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Gu G, Hou X, Xue M, Pan X, Dong J, Yang Y, Amuzu P, Xu D, Lai D, Zhou L. Diphenyl ethers from endophytic fungus Rhexocercosporidium sp. Dzf14 and their antibacterial activity by affecting homeostasis of cell membranes. Pest Manag Sci 2024; 80:2658-2667. [PMID: 38284314 DOI: 10.1002/ps.7972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/03/2024] [Accepted: 01/11/2024] [Indexed: 01/30/2024]
Abstract
BACKGROUND Phytopathogenic bacteria cause severe losses to crops every year. The management of crop bacterial diseases with chemical agents has been considered as the main strategy. In order to cope with the bactericide resistance made by the pathogens, new antibacterials need to be continuously developed. RESULTS A chemical investigation from the endophytic fungus Rhexocercosporidium sp. Dzf14 has led to the isolation of 12 diphenyl ethers including two new ones named rhexocerin E (1) and rhexocercosporin G (2), along with two new depsides named rhexocerdepsides A (3) and B (4). The structures and absolute configurations of the new compounds were determined through comprehensive analysis of spectroscopic data and quantum chemical ECD calculations. Diphenyl ethers showed obviously antibacterial activity on Gram-positive bacteria. The structure-activity relationship of diphenyl ethers revealed that prenylation was critical to the antibacterial activity. Among them, rhexocercosporin D (12) possessed the strongest activity against Clavibacter michiganensis and Bacillus subtilis, and was selected for further mechanistic studies. It was found that rhexocercosporin D displayed bactericidal activity by affecting homeostasis of cell membranes. In addition to its rapid bactericidal effects on Gram-positive bacteria, rhexocercosporin D could restore the susceptibility against Gram-negative Agrobacterium tumefaciens by synergistic action with colistin. CONCLUSION Twelve diphenyl ethers and two depsides were isolated from endophytic fungus Rhexocercosporidium sp. Dzf14. Isopentenyl was critical for diphenyl ethers against Gram-positive bacteria. Rhexocercosporin D could affect homeostasis of bacterial cell membrane to exert rapid bactericidal activity. These findings highlight the antibacterial potential of the diphenyl ethers in crop bacterial disease management. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Gan Gu
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xuwen Hou
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Mengyao Xue
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xiaoqian Pan
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Jie Dong
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yonglin Yang
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Prosper Amuzu
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Dan Xu
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Daowan Lai
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Ligang Zhou
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
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He X, Sun S, Kong W, Li M, Li S. Eudistomins Y-Inspired Design and Divergent Optimization of Heteroaryl Ketones for New Antifungal Leads. J Agric Food Chem 2024. [PMID: 38753466 DOI: 10.1021/acs.jafc.3c09874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
The discovery of structurally distinct leads is imperative in modern agrochemical science. Inspired by eudistomins Y and the framework-related pharmaceuticals, aryl heteroaryl ketone was drawn as a common model intriguing the design and divergent synthesis of 14 kinds of heteroaryl ketones aligned with their oxime derivatives. Antifungal function-oriented phenotypical screen protruded benzothiazolyl-phenyl oxime 5a as a promising model, and the concomitant modification led to benzothiazolyl oxime 5am (EC50 = 5.17 μM) as a superior lead than fluoxastrobin (EC50 = 7.54 μM) against Sclerotinia sclerotiorum. Scaffold hopping of the phenyl subunit identified benzothiazolyl-pyridyl oxime as a novel antifungal scaffold accompanied by acquiring oxime 5bm with remarkable activity (EC50 = 3.57 μM) against Pyricularia oryzae. Molecular docking showed that candidate 5am could form more hydrogen bonds with the amino acid residues of actin than metrafenone. This compound also demonstrated better curative efficacy than that of fluoxastrobin and metrafenone in controlling the plant disease caused by S. sclerotiorum. These results rationalize the discovery of antifungal candidates based on aryl heteroaryl ketone.
