Publications by authors named "Xing-hai Liu"

Article Synopsis
  • * These compounds showed strong antifungal activity against several plant pathogens, outperforming a commercial fungicide (bixafen) and being comparable to another (fluxapyroxad) in effectiveness.
  • * They were found to be safe for both monocotyledonous and dicotyledonous plants and their structure-activity relationships were analyzed, confirming their role as succinate dehydrogenase inhibitors through computational studies.
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  • Developing eco-friendly fungicides is essential to combat increasing pesticide resistance, leading to the creation of new pyrazole-4-carboxamide derivatives.
  • The target compounds were confirmed through various chemical analysis techniques, and one particularly active compound's structure was determined via X-ray diffraction.
  • Bioassays showed effective antifungal activity in vitro and in vivo for select compounds, with promising results in structure-function relationships and interactions with key enzymes, emphasizing their potential over traditional fungicides.
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  • New insecticides with unique mechanisms are needed to combat rising pesticide resistance.
  • Researchers designed and tested novel aryl isoxazoline derivatives, confirming their structures and finding excellent insecticidal activity against certain pests.
  • One specific compound showed promising results comparable to an existing insecticide, with potential for further development based on structure-activity relationships and molecular analysis.
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  • * The research focused on synthesizing these compounds and confirmed their structures using advanced techniques such as H NMR and HRMS.
  • * One specific compound showed significant fungicidal activity with 92.3% inhibition against a plant pathogen and had no harmful effects on crops, indicating its potential as a safe fungicide.
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  • A series of new compounds known as cyclopropane-1,1-dicarboxylic acid analogues were created to inhibit the enzyme ketol-acid reductoisomerase (KARI), which plays a role in plant amino acid pathways.
  • The structures of these compounds were analyzed using techniques like H NMR and X-ray diffraction, confirming their chemical makeup.
  • Testing showed that while most analogues had low herbicidal activity on lettuce and bentgrass, one compound exhibited moderate effectiveness against bentgrass, indicating potential for developing stronger KARI inhibitors.
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  • - Thirty new dioxolane ring compounds were created and analyzed using methods like H NMR and single crystal X-ray diffraction, confirming their chemical structures.
  • - These compounds showed strong fungicidal effects against various fungi and herbicidal activity against plants like lettuce and duckweed, with specific compounds demonstrating broad-spectrum effectiveness.
  • - The research indicated that these compounds target brassinosteroid biosynthesis in plants, and molecular docking studies revealed their potential to inhibit a key enzyme in fungal ergosterol production, providing insights for future compound design.
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It is important to discover new pesticides with new modes of action because of the increasing evolution of pesticide resistance. In this study, a series of novel pyrimidin-4-amine derivatives containing a 5-(trifluoromethyl)-1,2,4-oxadiazole moiety were designed and synthesized. Their structures were confirmed by H NMR, C NMR, and HRMS.

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Nicotinic acid, also known as niacin, is a natural product, which is widely found in plants and animals. To discover novel natural-product-based herbicides, a series of -(arylmethoxy)-2-chloronicotinamides were designed and synthesized. Some of the new -(arylmethoxy)-2-chloronicotinamides exhibited excellent herbicidal activity against (bentgrass) at 100 μM.

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To discover new compounds with broad spectrum and high activity, we designed a series of novel benzamides containing 1,2,4-oxadiazole moiety by bioisosterism, and 28 benzamides derivatives with antifungal activity were synthesized. These compounds were evaluated against four fungi: , , , and . The results indicated that most of the compounds displayed good fungicidal activities, especially against .

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To find pesticidal lead compounds with high activity, a series of novel benzamides substituted with pyridine-linked 1,2,4-oxadiazole were designed by bioisosterism, and synthesized easily via esterification, cyanation, cyclization and aminolysis reactions. The structures of the target compounds were confirmed by H-NMR, C-NMR and HRMS. The preliminary bioassay showed that most compounds had good larvicidal activities against mosquito larvae at 10 mg/L, especially compound , with a larvicidal activity as high as 100%, and even at 1 mg/L was still 40%; at 50 mg/L, all the target compounds showed good fungicidal activities against the eight tested fungi.

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Natural products are a source of many novel compounds with biological activity for the discovery of new pesticides and pharmaceuticals. Quinoxaline is a fused -heterocycle in many natural products and synthetic compounds, and seven novel quinoxaline derivatives were designed and synthesized three steps. Pesticidal activities of title quinoxaline derivatives were bioassayed.

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Thirty-six novel threoninamide carbamate derivatives were designed and synthesised using active fragment-based pharmacophore model. Antifungal activities of these compounds were tested against fungi and Interestingly, compound and exhibited moderate control effect (>50%) against in greenhouse at 6.25 μg/mL, which is better than that of control.

