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Ngo MT, Han JW, Nguyen MV, Choi Y, Kim B, Gho ES, Kim H, Choi GJ. Discovery of Novel Antioomycete Metabolites from the Marine-Derived Fungus Paraconiothyrium sporulosum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:16359-16367. [PMID: 39011851 DOI: 10.1021/acs.jafc.4c04706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
In our screening program for natural products that are effective in controlling plant diseases, we found that the culture filtrate of Paraconiothyrium sporulosum SFC20160907-M11 effectively suppressed the development of tomato late blight disease caused by Phytophthora infestans. Using a bioassay-guided fractionation of antioomycete activity, 12 active compounds (1-12) were obtained from an ethyl acetate extract of the culture filtrate. Chemical structures of five new compounds 1-5 were determined by the extensive analyses of nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS), and circular dichroism (CD) data. Interestingly, mycosporulonol (1) and botrallin (8) completely inhibited the growth of P. infestans at concentrations of 8 and 16 μg/mL, respectively. Furthermore, the spray treatment of 1 and 8 (500 μg/mL) successfully protected tomato seedlings against P. infestans with disease control values of 92%. Taken together, these results suggest that the culture filtrates of P. sporulosum SFC20160907-M11 and their bioactive metabolites can be used as new antioomycete agents for Phytophthora late blight control.
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Affiliation(s)
- Men Thi Ngo
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Jae Woo Han
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Minh Van Nguyen
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Yugyeong Choi
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Bomin Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Eun Sol Gho
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Hun Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Gyung Ja Choi
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113, Republic of Korea
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Palasarn S, Srichomthong K, Thummarukcharoen T, Thongpanchang C, Isaka M. Antimalarial 9-methoxystrobilurin derivatives from cultures of the basidiomycete Favolaschia minutissima. J Antibiot (Tokyo) 2024; 77:422-427. [PMID: 38724629 DOI: 10.1038/s41429-024-00733-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 04/09/2024] [Accepted: 04/15/2024] [Indexed: 06/28/2024]
Abstract
Investigation of cultures of the basidiomycete Favolaschia minutissima TBRC-BCC 19434 led to the isolation of two undescribed β-methoxyacrylate metabolites, 9-methoxystrobilurins R (1) and S (2), and a degraded aldehyde derivative, favodehyde E (3). 9-Methoxystrobilurin derivatives 1 and 2 exhibited significant antimalarial activity against Plasmodium falciparum K1 (multidrug-resistant strain) with IC50 values of 0.12 and 0.21 μM, respectively.
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Affiliation(s)
- Somporn Palasarn
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani, 12120, Thailand
| | - Kitlada Srichomthong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani, 12120, Thailand
| | - Tuksaporn Thummarukcharoen
- National Biobank of Thailand, National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani, 12120, Thailand
| | - Chawanee Thongpanchang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani, 12120, Thailand
| | - Masahiko Isaka
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani, 12120, Thailand.
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3
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Sang M, Feng P, Chi LP, Zhang W. The biosynthetic logic and enzymatic machinery of approved fungi-derived pharmaceuticals and agricultural biopesticides. Nat Prod Rep 2024; 41:565-603. [PMID: 37990930 DOI: 10.1039/d3np00040k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Covering: 2000 to 2023The kingdom Fungi has become a remarkably valuable source of structurally complex natural products (NPs) with diverse bioactivities. Since the revolutionary discovery and application of the antibiotic penicillin from Penicillium, a number of fungi-derived NPs have been developed and approved into pharmaceuticals and pesticide agents using traditional "activity-guided" approaches. Although emerging genome mining algorithms and surrogate expression hosts have brought revolutionary approaches to NP discovery, the time and costs involved in developing these into new drugs can still be prohibitively high. Therefore, it is essential to maximize the utility of existing drugs by rational design and systematic production of new chemical structures based on these drugs by synthetic biology. To this purpose, there have been great advances in characterizing the diversified biosynthetic gene clusters associated with the well-known drugs and in understanding the biosynthesis logic mechanisms and enzymatic transformation processes involved in their production. We describe advances made in the heterogeneous reconstruction of complex NP scaffolds using fungal polyketide synthases (PKSs), non-ribosomal peptide synthetases (NRPSs), PKS/NRPS hybrids, terpenoids, and indole alkaloids and also discuss mechanistic insights into metabolic engineering, pathway reprogramming, and cell factory development. Moreover, we suggest pathways for expanding access to the fungal chemical repertoire by biosynthesis of representative family members via common platform intermediates and through the rational manipulation of natural biosynthetic machineries for drug discovery.
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Affiliation(s)
- Moli Sang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, China.
| | - Peiyuan Feng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, China.
| | - Lu-Ping Chi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, China.
| | - Wei Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, China.
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong 266071, China
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4
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Palasarn S, Pruksatrakul T, Choowong W, Wiriyathanawudhiwong N, Boonpratuang T, Surawatanawong P, Thongpanchang C, Isaka M. Oudemansin and 9-methoxystrobilurin derivatives with antimalarial activity from cultures of the basidiomycete Favolaschia minutissima: assignments of the absolute configurations of the isoprene-derived units. Org Biomol Chem 2023; 21:7944-7953. [PMID: 37740400 DOI: 10.1039/d3ob01472j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Five undescribed polyketide metabolites, oudemansins E (1), M (2), P (3), and Q (4), and 9-methoxystrobilurin I (5), were isolated from cultures of basidiomycete Favolaschia minutissima TBRC-BCC 19434. A γ-lactone derivative (6) of noroudemansin A (8), which was previously reported as a semisynthetic compound, was also isolated. The absolute configuration of the isoprene-derived moiety of the known cometabolite 9-methoxystrobilurin E (9) was determined to be 2'R,6'S by comparison of the experimental and calculated ECD data, which was correlated to the new derivative 1. These compounds exhibited antimalarial activity against Plasmodium falciparum K1 (multidrug-resistant strain). A putative minor natural product, namely 9-methoxystrobilurin P (13), was prepared by semisynthesis, which exhibited significant antimalarial activity (IC50 0.086 μM).
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Affiliation(s)
- Somporn Palasarn
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand.
| | - Thapanee Pruksatrakul
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand.
| | - Wilunda Choowong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand.
| | - Natthawut Wiriyathanawudhiwong
- National Biobank of Thailand, National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Thitiya Boonpratuang
- National Biobank of Thailand, National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Panida Surawatanawong
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Chawanee Thongpanchang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand.
| | - Masahiko Isaka
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Klong Luang, Pathumthani 12120, Thailand.
