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Brocaeloid D, a novel compound isolated from a wheat pathogenic fungus, Microdochium majus 99049. Synth Syst Biotechnol 2019; 4:173-179. [PMID: 31667367 PMCID: PMC6807035 DOI: 10.1016/j.synbio.2019.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/10/2019] [Accepted: 09/15/2019] [Indexed: 11/23/2022] Open
Abstract
Microbes serve as the most important resource for drug discovery. During our screening for bioactive compounds from our natural products library, a pathogenic fungus, Microdochium majus strain 99049, from wheat was selected for further investigation. A new alkaloid named brocaeloid D (1), together with six previously characterized compounds (2–7) were identified. Compound 1 belongs to 4-oxoquinoline with C-2 reversed prenylation and a succinimide substructure. All the structures of these newly isolated compounds were determined by different means in spectroscopic experiments. The absolute configurations of 1 was further deduced from comparison of its CD spectrum with that of known compound 2. The bioactivities of these identified compounds were evaluated against several pathogenic microorganisms and cancer cell lines. Compounds 1–5 showed activity against HUH-7 human hepatoma cells with IC50 values of 80 μg/mL. Compound 6 showed mild activity against HeLa cells (IC50 = 51.9 μg/mL), weak anti-MTB activity (MIC = 80 μg/mL), and moderate anti-MRSA activity (MIC = 25 μg/mL), and compound 7 showed weak anti-MRSA activity (MIC = 100 μg/mL).
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Almasry M, Jemaà M, Mischitelli M, Lang F, Faggio C. Camalexin-Induced Cell Membrane Scrambling and Cell Shrinkage in Human Erythrocytes. Cell Physiol Biochem 2017; 41:731-741. [DOI: 10.1159/000458733] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/28/2017] [Indexed: 12/22/2022] Open
Abstract
Background/Aims: The thaliana phytoalexin Camalexin has been proposed for the treatment of malignancy. Camalexin counteracts tumor growth in part by stimulation of suicidal death or apoptosis of tumor cells. Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Cellular mechanisms contributing to the complex machinery executing eryptosis include increase of cytosolic Ca2+ activity ([Ca2+]i), oxidative stress, ceramide, protein kinase C and caspases. The present study explored, whether Camalexin induces eryptosis and, if so, to shed light on mechanisms involved. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca2+]i from Fluo-3 fluorescence, ROS formation from DCFDA dependent fluorescence, and ceramide abundance utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to Camalexin significantly increased the percentage of annexin-V-binding cells (≥ 10 µg/ml), significantly decreased forward scatter (≥ 5 µg/ml) and significantly increased Fluo-3-fluorescence (≥ 10 µg/ml), but did not significantly modify DCFDA fluorescence or ceramide abundance. The effect of Camalexin on annexin-V-binding was significantly blunted by removal of extracellular Ca2+, by kinase inhibitors staurosporine (1 µM) and chelerythrine (10 µM), as well as by caspase inhibitors zVAD (10 µM) and zIETD-fmk (50 µM). Conclusions: Camalexin triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part depending on Ca2+ entry, as well as staurosporine and chelerythrine sensitive kinase(s) as well as zVAD and zIETD-fmk sensitive caspase(s).
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Pedras MSC, Yaya EE, Glawischnig E. The phytoalexins from cultivated and wild crucifers: chemistry and biology. Nat Prod Rep 2011; 28:1381-405. [PMID: 21681321 DOI: 10.1039/c1np00020a] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Phytoalexins are antimicrobial secondary metabolites produced de novo by plants in response to stress, including microbial attack. In general, phytoalexins are important components of plant defenses against fungal and bacterial pathogens. The phytoalexins of crucifers are indole alkaloids derived from (S)-tryptophan, most of which contain a sulfur atom derived from cysteine. Beside their antimicrobial activity against different plant pathogenic species, cruciferous phytoalexins have shown anticarcinogenic effects on various human cell lines. This review focuses on the phytoalexins produced by cruciferous plants reported to date, with particular emphasis on their chemical synthesis, biosynthesis, metabolism by plant fungal pathogens and biological activities. A summary table containing all phytoalexins, their cultivated and wild cruciferous sources, their synthetic starting materials, biotransformation products and biological activities is provided.
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Affiliation(s)
- M Soledade C Pedras
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada.
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Gaspari P, Banerjee T, Malachowski WP, Muller AJ, Prendergast GC, DuHadaway J, Bennett S, Donovan AM. Structure-activity study of brassinin derivatives as indoleamine 2,3-dioxygenase inhibitors. J Med Chem 2006; 49:684-92. [PMID: 16420054 PMCID: PMC2527235 DOI: 10.1021/jm0508888] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A screen of indole-based structures revealed the natural product brassinin to be a moderate inhibitor of indoleamine 2,3-dioxygenase (IDO), a new cancer immunosuppression target. A structure-activity study was undertaken to determine which elements of the brassinin structure could be modified to enhance potency. Three important discoveries have been made, which will impact future IDO inhibitor development: (i) The dithiocarbamate portion of the brassinin lead is a crucial moiety, which may be binding to the heme iron of IDO; (ii) an indole ring is not necessary for IDO inhibition; and (iii) substitution of the S-methyl group of brassinin with large aromatic groups provides inhibitors that are three times more potent in vitro than the most commonly used IDO inhibitor, 1-methyl-tryptophan.
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Affiliation(s)
- Paul Gaspari
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010-2899
| | - Tinku Banerjee
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096 USA
| | - William P. Malachowski
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010-2899
- Address correspondence regarding the chemistry to William P. Malachowski at the Department of Chemistry, Bryn Mawr College, 101 N. Merion Ave., Bryn Mawr, PA 19010-2899; phone: 610-526-5016; fax: 610-526-5086; e-mail: . Address correspondence regarding the biology to Alexander J. Muller or George C. Prendergast at Lankenau Institute for Medical Research, Wynnewood, PA 19010; phone: 610-645-8034; fax: 610-645-2095; e-mail:
| | - Alexander J. Muller
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096 USA
- Address correspondence regarding the chemistry to William P. Malachowski at the Department of Chemistry, Bryn Mawr College, 101 N. Merion Ave., Bryn Mawr, PA 19010-2899; phone: 610-526-5016; fax: 610-526-5086; e-mail: . Address correspondence regarding the biology to Alexander J. Muller or George C. Prendergast at Lankenau Institute for Medical Research, Wynnewood, PA 19010; phone: 610-645-8034; fax: 610-645-2095; e-mail:
| | - George C. Prendergast
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096 USA
- Address correspondence regarding the chemistry to William P. Malachowski at the Department of Chemistry, Bryn Mawr College, 101 N. Merion Ave., Bryn Mawr, PA 19010-2899; phone: 610-526-5016; fax: 610-526-5086; e-mail: . Address correspondence regarding the biology to Alexander J. Muller or George C. Prendergast at Lankenau Institute for Medical Research, Wynnewood, PA 19010; phone: 610-645-8034; fax: 610-645-2095; e-mail:
| | - James DuHadaway
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096 USA
| | - Shauna Bennett
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010-2899
| | - Ashley M. Donovan
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010-2899
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