{"doi":"10.1021/acs.jnatprod.1c00586","title":"Alkali Metal- and Acid-Catalyzed Interconversion of Goniodomin A with Congeners B and C","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.","journal":"Journal of Natural Products","year":2021,"id":195039,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":9,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.953,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":765708,"name":"Bernd Krock","orcid":"0000-0003-4022-9101","position":1,"is_corresponding":false},{"id":765709,"name":"Urban Tillmann","orcid":"0000-0002-8207-4382","position":2,"is_corresponding":false},{"id":442052,"name":"Craig J. Tainter","orcid":"0000-0001-5924-4972","position":3,"is_corresponding":false},{"id":295362,"name":"Donald F. Stec","orcid":"0000-0001-9217-0362","position":4,"is_corresponding":false},{"id":765710,"name":"Aaron J.C. Andersen","orcid":"0000-0002-3876-7480","position":5,"is_corresponding":false},{"id":765711,"name":"Thomas Ostenfeld Larsen","orcid":"0000-0002-3362-5707","position":6,"is_corresponding":false},{"id":442057,"name":"Kimberly S. Reece","orcid":"0000-0002-1751-1566","position":7,"is_corresponding":false},{"id":442058,"name":"Thomas M. Harris","orcid":"0000-0002-3062-344X","position":8,"is_corresponding":false},{"id":442054,"name":"Constance M. Harris","orcid":"0000-0002-4982-3900","position":0,"is_corresponding":true}],"reference_count":37,"raw_metadata":null,"created_at":"2026-07-18T23:50:03.719152Z","pmid":"34520205","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}