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Nalawade J, Shinde A, Abhale YK, Nandurkar Y, Bobade VD, Sarkar D, Mhaske PC. Synthesis and antimicrobial Evaluation of Novel 2'-aryl-4-aryl-2,4'-Bisthiazole and 2'-aryl-4-Pyridyl-2,4'-Bisthiazole Derivatives as Potential Antibacterial Agents. Polycycl Aromat Compd 2023. [DOI: 10.1080/10406638.2023.2180524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- Jitendra Nalawade
- Department of Chemistry, H. P. T. Arts and R. Y. K. Science College (Affiliated to Savitribai Phule Pune University), Nashik, India
| | - Abhijit Shinde
- Department of Chemistry, S. P. Mandali’s Sir Parashurambhau College (Affiliated to Savitribai Phule Pune University), Pune, India
| | | | - Yogesh Nandurkar
- Department of Chemistry, S. P. Mandali’s Sir Parashurambhau College (Affiliated to Savitribai Phule Pune University), Pune, India
| | - Vivek D. Bobade
- Department of Chemistry, H. P. T. Arts and R. Y. K. Science College (Affiliated to Savitribai Phule Pune University), Nashik, India
| | - Dhiman Sarkar
- CSIR-National Chemical Laboratory, Combi Chem Bio Resource Centre, Pune, India
| | - Pravin C. Mhaske
- Department of Chemistry, S. P. Mandali’s Sir Parashurambhau College (Affiliated to Savitribai Phule Pune University), Pune, India
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Design, Synthesis, Antifungal Activity, and Molecular Docking of Streptochlorin Derivatives Containing the Nitrile Group. Mar Drugs 2023; 21:md21020103. [PMID: 36827144 PMCID: PMC9958711 DOI: 10.3390/md21020103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
Based on the structures of natural products streptochlorin and pimprinine derived from marine or soil microorganisms, a series of streptochlorin derivatives containing the nitrile group were designed and synthesized through acylation and oxidative annulation. Evaluation for antifungal activity showed that compound 3a could be regarded as the most promising candidate-it demonstrated over 85% growth inhibition against Botrytis cinerea, Gibberella zeae, and Colletotrichum lagenarium, as well as a broad antifungal spectrum in primary screening at the concentration of 50 μg/mL. The SAR study revealed that non-substituent or alkyl substituent at the 2-position of oxazole ring were favorable for antifungal activity, while aryl and monosubstituted aryl were detrimental to activity. Molecular docking models indicated that 3a formed hydrogen bonds and hydrophobic interactions with Leucyl-tRNA Synthetase, offering a perspective for the possible mechanism of action for antifungal activity of the target compounds.
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Effect of Inoculation with Arbuscular Mycorrhizal Fungi and Fungicide Application on the Secondary Metabolism of Solanum tuberosum Leaves. PLANTS 2022; 11:plants11030278. [PMID: 35161259 PMCID: PMC8838535 DOI: 10.3390/plants11030278] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 11/18/2022]
Abstract
In potato (Solanum tuberosum) crops, the use of fungicides to control some diseases is widespread; however, it has been reported that this practice can modify the potato polyphenolic content, and new strategies oriented to the potato defense system are necessary. One alternative is the use of arbuscular mycorrhizal fungi (AMF) to improve the defense mechanisms of plants. In this study, phenolic profiles and antioxidant activities in leaves of three potato genotypes (CB2011-509, CB2011-104, and VR808) were evaluated in crops inoculated with three AMF strains (Claroideoglomus claroideum, Claroideoglomus lamellosum, and Fumneliformis mosseae) and with AMF in combination with the use of two commercial fungicides (MONCUT [M] and ReflectXtra [R]). Eight phenolic compounds were detected, mainly hydroxycinnamic acids (HCAD) and flavonols, in samples where the highest concentrations of HCAD were obtained, 5-caffeoylquinic acid was the most abundant phenolic. The antioxidant activity was higher using the cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP) methods. The association of AMF with plants had benefits on the secondary metabolism; however, the response differed according to genotype. The different combinations of potato genotypes, AMF strain, and fungicide modified the content of phenolic compounds in leaves in different ways; the treatment using C. lamellosum and ReflectXtra was the ideal combination for the genotypes analyzed here, with the higher antioxidant response, which supports the further technological evaluation of efficient AMF strains and fungicides in potato crops.
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8
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Li W, Zhang S, Wang H, Wang Y, Guo W, Yu Z, Ye Q. Translocation and residue of 14C-benzene kresoxim-methyl in mature cucumber (Cucumis sativus L.). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 766:144426. [PMID: 33421785 DOI: 10.1016/j.scitotenv.2020.144426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
The broad application of strobilurin fungicide led to pathogen resistance, and toxic effects have been reported for several species. Benzene kresoxim-methyl (BKM) is a novel strobilurin fungicide mainly used to control the cucumber powdery mildew. However, information about the fate of BKM in agrofood systems and related human exposure is limited. In this study, greenhouse experiments were conducted to investigate the distribution, translocation, and residual of the 10% suspension concentrate (SC) commercial BKM formulations on mature cucumber plants using 14C tracer technology. After foliage and fruit application, 25.84% of the applied 14C-labeled BKM can be absorbed into mature cucumber plants at 21 days after treatment. The absorbed BKM transferred throughout the plant acropetally and basipetally, although over 81.13% of absorbed BKM remained in the labeled leaves. In the edible parts, 14.35% of the absorbed BKM remained in the pericarp of labeled fruits, only 0.027 mg kg-1 accumulated in the sarcocarp. The concentration of BKM in newborn fruits was 0.005 mg kg-1, indicating low dietary exposure. These findings develop a better understanding of the fate of BKM in the cucumber plants, provide guidance in the rational use of BKM and can be incorporated into food and environmental assessments of BKM.
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Affiliation(s)
- Wei Li
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Sufen Zhang
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Haiyan Wang
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Yichen Wang
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Wei Guo
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Zhiyang Yu
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Qingfu Ye
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310058, China.
