR) revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.展开更多
Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that...Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that HDZ-9-47 parasitized eggs of M.incognita within 7 days.In vitro,the culture filtrate of HDZ-9-47 caused 97.0%mortality of second-stage juveniles(J2s)of M.incognita and inhibited more than 50%egg hatching.In the field,compared with the control,the rootknot index and J2s density in the treatment of drench the broth contained 1012 HDZ-9-47 spores were respectively reduced by 51.1 and 80.7%at 90 days post transplantation,which were better than that in other application doses and methods.In addition,reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%,respectively,better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.And tomato yield also increased by 16.1%.Together,our results suggest that HDZ-9-47 could be an effective biocontrol agent of M.incognita,and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M.incognita control.展开更多
In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inh...In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inhibitor(SDHI)fungicide developed by Bayer AG in Germany,has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action.In this paper,two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures.The structures were identified and characterized by 1H nuclear magnetic resonance(NMR),13C NMR,and high-resolution mass spectrometer(HRMS).The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 lgmL-1 in comparison with fluopyram,while the nematode mortality rate dropped sharply at 100μg·mL-1,except for compounds I-11 and II-6.In terms of fungicidal activity,compound I-9 was discovered to have an excellent inhibitory rate,and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.展开更多
The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas,and nematicides are neither ecofriendly nor cost effective.More acceptable biological agents are r...The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas,and nematicides are neither ecofriendly nor cost effective.More acceptable biological agents are required for controlling this destructive pathogen.In this study,the biocontrol potential of Aspergillus welwitschiae AW2017 was investigated in laboratory and greenhouse experiments.The in vitro ovicidal and larvicidal activities of A.welwitschiae metabolites were tested on M.graminicola in laboratory experiments.The effect of A.welwitschiae on the attraction of M.graminicola to rice and the infection of rice by M.graminicola was evaluated in a greenhouse.The bioagent AW2017 displayed good nematicidal potential via its ovicidal and larvicidal action.The best larvicidal activity was observed at a concentration of 5×AW2017,which caused an 86.2%mortality rate at 48 h post inoculation.The highest ovicidal activity was recorded at a concentration of 5×AW2017,which resulted in an approximately 47.3%reduction in egg hatching after 8 d compared to the control.Under greenhouse conditions,the application of A.welwitschiae significantly reduced the root galls and nematodes in rice roots compared to the control.At a concentration of 5×AW2017,juveniles and root galls in rice roots at 14 d post inoculation(dpi)were reduced by 24.5 and 40.5%,respectively.In addition,the attraction of M.graminicola to rice roots was significantly decreased in the AW2017 treatment,and the development of nematodes in the AW2017-treated plants was slightly delayed compared with that in the PDB-treated control plants.The results indicate that A.welwitschiae is a potential biological control agent against M.graminicola in rice.展开更多
Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine...Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine parameters which characterize the global and local reactivity on five molecules of the series. These compounds differ from one to another with the aryl groups. There are: 1-(2-methylimidazo[1,2-a]pyridin-3-yl)-3-phenylprop-2-en-1-one, 3-(4-fluorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-[4-(dimethylamino)phenyl]-1-(2-methylimidazo [1,2-a]pyridin- 3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one. All results lead to finding out that local nucleophilicity and electrophilicity of compounds are not substituent-dependant contrarily to their global nucleophilicity which prove to be more sensitive to the electron-donating character of the substituents. 3-[4-(Dimethylamino) phenyl]-1-(2-methylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one was identified as the unique nucleophile compound by global reactivity. Respectively, the carbon atoms C5 and C14 are the prediction sites of electrophilic and nucleophilic attacks in the molecular skeleton of both molecules. Identification of interactions centres on IPC series is of great importance for organic synthesis and medicinal chemistry where the molecular hybridization strategy is very often used to improve biological activities of interesting therapeutic systems.展开更多