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Affiliation(s)
- Xiaodan He
- State Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Shengxin Sun
- State Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Wenlong Kong
- State Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Mengyang Li
- State Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Shengkun Li
- State Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
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López-Cabeza R, Rodríguez-Sabina S, Reyes CP, Expósito DG, Giménez C, Jiménez IA, Cabrera R, Bazzocchi IL. Bio-guided isolation of aromatic abietane diterpenoids from Salvia canariensis as biopesticides in the control of phytopathogenic fungi. Pest Manag Sci 2024; 80:2199-2207. [PMID: 38258969 DOI: 10.1002/ps.7958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/22/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024]
Abstract
BACKGROUND Biofungicides arise as a promising alternative to the indiscriminate use of harmful synthetic fungicides in crop management. RESULTS The present study reports the bio-guided fractionation of an endemic plant from the Canary Islands, Salvia canariensis against the phytopathogens, Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum. This procedure allowed identifying a series of diterpenoids with an abietane skeleton (1-5), which exhibited remarkable activity against the phytopathogenic fungi assayed. Their structures were established by means of spectroscopic and spectrometric methods, as well as comparison with reported data. Compounds 2 (carnosic acid), 4 (11-acetoxy carnosic acid) and 5 (11,12-diacetoxy carnosic acid) showed significant mycelium growth inhibition (%GI > 50 at 0.1 mg/mL concentration) on all the assayed fungi, and with a potency also higher than the positive control, Fosbel-Plus, a fungicide commonly used in agriculture. A preliminary structure-activity relationship is also discussed. CONCLUSIONS These findings underline the aromatic abietane diterpenoids as promising eco-friendly alternatives to conventional fungicides to use in integrated pest management. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Rocío López-Cabeza
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, La Laguna, Spain
- Departamento de Agroquímica, Microbiología Ambiental y Protección de Suelos y Agua, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Sevilla, Spain
| | - Samuel Rodríguez-Sabina
- Departamento de Botánica, Ecología y Fisiología Vegetal, Facultad de Biología, Universidad de La Laguna, La Laguna, Spain
| | - Carolina P Reyes
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, La Laguna, Spain
| | - Daniela G Expósito
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, La Laguna, Spain
| | - Cristina Giménez
- Departamento de Botánica, Ecología y Fisiología Vegetal, Facultad de Biología, Universidad de La Laguna, La Laguna, Spain
| | - Ignacio A Jiménez
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, La Laguna, Spain
| | - Raimundo Cabrera
- Departamento de Botánica, Ecología y Fisiología Vegetal, Facultad de Biología, Universidad de La Laguna, La Laguna, Spain
| | - Isabel L Bazzocchi
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, La Laguna, Spain
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Li L, Xu C, Zou J, Deng Z, You S, Wang Q. Novel Cyclopenta[ c]pyridine Derivatives Based on Natural Cerbinal as Potential Agrochemical Anti-TMV Agents and Insecticides. J Agric Food Chem 2024; 72:6684-6690. [PMID: 38485919 DOI: 10.1021/acs.jafc.3c07422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Based on natural cerbinal, a series of novel 4-bit modified cyclopenta[c]pyridine derivatives containing a substituted amide or ester moiety were designed and synthesized for the first time. Their structures were systematically characterized by NMR and high-resolution mass spectra (HRMS). The anti-TMV activities, such as protection, inactivation, and curative effects in vivo, were evaluated methodically. The lethal activities of the target compounds against the agriculturally common pests Plutella xylostella larvae and Aphis laburni kaltenbach were evaluated by the immersion method. The bioassay results indicated that most of the target compounds exhibited good to excellent anti-TMV activity levels, good lethal activity against P. xylostella larvae at 600 μg/mL, and greater insecticidal activities against A. laburni Kaltenbach compared to the plant-derived insecticide rotenone. The binding mode of cerbinal and cyclopenta[c]pyridine derivatives 4b, 4p, and 4v with the TMV protein was studied with a molecular docking method, which indicated that the functional group of the 2- and 4-positions is vital for anti-TMV activity. The systematic research provides strong evidence that these novel 4-bit modified cyclopenta[c]pyridine derivatives could become potential agrochemical insecticides and anti-TMV agents.
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Affiliation(s)
- Ling Li
- Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Changjiang Xu
- Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Jiyong Zou
- Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Zhaoyang Deng
- Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Shengyong You
- Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Qingmin Wang
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
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Xie Y, Du S, Su Z, Wang H, Qi H, Wang J, Wang X, Xiang W, Zhang H, Zhang J. Identification of Lydicamycins as Main Antioomycete Compounds from the Biocontrol Agent Streptomyces sp. NEAU-S7GS2. J Agric Food Chem 2024; 72:4649-4657. [PMID: 38383306 DOI: 10.1021/acs.jafc.3c08149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Oomycetes are well-known phytopathogens that seriously threaten many important crops worldwide. In this study, the endophytic actinobacterium Streptomyces sp. NEAU-S7GS2 demonstrated significant antagonistic activity against Phytophthora and Pythium and showed a potent biocontrol effect on suppression of soybean phytophthora root rot and pepper phytophthora blight. Two compounds were subsequently isolated as the main active components by bioassay-guided fractionation and identified as lydicamycins A and B. These two compounds showed high antioomycete activity against Phytophthora and Pythium with EC50 values of 0.73-2.67 μg/mL, which are equal to or lower than those of commercialized drug metalaxyl. In vivo bioassay using detached leaves demonstrated that lydicamycin A had a better control efficiency against soybean phytophthora root rot than metalaxyl. Taken together, these results suggest that the biocontrol agent Streptomyces sp. NEAU-S7GS2 and lydicamycins have the potential to be developed as promising pesticides to control diseases caused by oomycetes.
