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Zhou Y, He N, Liu Q, Li R, Yang L, Kang W, Zhang X, Xu X, Yao G, Wang P, Wang CY, Yang J, Liu Z. Structural Optimization of Marine Natural Product Pretrichodermamide B for the Treatment of Colon Cancer by Targeting the JAK/STAT3 Signaling Pathway. J Med Chem 2024. [PMID: 38888591 DOI: 10.1021/acs.jmedchem.4c00278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Marine natural product (MNP) pretrichodermamide B (Pre B, 9) was identified as a novel STAT3 inhibitor in our previous work, while its metabolic instability hindered its further development. To address this drawback, ligand structure-based drug design was adopted leading to a series of Pre B derivatives. Among them, MNP trichodermamide B (tri B, 24) obtained by skeletal rearrangement exhibited more potent antiproliferative activity with an IC50 value of 0.12 μM against HCT116. Notably, 24 stood out with improved metabolic stability (T1/2 = 31 min) and more favorable oral bioavailability (F = 37.5%). Further studies indicated that 24 blocked JAK/STAT3 signaling in dose- and time-dependent manner. In vivo, 24 suppressed tumor growth (TGI = 65%) at a dose of 20 mg/kg in a HCT116-derived xenograft mouse model. Overall, 24 might be a promising lead compound for colon cancer and is worthy of further investigation.
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Affiliation(s)
- Yue Zhou
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Na He
- Key Laboratory of Marine Drugs of Ministry of Education & Qingdao Marine Biomedical Research Institute, Ocean University of China, Qingdao 266003, China
| | - Qian Liu
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Rui Li
- Key Laboratory of Marine Drugs of Ministry of Education & Qingdao Marine Biomedical Research Institute, Ocean University of China, Qingdao 266003, China
| | - Lujia Yang
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Wei Kang
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Xinxin Zhang
- Key Laboratory of Marine Drugs of Ministry of Education & Qingdao Marine Biomedical Research Institute, Ocean University of China, Qingdao 266003, China
| | - Xiaoyu Xu
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Guangshan Yao
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Institute of Oceanography, Minjiang University, Fuzhou 350108, China
| | - Pingyuan Wang
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Chang-Yun Wang
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Jinbo Yang
- Key Laboratory of Marine Drugs of Ministry of Education & Qingdao Marine Biomedical Research Institute, Ocean University of China, Qingdao 266003, China
| | - Zhiqing Liu
- Key Laboratory of Marine Drugs and Key Laboratory of Evolution and Marine Biodiversity (Ministry of Education), School of Medicine and Pharmacy, Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, Qingdao 266237, China
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Riedling O, Walker AS, Rokas A. Predicting fungal secondary metabolite activity from biosynthetic gene cluster data using machine learning. Microbiol Spectr 2024; 12:e0340023. [PMID: 38193680 PMCID: PMC10846162 DOI: 10.1128/spectrum.03400-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 12/04/2023] [Indexed: 01/10/2024] Open
Abstract
Fungal secondary metabolites (SMs) contribute to the diversity of fungal ecological communities, niches, and lifestyles. Many fungal SMs have one or more medically and industrially important activities (e.g., antifungal, antibacterial, and antitumor). The genes necessary for fungal SM biosynthesis are typically located right next to each other in the genome and are known as biosynthetic gene clusters (BGCs). However, whether fungal SM bioactivity can be predicted from specific attributes of genes in BGCs remains an open question. We adapted machine learning models that predicted SM bioactivity from bacterial BGC data with accuracies as high as 80% to fungal BGC data. We trained our models to predict the antibacterial, antifungal, and cytotoxic/antitumor bioactivity of fungal SMs on two data sets: (i) fungal BGCs (data set comprised of 314 BGCs) and (ii) fungal (314 BGCs) and bacterial BGCs (1,003 BGCs). We found that models trained on fungal BGCs had balanced accuracies between 51% and 68%, whereas training on bacterial and fungal BGCs had balanced accuracies between 56% and 68%. The low prediction accuracy of fungal SM bioactivities likely stems from the small size of the data set; this lack of data, coupled with our finding that including bacterial BGC data in the training data did not substantially change accuracies currently limits the application of machine learning approaches to fungal SM studies. With >15,000 characterized fungal SMs, millions of putative BGCs in fungal genomes, and increased demand for novel drugs, efforts that systematically link fungal SM bioactivity to BGCs are urgently needed.IMPORTANCEFungi are key sources of natural products and iconic drugs, including penicillin and statins. DNA sequencing has revealed that there are likely millions of biosynthetic pathways in fungal genomes, but the chemical structures and bioactivities of >99% of natural products produced by these pathways remain unknown. We used artificial intelligence to predict the bioactivities of diverse fungal biosynthetic pathways. We found that the accuracies of our predictions were generally low, between 51% and 68%, likely because the natural products and bioactivities of only very few fungal pathways are known. With >15,000 characterized fungal natural products, millions of putative biosynthetic pathways present in fungal genomes, and increased demand for novel drugs, our study suggests that there is an urgent need for efforts that systematically identify fungal biosynthetic pathways, their natural products, and their bioactivities.