Fifteen novel N-sulfonyl aromatic amide derivatives were designed and synthesized, and the structures were characterized by 1H-and 13C-NMR, EA and HRMS. The crystal structures of compounds I-8 and I-9 were obtained fr...Fifteen novel N-sulfonyl aromatic amide derivatives were designed and synthesized, and the structures were characterized by 1H-and 13C-NMR, EA and HRMS. The crystal structures of compounds I-8 and I-9 were obtained from X-ray diffraction: I-8 is of triclinic system, Mr = 372.35, space group P2_(1/n) with a = 7.9151(10), b = 8.5637(11), c = 12.2022(15) A, β = 86.865(2)o, V = 807.09(18) A^(3), Z = 2, F(000) = 384, D_(c) = 1.532 g/cm^(3), the final R = 0.0408 and wR = 0.1068 for 2836 unique reflections with 2435 observed ones(I > 2σ(I)). I-9 belongs to triclinic system, M_r = 407.39, space group P2_1/n, with a = 8.4911(8), b = 8.6053(9), c = 14.5808(15) A, β = 77.1190(10)o, V = 995.44(17)A^(3), Z = 2, F(000) = 416, D_(c) = 1.359 g/cm^(3), the final R = 0.0567 and wR = 0.1779 for 3475 unique reflections with 2392 observed ones(I > 2σ(I)). The preliminary bioassay results indicated that the target compounds showed weak nematicidal activity, while compound I-5 displayed good fungicidal activity against Colletotrichum capsici with the inhibition rate of 61.7%.展开更多
基金the National Natural Science Foundation(No.20562010)Ministry of National Education(No.203143)for financial support
文摘The total synthesis of (+)-8-(3-methylbut-2-enyl)-2-phenyl-2,3-dihydrochromen-4-one and (±)-2-(4-hydroxyphenyl)-8-(3- methylbut-2-enyl)-2,3-dihydrochromen-4-one was first achieved through C-prenylation, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxyace- tophenone, with total yield of 20 and 16.3%. All structures of new compounds were confirmed by IR, 1H NMR and MS. 2009 Jin Hui Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Guangzhou Science and Technology Plan Projects, Guangzhou, China(10C62101593)
文摘In this study, nano-capsules of lansiumamide B (NCLB) was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B (LB). An optimal formulation was gained by orthogonal experiment design based on the encapsulation efficiency (E, %) value. The optimized NCLB were spherical and uniform under transmission electron microscopy (TEM). The mean particle size, zeta potential and E, were (38.50~0.64) nm, (-70.5~0.76) mV and (95.13± 1.16)%, respectively. The release profile indicated that the accumulated release of LB in NCLB reached up to 82% within 96 h. Effects of NCLB against Bursaphelenehus xylophilus and J2 ofMeloidogyne incognita were reported in this paper. The nematicidal activity of NCLB has been remarkably increased, with LCs0 values of 2.1407 mg L-1 and 19.3608 mg L-1, respectively, at 24 h after treatment. The disease progression and the average number of root knots of Ipomoea aquatica were 1.50 and 7.25, respectively, in the treatment of NCLB, at concentration of 200 mg L-1 significantly lower than the treatment of LB and ethoprophos. Compared to control, the treatments of NCLB, LB and ethoprophos leaded the disease progression to drop 68.42, 36.84 and 26.32%, respectively, and caused the average number of root knots to fall 83.94, 78.03 and 63.66%. These results suggested that NCLB, as a novel nematicides formulation, performed more efficient and longer effective maintenance against plant parasitic nematodes.
基金The authors are grateful to the National Key Research and Development Program of China(2018YFD0200100)for supporting the project.
文摘Plant-parasitic nematodes cause substantial economic losses to global agriculture yearly.The use of nematicides is an effective way of controlling plant-parasitic nematodes.However,the long-term use of traditional organophosphorus and carbamate chemical nematicides can lead to increased nematode resistance.With the increasing awareness of the necessity for the protection of the environment and human health,highly toxic nematicides no longer meet the developmental requirements of modern agriculture.Recently,many studies have been undertaken on the isolation and nematicidal activity of natural products against plant-parasitic nematodes and Caenorhabditis elegans.As an important model nematode,C.elegans plays a vital reference role in studying plant-parasitic nematodes regarding nematicidal activity,metabolic mechanism,and modes of action and target.We reviewed the latest research progress of natural nematicidal active compounds against plantparasitic nematodes and C.elegans over the past ten years,discussed the structure-activity relationship and mechanism of action,and examined the development and application of natural nematicidal active compounds.
基金financial supported by the National Natural Science Foundation of China(No.21672061)National Key Research Program of China(No.2018YFD0200105)+1 种基金supported by Innovation Program of Shanghai Municipal Education Commission(No.201701070002E00037)the Fundamental Research Funds for the Central Universities。
文摘Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72 hvalue reached 3.20 mg/L in vitro and the inhibition rate was 100.00%at 40 mg/L in the matrix.The structure-activity relationship of synthesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.