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Affiliation(s)
- Yimeng Xie
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
| | - Shihua Du
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
| | - Ziwei Su
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
| | - Han Wang
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
| | - Huan Qi
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Science, Huzhou University, Huzhou 313000, China
| | - Jidong Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Science, Huzhou University, Huzhou 313000, China
| | - Xiangjing Wang
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
| | - Wensheng Xiang
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
| | - Hui Zhang
- Taizhou Key Laboratory of Horticultural Biotechnology, Taizhou Vovational College of Science and Technology, Taizhou 318020, China
| | - Ji Zhang
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China
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Maimone NM, Apaza-Castillo GA, Quecine MC, de Lira SP. Accessing the specialized metabolome of actinobacteria from the bulk soil of Paullinia cupana Mart. on the Brazilian Amazon: a promising source of bioactive compounds against soybean phytopathogens. Braz J Microbiol 2024:10.1007/s42770-024-01286-1. [PMID: 38421597 DOI: 10.1007/s42770-024-01286-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/10/2024] [Indexed: 03/02/2024] Open
Abstract
The Amazon rainforest, an incredibly biodiverse ecosystem, has been increasingly vulnerable to deforestation. Despite its undeniable importance and potential, the Amazonian microbiome has historically received limited study, particularly in relation to its unique arsenal of specialized metabolites. Therefore, in this study our aim was to assess the metabolic diversity and the antifungal activity of actinobacterial strains isolated from the bulk soil of Paullinia cupana, a native crop, in the Brazilian Amazon Rainforest. Extracts from 24 strains were subjected to UPLC-MS/MS analysis using an integrative approach that relied on the Chemical Structural and Compositional Similarity (CSCS) metric, GNPS molecular networking, and in silico dereplication tools. This procedure allowed the comprehensive understanding of the chemical space encompassed by these actinobacteria, which consists of features belonging to known bioactive metabolite classes and several unannotated molecular families. Among the evaluated strains, five isolates exhibited bioactivity against a panel of soybean fungal phytopathogens (Rhizoctonia solani, Macrophomina phaseolina, and Sclerotinia sclerotiorum). A focused inspection led to the annotation of pepstatins, oligomycins, hydroxamate siderophores and dorrigocins as metabolites produced by these bioactive strains, with potentially unknown compounds also comprising their metabolomes. This study introduces a pragmatic protocol grounded in established and readily available tools for the annotation of metabolites and the prioritization of strains to optimize further isolation of specialized metabolites. Conclusively, we demonstrate the relevance of the Amazonian actinobacteria as sources for bioactive metabolites useful for agriculture. We also emphasize the importance of preserving this biome and conducting more in-depth studies on its microbiota.
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Affiliation(s)
- Naydja Moralles Maimone
- College of Agriculture "Luiz de Queiroz", Department of Exact Sciences, University of São Paulo, Piracicaba, SP, 13418-900, Brazil
| | - Gladys Angélica Apaza-Castillo
- College of Agriculture "Luiz de Queiroz", Department of Genetics, University of São Paulo, Piracicaba, SP, 13418-900, Brazil
| | - Maria Carolina Quecine
- College of Agriculture "Luiz de Queiroz", Department of Genetics, University of São Paulo, Piracicaba, SP, 13418-900, Brazil
| | - Simone Possedente de Lira
- College of Agriculture "Luiz de Queiroz", Department of Exact Sciences, University of São Paulo, Piracicaba, SP, 13418-900, Brazil.
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Wang D, Yuan C, Li Y, Bai S, Feng J, Wang Y, Fang Y, Zhang Z. Chelation of the Optimal Antifungal Pogostone Analogue with Copper(II) to Explore the Dual Antifungal and Antibacterial Agent. J Agric Food Chem 2024; 72:3894-3903. [PMID: 38366986 DOI: 10.1021/acs.jafc.3c07050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
In an ongoing effort to explore more potent antifungal pogostone (Po) analogues, we maintained the previously identified 3-acetyl-4-hydroxy-2-pyrone core motif while synthesizing a series of Po analogues with variations in the alkyl side chain. The in vitro bioassay results revealed that compound 21 was the most potent antifungal analogue with an EC50 value of 1.1 μg/mL against Sclerotinia sclerotiorum (Lib.) de Bary. Meanwhile, its Cu(II) complex 34 manifested significantly enhanced antibacterial activity against Xanthomonas campestris pv campestris (Xcc) with a minimum inhibitory concentration (MIC) value of 300 μg/mL compared with 21 (MIC = 700 μg/mL). Complex 34 exhibited a striking preventive effect against S. sclerotiorum and Xcc in rape leaves, with control efficacies of 98.8% (50 μg/mL) and 80.7% (1000 μg/mL), respectively. The 3D-QSAR models generated using Topomer comparative molecular field analysis indicated that a shorter alkyl chain (carbon atom number <8), terminal rings, or electron-deficient groups on the alkyl side chain are beneficial for antifungal potency. Further, bioassay results revealed that the component of 21 in complex 34 dominated the antifungal activity, but the introduction of Cu(II) significantly enhanced its antibacterial activity. The toxicological observations demonstrated that 21 could induce abnormal mitochondrial morphology, loss of mitochondrial membrane potential, and reactive oxygen species (ROS) accumulation in S. sclerotiorum. The enzyme assay results showed that 21 is a moderate promiscuous inhibitor of mitochondrial complexes II and III. Besides, the introduction of Cu(II) to 34 could promote the disruption of the cell membrane and intracellular proteins and the ROS level in Xcc compared with 21. In summary, these results highlight the potential of 34 as a dual antifungal and antibacterial biocide for controlling rape diseases or as a promising candidate for further optimization.
