Publications by authors named "Aiying Guan"

Article Synopsis
  • Downy mildew is a significant fungal threat to crops, with increasing resistance to current fungicides, highlighting the need for new treatments.
  • Researchers developed and tested a series of pyrazole amide derivatives for their effectiveness against the fungus Pseudoperonospora cubensis, responsible for cucumber downy mildew.
  • Among the compounds, T24 showed the best fungicidal activity and was further analyzed to understand how its structure contributes to its effectiveness, suggesting it could be a promising new fungicide.
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Background: A series of pyrimidine amine derivatives has been synthesized by modifying the pyrimidine ring group of diflumetorim-a mitochondrial complex I inhibiting fungicide. One derivative, code number SYP-34773, is investigated in this study involving Magnaporthe oryzae, the causal agent of rice blast, which is the most devastating disease in rice. The response, resistance profile and mechanism of M.

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Background: Glyphosate is the most widely used and successful herbicide discovered to date, but its utility is now threatened by the occurrence of several glyphosate-resistant weed species. Saflufenacil is a relatively new herbicide developed by BASF in 2010. It is a highly effective selective herbicide showing excellent control on broadleaf weeds (more than 90 species), significantly superior to other protoporphyrinogen oxidase (PPO) inhibitor herbicides at the level of weeds controlled.

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Harmful fungus and the developed resistance to available fungicides seriously threaten the yield and quality of crops; thus, the search for new, highly efficient, and resistance-overcoming fungicides remains a quite urgent goal of agricultural scientists. In this study, a series of novel spiropyrimidinamine derivatives were designed and synthesized by employing the intermediate derivatization method (IDM). Their structures were identified by H NMR, elemental analyses, and MS spectra.

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Proguanil, a member of biguanide family, has excellent anti-proliferative activities. Fluorine-containing compounds have been demonstrated to have super biological activities including enhanced binding interactions, metabolic stability, and reduced toxicity. In this study, based on the intermediate derivatization methods, we synthesized 13 new fluorine-containing proguanil derivatives, and found that 7a,7d and 8e had much lower IC than proguanil in 5 human cancerous cell lines.

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To explore a novel fungicide effectively against cucumber downy mildew (CDM), a series of new arylpyrazole containing pyrimidine ether derivatives were designed and synthesized by employing the intermediate derivatization method (IDM). The structures of synthesized compounds were identified by H NMR, C NMR, elemental analyses, MS, and X-ray diffraction. Bioassays demonstrated that some of the title compounds exhibited excellent fungicidal activities against CDM.

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Biguanides, including metformin and phenformin, have emerged as promising anticancer agents. However, the high dose needed for their efficient anticancer properties restricts their clinical application. In an attempt to obtain higher active compounds than these parent compounds, pyrazole-containing biguanide derivatives were synthesized and screened for in vitro cytotoxicity against human cancer cell lines.

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A series of novel quaternary ammonium salt derivatives were designed and synthesized by introducing the herbicide carboxylic acid into substituted aminoacetanilide compounds which derived from herbicides alachlor or acetochlor, using the intermediate derivatization methods in an attempt to obtain novel candidates for weed control. The herbicidal activity assays in greenhouse demonstrated that some of the title compounds exhibited good herbicidal activities against velvet leaf, youth-and-old age, barnyard grass, and foxtail. Especially, III9 gave the best activity (EC (ga.

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Downy mildew is one of the most highly destructive of the diseases that cause damage to fruits and vegetables. Because of the continual development of resistance, it is important to discover new fungicides with different modes of action from existing fungicides for the control of downy mildew. This study is a continuation of our previous work on the novel pyrimidinamine lead compound, 9, and includes field trials for the identification of the optimal candidate.

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Benzoylcyclohexanedione herbicides work by inhibiting 4-hydroxyphenylpyruvate dioxygenase which was the last new target site introduced for herbicides. In an attempt to find new 4-hydroxyphenylpyruvate dioxygenase inhibitors with high efficacy and selectivity, a novel benzoylcyclohexanedione compound SYP-9121 was synthesized and studied in greenhouse and field. In the greenhouse, SYP-9121 showed broad spectrum herbicidal activity and good safety to maize.

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The pyrimidinamine diflumetorim is an ideal template for the discovery of agrochemical lead compounds due to its unique mode of action, novel chemical structure, and lack of reported resistance. To develop a new pyrimidinamine fungicide effective against cucumber downy mildew (CDM), a series of new pyrimidinamine derivatives containing an aryloxy pyridine moiety were designed and synthesized by employing the recently reported intermediate derivatization method (IDM). The structures of all compounds were identified by H NMR, elemental analyses, HRMS, and X-ray diffraction.

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Background: To discover and exploit novel acaricidal compounds, a series of novel N-substituted piperazine derivatives were designed and synthesised using a tert-butyl piperazine-1-carboxylate as the starting material by intermediate derivatisation methods, and their acaricidal activities were evaluated.