基金financial supported by the National Natural Science Foundation of China (No. 21672061)National Key Research Program of China (No. 2017YFD0200505)Fundamental Research Funds for the Central Universities (No. 222201718004)
文摘A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L. Among the tested compounds, A10 and A11 exhibited 100% inhibition rates. In addition, the molecular docking results indicated that both compound A10 and A11 interacts with amino acid residue Tyr121, Trp279, Tyr70, Trp84 and Phe330 of ACh E via hydrogen bond and p–p stacking. This investigation suggested that the chromone containing substituted pyrazole scaffold could be further optimized to explore novel, high-bioactivity nematicidal leads.
基金This work was financially supported by the National Key Re- search Development Program of China (2018YFD0200100) and the National Natural Science Foundation of China (No. 21672044) and Subsidy Project for Outstanding Key Laboratory of Guizhou Prov- ince in China (20154004).
文摘Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchufus semipenetruns in vitro and in vivo. Compounds 20, 21, 35 and 39 showed excellent lethal activities after treatment for 48 h in vitro, with LC50 values of 13.4±1.8, 11.7±2.5, 13.7±2.4 and 13.31.1 mg.L-1, respectively, which were obviously superior to fosthiazate (49.1±2.8 mg.L-1) and avermectin (26.6±2.3 mg.L-1). Compound 23. can effectively control the citrus nema- tode disease caused by T. semipenetruns at 200 mg.L-1 in vivo with (68±3)% inhibitory effect, which was even better than that of avermectin ((63±2)%). The CoMFA and CoMSIA models of three-dimensional quantitative structure-activity relationships (3D-QSARs) were established. The compound 33 was designed based on the 3D-QSAR models with more vigorous nematicidal activities in vitro (LC50:9.8±1.4 mg.L-1) and in vivo ((70±5)%). These results demonstrated that compound 33 can be considered as a potential nematicide.
基金financial supported by the National Natural Science Foundation of China(No. 21672061)National Key Research Program of China(Nos.2017YFD0200505 and 2018YFD0200105)the Fundamental Research Funds for the Central Universities(No. 222201718004)
文摘To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structure diversity of the new skeleton. Their inhibitory activities in vivo were evaluated against Meloidogyne incognita. The newly prepared compounds A6, A8, A21, A28 and A38 exhibited more than 50% inhibition at the concentration of 20 mg/L. Especially compound A6 displayed 71.4% inhibition against Meloidogyne incognita at the concentration of 20 mg/L. The nematicidal activities varied significantly depending on the types and positions of the substituents, which provided guidance for further structure modification.
基金financially supported by the National Natural Science Foundation of China (No. 21572060)
文摘Nematodes are serious constraints of crop production worldwide. However, the traditional nematicides suffer from the side-effects, including environmental and human toxicity. Herein, more than 70 novel piperazinedione derivatives based on the natural product Barettin were synthesized and evaluated against the root-knot nematode Meloidogyne incognita(M. incognita). While most of synthesized compounds exhibited certain nematicidal activity at high concentration, the best one showed a nematicidal activity of 75% at 2.4 mmol/L.
基金the National Natural Science Foundation of China(Nos.31070386,21302195 and 31300290)135 Key Cultivation Program of the Chinese Academy of Sciencesthe Province-Academy Cooperation Program of Henan Province of China(No.102106000021)for financial support
文摘The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita(5.1 mmol/L), Ditylenchus destructor(3.7 mmol/L), Bursaphelenchus mucronatus(6.4 mmol/L), Bursaphelenchus B. xylophilus(2.5 mmol/L) and Aphelenchoides besseyi(3.1 mmol/L),respectively. A brief investigation on the structure–activity relationships(SAR) revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.
基金financially supported by the National Basic Research Program of China (2013CB127501)the National Key Research and Development Program of China (2016YFD0201003)the National Natural Science Foundation of China (31272021, 31571987)
文摘Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that HDZ-9-47 parasitized eggs of M.incognita within 7 days.In vitro,the culture filtrate of HDZ-9-47 caused 97.0%mortality of second-stage juveniles(J2s)of M.incognita and inhibited more than 50%egg hatching.In the field,compared with the control,the rootknot index and J2s density in the treatment of drench the broth contained 1012 HDZ-9-47 spores were respectively reduced by 51.1 and 80.7%at 90 days post transplantation,which were better than that in other application doses and methods.In addition,reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%,respectively,better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.And tomato yield also increased by 16.1%.Together,our results suggest that HDZ-9-47 could be an effective biocontrol agent of M.incognita,and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M.incognita control.
基金This work was financially supported by the Natural Science Foundation of Shandong Province,China(ZR2017BC053)the Doctoral Research Startup Foundation of Liaocheng University(318051625).