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Affiliation(s)
- Olivia Riedling
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Allison S. Walker
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
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Riedling O, Walker AS, Rokas A. Predicting fungal secondary metabolite activity from biosynthetic gene cluster data using machine learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.12.557468. [PMID: 37745539 PMCID: PMC10515863 DOI: 10.1101/2023.09.12.557468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Fungal secondary metabolites (SMs) play a significant role in the diversity of ecological communities, niches, and lifestyles in the fungal kingdom. Many fungal SMs have medically and industrially important properties including antifungal, antibacterial, and antitumor activity, and a single metabolite can display multiple types of bioactivities. The genes necessary for fungal SM biosynthesis are typically found in a single genomic region forming biosynthetic gene clusters (BGCs). However, whether fungal SM bioactivity can be predicted from specific attributes of genes in BGCs remains an open question. We adapted previously used machine learning models for predicting SM bioactivity from bacterial BGC data to fungal BGC data. We trained our models to predict antibacterial, antifungal, and cytotoxic/antitumor bioactivity on two datasets: 1) fungal BGCs (dataset comprised of 314 BGCs), and 2) fungal (314 BGCs) and bacterial BGCs (1,003 BGCs); the second dataset was our control since a previous study using just the bacterial BGC data yielded prediction accuracies as high as 80%. We found that the models trained only on fungal BGCs had balanced accuracies between 51-68%, whereas training on bacterial and fungal BGCs yielded balanced accuracies between 61-74%. The lower accuracy of the predictions from fungal data likely stems from the small number of BGCs and SMs with known bioactivity; this lack of data currently limits the application of machine learning approaches in studying fungal secondary metabolism. However, our data also suggest that machine learning approaches trained on bacterial and fungal data can predict SM bioactivity with good accuracy. With more than 15,000 characterized fungal SMs, millions of putative BGCs present in fungal genomes, and increased demand for novel drugs, efforts that systematically link fungal SM bioactivity to BGCs are urgently needed.