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9
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Zhao H, Zhao Y, Hu J. Dissipation, residues and risk assessment of pyraclostrobin and picoxystrobin in cucumber under field conditions. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:5145-5151. [PMID: 32519755 DOI: 10.1002/jsfa.10563] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/29/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Pyraclostrobin and picoxystrobin are two representative pesticides of strobilurins used to treat cucumber downy mildew, which have raised issues of food safety and human health. A new formulation containing these two compounds is being prepared for marketing in China. RESULTS The dissipation and residual levels of pyraclostrobin and picoxystrobin in cucumbers under field conditions were determined simultaneously by a validated method via liquid chromatography-tandem mass spectrometry (LC-MS/MS). The dissipation rules were described by first-order kinetics and the half-lives of pyraclostrobin and picoxystrobin were less than 8.2 days and 3.4 days. The highest terminal residue of pyraclostrobin was 0.014 mg kg-1 which was lower than maximum residue limit (MRL) in China (0.5 mg kg-1 ) and of picoxystrobin was 0.029 mg kg-1 , respectively. In the long-term intake risk assessment of pyraclostrobin and picoxystrobin for general population (18-79 years), the chronic risk quotient (RQc ) varied from 5.64% to 21.97%. The assessment of short-term risks included children (1-6 years) and adults (18-79 years) and in which the RQa values were 0.38% and 2.85%. Both results showed the intake risks of cucumber were acceptable. CONCLUSION Pyraclostrobin and picoxystrobin degraded easily in cucumbers under open field conditions. The long-term and short-term risks caused by final residues of pyraclostrobin and picoxystrobin were insignificant. The recommended pre-harvest interval of 3 days was safe. The article will be helpful in rational use of these pesticides and MRL formulation of picoxystrobin on cucumber. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Honglei Zhao
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Yue Zhao
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Jiye Hu
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
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Kornsakulkarn J, Palasarn S, Choowong W, Thongpanchang T, Boonyuen N, Choeyklin R, Boonpratuang T, Isaka M, Thongpanchang C. Antimalarial 9-Methoxystrobilurins, Oudemansins, and Related Polyketides from Cultures of Basidiomycete Favolaschia Species. JOURNAL OF NATURAL PRODUCTS 2020; 83:905-917. [PMID: 32193929 DOI: 10.1021/acs.jnatprod.9b00647] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fourteen new compounds, oudemansins 1-4, oudemansinols 5-7, favolasins 8-10, favolasinin (12), polyketides 13-15, and (R,E)-2,4-dimethyl-5-phenyl-4-pentene-2,3-diol (16), together with nine known compounds were isolated from the basidiomycete fungus Favolaschia sp. BCC 18686. Two new compounds, favolasin E (11) and 9-oxostrobilurin E (17), were isolated from the closely related organism Favolaschia calocera BCC 36684 along with nine β-methoxyacrylate-type derivatives. Compounds in the class of oudemansins and strobilurins exhibited moderate to strong antimalarial activity with relatively low cytotoxicity against Vero cells (African green monkey kidney fibroblasts). Potent antimalarial activity was demonstrated for 9-methoxystrobilurins G, K, and E (IC50 values 0.061, 0.089, and 0.14 μM, respectively). The structure-activity relationships (SAR) for antimalarial activity is proposed on the basis of the activity of the new and several known β-methoxyacrylate derivatives in combination with the data from previously isolated compounds. Furthermore, several compounds showed specific cytotoxicity against NCI-187 cells (human small-cell lung cancer), although the SAR was different from that for antimalarial activity.
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Affiliation(s)
- Jittra Kornsakulkarn
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Somporn Palasarn
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Wilunda Choowong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Tienthong Thongpanchang
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Nattawut Boonyuen
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
- National Biobank of Thailand (NBT), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Rattaket Choeyklin
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
- National Biobank of Thailand (NBT), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Thitiya Boonpratuang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
- National Biobank of Thailand (NBT), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Masahiko Isaka
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
| | - Chawanee Thongpanchang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
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11
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Jakubczyk D, Dussart F. Selected Fungal Natural Products with Antimicrobial Properties. Molecules 2020; 25:E911. [PMID: 32085562 PMCID: PMC7070998 DOI: 10.3390/molecules25040911] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 01/14/2023] Open
Abstract
Fungal natural products and their effects have been known to humankind for hundreds of years. For example, toxic ergot alkaloids produced by filamentous fungi growing on rye poisoned thousands of people and livestock throughout the Middle Ages. However, their later medicinal applications, followed by the discovery of the first class of antibiotics, penicillins and other drugs of fungal origin, such as peptidic natural products, terpenoids or polyketides, have altered the historically negative reputation of fungal "toxins". The development of new antimicrobial drugs is currently a major global challenge, mainly due to antimicrobial resistance phenomena. Therefore, the structures, biosynthesis and antimicrobial activity of selected fungal natural products are described here.
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Affiliation(s)
- Dorota Jakubczyk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznań, Poland
| | - Francois Dussart
- Department of Agriculture, Horticulture and Engineering Science, Scotland’s Rural College (SRUC), Edinburgh EH9 3JG, UK;
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12
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13
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Abstract
Strobilurins from fungi are the inspiration for the creation of the β-methoxyacrylate class of agricultural fungicides. However, molecular details of the biosynthesis of strobilurins have remained cryptic. Here we report the sequence of genomes of two fungi that produce strobilurins and show that each contains a biosynthetic gene cluster, which encodes a highly reducing polyketide synthase with very unusual C-terminal hydrolase and methyltransferase domains. Expression of stpks1 in Aspergillus oryzae leads to the production of prestrobilurin A when the fermentation is supplemented with a benzoyl coenzyme A (CoA) analogue. This enables the discovery of a previously unobserved route to benzoyl CoA. Reconstruction of the gene cluster in A. oryzae leads to the formation of prestrobilurin A, and addition of the gene str9 encoding an FAD-dependent oxygenase leads to the key oxidative rearrangement responsible for the creation of the β-methoxyacrylate toxophore. Finally, two methyltransferases are required to complete the synthesis. Strobilurins are fungal metabolites that inspired the creation of β-methoxyacrylate agricultural fungicides. Here, Nofiani et al. identify the strobilurin biosynthesis gene cluster, encoding a polyketide synthase as well as an FAD-dependent oxygenase for an oxidative rearrangement leading to β-methoxyacrylate formation.
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14
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Iqbal Z, Han LC, Soares-Sello AM, Nofiani R, Thormann G, Zeeck A, Cox RJ, Willis CL, Simpson TJ. Investigations into the biosynthesis of the antifungal strobilurins. Org Biomol Chem 2018; 16:5524-5532. [PMID: 30027987 PMCID: PMC6085771 DOI: 10.1039/c8ob00608c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/22/2018] [Indexed: 11/21/2022]
Abstract
The strobilurins are important antifungal metabolites isolated from a number of basidiomycetes and have been valuable leads for the development of commercially important fungicides. Isotopic labelling studies with early and advanced intermediates confirm for the first time that they are produced via a linear tetraketide, primed with the rare benzoate starter unit, itself derived from phenylalanine via cinnamate. Isolation of a novel biphenyl metabolite, pseudostrobilurin B, provides evidence for the involvement of an epoxide in the key rearrangement to form the β-methoxyacrylate moiety essential for biological activity. Formation of two bolineol related metabolites, strobilurins Y and Z, also probably involves epoxide intermediates. Time course studies indicate a likely biosynthetic pathway from strobilurin A, with the simplest non-subsubstituted benzoate ring, to strobilurin G with a complex dioxepin terpenoid-derived substituent. Precursor-directed biosynthetic studies allow production of a number of novel ring-halogenated analogues as well as a new pyridyl strobilurin. These studies also provide evidence for a non-linear biosynthetic relationship between strobilurin A and strobilurin B.
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Affiliation(s)
- Zafar Iqbal
- School of Chemistry
, University of Bristol
,
Cantocks Close
, Bristol
, BS8 1TS
, UK
.
;
| | - Li-Chen Han
- School of Chemistry
, University of Bristol
,
Cantocks Close
, Bristol
, BS8 1TS
, UK
.