文摘In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inhibitor(SDHI)fungicide developed by Bayer AG in Germany,has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action.In this paper,two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures.The structures were identified and characterized by 1H nuclear magnetic resonance(NMR),13C NMR,and high-resolution mass spectrometer(HRMS).The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 lgmL-1 in comparison with fluopyram,while the nematode mortality rate dropped sharply at 100μg·mL-1,except for compounds I-11 and II-6.In terms of fungicidal activity,compound I-9 was discovered to have an excellent inhibitory rate,and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.
基金financially supported by grants from the National Key Research and Development Program (2018YFD0201202 & 2017YFD0201102)the National Natural Science Foundation of China (31571986)
文摘The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas,and nematicides are neither ecofriendly nor cost effective.More acceptable biological agents are required for controlling this destructive pathogen.In this study,the biocontrol potential of Aspergillus welwitschiae AW2017 was investigated in laboratory and greenhouse experiments.The in vitro ovicidal and larvicidal activities of A.welwitschiae metabolites were tested on M.graminicola in laboratory experiments.The effect of A.welwitschiae on the attraction of M.graminicola to rice and the infection of rice by M.graminicola was evaluated in a greenhouse.The bioagent AW2017 displayed good nematicidal potential via its ovicidal and larvicidal action.The best larvicidal activity was observed at a concentration of 5×AW2017,which caused an 86.2%mortality rate at 48 h post inoculation.The highest ovicidal activity was recorded at a concentration of 5×AW2017,which resulted in an approximately 47.3%reduction in egg hatching after 8 d compared to the control.Under greenhouse conditions,the application of A.welwitschiae significantly reduced the root galls and nematodes in rice roots compared to the control.At a concentration of 5×AW2017,juveniles and root galls in rice roots at 14 d post inoculation(dpi)were reduced by 24.5 and 40.5%,respectively.In addition,the attraction of M.graminicola to rice roots was significantly decreased in the AW2017 treatment,and the development of nematodes in the AW2017-treated plants was slightly delayed compared with that in the PDB-treated control plants.The results indicate that A.welwitschiae is a potential biological control agent against M.graminicola in rice.
文摘Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine parameters which characterize the global and local reactivity on five molecules of the series. These compounds differ from one to another with the aryl groups. There are: 1-(2-methylimidazo[1,2-a]pyridin-3-yl)-3-phenylprop-2-en-1-one, 3-(4-fluorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-[4-(dimethylamino)phenyl]-1-(2-methylimidazo [1,2-a]pyridin- 3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one. All results lead to finding out that local nucleophilicity and electrophilicity of compounds are not substituent-dependant contrarily to their global nucleophilicity which prove to be more sensitive to the electron-donating character of the substituents. 3-[4-(Dimethylamino) phenyl]-1-(2-methylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one was identified as the unique nucleophile compound by global reactivity. Respectively, the carbon atoms C5 and C14 are the prediction sites of electrophilic and nucleophilic attacks in the molecular skeleton of both molecules. Identification of interactions centres on IPC series is of great importance for organic synthesis and medicinal chemistry where the molecular hybridization strategy is very often used to improve biological activities of interesting therapeutic systems.
基金supported by the National Natural Science Foundation of China(32001929)the Natural Science Foundation of Shandong Province(ZR2017BC053)the Innovation and Entrepreneurship Training Program for College Students of Liaocheng University(CXCY2020Y116)。
文摘Fifteen novel N-sulfonyl aromatic amide derivatives were designed and synthesized, and the structures were characterized by 1H-and 13C-NMR, EA and HRMS. The crystal structures of compounds I-8 and I-9 were obtained from X-ray diffraction: I-8 is of triclinic system, Mr = 372.35, space group P2_(1/n) with a = 7.9151(10), b = 8.5637(11), c = 12.2022(15) A, β = 86.865(2)o, V = 807.09(18) A^(3), Z = 2, F(000) = 384, D_(c) = 1.532 g/cm^(3), the final R = 0.0408 and wR = 0.1068 for 2836 unique reflections with 2435 observed ones(I > 2σ(I)). I-9 belongs to triclinic system, M_r = 407.39, space group P2_1/n, with a = 8.4911(8), b = 8.6053(9), c = 14.5808(15) A, β = 77.1190(10)o, V = 995.44(17)A^(3), Z = 2, F(000) = 416, D_(c) = 1.359 g/cm^(3), the final R = 0.0567 and wR = 0.1779 for 3475 unique reflections with 2392 observed ones(I > 2σ(I)). The preliminary bioassay results indicated that the target compounds showed weak nematicidal activity, while compound I-5 displayed good fungicidal activity against Colletotrichum capsici with the inhibition rate of 61.7%.