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Affiliation(s)
- Olivia Riedling
- Department of Biological Science, Vanderbilt University, Nashville, TN, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN, USA
| | - Allison S Walker
- Department of Biological Science, Vanderbilt University, Nashville, TN, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Antonis Rokas
- Department of Biological Science, Vanderbilt University, Nashville, TN, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN, USA
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Urquhart AS, Elliott CE, Zeng W, Idnurm A. Constitutive expression of transcription factor SirZ blocks pathogenicity in Leptosphaeria maculans independently of sirodesmin production. PLoS One 2021; 16:e0252333. [PMID: 34111151 PMCID: PMC8191991 DOI: 10.1371/journal.pone.0252333] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 05/14/2021] [Indexed: 11/28/2022] Open
Abstract
Sirodesmin, the major secondary metabolite produced by the plant pathogenic fungus Leptosphaeria maculans in vitro, has been linked to disease on Brassica species since the 1970s, and yet its role has remained ambiguous. Re-examination of gene expression data revealed that all previously described genes and two newly identified genes within the sir gene cluster in the genome are down-regulated during the crucial early establishment stages of blackleg disease on Brassica napus. To test if this is a strategy employed by the fungus to avoid damage to and then detection by the host plant during the L. maculans asymptomatic biotrophic phase, sirodesmin was produced constitutively by overexpressing the sirZ gene encoding the transcription factor that coordinates the regulation of the other genes in the sir cluster. The sirZ over-expression strains had a major reduction in pathogenicity. Mutation of the over-expression construct restored pathogenicity. However, mutation of two genes, sirP and sirG, required for specific steps in the sirodesmin biosynthesis pathway, in the sirZ over-expression background resulted in strains that were unable to synthesize sirodesmin, yet were still non-pathogenic. Elucidating the basis for this pathogenicity defect or finding ways to overexpress sirZ during disease may provide new strategies for the control of blackleg disease.
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Affiliation(s)
- Andrew S. Urquhart
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
- Applied BioSciences, Macquarie University, Macquarie Park, New South Wales, Australia
| | - Candace E. Elliott
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
- Biosecurity Operations Division, Department of Agriculture, Water and the Environment, Post Entry Quarantine, Mickleham, Victoria, Australia
| | - Wei Zeng
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
- Sino-Australia Plant Cell Wall Research Centre, State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
| | - Alexander Idnurm
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
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5
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Li Y, Yuan S, Yong X, zhao T, Liu J. Research progress on small peptides in Chinese Baijiu. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.104081] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Wang Q, Zhang K, Wang W, Zhang G, Zhu T, Che Q, Gu Q, Li D. Amphiepicoccins A-J: Epipolythiodioxopiperazines from the Fish-Gill-Derived Fungus Epicoccum nigrum HDN17-88. JOURNAL OF NATURAL PRODUCTS 2020; 83:524-531. [PMID: 31975590 DOI: 10.1021/acs.jnatprod.9b01242] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ten new epipolythiodioxopiperazines (ETPs), namely, amphiepicoccins A-J (1-10), were isolated from the fish-gill-derived fungus Epicoccum nigrum HDN17-88. Their structures were deduced from extensive spectroscopic data and electronic circular dichroism (ECD) calculations. Amphiepicoccin A (1) which contains an aromatic indole motif is unprecedented among the epicoccin type of ETPs. Compounds 1, 3, and 6 displayed anti-HSV-2 activities, with IC50 values of 70, 64, and 29 μM, respectively (acyclovir as positive control with an IC50 value of 31 μM), while 5 and 6 also revealed inhibitory activity against Bacillus subtilis with minimum inhibitory concentration (MIC) values of 13 and 25 μM, respectively.
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Affiliation(s)
- Qiuying Wang
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Kaijin Zhang
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Wei Wang
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Guojian Zhang
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Tianjiao Zhu
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Qian Che
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Qianqun Gu
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
| | - Dehai Li
- School of Medicine and Pharmacy , Ocean University of China , Qingdao 266003 , People's Republic of China
- Laboratory for Marine Drugs and Bioproducts , Pilot National Laboratory for Marine Science and Technology , Qingdao , 266237 , People's Republic of China
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7
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Rocha TL, Soll CB, Boughton BA, Silva TS, Oldach K, Firmino AA, Callahan DL, Sheedy J, Silveira ER, Carneiro RM, Silva LP, Polez VL, Pelegrini PB, Bacic A, Grossi-de-Sa MF, Roessner U. Prospection and identification of nematotoxic compounds from Canavalia ensiformis seeds effective in the control of the root knot nematode Meloidogyne incognita. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.biori.2017.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kim W, Park CM, Park JJ, Akamatsu HO, Peever TL, Xian M, Gang DR, Vandemark G, Chen W. Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:482-96. [PMID: 25372118 DOI: 10.1094/mpmi-08-14-0234-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here, we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both Ascochyta rabiei and Alternaria solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound, prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of Ascochyta rabiei and Alternaria solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity.