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Affiliation(s)
- Delong Wang
- College of Plant Protection, Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China
| | - Chunxia Yuan
- College of Plant Protection, Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China
| | - Yunpeng Li
- College of Plant Protection, Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China
| | - Shuhong Bai
- College of Plant Protection, Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China
| | - Juntao Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yali Fang
- College of Plant Protection, Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China
| | - Zhijia Zhang
- College of Plant Protection, Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Shanxi Agricultural University, Taiyuan 030031, Shanxi, China
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Liu J, Guo B, Zhong S, Shi Y, Li Z, Yu Z, Hao Z, Zhang L, Li F, Wang Y, Li Y. Novel Evodiamine-Based Sulfonamide Derivatives as Potent Insecticide Candidates Targeting Insect Ryanodine Receptors. J Agric Food Chem 2024; 72:1292-1301. [PMID: 38178001 DOI: 10.1021/acs.jafc.3c05680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Pests represent an important impediment to efficient agricultural production and pose a threat to global food security. On the basis of our prior research focused on identifying insecticidal leads targeting insect ryanodine receptors (RyRs), we aimed to identify evodiamine scaffold-based novel insecticides. Thus, a variety of evodiamine-based derivatives were designed, synthesized, and assessed for their insecticidal activity against the larvae of Mythimna separata (M. separata) and Plutella xylostella (P. xylostella). The preliminary bioassay results revealed that more than half of the target compounds exhibited superior activity compared to evodiamine, matrine, and rotenone against M. separata. Among these, compound 21m displayed the most potent larvicidal efficiency, with a remarkable mortality rate of 93.3% at 2.5 mg/L, a substantial improvement over evodiamine (10.0% at 10 mg/L), matrine (10.0% at 200 mg/L), and rotenone (30.0% at 200 mg/L). In the case of P. xylostella, compounds 21m and 21o displayed heightened larvicidal activity, boasting LC50 values of 9.37 × 10-2 and 0.13 mg/L, respectively, surpassing that of evodiamine (13.41 mg/L), matrine (291.78 mg/L), and rotenone (18.39 mg/L). A structure-activity relationship analysis unveiled that evodiamine-based derivatives featuring a cyclopropyl sulfonyl group at the nitrogen atom of the B ring and a fluorine atom in the E ring exhibited more potent larvicidal effects. This finding was substantiated by calcium imaging experiments and molecular docking, which suggested that 21m could target insect RyRs, including resistant mutant RyRs of P. xylostella (G4946E and I4790M), with higher affinity than chlorantraniliprole (CHL). Additionally, cytotoxicity assays highlighted that the potent compounds 21i, 21m, and 21o displayed favorable selectivity and low toxicity toward nontarget organisms. Consequently, compound 21m emerges as a promising candidate for further development as an insecticide targeting insect RyRs.
