In the face of increasing resistance to the currently used commercial herbicides and the lack of success in identifying new herbicide targets, alternative herbicides need to be developed to control unwanted monocotyledon grasses in food crops. Here, a panel of 29 novel sulfonylurea-based compounds with fluoroalkoxy substitutions at the phenyl ring were designed and synthesized. Pot assays demonstrated that two of these compounds, and , have strong herbicidal activities against , , , and Steudel at a dosage of 15 g ha.
View Article and Find Full Text PDFBackground: In order to design compounds with fresh molecular skeleton to break through the limitation of available agrochemicals, a series of 36 novel selenenyl sulfide compounds were chemically synthesized, and their biological activities were fully evaluated against tobacco mosaic virus (TMV), 14 plant pathogenic fungi, three insect species and plant acetohydroxyacid synthase (AHAS).
Results: All the target compounds were characterized by proton nuclear magnetic resonance ( H-NMR), carbon-13 ( C)-NMR, selenium-77 ( Se)-NMR, and high-resolution mass spectrometry (HRMS). The crystal structure of 10j indicated that the Se-S bond was successfully constructed.
Based on the previous finding that a substitution at 5-position of the benzene ring is favorable to enhance the degradation rates of sulfonylurea herbicides, a total of 16 novel 2,5-disubsituted sulfonylurea compounds were chemically synthesized and fully characterized by means of H NMR, C NMR, HRMS and X-ray diffraction. By using HPLC analysis, the degradation behavior of M03, a compound belonging to this family, was studied and confirmed that chlorsulfuron itself is not a degraded product of the 2,5-disubstituted sulfonylureas. Inhibition constants against plant acetohydroxyacid synthase (AHAS) were determined for selected compounds, among which SU3 showed seven times stronger activity against the mutant W574L enzyme than chlorsulfuron.
View Article and Find Full Text PDFA series of 51 novel sulfonylurea compounds with ortho-alkoxy substituent at phenyl ring were chemically synthesized and spectroscopically characterized. The biological activities of the target compounds were evaluated using the enzyme inhibition against acetohydroxyacid synthase (AHAS; EC 2.2.
View Article and Find Full Text PDFIn the present study, we have designed and synthesized a series of 42 novel sulfonylurea compounds with alkoxy substitutions at the phenyl ring and evaluated their herbicidal activities. Some target compounds showed excellent herbicidal activity against monocotyledon weed species. When applied at 7.
View Article and Find Full Text PDFBackground: Intensifying weed resistance has challenged the use of existing acetohydroxyacid synthase (AHAS)-inhibiting herbicides. Hence, there is currently an urgent requirement for the discovery of a new AHAS inhibitor to effectively control AHAS herbicide-resistant weed species produced by target mutation.
Results: To combat weed resistance caused by AHAS with P197L mutation, we built a structure library consisting of pyrimidinyl-salicylic acid derivatives.
Since pyrithiobac (PTB) is a successful commercial herbicide with very low toxicity against mammals, it is worth exploring its derivatives for an extensive study. Herein, a total of 35 novel compounds were chemically synthesized and single crystal of 6-6 was obtained to confirm the molecular structure of this family of compounds. The novel PTB derivatives were fully evaluated against various biological platforms.
View Article and Find Full Text PDFAccetohydroxyacid synthase (AHAS) is the first enzyme involved in the biosynthetic pathway of branched-chain amino acids. Earlier gene mutation of Candida albicans in a mouse model suggested that this enzyme is a promising target of antifungals. Recent studies have demonstrated that some commercial AHAS-inhibiting sulfonylurea herbicides exerted desirable antifungal activity.
View Article and Find Full Text PDFThe issue of weed resistance to acetohydroxyacid synthase (EC 2.2.1.
View Article and Find Full Text PDFIn the search for new antiresistance acetohydroxyacid synthase (AHAS, EC 2.2.1.
View Article and Find Full Text PDFTuning the binding selectivity through appropriate ways is a primary goal in the design and optimization of a lead toward agrochemical discovery. However, how to achieve rational design of selectivity is still a big challenge. Herein, we developed a novel computational fragment generation and coupling (CFGC) strategy that led to a series of highly potent and bioselective inhibitors targeting protoporphyrinogen IX oxidase.
View Article and Find Full Text PDFAcetohydroxyacid synthase (AHAS; also known as acetolactate synthase; EC 2.2.1.
View Article and Find Full Text PDF46 Novel nonsymmetrical aromatic disulfides containing [1,3,4]thiadiazole or [1,3,4]oxadiazole groups were synthesized and their biological activities were evaluated as inhibitors of acetohydroxyacid synthase (AHAS, EC 2.2.1.
View Article and Find Full Text PDFThe triazolopyrimidine-2-sulfonanilide, discovered from preparing bioisosteres of the sulfonylurea herbicides, is an important class of acetohydroxyacid synthase (AHAS, EC 4.1.3.
View Article and Find Full Text PDFTriazolopyrimidine-2-sulfonamide belongs to a herbicide group called acetohydroxyacid synthase inhibitors. With the aim to discover new triazolopyrimidine sulfonanilide compounds with high herbicidal activity and faster degradation rate in soil, the methyl group of Flumetsulam (FS) was modified into a methoxy group to produce a new herbicidal compound, N-2,6-difluorophenyl-5-methoxy-1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonamide (experimental code: Y6610). The enzymatic kinetic results indicated that compound Y6610 and FS have k(i) values of 3.
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