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9
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Kim W, Park CM, Park JJ, Akamatsu HO, Peever TL, Xian M, Gang DR, Vandemark G, Chen W. Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 2015:1-15. [PMID: 27839072 DOI: 10.1094/mpmi-08-14-0234-r.testissue] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here, we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both Ascochyta rabiei and Alternaria solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound, prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of Ascochyta rabiei and Alternaria solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity.
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Affiliation(s)
| | | | - Jeong-Jin Park
- 3 Institute of Biological Chemistry, Washington State University, Pullman 99164, U.S.A.; and
| | | | | | | | - David R Gang
- 3 Institute of Biological Chemistry, Washington State University, Pullman 99164, U.S.A.; and
| | - George Vandemark
- 1 Department of Plant Pathology
- 4 United States Department of Agriculture-Agricultural Research Service, Grain Legume Genetics and Physiology Research Unit, Washington State University, Pullman
| | - Weidong Chen
- 1 Department of Plant Pathology
- 4 United States Department of Agriculture-Agricultural Research Service, Grain Legume Genetics and Physiology Research Unit, Washington State University, Pullman
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Welch TR, Williams RM. Epidithiodioxopiperazines. occurrence, synthesis and biogenesis. Nat Prod Rep 2014; 31:1376-404. [PMID: 24816491 DOI: 10.1039/c3np70097f] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Epidithiodioxopiperazine alkaloids possess an astonishing array of molecular architecture and generally exhibit potent biological activity. Nearly twenty distinct families have been isolated and characterized since the seminal discovery of gliotoxin in 1936. Numerous biosynthetic investigations offer a glimpse at the relative ease with which Nature is able to assemble this class of molecules, while providing synthetic chemists inspiration for the development of more efficient syntheses. Herein, we discuss the isolation and characterization, proposed fungal biogeneses, and total syntheses of epidithiodioxopiperazines.
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Affiliation(s)
- Timothy R Welch
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
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Stergiopoulos I, Collemare J, Mehrabi R, De Wit PJGM. Phytotoxic secondary metabolites and peptides produced by plant pathogenic Dothideomycete fungi. FEMS Microbiol Rev 2012; 37:67-93. [PMID: 22931103 DOI: 10.1111/j.1574-6976.2012.00349.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/01/2012] [Accepted: 07/19/2012] [Indexed: 01/25/2023] Open
Abstract
Many necrotrophic plant pathogenic fungi belonging to the class of Dothideomycetes produce phytotoxic metabolites and peptides that are usually required for pathogenicity. Phytotoxins that affect a broad range of plant species are known as non-host-specific toxins (non-HSTs), whereas HSTs affect only a particular plant species or more often genotypes of that species. For pathogens producing HSTs, pathogenicity and host specificity are largely defined by the ability to produce the toxin, while plant susceptibility is dependent on the presence of the toxin target. Non-HSTs are not the main determinants of pathogenicity but contribute to virulence of the producing pathogen. Dothideomycetes are remarkable for the production of toxins, particularly HSTs because they are the only fungal species known so far to produce them. The synthesis, regulation, and mechanisms of action of the most important HSTs and non-HSTs will be discussed. Studies on the mode of action of HSTs have highlighted the induction of programed cell death (PCD) as an important mechanism. We discuss HST-induced PCD and the plant hypersensitive response upon recognition of avirulence factors that share common pathways. In this respect, although nucleotide-binding-site-leucine-rich repeat types of resistance proteins mediate resistance against biotrophs, they can also contribute to susceptibility toward necrotrophs.