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Affiliation(s)
- Jingbo Liu
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Bingyan Guo
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Siying Zhong
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Yabing Shi
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Zhengping Li
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Zhenwu Yu
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Zesheng Hao
- Key Laboratory for Chemical Pesticide of Shandong Province, Shandong Academy of Pesticide Sciences, Jinan 250100, P. R. China
| | - Li Zhang
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Fengyun Li
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Yuanhong Wang
- College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin 300392, P. R. China
| | - Yuxin Li
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
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Duke SO. Why are there no widely successful microbial bioherbicides for weed management in crops? Pest Manag Sci 2024; 80:56-64. [PMID: 37271934 DOI: 10.1002/ps.7595] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 05/21/2023] [Indexed: 06/06/2023]
Abstract
Microbial biopesticides to control plant pathogens and insects in crops have had significant success. However, there have been relatively few successes for microbial bioherbicides in crops, despite considerable numbers of publications and commercial product introductions in this area. Marketed microbial bioherbicide products for use in agriculture have been largely unsuccessful. This article covers the potential advantages of successful microbial bioherbicides, as well as the biological and technical issues that have limited their success. Technologies to overcome the problems that have limited the success of these products are discussed. The many advantages of using killed microbial products (e.g. cell-free filtrates) over living microbial products as bioherbicides are detailed. A commercialized mycoherbicide that has been selected for in the laboratory for control of the parasitic weed Striga hermonthica is being used with some success in Africa, indicating that non-transgenic modification of the genetics of bioherbicide microbes for improved efficacy is acceptable to some regulatory authorities. Genetic modifications to improve efficacy and host range, as well as improved application technology to greatly reduce the amount of product needed are two technologies that are likely to expand the use of microbial bioherbicides in the future. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Stephen O Duke
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, Mississippi, USA
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Yang Q, Guo Y, Wang H, Luo Z, Chen Y, Jiang M, Lu H, Valverde BE, Qiang S, Strasser RJ, Chen S. Action of the fungal compound citrinin, a bioherbicide candidate, on photosystem II. Pest Manag Sci 2024; 80:133-148. [PMID: 37103431 DOI: 10.1002/ps.7513] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/06/2023] [Accepted: 04/27/2023] [Indexed: 05/12/2023]
Abstract
BACKGROUND Bioherbicides are becoming more attractive as safe weed control tools towards sustainable agriculture. Natural products constitute an important source chemicals and chemical leads for discovery and development of novel pesticide target sites. Citrinin is a bioactive compound produced by fungi of the genera Penicillium and Aspergillus. However, its physiological-biochemical mechanism as a phytotoxin remains unclear. RESULTS Citrinin causes visible leaf lesions on Ageratina adenophora similar to those produced by the commercial herbicide bromoxynil. Phytotoxicity bioassay tests using 24 plant species confirmed that citrinin has a broad activity spectrum and therefore has potential as a bioherbicide. Based on chlorophyll fluorescence studies, citrinin mainly blocks PSII electron flow beyond plastoquinone QA at the acceptor side, resulting in the inactivation of PSII reaction centers. Furthermore, molecular modeling of citrinin docking to the A. adenophora D1 protein suggests that it binds to the plastoquinone QB site by a hydrogen bond between the O1 hydroxy oxygen atom of citrinin and the histidine 215 of the D1 protein, the same way as classical phenolic PSII herbicides do. Finally, 32 new citrinin derivatives were designed and sorted according to free energies on the basis of the molecular model of an interaction between the citrinin molecule and the D1 protein. Five of the modeled compounds had much higher ligand binding affinity within the D1 protein compared with lead compound citrinin. CONCLUSION Citrinin is a novel natural PSII inhibitor that has the potential to be developed into a bioherbicide or utilized as a lead compound for discovery of new derivatives with high herbicidal potency. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Qian Yang
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Yanjing Guo
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - He Wang
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Zhi Luo
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Ying Chen
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Mengyun Jiang
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Huan Lu
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Bernal E Valverde
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
- Research and Development in Tropical Agriculture, Alajuela, Costa Rica
| | - Sheng Qiang
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
| | - Reto Jörg Strasser
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
- Bioenergetics Laboratory, University of Geneva, Geneva, Switzerland
| | - Shiguo Chen
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing, China
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11
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Ribeiro VP, Bajsa-Hirschel J, Tamang P, Meepagala K, Duke SO. Antifungal and Phytotoxic Activities of Isolated Compounds from Helietta parvifolia Stems. Molecules 2023; 28:7930. [PMID: 38067660 PMCID: PMC10708216 DOI: 10.3390/molecules28237930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/03/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
The identification of natural and environmentally friendly pesticides is a key area of interest for the agrochemical industry, with many potentially active compounds being sourced from numerous plant species. In this study, we report the bioassay-guided isolation and identification of phytotoxic and antifungal compounds from the ethyl acetate extract of Helietta parvifolia stems. We identified eight compounds, consisting of two coumarins and six alkaloids. Among these, a new alkaloid, 2-hydroxy-3,6,7-trimethoxyquinoline-4-carbaldehyde (6), was elucidated, along with seven known compounds. The phytotoxicity of purified compounds was evaluated, and chalepin (4) was active against Agrostis stolonifera at 1 mM with 50% inhibition of seed germination and it reduced Lemna pausicotata (duckweed) growth by 50% (IC50) at 168 μM. Additionally, we evaluated the antifungal activity against the fungal plant pathogen Colletotrichum fragariae using a thin-layer chromatography bioautography assay, which revealed that three isolated furoquinoline alkaloids (flindersiamine (3), kokusagenine (7), and maculine (8)) among the isolated compounds had the strongest inhibitory effects on the growth of C. fragariae at all tested concentrations. Our results indicate that these active natural compounds, i.e., (3), (4), (7), and (8), could be scaffolds for the production of more active pesticides with better physicochemical properties.