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Background: In recent years, carboxamide fungicides, targeting succinate dehydrogenase (SDH), have shown highly efficient and broad spectrum fungicidal activity. Structure-activity relationship (SAR) results for these commercial fungicides show that the carboxamide group was a key active group. This is useful information for the discovery of new pyrazole carboxamide derivatives with fungicidal activity.

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A series of new 3-substitutedphenyl-4-substitutedbenzylideneamino-1,2,4-triazole Mannich bases and bis-Mannich bases were synthesized through Mannich reaction with high yields. Their structures were confirmed by means of IR, H NMR, C NMR and elemental analysis. The preliminary bioassay indicated that compounds 7g, 7h and 7l exhibited potent in vitro inhibitory activities against ketol-acid reductoisomerase (KARI) with K value of (0.

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Background: Quinoline derivatives possess excellent fungicidal activity against rice blast, but quinoline derivatives have not been thoroughly explored as fungicides. In the process of designing new fungicides, the 1,1,1,2,3,3,3-heptafluoropropan-2-yl group was introduced in order to find new structure quinoline derivatives.

Results: Seventeen new quinoline derivatives containing 1,1,1,2,3,3,3-heptafluoropropan-2-yl moiety were designed and synthesised.

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A series of novel difluoromethylpyrazole carboxamides derivatives were synthesized by introduction of flexible alkyl chain. Nematicidal bioassay results showed that some of them exhibited good control efficacy against M. incognita, which indicated that these difluoromethylpyrazole carboxamides derivatives might be potential novel lead compounds for discovery new nematicides.

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A series of novel 5-substituted-1,3,4-oxadiazole Mannich bases and bis-Mannich bases have been conveniently synthesized in good yields. Their structures were characterized by IR, (1)H NMR, (13)C NMR and elemental analysis. The preliminary bioassay results indicated that some of the compounds showed promising in vitro fungicidal activities towards several test plant fungi; some of them exhibited significant herbicidal activities against Brassica campestris and excellent in vitro inhibitory activities against rice ketol-acid reductoisomerase (KARI).

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Background: The increasing prevalence of multi-drug resistant fungal infections has encouraged the search for new antifungal agents. Hydrazone derivatives always exhibited diversity activities, including antifungal, anti-inflammatory, anti-oxidation, anti-cancer activity. Regarding the heterocyclic moiety, 1,2,4-triazolo[4,3-a]pyridine derivatives also display broad activities, such as antifungal activity, anticonvulsant activity, herbicidal activity, antimicrobial activity and anticancer activity.

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Background: Aedes aegypti is a major mosquito vector for the transmission of serious diseases, especially dengue and yellow fever. More than 1 billion people in developing countries are at risk. The widespread and continual use of pesticides can lead to resistant mosquitoes.

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A series of novel chiral fluorinated pyrazole carboxamides derivatives were designed and synthesized. All these title compounds were confirmed by NMR and MS. The primarily nematocidal activity results indicated that some of them exhibited good control efficacy against the tomato root-knot nematode disease caused by Meloidogyne incognita.

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A series of novel carboxamide compounds 19a-19j, 20a-20j and 22a-22d containing piperazine and arylsulfonyl moieties have been synthesized. The bioassay results showed that some compounds exhibited favorable herbicidal activities against dicotyledonous plants and many of them possessed excellent antifungal activities. Among 24 novel compounds, some showed superiority over the commercial fungicides Chlorothalonil, Dimethomorph, Thiophanate-methyl, Iprodione, and Zhongshengmycin at 500 mg/L concentration.

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A series of novel pyrazole amide derivatives were designed and synthesized by multi-step reactions from phenylhydrazine and ethyl 3-oxobutanoate as starting materials, and their structures were characterized by NMR, MS and elemental analysis. The antifungal activity of the title compounds was determined. The results indicated that some of title compounds exhibited moderate antifungal activity.

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A series of novel 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one derivatives were synthesized and identified by (1)H NMR, single crystal X-ray diffraction, elemental analysis or HRMS, and their herbicidal activities were determined at different concentrations. It was found that some of the title compounds possess high herbicidal activity. Furthermore, DFT calculation was used to study the SAR.

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A field experiment was conducted to study the effects of foliar spraying of three kinds of compound agents [plant polysaccharides (P1), plant polysaccharides plus 5-aminolevulinic acid (P2), and plant polysaccharides plus 5-aminolevulinic acid and dimethylpiperidinium chloride (P3)] at the initial flowering stage of winter wheat on its yield components, sucrose content, soluble sugar content, the accumulation and translocation of dry matter, nitrogen and phosphorus. The grain number per spike and kilo-grains mass of winter wheat increased with the spray of the compound agents. The grain yield increased by more than 8.

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