;
| | - Anna M. Soares-Sello
- School of Chemistry
, University of Bristol
,
Cantocks Close
, Bristol
, BS8 1TS
, UK
.
;
| | - Risa Nofiani
- School of Chemistry
, University of Bristol
,
Cantocks Close
, Bristol
, BS8 1TS
, UK
.
;
| | - Gerald Thormann
- Institut für Organische und Biomolekulare Chemie
, Georg-August Universität
,
Tammannstraße 2
, 37077 Göttingen
, Germany
| | - Axel Zeeck
- Institut für Organische und Biomolekulare Chemie
, Georg-August Universität
,
Tammannstraße 2
, 37077 Göttingen
, Germany
| | - Russell J. Cox
- Institut für Organische Chemie Chemistry
, Schneiderberg 1B, Leibniz Universität
,
30167 Hannover
, Germany
| | - Christine L. Willis
- School of Chemistry
, University of Bristol
,
Cantocks Close
, Bristol
, BS8 1TS
, UK
.
;
| | - Thomas J. Simpson
- School of Chemistry
, University of Bristol
,
Cantocks Close
, Bristol
, BS8 1TS
, UK
.
;
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15
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Nakatsuji H, Kamada R, Kitaguchi H, Tanabe Y. Dehydration-type Ti-Claisen Condensation (Carbonhomologation) of α-Heteroatom-substituted Acetates with Alkyl Formates: Utilization as (Z
)-Stereodefined Cross-coupling Partners and Application to Concise Synthesis of Strobilurin A. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700879] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hidefumi Nakatsuji
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| | - Risa Kamada
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| | - Hideya Kitaguchi
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| | - Yoo Tanabe
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
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16
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Kabir MH, Rahman MM, Abd El-Aty AM, Chung HS, Lee HS, Park SH, Hacımüftüoğlu F, Chang BJ, Shin HC, Shim JH. Residue analysis of picoxystrobin in oriental melon using gas chromatography coupled with electron capture detection and mass spectrometric confirmation: application to dissipation kinetics and risk assessment. Food Sci Biotechnol 2017; 26:1145-1153. [PMID: 30263647 PMCID: PMC6049560 DOI: 10.1007/s10068-017-0145-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/17/2017] [Accepted: 04/20/2017] [Indexed: 10/19/2022] Open
Abstract
This study was carried out to determine the residual amounts of picoxystrobin in oriental melon (Cucumis melo L.) grown under plastic house conditions at two different sites. Samples collected over 10 days were extracted using acetonitrile and salting out (using solid sodium chloride) and purified using Florisil SPE cartridges. The analyte was determined using GC-ECD and field-incurred residues were verified using GC-MS. The calibration curve was linear over the range 0.02-2.0 mg/L with a R 2 = 0.9998. The LOD and LOQ were 0.003 and 0.01 mg/kg, respectively. Recoveries, tested at three spiking levels, were satisfactory with rates in the range 87.7-101.5% and relative standard deviations ≤9.6. The dissipation half-lives were 3.4 and 3.7 days for sites 1 and 2, respectively. Hazard estimates obtained using hazard quotients revealed no health risk from the suggested pesticide application dosage when considering an adult's body weight, oriental melon consumption, and the acceptable daily intake of picoxystrobin.
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Affiliation(s)
- Md. Humayun Kabir
- Natural Products Chemistry Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186 Korea
| | - Md. Musfiqur Rahman
- Natural Products Chemistry Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186 Korea
| | - A. M. Abd El-Aty
- Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, Giza, 12211 Egypt
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, Konkuk University, Seoul, 05029 Korea
| | - Hyung Suk Chung
- Natural Products Chemistry Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186 Korea
| | - Han Sol Lee
- Natural Products Chemistry Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186 Korea
| | - Sun-Hyang Park
- Department of Anatomy, School of Medicine, Wonkwang University, Iksan, Jeonbuk 54538 Korea
| | - Fazil Hacımüftüoğlu
- Department of Soil Sciences and Plant Nutrition, Faculty of Agriculture, Atatürk University, 25240 Erzurum, Turkey
| | - Byung-Joon Chang
- Department of Veterinary Anatomy, College of Veterinary Medicine, Konkuk University, Seoul, 05029 Korea
| | - Ho-Chul Shin
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, Konkuk University, Seoul, 05029 Korea
| | - Jae-Han Shim
- Natural Products Chemistry Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186 Korea
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17
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Zhao J, Wang L, Cheng J, Wang W, Ye Q. Fate Characterization of Benzene Kresoxim-Methyl (a Strobilurin Fungicide) in Different Aerobic Soils. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:546-552. [PMID: 28724104 DOI: 10.2134/jeq2016.08.0288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Benzene kresoxim-methyl (BKM) is a promising broad-spectrum strobilurin fungicide widely used to control fungal pathogens in crops. However, information on its environmental fate is limited. To broaden our understanding of this fungicide's kinetic fate in aerobic soils, we labeled BKM with C on its benzoate ring and used ultralow-level liquid scintillation counting coupled with high-performance liquid chromatography analysis. Results show that degradation, mineralization, and bound residue (BR) formation of BKM was controlled by soil type and microbial community composition. Degradation of BKM followed first-order dynamics, and the half-lives () were 51.7, 30.8, and 26.8 d for clay, loamy, and saline soils, respectively. After 100 d, about 0.13, 4.35, and 5.94% of the initial C-BKM was mineralized, and 14.43, 19.90, and 28.81% was formed as BRs in the clay, loamy, and saline soils, respectively. About 60 to 85% of the C-BKM residue in soil was extractable; of this fraction, 30 to 50% was composed of incomplete degradation intermediates. Up to 40% of extractable C-BKM in soil was readily available. Our results suggest that BKM and its incomplete intermediates had a relatively long persistence in soil, which may lead to exposure for nontarget organisms. Soil microbes may play a dominant role in controlling the fate of BKM in soil as sterilization sharply decreased its mineralization rate from 4.35 to 0.03%, increased from 30.8 to 85.6 d, and decreased the BR fraction from 19.90 to 3.25%.
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18
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Fluorescence polarisation immunoassays for strobilurin fungicides kresoxim-methyl, trifloxystrobin and picoxystrobin. Talanta 2017; 162:495-504. [DOI: 10.1016/j.talanta.2016.10.063] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/11/2016] [Accepted: 10/15/2016] [Indexed: 11/19/2022]
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Abstract
The study of natural products is entering a renaissance, driven by the discovery that the majority of bacterial secondary metabolites are not produced under standard laboratory conditions. Understanding the ecological role of natural products is key to efficiently directing our screening efforts, and to ensuring that each screen efficiently captures the full biosynthetic repertoire of the producing organisms. Myxobacteria represent one of the most common and diverse groups of bacteria, with roughly 2500 strains publically available. Fed largely through predation, the myxobacteria have developed a large repertoire of natural products that target other microorganisms, including bacteria and fungi. Many of these interactions can be observed in predation assays, providing direct evidence for environmental interactions. With a focus on Myxococcus xanthus, this review will highlight how recent advances in myxobacteria are revealing the chemical ecology of bacterial natural products.