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Affiliation(s)
- Victor Pena Ribeiro
- Agricultural Research Service, Natural Products Utilization Research Unit, U.S. Department of Agriculture, University, MS 38677, USA; (V.P.R.); (J.B.-H.); (P.T.)
| | - Joanna Bajsa-Hirschel
- Agricultural Research Service, Natural Products Utilization Research Unit, U.S. Department of Agriculture, University, MS 38677, USA; (V.P.R.); (J.B.-H.); (P.T.)
| | - Prabin Tamang
- Agricultural Research Service, Natural Products Utilization Research Unit, U.S. Department of Agriculture, University, MS 38677, USA; (V.P.R.); (J.B.-H.); (P.T.)
| | - Kumudini Meepagala
- Agricultural Research Service, Natural Products Utilization Research Unit, U.S. Department of Agriculture, University, MS 38677, USA; (V.P.R.); (J.B.-H.); (P.T.)
| | - Stephen O. Duke
- National Center for Natural Products Research, University, MS 38677, USA;
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12
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He HW, Xu D, Wu KH, Lu ZY, Liu X, Xu G. Discovery of novel salicylaldehyde derivatives incorporating an α-methylene-γ-butyrolactone moiety as fungicidal agents. Pest Manag Sci 2023; 79:5015-5028. [PMID: 37544900 DOI: 10.1002/ps.7703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/20/2023] [Accepted: 08/03/2023] [Indexed: 08/08/2023]
Abstract
BACKGROUND Plant diseases caused by phytopathogenic fungi and oomycetes pose a serious threat to ensuring crop yield and quality. Finding novel fungicidal candidates based on natural products is one of the critical methods for developing effective and environmentally friendly pesticides. In this study, a series of salicylaldehyde derivatives containing an α-methylene-γ-butyrolactone moiety were designed, synthesized, and their fungicidal activities were evaluated. RESULTS The bioassay studies indicated that compound C3 displayed an excellent in vitro activity against Rhizoctonia solani with a half-maximal effective concentration (EC50 ) value of 0.65 μg/mL, higher than that of pyraclostrobin (EC50 = 1.44 μg/mL) and comparable to that of carbendazim (EC50 = 0.33 μg/mL). For Valsa mali and Phytophthora capsici, compound C3 also showed good fungicidal activities with EC50 values of 0.91 and 1.33 μg/mL, respectively. In addition, compound C3 exhibited promising protective in vivo activity against R. solani (84.1%) at 100 μg/mL, which was better than that of pyraclostrobin (78.4%). The pot experiment displayed that compound C3 had 74.8% protective efficacy against R. solani at 200 μg/mL, which was comparable to that of validamycin (78.2%). The antifungal mode of action research indicated that compound C3 could change the mycelial morphology and ultrastructure, increase cell membrane permeability, affect respiratory metabolism by binding to complex III, and inhibit the germination and formation of sclerotia, thereby effectively controlling the disease. CONCLUSION The present study provides support for the application of these salicylaldehyde derivatives as promising potential pesticides with remarkable and broad-spectrum fungicidal activities against phytopathogenic fungi and oomycetes in crop protection. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Hong-Wei He
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Dan Xu
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, China
| | - Ke-Huan Wu
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Zheng-Yi Lu
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Xili Liu
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, China
| | - Gong Xu
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, China
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13
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Gao K, Lin Y, Li L, Zha W, Zhu J, Zi J. Characterization of SchTPSs Enables Construction of Yeast for the Bioproduction of α-Cadinol and the Related Sesquiterpenes. J Agric Food Chem 2023; 71:18424-18430. [PMID: 37966253 DOI: 10.1021/acs.jafc.3c06394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
Plant volatile sesquiterpenes (PVSs) play important roles in chemical plant defense. However, it is difficult to isolate sufficient PVSs for deep investigations due to their low contents and chemical and physical properties close to those of other lipids. The extracts of Stellera chamaejasme L. exhibit insecticidal, fungicidal, and allelopathic activities. In this study, we identified three sesquiterpene synthase genes (SchTPS5, SchTPS6, and SchTPS7) from S. chamaejasme L. SchTPS7 is an α-farnesene synthase. SchTPS5 and SchTPS6 are two catalytically promiscuous sesquiterpene synthases, and α-cadinol and τ-muurolol are the predominant products for both of them in Saccharomyces cerevisiae. This study, for the first time, reports plant sesquiterpene synthases capable of producing α-cadinol and/or τ-muurolol in a heterologous host. More intriguingly, seven out of eight products of SchTPS6 in S. cerevisiae possess various insecticidal, fungicidal, and herbicidal activities. Building on this finding, we used SchTPS6 to construct an engineered S. cerevisiae for the production of these sesquiterpenes. The titers of two major products α-cadinol and τ-muurolol, respectively, reached 46.2 ± 4.0 and 11.2 ± 1.4 mg/L in a flask. This study lays a foundation for the development of new agrochemical mixtures.
