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Harris CM, Hintze L, Gaillard S, Tanniou S, Small H, Reece KS, Tillmann U, Krock B, Harris TM. Mass spectrometric characterization of the seco acid formed by cleavage of the macrolide ring of the algal metabolite goniodomin A. Toxicon 2023; 231:107159. [PMID: 37210046 DOI: 10.1016/j.toxicon.2023.107159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 05/22/2023]
Abstract
Goniodomin A (GDA) is a polyketide macrolide produced by multiple species of the marine dinoflagellate genus Alexandrium. GDA is unusual in that it undergoes cleavage of the ester linkage under mild conditions to give mixtures of seco acids (GDA-sa). Ring-opening occurs even in pure water although the rate of cleavage accelerates with increasing pH. The seco acids exist as a dynamic mixture of structural and stereo isomers which is only partially separable by chromatography. Freshly prepared seco acids show only end absorption in the UV spectrum but a gradual bathochromic change occurs, which is consistent with formation of α,β-unsaturated ketones. Use of NMR and crystallography is precluded for structure elucidation. Nevertheless, structural assignments can be made by mass spectrometric techniques. Retro-Diels-Alder fragmentation has been of value for independently characterizing the head and tail regions of the seco acids. The chemical transformations of GDA revealed in the current studies help clarify observations made on laboratory cultures and in the natural environment. GDA has been found to reside mainly within the algal cells while the seco acids are mainly external with the transformation of GDA to the seco acids occurring largely outside the cells. This relationship, plus the fact that GDA is short-lived in growth medium whereas GDA-sa is long-lived, suggests that the toxicological properties of GDA-sa in its natural environment are more important for the survival of the Alexandrium spp. than those of GDA. The structural similarity of GDA-sa to that of monensin is noted. Monensin has strong antimicrobial properties, attributed to its ability to transport sodium ions across cell membranes. We propose that toxic properties of GDA may primarily be due to the ability of GDA-sa to mediate metal ion transport across cell membranes of predator organisms.
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Affiliation(s)
- Constance M Harris
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Luisa Hintze
- Alfred Wegener Institut-Helmholtz Zentrum für Polar- und Meeresforschung (AWI), 27570, Bremerhaven, Germany
| | - Sylvain Gaillard
- Department of Aquatic Health Sciences, Virginia Institute of Marine Science (VIMS), William & Mary, Gloucester Point, VA, 23062, USA
| | - Simon Tanniou
- Ifremer, PHYTOX, Laboratoire METALG, F-44000, Nantes, France
| | - Hamish Small
- Department of Aquatic Health Sciences, Virginia Institute of Marine Science (VIMS), William & Mary, Gloucester Point, VA, 23062, USA
| | - Kimberly S Reece
- Department of Aquatic Health Sciences, Virginia Institute of Marine Science (VIMS), William & Mary, Gloucester Point, VA, 23062, USA
| | - Urban Tillmann
- Alfred Wegener Institut-Helmholtz Zentrum für Polar- und Meeresforschung (AWI), 27570, Bremerhaven, Germany
| | - Bernd Krock
- Alfred Wegener Institut-Helmholtz Zentrum für Polar- und Meeresforschung (AWI), 27570, Bremerhaven, Germany
| | - Thomas M Harris
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA.
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Abstract
Covering: 2020This review covers the literature published in 2020 for marine natural products (MNPs), with 757 citations (747 for the period January to December 2020) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1407 in 420 papers for 2020), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. A meta analysis of bioactivity data relating to new MNPs reported over the last five years is also presented.
