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Oliveira HJ, Aperibense MD, Yves A, Machado RR, Santana DJ, Costa HC. Trophic ecology of
Thoropa miliaris
(Anura: Cycloramphidae) in two mountain ranges of south‐eastern Brazil. AUSTRAL ECOL 2023. [DOI: 10.1111/aec.13316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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2
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Gu ZY, Li WD, Li YL, Cui K, Xia JB. Selective Reductive Coupling of Vinyl Azaarenes and Alkynes via Photoredox Cobalt Dual Catalysis. Angew Chem Int Ed Engl 2023; 62:e202213281. [PMID: 36178079 DOI: 10.1002/anie.202213281] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Indexed: 12/30/2022]
Abstract
A visible light-induced Co-catalyzed highly regio- and stereoselective reductive coupling of vinyl azaarenes and alkynes has been developed. Notably, Hünig's base together with simple ethanol has been successfully applied as the hydrogen sources instead of commonly used Hantzsch esters in this catalytic photoredox reaction. This approach has considerable advantages for the straightforward synthesis of stereodefined multiple substituted alkenes bearing an azaarene motif, such as excellent regioselectivity (>20 : 1 for >30 examples) and stereoselectivity (>20 : 1 E/Z), broad substrate scope and good functional group compatibility under mild reaction conditions, which has been utilized in the concise synthesis of natural product monomorine I. A reasonable catalytic reaction pathway involving protolysis of the cobaltacyclopentene intermediate has been proposed based on the mechanistic studies.
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Affiliation(s)
- Zheng-Yang Gu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Textiles and Clothing, Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng, 224003, China
| | - Wen-Duo Li
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Yan-Lin Li
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Kun Cui
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Ji-Bao Xia
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
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3
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Pearson KC, Tarvin RD. A review of chemical defense in harlequin toads (Bufonidae: Atelopus). Toxicon X 2022; 13:100092. [PMID: 35146414 PMCID: PMC8801762 DOI: 10.1016/j.toxcx.2022.100092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/12/2022] [Accepted: 01/17/2022] [Indexed: 12/29/2022] Open
Abstract
Toads of the genus Atelopus are chemically defended by a unique combination of endogenously synthesized cardiotoxins (bufadienolides) and neurotoxins which may be sequestered (guanidinium alkaloids). Investigation into Atelopus small-molecule chemical defenses has been primarily concerned with identifying and characterizing various forms of these toxins while largely overlooking their ecological roles and evolutionary implications. In addition to describing the extent of knowledge about Atelopus toxin structures, pharmacology, and biological sources, we review the detection, identification, and quantification methods used in studies of Atelopus toxins to date and conclude that many known toxin profiles are unlikely to be comprehensive because of methodological and sampling limitations. Patterns in existing data suggest that both environmental (toxin availability) and genetic (capacity to synthesize or sequester toxins) factors influence toxin profiles. From an ecological and evolutionary perspective, we summarize the possible selective pressures acting on Atelopus toxicity and toxin profiles, including predation, intraspecies communication, disease, and reproductive status. Ultimately, we intend to provide a basis for future ecological, evolutionary, and biochemical research on Atelopus.
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Affiliation(s)
- Kannon C. Pearson
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Rebecca D. Tarvin
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA, 94720, USA
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Schwelm HM, Zimmermann N, Scholl T, Penner J, Autret A, Auwärter V, Neukamm MA. Qualitative and Quantitative Analysis of Tryptamines in the Poison of Incilius alvarius (Amphibia: Bufonidae). J Anal Toxicol 2021; 46:540-548. [PMID: 33851996 DOI: 10.1093/jat/bkab038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/11/2021] [Accepted: 04/14/2021] [Indexed: 11/14/2022] Open
Abstract
Rising numbers of psychoactive tryptamine derivatives have become available on the drug market over the last decade, making these naturally occurring or synthetically manufactured compounds highly relevant for forensic analysis. One of these compounds is 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), a constituent of the dried poison of Incilius alvarius (Colorado River toad) which has a history of ritual and/or recreational use. Still, comprehensive and validated qualitative as well as quantitative analytical data on the psychoactive components of this poison are scarce. In this study samples of the poison of Incilius alvarius were collected from live toads in the Sonoran Desert, Arizona (USA) and analyzed with a set of complementary methods. Acetone/water (70/30, v/v) proved to be the solvent of choice for the extraction of tryptamine derivatives. Trace compounds were enriched and overload with 5-MeO-DMT was prevented by chromatographic separation of 5-MeO-DMT prior to qualitative analysis. The method for quantification was validated. Applying attenuated total reflection-Fourier transform infrared spectroscopy to samples of the poison, 5-MeO-DMT was identified as the main tryptamine by comparison to the reference spectrum. The combined evaluation of analytical data gained from gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadrupole time-of-flight high resolution MS (HPLC-qToF-HRMS), and HPLC-MS/MS confirmed the presence of 5-MeO-DMT, 5-MeO-N-methyltryptamine, 5-MeO-tryptamine, 5-MeO-tryptophol, 2-(5-methoxy-1H-indol-3-yl)-acetic-acid (5-MIAA), 5-HO-N-methyltryptamine, bufotenin, DMT, and tryptophan. For the first time, 5-MeO-tryptamine and two positional isomers of indole-substituted HO-MeO-DMT were detected in the poison of Incilius alvarius. The tryptamine present in the highest concentrations was 5-MeO-DMT (mean ± standard deviation: 410,000 ± 30,000 µg/g). Mean concentrations of 5-MeO-tryptamine (490 ± 260 µg/g), 5-HO-N-methyltryptamine (270 ± 120 µg/g), bufotenin (2,800 ± 1,900 µg/g), and DMT (250 ± 80 µg/g), showed a relatively high variability between individual samples. The comprehensive analytical reference data of Incilius alvarius poison presented here might prove useful for forensic chemists.