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Affiliation(s)
- Brandon L. Findlay
- Department of Chemistry and
Biochemistry, Faculty of Arts and Science, Concordia University, Montreal, Quebec, Canada H4B 1R6
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20
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Li YF, Tsai KJS, Harvey CJB, Li JJ, Ary BE, Berlew EE, Boehman BL, Findley DM, Friant AG, Gardner CA, Gould MP, Ha JH, Lilley BK, McKinstry EL, Nawal S, Parry RC, Rothchild KW, Silbert SD, Tentilucci MD, Thurston AM, Wai RB, Yoon Y, Aiyar RS, Medema MH, Hillenmeyer ME, Charkoudian LK. Comprehensive curation and analysis of fungal biosynthetic gene clusters of published natural products. Fungal Genet Biol 2016; 89:18-28. [PMID: 26808821 DOI: 10.1016/j.fgb.2016.01.012] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 12/11/2022]
Abstract
Microorganisms produce a wide range of natural products (NPs) with clinically and agriculturally relevant biological activities. In bacteria and fungi, genes encoding successive steps in a biosynthetic pathway tend to be clustered on the chromosome as biosynthetic gene clusters (BGCs). Historically, "activity-guided" approaches to NP discovery have focused on bioactivity screening of NPs produced by culturable microbes. In contrast, recent "genome mining" approaches first identify candidate BGCs, express these biosynthetic genes using synthetic biology methods, and finally test for the production of NPs. Fungal genome mining efforts and the exploration of novel sequence and NP space are limited, however, by the lack of a comprehensive catalog of BGCs encoding experimentally-validated products. In this study, we generated a comprehensive reference set of fungal NPs whose biosynthetic gene clusters are described in the published literature. To generate this dataset, we first identified NCBI records that included both a peer-reviewed article and an associated nucleotide record. We filtered these records by text and homology criteria to identify putative NP-related articles and BGCs. Next, we manually curated the resulting articles, chemical structures, and protein sequences. The resulting catalog contains 197 unique NP compounds covering several major classes of fungal NPs, including polyketides, non-ribosomal peptides, terpenoids, and alkaloids. The distribution of articles published per compound shows a bias toward the study of certain popular compounds, such as the aflatoxins. Phylogenetic analysis of biosynthetic genes suggests that much chemical and enzymatic diversity remains to be discovered in fungi. Our catalog was incorporated into the recently launched Minimum Information about Biosynthetic Gene cluster (MIBiG) repository to create the largest known set of fungal BGCs and associated NPs, a resource that we anticipate will guide future genome mining and synthetic biology efforts toward discovering novel fungal enzymes and metabolites.
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Affiliation(s)
- Yong Fuga Li
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, United States; Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Kathleen J S Tsai
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Colin J B Harvey
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, United States
| | - James Jian Li
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, United States
| | - Beatrice E Ary
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, PA, United States
| | - Erin E Berlew
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Brenna L Boehman
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - David M Findley
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Alexandra G Friant
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, PA, United States
| | | | - Michael P Gould
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Jae H Ha
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, PA, United States
| | - Brenna K Lilley
- Department of Biology, Haverford College, Haverford, PA, United States
| | - Emily L McKinstry
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Saadia Nawal
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Robert C Parry
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | | | - Samantha D Silbert
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, PA, United States
| | | | - Alana M Thurston
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Rebecca B Wai
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Yongjin Yoon
- Department of Chemistry, Haverford College, Haverford, PA, United States
| | - Raeka S Aiyar
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, United States
| | - Marnix H Medema
- Bioinformatics Group, Wageningen University, The Netherlands
| | - Maureen E Hillenmeyer
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, United States.
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21
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Pseudomonas putida-a versatile host for the production of natural products. Appl Microbiol Biotechnol 2015; 99:6197-214. [PMID: 26099332 PMCID: PMC4495716 DOI: 10.1007/s00253-015-6745-4] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 05/26/2015] [Accepted: 05/29/2015] [Indexed: 10/30/2022]
Abstract
The biosynthesis of natural products by heterologous expression of biosynthetic pathways in amenable production strains enables biotechnological access to a variety of valuable compounds by conversion of renewable resources. Pseudomonas putida has emerged as a microbial laboratory work horse, with elaborated techniques for cultivation and genetic manipulation available. Beyond that, this bacterium offers several particular advantages with regard to natural product biosynthesis, notably a versatile intrinsic metabolism with diverse enzymatic capacities as well as an outstanding tolerance to xenobiotics. Therefore, it has been applied for recombinant biosynthesis of several valuable natural products. This review provides an overview of applications of P. putida as a host organism for the recombinant biosynthesis of such natural products, including rhamnolipids, terpenoids, polyketides and non-ribosomal peptides, and other amino acid-derived compounds. The focus is on de novo natural product synthesis from intrinsic building blocks by means of heterologous gene expression and strain engineering. Finally, the future potential of the bacterium as a chassis organism for synthetic microbiology is pointed out.
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22
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The total synthesis of strobilurin B. Russ Chem Bull 2014. [DOI: 10.1007/s11172-014-0458-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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Abstract
Oxidative rearrangements are key reactions during the biosyntheses of many secondary metabolites in fungi.
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Affiliation(s)
- Russell Cox
- Institute for Organic Chemistry
- Leibniz University of Hannover
- 30167 Hannover, Germany
- School of Chemistry
- University of Bristol
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24
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Popovsky VA, Stepanov AV, Grigorieva NY. Preparation of (2E,4E)-2-(2-benzyloxyethyl)-5-(3-methoxy-4-chlorophenyl)penta-2,4-dienal as a key intermediate in the synthesis of strobilurin B. Russ Chem Bull 2013. [DOI: 10.1007/s11172-012-0215-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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25
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Popovsky VA, Stepanov AV, Grigorieva NY. Total synthesis of strobilurin B. MENDELEEV COMMUNICATIONS 2013. [DOI: 10.1016/j.mencom.2013.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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26
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Abrahams KA, Cox JAG, Spivey VL, Loman NJ, Pallen MJ, Constantinidou C, Fernández R, Alemparte C, Remuiñán MJ, Barros D, Ballell L, Besra GS. Identification of novel imidazo[1,2-a]pyridine inhibitors targeting M. tuberculosis QcrB. PLoS One 2012; 7:e52951. [PMID: 23300833 PMCID: PMC3534098 DOI: 10.1371/journal.pone.0052951] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 11/22/2012] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB). Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. Through the use of high throughput whole cell screening of an extensive compound library a number of imidazo[1,2-a]pyridine (IP) compounds were obtained as potent lead molecules active against M. tuberculosis and Mycobacterium bovis BCG. The IP inhibitors (1-4) demonstrated minimum inhibitory concentrations (MICs) in the range of 0.03 to 5 µM against a panel of M. tuberculosis strains. M. bovis BCG spontaneous resistant mutants were generated against IP 1, 3, and 4 at 5× MIC and subsequent whole genome sequencing identified a single nucleotide polymorphism (937)ACC>(937)GCC (T313A) in qcrB, which encodes the b subunit of the electron transport ubiquinol cytochrome C reductase. This mutation also conferred cross-resistance against IP 1, 3 and 4 demonstrating a common target. Gene dosage experiments confirmed M. bovis BCG QcrB as the target where over-expression in M. bovis BCG led to an increase in MIC from 0.5 to >8 µM for IP 3. An acute murine model of TB infection established bacteriostatic activity of the IP series, which await further detailed characterization.