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12
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Rai M, Deshmukh P, Gade A, Ingle A, Kövics GJ, Irinyi L. Phoma Saccardo: distribution, secondary metabolite production and biotechnological applications. Crit Rev Microbiol 2010; 35:182-96. [PMID: 19624254 DOI: 10.1080/10408410902975992] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Phoma Sacc. is an ubiquitous fungus, which has been reported from plants, soil, human beings, animals, and air. Some species of Phoma like P. sorghina, P. herbarum, P. exigua var. exigua, P. macrostoma, P. glomerata, Phoma macdonaldii, Phoma tracheiphila, Phoma proboscis, P. multirostrata, and Phoma foveata secrete phytotoxin and anthraquinone pigments as secondary metabolites, which have great potential for the biological control of weeds, and can be exploited for the production of mycopesticides, agrophytochemicals, and dyes. Some other species produce pharmaceutically active metabolites, viz., Sirodesmins, Phomenoic acid, Phomenolactone, Phomadecalins, Phomactin A, Phomasetin, Squalestatin-1 (S1), and Squalestatin-2 (S2). The secondary metabolites secreted by some species of Phoma are antitumor, antimicrobial, and anti-HIV. Equisetin and Phomasetin obtained from species of Phoma are useful against AIDS. The main goal of the present review is to discuss secondary metabolite production by species of Phoma and their utilization as antibiotics and as biocontrol agents.
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Affiliation(s)
- Mahendra Rai
- Department of Biotechnology, SGB Amravati University, Amravati, Maharashtra, India.
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Kremer A, Li SM. A tyrosine O-prenyltransferase catalyses the first pathway-specific step in the biosynthesis of sirodesmin PL. MICROBIOLOGY-SGM 2009; 156:278-286. [PMID: 19762440 DOI: 10.1099/mic.0.033886-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A putative prenyltransferase gene sirD has been identified in the gene cluster encoding the biosynthesis of the phytotoxin sirodesmin PL in Leptosphaeria maculans. The gene product was found to comprise 449 aa, with a molecular mass of 51 kDa. In this study, the coding region of sirD was amplified by PCR from cDNA, cloned into pQE70, and overexpressed in Escherichia coli. The overproduced protein was purified to apparent homogeneity, and characterized biochemically. The dimeric recombinant SirD was found to catalyse the O-prenylation of L-Tyr in the presence of dimethylallyl diphosphate; this was demonstrated unequivocally by isolation and structural elucidation of the enzymic product. Therefore, SirD catalyses the first pathway-specific step in the biosynthesis of sirodesmin PL. K(m) values for L-Tyr and dimethylallyl diphosphate were determined as 0.13 and 0.17 mM, respectively. Interestingly, SirD was found to share significant sequence similarity with indole prenyltransferases, which catalyse prenyl transfer reactions onto different positions of indole rings. In contrast to indole prenyltransferases, which accept indole derivatives, but not Tyr or structures derived thereof, as substrates, SirD also prenylated L-Trp, resulting in the formation of 7-dimethylallyltryptophan. A K(m) value of 0.23 mM was determined for L-Trp. Turnover numbers of 1.0 and 0.06 S(-1) were calculated for L-Tyr and L-Trp, respectively.
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Affiliation(s)
- Anika Kremer
- Philipps-Universität Marburg, Institut für Pharmazeutische Biologie, Deutschhausstrasse 17A, D-35037 Marburg, Germany
| | - Shu-Ming Li
- Philipps-Universität Marburg, Institut für Pharmazeutische Biologie, Deutschhausstrasse 17A, D-35037 Marburg, Germany
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Elliott CE, Gardiner DM, Thomas G, Cozijnsen A, VAN DE Wouw A, Howlett BJ. Production of the toxin sirodesmin PL by Leptosphaeria maculans during infection of Brassica napus. MOLECULAR PLANT PATHOLOGY 2007; 8:791-802. [PMID: 20507539 DOI: 10.1111/j.1364-3703.2007.00433.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Sirodesmin PL is a non-host-selective phytotoxin produced by Leptosphaeria maculans, which causes blackleg disease of canola (Brassica napus). Previous studies have shown that sirodesmin PL biosynthesis involves a cluster of 18 co-regulated genes and that disruption of the two-module non-ribosomal peptide synthetase gene (sirP) in this cluster prevents the production of sirodesmin PL. Loss of sirodesmin PL did not affect the growth or fertility of the sirP mutant in vitro, but this mutant had less antibacterial and antifungal activity than the wild-type. When the sirP mutant was inoculated on to cotyledons of B. napus, it caused similar-sized lesions on cotyledons as the wild-type isolate, but subsequently caused fewer lesions and was half as effective as the wild-type in colonizing stems, as shown by quantitative PCR analyses. However, no significant difference was observed in size of lesions when either wild-type or mutant isolates were injected directly into the stem. The expression of two cluster genes, sirP and an ABC transporter, sirA, was studied in planta. Fungal isolates containing fusions of the green fluorescent protein gene with the promoters of these genes fluoresced after 10 days post-inoculation (dpi). Transcripts of sirP and sirA were detected after 11 dpi in cotyledons by reverse transcriptase PCR, and expression of both genes increased dramatically in stem tissue. This expression pattern was consistent with the distribution of sirodesmin PL in planta as revealed by mass spectrometry experiments.