Results: Compounds 11 and 12 exhibited significant acaricidal activity against adults of Tetranychus cinnabarinus in greenhouse tests. Compound 12, in particular, was found to be the best potential candidate acaricide and proved to be more active than the commercial positive controls spirodiclofen and pyridaben, with an LC of 0.

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Pyridine-based compounds have been playing a crucial role as agrochemicals or pesticides including fungicides, insecticides/acaricides and herbicides, etc. Since most of the agrochemicals listed in the Pesticide Manual were discovered through screening programs that relied on trial-and-error testing and new agrochemical discovery is not benefiting as much from the in silico new chemical compound identification/discovery techniques used in pharmaceutical research, it has become more important to find new methods to enhance the efficiency of discovering novel lead compounds in the agrochemical field to shorten the time of research phases in order to meet changing market requirements. In this review, we selected 18 representative known agrochemicals containing a pyridine moiety and extrapolate their discovery from the perspective of Intermediate Derivatization Methods in the hope that this approach will have greater appeal to researchers engaged in the discovery of agrochemicals and/or pharmaceuticals.

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Diphenylamine derivatives have been reported with good fungicidal, insecticidal, acaricidal, rodenticidal and/or herbicidal activities. To find new lead compound of this kind, a series of novel diphenylamine derivatives were designed and synthesized by the approach of Intermediate Derivatization Methods. All compounds were identified by (1)H NMR and elemental analysis.

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In an attempt to obtain novel candidate compound for weed control, a series of newly substituted 3-(pyridin-2-yl)benzenesulfonamide derivatives 2 were designed and synthesized using compound II7 as a lead compound by Intermediate Derivatization Methods and their herbicidal activities were evaluated. The herbicidal activity assay in greenhouse tests showed several compounds (2g, 2i, 2j, 2k, 2l, 2m, 2n and 2o) exhibited significant herbicidal activity for controlling velvet leaf (Abutilon theophrasti medic.) and youth-and-old age (Zinnia elegans jacq.

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Intensive competition of intellectual property, easy development of agrochemical resistance, and stricter regulations of environmental concerns make the successful rate for agrochemical discovery extremely lower using traditional agrochemical discovery methods. Therefore, there is an urgent need to find a novel approach to guide agrochemical discovery with high efficiency to quickly keep pace with the changing market. On the basis of these situations, here we summarize the intermediate derivatization method (IDM) between conventional methods in agrochemicals and novel ones in pharmaceuticals.

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A series of novel substituted 3-(pyridin-2-yl)benzenesulfonamide derivatives were designed and synthesized using 2-phenylpridines as the lead compound by intermediate derivatization methods in an attempt to obtain novel compound candidates for weed control. The herbicidal activity assay in glasshouse tests showed several compounds (II6, II7, II8, II9, II10, II11, III2, III3, III4, and III5) could efficiently control velvet leaf, youth-and-old age, barnyard grass, and foxtail at the 37.5 g/ha active substance.

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Chlorothalonil with both low cost and low toxicity is a popularly used fungicide in the agrochemical field. The presence of nucleophilic groups on this compound allows further chemical modifications to obtain novel chlorothalonil derivatives. Fluazinam, another commercially available agent with a broad fungicidal spectrum, has a scaffold of diaryl amine structure.

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A series of coumarin derivatives (6-8) containing (E)-methyl 2-(methoxyimino)-2-phenylacetate, (E)-2-(methoxyimino)-N-methyl-2-phenylacetamide and methyl methoxy(phenyl)carbamate were synthesized from substituted resorcinols (1) and substituted beta-keto esters (2) as starting material via cyclization and condensation reactions. The test results indicated that (E)-methyl 2-{2-[(3-hexyl-4-methyl-coumarin-7-yloxy)methyl]phenyl}-2-(methoxyimino)acetate (6f) was the optimal structure with good fungicidal activity against cucumber grey mold (CGM) giving 100% control at 100 mg L(-1) concentration, much higher than that of coumoxystrobin. Methyl 2-[(3,4-dimethyl-coumarin -7-yloxy)methyl]phenyl(methoxy)carbamate (8a) was another optimal structure with good fungicidal activity against wheat powdery mildew (WPM) showing 100% control at 50 mg L(-1) concentration, at the same level as that of the commercial kresoxim-methyl, and very significantly higher than that of coumoxystrobin (no control against WPM at 400 mg L(-1)).

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Background: The lead coumarin derivative (E)-methyl 3-methoxy-2-[2-(4-methylcoumarin-7-yloxymethyl)phenyl]acrylate was discovered by using an intermediate derivatisation method. To discover new coumarin derivatives with improved activity, a series of substituted coumarins were synthesised and bioassayed.

Results: The compounds were identified by ¹H NMR, IR, MS and elemental analysis.

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