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Affiliation(s)
- Anthony R Carroll
- School of Environment and Science, Griffith University, Gold Coast, Australia. .,Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia
| | - Brent R Copp
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia.,School of Enivironment and Science, Griffith University, Brisbane, Australia
| | - Robert A Keyzers
- Centre for Biodiscovery, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
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Paralytic Shellfish Poisoning (PSP) in Mussels from the Eastern Cantabrian Sea: Toxicity, Toxin Profile, and Co-Occurrence with Cyclic Imines. Toxins (Basel) 2021; 13:toxins13110761. [PMID: 34822545 PMCID: PMC8617803 DOI: 10.3390/toxins13110761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
In the late autumn of 2018 and 2019, some samples taken by the official monitoring systems of Cantabria and the Basque Country were found to be paralytic shellfish poisoning (PSP)-positive using a mouse bioassay. To confirm the presence of PSP toxins and to obtain their profile, these samples were analyzed using an optimized version of the Official Method AOAC 2005.06 and using LC–MS/MS (HILIC). The presence of some PSP toxins (PSTs) in that geographical area (~600 km of coast) was confirmed for the first time. The estimated toxicities ranged from 170 to 983 µg STXdiHCl eq.·kg−1 for the AOAC 2005.06 method and from 150 to 1094 µg STXdiHCl eq.·kg−1 for the LC–MS/MS method, with a good correlation between both methods (r2 = 0.94). Most samples contained STX, GTX2,3, and GTX1,4, and some also had NEO and dcGTX2. All of the PSP-positive samples also contained gymnodimine A, with the concentrations of the two groups of toxins being significantly correlated. The PSP toxin profiles suggest that a species of the genus Alexandrium was likely the causative agent. The presence of gymnodimine A suggests that A. ostenfeldii could be involved, but the contribution of a mixture of Alexandrium species cannot be ruled out.
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Harris CM, Krock B, Tillmann U, Tainter CJ, Stec DF, Andersen AJC, Larsen TO, Reece KS, Harris TM. Alkali Metal- and Acid-Catalyzed Interconversion of Goniodomin A with Congeners B and C. JOURNAL OF NATURAL PRODUCTS 2021; 84:2554-2567. [PMID: 34520205 DOI: 10.1021/acs.jnatprod.1c00586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Goniodomin A (GDA, 1) is a phycotoxin produced by at least four species of Alexandrium dinoflagellates that are found globally in brackish estuaries and lagoons. It is a linear polyketide with six oxygen heterocyclic rings that is cyclized into a macrocyclic structure via lactone formation. Two of the oxygen heterocycles in 1 comprise a spiro-bis-pyran, whereas goniodomin B (GDB) contains a 2,7-dioxabicyclo[3.3.1]nonane ring system fused to a pyran. When H2O is present, 1 undergoes facile conversion to isomer GDB and to an α,β-unsaturated ketone, goniodomin C (GDC, 7). GDB and GDC can be formed from GDA by cleavage of the spiro-bis-pyran ring system. GDA, but not GDB or GDC, forms a crown ether-type complex with K+. Equilibration of GDA with GDB and GDC is observed in the presence of H+ and of Na+, but the equilibrated mixtures revert to GDA upon addition of K+. Structural differences have been found between the K+ and Na+ complexes. The association of GDA with K+ is strong, while that with Na+ is weak. The K+ complex has a compact, well-defined structure, whereas Na+ complexes are an ill-defined mixture of species. Analyses of in vitro A. monilatum and A. hiranoi cultures indicate that only GDA is present in the cells; GDB and GDC appear to be postharvest transformation products.
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Affiliation(s)
- Constance M Harris
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Bernd Krock
- Alfred Wegener Institut-Helmholtz Zentrum für Polar- und Meeresforschung (AWI), Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Urban Tillmann
- Alfred Wegener Institut-Helmholtz Zentrum für Polar- und Meeresforschung (AWI), Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Craig J Tainter
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Donald F Stec
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Aaron J C Andersen
- Department of Biotechnology and Biomedicine, Søltofts Plads, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Thomas O Larsen
- Department of Biotechnology and Biomedicine, Søltofts Plads, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Kimberly S Reece
- Virginia Institute of Marine Science (VIMS), William & Mary, Gloucester Point, Virginia 23062, United States
| | - Thomas M Harris
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Virginia Institute of Marine Science (VIMS), William & Mary, Gloucester Point, Virginia 23062, United States
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