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Affiliation(s)
- Katherine A. Abrahams
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Jonathan A. G. Cox
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Vickey L. Spivey
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Nicholas J. Loman
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Mark J. Pallen
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | | | - Raquel Fernández
- Diseases of the Developing World, GlaxoSmithKline, Tres Cantos, Madrid, Spain
| | - Carlos Alemparte
- Diseases of the Developing World, GlaxoSmithKline, Tres Cantos, Madrid, Spain
| | - Modesto J. Remuiñán
- Diseases of the Developing World, GlaxoSmithKline, Tres Cantos, Madrid, Spain
| | - David Barros
- Diseases of the Developing World, GlaxoSmithKline, Tres Cantos, Madrid, Spain
| | - Lluis Ballell
- Diseases of the Developing World, GlaxoSmithKline, Tres Cantos, Madrid, Spain
- * E-mail: (GSB); (LB)
| | - Gurdyal S. Besra
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (GSB); (LB)
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27
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Mercader JV, Parra J, Esteve-Turrillas FA, Agulló C, Abad-Somovilla A, Abad-Fuentes A. Development of monoclonal antibody-based competitive immunoassays for the detection of picoxystrobin in cereal and oilseed flours. Food Control 2012. [DOI: 10.1016/j.foodcont.2012.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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28
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Wang L, Xia XD, Guo W, Chen JR, Xiao WJ. Palladium-catalyzed C–H acetoxylation of 2-methoxyimino-2-aryl-acetates and acetamides. Org Biomol Chem 2011; 9:6895-8. [DOI: 10.1039/c1ob05887h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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30
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Kornsakulkarn J, Thongpanchang C, Chainoy R, Choowong W, Nithithanasilp S, Thongpanchang T. Bioactive metabolites from cultures of basidiomycete Favolaschia tonkinensis. JOURNAL OF NATURAL PRODUCTS 2010; 73:759-762. [PMID: 20329738 DOI: 10.1021/np900777r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Two strobilurins, 9-methoxystrobilurin B (1) and 9-methoxystrobilurin G (2), two monochlorinated 2,3-dihydro-1-benzoxepin derivatives, 3 and 4a, and butenolide 5, together with four known compounds, strobilurin B, 9-methoxystrobilurin A, and oudemansins A and B, were isolated from culture BCC 18689 of the fungus Favolaschia tonkinensis. 9-Methoxystrobilurins A, B (1), and G (2) and oudemansins A and B exhibited antimalarial, antifungal, and cytotoxic activities, while compounds 3, 4a, and 5 displayed only cytotoxic activity.
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Affiliation(s)
- Jittra Kornsakulkarn
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, 113 Phaholyothin Road, Klong Luang, Pathumthani 12120, Thailand
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31
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Lamberth C. Alkyne chemistry in crop protection. Bioorg Med Chem 2009; 17:4047-63. [DOI: 10.1016/j.bmc.2008.11.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 10/29/2008] [Accepted: 11/14/2008] [Indexed: 10/21/2022]
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32
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33
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Mercader JV, Suárez-Pantaleón C, Agulló C, Abad-Somovilla A, Abad-Fuentes A. Production and characterization of monoclonal antibodies specific to the strobilurin pesticide pyraclostrobin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:7682-7690. [PMID: 18690684 DOI: 10.1021/jf801340u] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Strobilurin fungicides are nowadays among the most important fungicides in the market of active agrochemicals. Pyraclostrobin, which belongs to the last generation of this family of molecules, shows a broader antifungal activity spectrum and higher efficiency and security profiles than previous fungicides. This paper describes the synthesis of functionalized haptens, the production of monoclonal antibodies, and the development of enzyme-linked immunosorbent assays (ELISA) for the detection of pyraclostrobin. A conformational analysis of hapten structure was performed, which provided relevant data concerning the length of the spacer arm. A very useful strategy has been followed for the screening of hybridomas, leading to the selection of a panel of high-affinity monoclonal antibodies to pyraclostrobin. Moreover, different immunoassays have been characterized using the conjugate-coated indirect ELISA format, and limits of detection below 0.1 microg/L have been obtained. Also, a simplified one-step procedure has been carried out with two indirect assays. Finally, these results have been compared with the performance of the same antibodies in the antibody-coated direct ELISA format.
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Affiliation(s)
- Josep V Mercader
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, P.O. Box 73, 46100 Burjassot, València, Spain
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34
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Zakharychev VV, Kovalenko LV. Natural compounds of the strobilurin series and their synthetic analogues as cell respiration inhibitors. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc1998v067n06abeh000426] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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35
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36
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Balba H. Review of strobilurin fungicide chemicals. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2007; 42:441-51. [PMID: 17474024 DOI: 10.1080/03601230701316465] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Strobilurins are natural products isolated and identified from specific fungi. Natural strobilurins were named in the order of their discovery as strobilurin-A followed by strobilurin-B, C, D etc. Their discovery opened the door for new chemistry of synthetic fungicides. Applying Quantitative Structural Activity Relationship (QSAR) on the structures of the natural strobilurins, many pesticide companies were able to discover many synthetic analogues that are more efficacious and more stable fungicides. At present there are about eight synthetic strobilurins in the fungicides worldwide market. Some of these products are worldwide registered for use as agrochemical and some are in the process of registration. This class of fungicides is relatively new, as crop protection products and information about them is still fairly scarce. In this review, syntheses and chemistry of natural and synthetic strobilurins are discussed. Also, the mode of action, efficacy, biotic/abiotic degradation, analytical methods, and agricultural uses are discussed.
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Bolgunas S, Clark DA, Hanna WS, Mauvais PA, Pember SO. Potent inhibitors of the Qi site of the mitochondrial respiration complex III. J Med Chem 2006; 49:4762-6. [PMID: 16854082 DOI: 10.1021/jm060408s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of azole-fused salicylamides were prepared as analogues of antimycin and assayed for activity at complex III of the mitochondrial respiratory chain. The activity of these compounds approached that of antimycin in inhibitory potency and some showed growth reduction of Septoria nodorum in vitro. Compound 8a was shown to bind at the Qi site of complex III by red-shift titration of the bc1 complex.