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Affiliation(s)
- Candace E Elliott
- School of Botany, The University of Melbourne, Victoria 3010 Australia
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Gardiner DM, Jarvis RS, Howlett BJ. The ABC transporter gene in the sirodesmin biosynthetic gene cluster of Leptosphaeria maculans is not essential for sirodesmin production but facilitates self-protection. Fungal Genet Biol 2005; 42:257-63. [PMID: 15707846 DOI: 10.1016/j.fgb.2004.12.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 11/26/2004] [Accepted: 12/03/2004] [Indexed: 11/26/2022]
Abstract
Epipolythiodioxopiperazine toxins are secreted by a range of fungi, including Leptosphaeria maculans, which produces sirodesmin, and Aspergillus fumigatus, which produces gliotoxin. The L. maculans biosynthetic gene cluster for sirodesmin includes an ABC transporter gene, sirA. Disruption of this gene led to increased secretion of sirodesmin into the medium and an altered ratio of sirodesmin to its immediate precursor. The transcription pattern of a peptide synthetase that catalyses an early step in sirodesmin biosynthesis was elevated in the sirA mutant by 47% over a 7-day period. This was consistent with the finding that the transporter mutant had elevated sirodesmin levels. Despite increased production of sirodesmin, the sirA mutant was more sensitive to both sirodesmin and gliotoxin. The putative gliotoxin transporter gene, gliA, (a major facilitator superfamily transporter) from A. fumigatus complemented the tolerance of the L. maculans sirA mutant to gliotoxin, but not to sirodesmin. The results indicate that SirA contributes to self-protection against sirodesmin in L. maculans and suggest a transporter other than SirA is primarily responsible for efflux of endogenously produced sirodesmin.
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Affiliation(s)
- Donald M Gardiner
- School of Botany, The University of Melbourne, Vic. 3010, Australia.
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Howlett BJ, Idnurm A, Pedras MS. Leptosphaeria maculans, the causal agent of blackleg disease of Brassicas. Fungal Genet Biol 2001; 33:1-14. [PMID: 11407881 DOI: 10.1006/fgbi.2001.1274] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The loculoascomycete Leptosphaeria maculans (anamorph: Phoma lingam) causes blackleg of Brassicas, including Brassica napus (canola or rapeseed). This fungus probably comprises several morphologically similar species; taxonomic relationships between them are being clarified and nomenclature is being revised. The pathotype ("A" group) responsible for major economic losses to canola has been studied in more detail than other members of this species complex and is the focus of this review. L. maculans is haploid, outcrossing, can be transformed, and has a genome size of about 34 Mb. Preliminary genetic and physical maps have been developed and three genes involved in host specificity have been mapped. As yet, few genes have been characterized. Chemical analysis of fungal secondary metabolites has aided understanding of taxonomic relationships and of the host-fungal interaction by the unraveling of pathways for detoxification of antimicrobial phytoalexins. Several phytotoxins (host and nonhost specific) have been identified and a complex pattern of regulation of their synthesis by fungal and host metabolites has been discovered.
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Affiliation(s)
- B J Howlett
- School of Botany, University of Melbourne, Parkville, Victoria, 3010, Australia.
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