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Affiliation(s)
- Ke Gao
- College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Ying Lin
- College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Linsheng Li
- College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Wenlong Zha
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs, and NHC Key Laboratory of Biosynthesis of Natural Products, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jianxun Zhu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs, and NHC Key Laboratory of Biosynthesis of Natural Products, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jiachen Zi
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs, and NHC Key Laboratory of Biosynthesis of Natural Products, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
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14
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Cruz-Cerino P, Cristóbal-Alejo J, Ruiz-Carrera V, Gamboa-Angulo M. Plant Extracts from the Yucatan Peninsula in the In Vitro Control of Curvularia lunata and Antifungal Effect of Mosannona depressa and Piper neesianum Extracts on Postharvest Fruits of Habanero Pepper. Plants (Basel) 2023; 12:2908. [PMID: 37631120 PMCID: PMC10459550 DOI: 10.3390/plants12162908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/05/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023]
Abstract
Plant extracts are a valuable alternative for the control of phytopathogenic fungi in horticultural crops. In the present work, the in vitro antifungal effect of ethanol and aqueous extracts from different vegetative parts of 40 native plants of the Yucatan Peninsula on Curvularia lunata ITC26, a pathogen of habanero pepper (Capsicum chinense), and effects of the most active extracts on postharvest fruits were investigated. Among these, the ethanol extracts of Mosannona depressa (bark from stems and roots) and Piper neesianum (leaves) inhibited 100% of the mycelial growth of C. lunata. The three extracts were partitioned between acetonitrile and n-hexane. The acetonitrile fraction from M. depressa stem bark showed the lowest mean inhibitory concentration (IC50) of 188 µg/mL against C. lunata. The application of this extract and its active principle α-asarone in the postharvest fruits of C. chinense (500 µg/mL) was shown to inhibit 100% of the severity of the infection caused by C. lunata after 11 days of contact. Both samples caused the distortion and collapse of the conidia of the phytopathogen when observed using electron microscopy at 96 h. The spectrum of M. depressa enriched antifungal action is a potential candidate to be a botanical fungicide in the control of C. lunata in cultivating habanero pepper.
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Affiliation(s)
- Patricia Cruz-Cerino
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Merida 97205, Mexico;
| | - Jairo Cristóbal-Alejo
- Laboratorio de Fitopatología, Tecnológico Nacional de México, Campus Conkal, Conkal 97345, Mexico
| | - Violeta Ruiz-Carrera
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa 86039, Mexico;
| | - Marcela Gamboa-Angulo
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Merida 97205, Mexico;
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15
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Shah FM, Guddeti DK, Paudel P, Chen J, Li XC, Khan IA, Ali A. Matricaria chamomilla Essential Oils: Repellency and Toxicity against Imported Fire Ants (Hymenoptera: Formicidae). Molecules 2023; 28:5584. [PMID: 37513455 PMCID: PMC10384828 DOI: 10.3390/molecules28145584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Matricaria chamomilla flower essential oils (EOs) blue Egyptian (EO-1), chamomile German CO2 (EO-2), and chamomile German (EO-3) and the pure compound α-bisabolol were evaluated against red imported fire ants (RIFA), Solenopsis invicta Buren, black imported fire ants, S. richteri Forel (BIFA), and hybrid imported fire ants (HIFA) for their repellency and toxicity. A series of serial dilutions were tested starting from 125 µg/g until the failure of the treatment. Based on the amount of sand removed, EO-1 showed significant repellency at dosages of 7.8, 7.8, and 31.25 µg/g against RIFA, BIFA, and HIFA, respectively. EO-3 was repellent at 3.9, 7.8, and 31.25 µg/g against BIFA, RIFA, and HIFA, whereas α-bisabolol was active at 7.8, 7.8, and 31.25 µg/g against BIFA, HIFA, and RIFA, respectively. DEET (N, N-diethyl-meta-toluamide) was active at 31.25 µg/g. Toxicity of EOs and α-bisabolol was mild to moderate. For EO-1, LC50 values were 93.6 and 188.11 µg/g against RIFA and BIFA; 98.11 and 138.4 µg/g for EO-2; and 142.92 and 202.49 µg/g for EO-3, respectively. The LC50 of α-bisabolol was 159.23 µg/g against RIFA. In conclusion, M. chamomilla EOs and α-bisabolol offer great potential to be developed as imported fire ant repellents.