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Affiliation(s)
- Stephen Bolgunas
- DuPont Agricultural Products, Stine/Haskell Research Center, Post Office Box 30, Newark, Delaware 19714, USA
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38
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Clough JM, Dube H, Martin BJ, Pattenden G, Reddy KS, Waldron IR. Total synthesis of myxothiazols, novel bis-thiazole β-methoxyacrylate-based anti-fungal compounds from myxobacteria. Org Biomol Chem 2006; 4:2906-11. [PMID: 16855739 DOI: 10.1039/b603433k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Convergent total syntheses of myxothiazols A and Z are described. The syntheses are based on elaboration of the (S)-E,E-diene thioamide 22, conversion of 22 into the bis-thiazole 27 and Wittig reactions between 27c and the aldehyde 30. The substituted beta-methoxyacrylate aldehyde 30 was produced via an Evans asymmetric aldol protocol or via the 2H-pyran-2-one 31. An E-selective Wittig reaction between the ylide derived from the phosphonium salt 27c and the (+)-aldehyde 30 led to (+)-myxothiazol Z (1b), and a corresponding reaction with the (+/-)-acrylamide aldehyde 44 gave (+/-)-myxothiazol A (1a). Complementary studies led to synthesis of the ester 47b, corresponding to myxothiazol R and myxothiazol S.
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Affiliation(s)
- John M Clough
- School of Chemistry, University of Nottingham, University Park, UK
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40
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Zheng YJ, Kleier DA. Conformational flexibility of antifungal atropisomeric strobilurin analogues: a quantum mechanical investigation. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.theochem.2005.01.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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41
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Le Sann C, Munoz DM, Saunders N, Simpson TJ, Smith DI, Soulas F, Watts P, Willis CL. Assembly intermediates in polyketide biosynthesis: enantioselective syntheses of β-hydroxycarbonyl compounds. Org Biomol Chem 2005; 3:1719-28. [PMID: 15858656 DOI: 10.1039/b419492f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A versatile approach for the enantioselective synthesis of functionalised beta-hydroxy N-acetylcysteamine thiol esters has been developed which allows the facile incorporation of isotopic labels. It has been shown that a remarkable reversal of selectivity occurs in the titanium mediated aldol reaction of acyloxazolidinone using either (S)- or (R)-tert-butyldimethylsilyloxybutanal. The aldol products are valuable intermediates in the synthesis of 4-hydroxy-6-substituted delta-lactones.
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Affiliation(s)
- Christine Le Sann
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UKBS8 1TS
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42
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Zjawiony JK. Biologically active compounds from Aphyllophorales (polypore) fungi. JOURNAL OF NATURAL PRODUCTS 2004; 67:300-10. [PMID: 14987072 DOI: 10.1021/np030372w] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This review describes biologically active natural products isolated from Aphyllophorales, many of which are known as polypores. Polypores are a large group of terrestrial fungi of the phylum Basdiomycota (basidiomycetes), and they along with certain Ascomycota are a major source of pharmacologically active substances. There are about 25 000 species of basidiomycetes, of which about 500 are members of the Aphyllophorales, a polyphyletic group that contains the polypores. Many of these fungi have circumboreal distributions in North America, Europe, and Asia and broad distributions on all inhabited continents and Africa; only a small number of the most common species with the most obvious fruiting bodies (basidiocarps) have been evaluated for biological activity. An estimated 75% of polypore fungi that have been tested show strong antimicrobial activity, and these may constitute a good source for developing new antibiotics. Numerous compounds from these fungi also display antiviral, cytotoxic, and/or antineoplastic activities. Additional important components of this vast arsenal of compounds are polysaccharides derived from the fungal cell walls. These compounds have attracted significant attention in recent years because of their immunomodulatory activities, resulting in antitumor effects. These high molecular weight compounds, often called biological response modifiers (BRM), or immunopotentiators, prevent carcinogenesis, show direct anticancer effects, and prevent tumor metastasis. Some of the protein-bound polysaccharides from polypores and other basidiomycetes have found their way to the market in Japan as anticancer drugs. Finally, numerous compounds with cardiovascular, phytotoxic, immunomodulatory, analgesic, antidiabetic, antioxidant, insecticidal, and nematocidal activities, isolated from polypores, are also presented. In fact many of the fungi mentioned in this paper have long been used in herbal medicine, including polypores such as Ganoderma lucidum (Reishi or Ling Zhi), Laetiporus sulphureus (Chicken-of-the-Woods), Trametes versicolor (Yun Zhi), Grifola umbellata (Zhu Lin), Inonotus obliquus (Chaga), and Wolfiporia cocos (Hoelen).
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Affiliation(s)
- Jordan K Zjawiony
- Department of Pharmacognosy and National Center for Natural Product Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, Mississippi 38677-1848, USA.
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Abstract
[structure: see text]. The total synthesis of cystothiazole A is described. Key steps of the synthesis include an Evans asymmetric catalytic aldol reaction, which established the required C4-C5 stereochemistry. The [2,4']-bis(thiazole) was obtained applying our methodology of electrophilic activation of amide. Semistabilized Wittig reaction between the phosphonium salt 3 and the aldehyde 2 afforded 1 in nine linear steps and 38% overall yield.
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Affiliation(s)
- Patrick L DeRoy
- Département de chimie, Université de Montréal, P.O. Box 6128, Station Downtown, Montréal, Québec, Canada H3C 3J7
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45
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Futagawa M, Rimando AM, Tellez MR, Wedge DE. pH modulation of zopfiellin antifungal activity to Colletotrichum and Botrytis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:7007-7012. [PMID: 12428951 DOI: 10.1021/jf025720z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Zopfiellin, a novel cyclooctanoid natural product isolated from Zopfiella curvata No. 37-3, was evaluated in a 96-well microtiter assay for fungicidal activity against Botrytis cinerea, Colletotrichum acutatum, Colletotrichum fragariae, Colletotrichum gloeosporioides, and Fusarium oxysporum. Zopfiellin exhibited pH-dependent activity, with the most mycelial growth inhibition demonstrated at pH 5.0. Mass spectrometry and nuclear magnetic resonance spectroscopy studies indicated that zopfiellin undergoes structural changes with changes in pH. At pH 5.0, zopfiellin showed the greatest activity against B. cinerea (IC(80) = 10 microM), C. gloeosporioides (IC(80) = 10 microM), and C. fragariae (IC(80) = 10 microM) and intermediate activity against C. acutatum (IC(80) = 30 microM), and was not active against F. oxysporum (IC(80) > 100 microM).