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Affiliation(s)
- Hannes M Schwelm
- Institute of Forensic Medicine, Forensic Toxicology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Hermann Staudinger Graduate School, University of Freiburg, Freiburg, Germany
| | - Nicole Zimmermann
- Institute of Forensic Medicine, Forensic Toxicology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Johannes Penner
- Chair of Wildlife Ecology and Wildlife Management, Faculty of Environment and Natural Resources, University of Freiburg, Germany.,Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - Amy Autret
- Tucson Police Department, Crime Laboratory/Toxicology, Tucson, AZ, USA
| | - Volker Auwärter
- Institute of Forensic Medicine, Forensic Toxicology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Merja A Neukamm
- Institute of Forensic Medicine, Forensic Toxicology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Basham EW, Saporito RA, González‐Pinzón M, Romero‐Marcucci A, Scheffers BR. Chemical defenses shift with the seasonal vertical migration of a Panamanian poison frog. Biotropica 2020. [DOI: 10.1111/btp.12842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Edmund W. Basham
- School of Natural Resources and Environment University of Florida Gainesville FL USA
| | - Ralph A. Saporito
- Department of Biology John Carroll University University Heights OH USA
| | - Macario González‐Pinzón
- Escuela de Biología Facultad de Ciencias naturales y Exactas Universidad Autónoma de Chiriquí David República de Panamá
| | - Angel Romero‐Marcucci
- Escuela de Biología Facultad de Ciencias naturales y Exactas Universidad Autónoma de Chiriquí David República de Panamá
| | - Brett R. Scheffers
- School of Natural Resources and Environment University of Florida Gainesville FL USA
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL USA
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Pyridoxal-5'-phosphate-dependent bifunctional enzyme catalyzed biosynthesis of indolizidine alkaloids in fungi. Proc Natl Acad Sci U S A 2019; 117:1174-1180. [PMID: 31882449 DOI: 10.1073/pnas.1914777117] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Indolizidine alkaloids such as anticancer drugs vinblastine and vincristine are exceptionally attractive due to their widespread occurrence, prominent bioactivity, complex structure, and sophisticated involvement in the chemical defense for the producing organisms. However, the versatility of the indolizidine alkaloid biosynthesis remains incompletely addressed since the knowledge about such biosynthetic machineries is only limited to several representatives. Herein, we describe the biosynthetic gene cluster (BGC) for the biosynthesis of curvulamine, a skeletally unprecedented antibacterial indolizidine alkaloid from Curvularia sp. IFB-Z10. The molecular architecture of curvulamine results from the functional collaboration of a highly reducing polyketide synthase (CuaA), a pyridoxal-5'-phosphate (PLP)-dependent aminotransferase (CuaB), an NADPH-dependent dehydrogenase (CuaC), and a FAD-dependent monooxygenase (CuaD), with its transportation and abundance regulated by a major facilitator superfamily permease (CuaE) and a Zn(II)Cys6 transcription factor (CuaF), respectively. In contrast to expectations, CuaB is bifunctional and capable of catalyzing the Claisen condensation to form a new C-C bond and the α-hydroxylation of the alanine moiety in exposure to dioxygen. Inspired and guided by the distinct function of CuaB, our genome mining effort discovers bipolamines A-I (bipolamine G is more antibacterial than curvulamine), which represent a collection of previously undescribed polyketide alkaloids from a silent BGC in Bipolaris maydis ATCC48331. The work provides insight into nature's arsenal for the indolizidine-coined skeletal formation and adds evidence in support of the functional versatility of PLP-dependent enzymes in fungi.
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