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Affiliation(s)
- Farhan Mahmood Shah
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Dileep Kumar Guddeti
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Pradeep Paudel
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Jian Chen
- Biological Control of Pests Research Unit, USDA-ARS, Stoneville, MS 38776, USA
| | - Xing-Cong Li
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Ikhlas A Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Abbas Ali
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
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16
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Sparks TC, Lorsbach BA. Insecticide discovery-"Chance favors the prepared mind". Pestic Biochem Physiol 2023; 192:105412. [PMID: 37105622 DOI: 10.1016/j.pestbp.2023.105412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
New options for pest insect control, including new insecticides, are needed to ensure a plentiful food supply for an expanding global population. Any new insecticides must meet the increasingly stringent regulatory requirements for mammalian and environmental safety, and also address the need for new chemistries and modes of action to deal with resistance to available insecticides. As underscored by a paraphrase of a quote from Louis Pasteur "Chance favors the prepared mind", the agrochemical industry uses a variety of approaches that attempt to improve on "chance" for the discovery of new insecticides. Although there are a number of approaches to the discovery of new insecticidal active ingredients (AIs), historically most insecticides are based on a pre-existing molecule or product either from a competitor or from an internal company source. As such the first examples of a new insecticide representing a new type or class of AI (First-in-Class: FIC) are important as prototypes for other AIs stimulating further spectrum, efficacy, physicochemical, and environmental safety refinements. FIC insecticides also represent a measure of innovation. Understanding the origins of these FIC compounds and the approaches used in their discovery can provide insights into successful strategies for future new classes of insecticides. This perspective will focus on an analysis of the approaches that have been used for discovery of FIC insecticides highlighting those approaches that have been the most successful and providing a reference point for current and future directions.
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Affiliation(s)
| | - Beth A Lorsbach
- Nufarm, 4020 Aerial Center Parkway Morrisville, NC 27560, USA
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17
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Bai YB, Zhang M, Li D, Zhao Y, Huang LZ, Gao JM. Synthesis and Antifungal Activity of Derivatives of the Natural Product Griseofulvin against Phytopathogenic Fungi. J Agric Food Chem 2023; 71:6236-6248. [PMID: 37061927 DOI: 10.1021/acs.jafc.2c09037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Natural products are important sources for the discovery of new pesticides. Chemical synthesis and structural modification can lead to pesticides. Despite abundant research in fungicide discovery for crop protection, there is an emerging need for the development of novel antifungal agrochemicals. Herein, 39 diversified griseofulvin derivatives were effectively synthesized from the natural product griseofulvin by diversity-oriented synthesis through the reactions of demethylation, ammonolysis, methylation, nitration, acylation, reduction, and chlorination. Among them, 31 derivatives were novel. All structures were characterized by 1H NMR, 13C NMR, and high-resolution mass spectrometry (HR-MS), and the antifungal activity was investigated against five phytopathogenic fungi. Compounds 5h and 5l had excellent activity against Botrytis cinerea (5h, IC50 = 17.29 ± 0.64 μg/mL) and Alternaria solani (5l, IC50 = 22.52 ± 0.79 μg/mL), respectively. Compound 9 exhibited the more promising activities against three target fungi, especially against Colletotrichum gloeosporioides (IC50 = 7.24 ± 0.66 μg/mL), which is obviously better than positive control hymexazol, thifluzamide, and parent compound griseofulvin. In addition, compound 10 showed significant and extensive activities against four target fungi Cytospora sp. (IC50 = 18.72 ± 0.35 μg/mL), C. gloeosporioides (IC50 = 31.39 ± 1.48 μg/mL), A. solani (IC50 = 40.82 ± 1.04 μg/mL), and Fusarium solani (IC50 = 36.81 ± 0.82 μg/mL). Unexpectedly, 11 and 12, the chlorinated products of compound 9, exhibited the most promising activity against C. gloeosporioides (IC50 = 4.48 ± 0.54 μg/mL for 11, 2.24 ± 0.76 μg/mL for 12). Furthermore, 12 showed remarkable activity against Cytospora sp. (IC50 = 5.85 ± 0.72 μg/mL). Additionally, in vivo antifungal activity against C. gloeosporioides, homology modeling, and docking analysis of 11, 12, and griseofulvin were conducted. All results indicated that 11 and 12 had potency as antifungal agents against C. gloeosporioides, and the modifications of the 2' and 4' positions of griseofulvin should be further explored for higher-activity lead compounds or potential agricultural fungicides.
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Affiliation(s)
- Yu-Bin Bai
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an, Shaanxi 716000, People's Republic of China
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Meng Zhang
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an, Shaanxi 716000, People's Republic of China
| | - Ding Li
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Yu Zhao
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an, Shaanxi 716000, People's Republic of China
| | - Liang-Zhu Huang
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an, Shaanxi 716000, People's Republic of China
| | - Jin-Ming Gao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
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