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Affiliation(s)
- Mitsugu Futagawa
- Shiraoka Research Station of Biological Science, Nissan Chemical Industries, Ltd., 1470 Shiraoka, Minamisaitama, Saitama 349-0294, Japan
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Ziogas BN, Markoglou AN, Tzima A. A non-Mendelian inheritance of resistance to strobilurin fungicides in Ustilago maydis. PEST MANAGEMENT SCIENCE 2002; 58:908-916. [PMID: 12233180 DOI: 10.1002/ps.543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mutants of Ustilago maydis (DC) Corda with high resistance to azoxystrobin (RF 164 to 4714, based on EC50 values), an inhibitor of mitochondrial electron transport at the cytochrome bc1 complex, were isolated in a mutation frequency of 2.3 x 10(-7) after nitrosoguanidine mutagenesis and selection on media containing 1 microgram ml-1 azoxystrobin in addition to 0.5 mM salicylhydroxamate (SHAM), a specific inhibitor of cyanide-resistant (alternative) respiration. Oxygen uptake in whole cells was strongly inhibited in the wild-type strains by azoxystrobin (1.5 micrograms ml-1) in addition to SHAM (1 mM), but not in the mutant isolates. Genetic analysis with nine such mutant isolates resulted in progeny phenotypes which did not follow Mendelian segregation, but satisfied the criteria of non-Mendelian (cytoplasmic) heredity. In crosses between three mutant isolates with the compatible wild-type strains, the sensitivity was inherited by progeny maternally from the wild-type parent strain (criterion of uniparental inheritance). In crosses between wild-type strains and remaining mutant isolates, a continuous distribution of sensitivity in the progeny was found (criterion of vegetative segregation). The third criterion of cytoplasmic resistance (criterion of intracellular selection) was fulfilled by experiments on the stability of resistance phenotypes. With two exceptions, a reduction of resistance was observed in the mutant strains when they were grown on inhibitor-free medium. Recovery of the high resistance level was observed after they were returned to the selection medium. Cross-resistance studies with other fungicides, which also inhibit electron transport through complex III of respiratory chain, showed that mutations for resistance to azoxystrobin were also responsible for reduced sensitivity to kresoxim-methyl (RF 18 to 1199) and to antimycin-A (RF 20 to 305), which act at the Qo and Qi sites of the cytochrome bc1 complex, respectively. Studies of the fitness of azoxystrobin-resistant isolates showed that these mutations appeared to be pleiotropic, having significant adverse effects on growth in liquid culture and pathogenicity on young corn plants.
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Affiliation(s)
- Basil N Ziogas
- Laboratory of Plant Pathology, Agricultural University of Athens, Votanikos, 118 55 Athens, Greece.
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47
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Carpita A, Ribecai A, Rossi R, Stabile P. Synthesis of the racemic forms of carbon–carbon double bond locked analogues of strobilurins which are characterized by a 2-arylcyclopropane ring cis-substituted at C-1 by the methyl (E)-3-methoxypropenoate unit. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00334-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Schirra M, Cabras P, Angioni A, Brandolini V. Residue levels and storage decay control in Cv. Star Ruby grapefruit after dip treatments with azoxystrobin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:1461-1464. [PMID: 11879021 DOI: 10.1021/jf0112567] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cv. Star Ruby grapefruit (Citrus paradisi Macf.) were subjected to a 3-min dip in water at room temperature (20 degrees C) or at 50 degrees C with or without 25, 50, or 100 mg/L azoxystrobin (AZX). Then, the fruits were subjected to cold quarantine at 2 degrees C and 90-95% relative humidity (RH) for 3 weeks and then stored for 5 weeks at 8 degrees C and approximately 85% RH and for another 2 weeks at 20 degrees C and 80% RH to simulate a 2-week marketing period (SMP). No AZX residues were detected in the albedo and pulp following treatments at 20 or 50 degrees C, the total amount of residues being recovered from the flavedo tissue. There was a relationship between the AZX uptake in fruit and the amount of fungicide employed at 20 or 50 degrees C. When AZX was applied to the fruit at 25 mg/L at 20 degrees C, the residue level averaged 0.11 mg/kg (active ingredient, whole fruit basis). This residue concentration increased by 50 and 75% when the application rate increased from 25 to 50 or 100 mg/L, respectively. A similar pattern of accumulation was detected in fruit subjected to treatments at 50 degrees C. However, treatments at 50 degrees C produced residue levels higher than the treatments at 20 degrees C, with increases ranging from 63 to 84%, for the same concentration. Storage conditions did not affect the amount of AZX residues in the fruit. Treatment at 50 or 100 mg/L at 20 degrees C reduced the incidence of moderate to severe chilling injury (CI). Water dips at 50 degrees C reduced the incidence and severity of CI to a very low extent, with no additional advantages when hot water was used in combination with AZX. Treatments with 50 or 100 mg/L of AZX at 20 degrees C produced beneficial effects in decay control similar to those of 25 mg/L AZX at 50 degrees C or hot water alone. Better results were achieved with 50 or 100 AZX at 50 degrees C, providing complete control of decay during cold storage and with negligible decay after SMP. It was concluded that when AZX was applied at 50 degrees C, low doses of fungicide and minimal residue levels in fruit were required to control the postharvest decay of grapefruit. This treatment does not impair fruit quality and offers very interesting prospects for large scale application, due to the reduced potential toxicity of AZX to nontarget organisms and to the environment.
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Affiliation(s)
- Mario Schirra
- CNR-Istituto di Scienza delle Produzioni Alimentari, Località Palloni, Nuraxinieddu, 09170 Oristano, Italy.
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Christensen HB, Granby K. Method validation for strobilurin fungicides in cereals and fruit. FOOD ADDITIVES AND CONTAMINANTS 2001; 18:866-74. [PMID: 11569766 DOI: 10.1080/02652030121435] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Strobilurins are a new class of fungicides that are active against a broad spectrum of fungi. In the present work a GC method for analysis of strobilurin fungicides was validated. The method was based on, extraction with ethyl acetate/cyclohexane, clean-up by gel permeation chromatography, (GPC) and determination of the content by gas chromatography (GC) with electron capture (EC-), nitrogen/phosphorous (NP-), and mass spectrometric (MS-) detection. Three strobilurins, azoxystrobin, kresoxim-methyl and trifloxystrobin were validated on three matrices, wheat, apple and grapes. The validation was based on recovery tests at three or four spiking levels, determined as double determinations and repeated three times (n = 6). The mean recoveries for the three detectors were in the range of 70-114%, and the LODs were between 0.004 mg/kg and 0.014 mg/kg, for all three strobilurins. The values for repeatability and reproducibility were within the limits for repeatability and reproducibility given by the Horwitz equation. Validation was not accepted for azoxystrobin in grapes on all three detectors and for azoxystrobin in apple for the MS-detector. A comparison of matrix-matched standards versus standards in solvent showed varying differences between the two calibration curves.
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Rossi R, Carpita A, Ribecai A, Mannina L. Stereocontrolled synthesis of carbon–carbon double bond locked analogues of strobilurins which are characterized by a trans-1,2-disubstituted cyclopropane ring. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00136-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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