(5S)-5-[(4aR,8aS,9E,11S,13R,14S,16R,17R,19S)-11,19-Dihydroxy-8,10,13,16-tetramethyl-18-methylidene-3,4,5,6,8a,11,12,13,14,15,16,17,18,19,20,21-hexadecahydro-2H-14,17-epoxybenzo[2,3]cyclohexadeca[1,2-b]pyridine-7-yl]-3-methylfuran-2(5H)-one (12-Methylgymnodimine B)

We present an overview of the toxicological profile of the fast acting, lipophilic macrocyclic imine toxins, an emerging family of organic compounds associated with algal blooms, shellfish contamination and neurotoxicity. Worldwide, shellfish contamination incidents are expanding; therefore the significance of these toxins for the shellfish food industry deserves further study. Emphasis is directed to the dinoflagellate species involved in their production, their chemical structures, and their specific mode of interaction with their principal natural molecular targets, the nicotinic acetylcholine receptors, or with the soluble acetylcholine-binding protein, used as a surrogate receptor model. The dinoflagellates Karenia selliformis and Alexandrium ostenfeldii / A. peruvianum have been implicated in the biosynthesis of gymnodimines and spirolides, while Vulcanodinium rugosum is the producer of pinnatoxins and portimine. The cyclic imine toxins are characterized by a macrocyclic skeleton comprising 14 to 27 carbon atoms, flanked by two conserved moieties, the cyclic imine and the spiroketal ring system. These phycotoxins generally display high affinity and broad specificity for the muscle-type and neuronal nicotinic acetylcholine receptors, a feature consistent with their binding site at the receptor subunit interfaces, composed of residues highly conserved among all nAChRs, and explaining the diverse toxicity among animal species.

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“…; Strangman et al . ). Also, a new gymnodimine D was found in A. ostenfeldii clonal cultures isolated from the Northern Baltic Sea (Harju et al .…”

Section: Dinoflagellate Species Involved In the Production Of Cyclic mentioning

confidence: 97%

Cyclic imine toxins from dinoflagellates: a growing family of potent antagonists of the nicotinic acetylcholine receptors

Molgó

Marchot

Aráoz

et al. 2017

Journal of Neurochemistry

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“…The chemical structure of GYM-A was first elucidated by nuclear magnetic resonance (NMR) in 1995 [1]; then, another seven analogues of GYM-A were discovered and identified successively (Figure 1), including GYM-B/C [11,12], 12-methyl GYM-A/B [13,14], GYM-D [15], 16-desmethyl GYM-D and GYM-E [16]. The GYM-A is mainly produced by the dinoflagellate Karenia selliformis isolated from several regions such as New Zealand, Tunisia and China [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Stability and Chemical Conversion of the Purified Reference Material of Gymnodimine-A under Different Temperature and pH Conditions

Wang

Qiu

et al. 2022

Toxins

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Gymnodimines (GYMs) are a group of fast-acting phycotoxins and their toxicological effects on human beings are still unclear due to the lack of sufficiently well-characterized large quantities of purified toxins for toxicology studies. In this study, a certified reference material (CRM) of GYM-A was prepared from the dinoflagellate Karenia selliformis, followed by multi-step chromatography separation and purification. Subsequently, the stability of GYM-A in methanolic media was evaluated at different temperature (−20, 4, and 20 °C) and pH (3, 5, and 7) conditions for 8 months, and the conversion products of GYM-A were explored by liquid chromatography–high resolution mass spectrometry (LC-HRMS). The results show that the stability of GYM-A decreased with increasing temperature and pH values. The GYM-A was stable during storage at −20 °C regardless of pH, but it decreased rapidly (81.8% ± 9.3%) at 20 °C in pH 7 solution after 8 months. Moreover, the concentrations of GYM-A did not significantly change at all temperatures in solutions with pH 3 (p > 0.05). It is recommended that GYM-A should be stored at low temperature (≤−20 °C) and pH (≤3) conditions for long-term storage in aqueous methanolic media. In addition, two conversion products of GYM-A, tentatively named as GYM-K (m/z 540) and GYM-L (m/z 524), were identified in the samples stored at high levels of pH and temperature. Based on the LC-HRMS data, the hypothetical chemical structures of both converting derivatives were proposed. A useful strategy for long-term storage of GYM-A CRM in aqueous methanolic media was suggested and two hypothesized conversion products of GYM-A were discovered in this study.

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Unraveling the Karenia selliformis complex with the description of a non-gymnodimine producing Patagonian phylotype

et al. 2020

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(5S)-5-[(4aR,8aS,9E,11S,13R,14S,16R,17R,19S)-11,19-Dihydroxy-8,10,13,16-tetramethyl-18-methylidene-3,4,5,6,8a,11,12,13,14,15,16,17,18,19,20,21-hexadecahydro-2H-14,17-epoxybenzo[2,3]cyclohexadeca[1,2-b]pyridine-7-yl]-3-methylfuran-2(5H)-one (12-Methylgymnodimine B)

Abstract: A new member of the gymnodimine class of spiroimine toxins has been isolated from a laboratory culture strain of Alexandrium ostenfeldii. Extensive one-dimensional (1D) and two-dimensional (2D) NMR data analysis was used to elucidate its structure as 12-methylgymnodimine B.

Cited by 6 publications

References 17 publications

Cyclic imine toxins from dinoflagellates: a growing family of potent antagonists of the nicotinic acetylcholine receptors

Cyclic imine toxins from dinoflagellates: a growing family of potent antagonists of the nicotinic acetylcholine receptors

Stability and Chemical Conversion of the Purified Reference Material of Gymnodimine-A under Different Temperature and pH Conditions

Unraveling the Karenia selliformis complex with the description of a non-gymnodimine producing Patagonian phylotype

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