{"id":"1dee7e1a-8cb9-52b2-9e99-ba25836257f8","stable_key":"788beb7b-7928-5f89-83d4-5556abf3702c:fulvic-acid-iron-redox","predicate":"promotes_contextual_reduction","statement":"Iron(III) reduction to iron(II) occurred over time at pH 2 but was not significant at pH 4.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"5afff863-c573-5b04-bff5-7b9659382ed3","mechanism_event_label":"Acidity changed the iron-redox outcome.","subject":{"id":"f17fcce7-092b-5eb4-b93f-cef2c95f2f9d","slug":"iron-binding-fulvic-2008","display_name":"Fulvic fraction used in 2008 iron EXAFS study","entity_type_key":"chemical_species"},"object":{"id":"59d6d1cd-df32-5b58-b950-3188bc7b95d6","slug":"iron-ii","display_name":"Ferrous iron","entity_type_key":"ion"},"evidence_count":1,"mechanism_event":{"id":"5afff863-c573-5b04-bff5-7b9659382ed3","stable_key":"788beb7b-7928-5f89-83d4-5556abf3702c:fulvic-acid-iron-redox-event","event_type":"observed_relationship","label":"Acidity changed the iron-redox outcome.","description":"Iron(III) reduction to iron(II) occurred over time at pH 2 but was not significant at pH 4.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"f17fcce7-092b-5eb4-b93f-cef2c95f2f9d","slug":"iron-binding-fulvic-2008","display_name":"Fulvic fraction used in 2008 iron EXAFS study","entity_type_key":"chemical_species"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"59d6d1cd-df32-5b58-b950-3188bc7b95d6","slug":"iron-ii","display_name":"Ferrous iron","entity_type_key":"ion"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"0aa6c0fc-8374-56e0-b172-6c40b6366d21","slug":"fulvic-acid","display_name":"Fulvic acid (heterogeneous humic fraction)","entity_type_key":"chemical_species"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"964be7ac-43bd-5f3e-8326-94f0590de67a","slug":"iron-iii","display_name":"Ferric iron","entity_type_key":"ion"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Cell-free EXAFS study of the specified fulvic fraction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Stomach-like acidity alone does not reproduce food, digestion, mucosal transport or human pharmacokinetics.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Fulvic acid collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"fulvic-acid","display_name":"Fulvic acid (heterogeneous humic fraction)","entity_type_key":"chemical_species"}},{"dimension":"plain_language","value_text":"Acidity changed the iron-redox outcome.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"EXAFS study on the reactions between iron and fulvic acid in acid aqueous solutions. · 2008 · https://pubmed.ncbi.nlm.nih.gov/18504967/ · DOI 10.1021/es072092z","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"131ce72e-99fe-56b1-aaf8-c9d9c294e1fa","evidence_kind":"source_excerpt","locator":"Lines 100-106","start_line":100,"end_line":106,"excerpt":"## fulvic-acid-iron-redox\nAcidity changed the iron-redox outcome.\nIron(III) reduction to iron(II) occurred over time at pH 2 but was not significant at pH 4.\nModel: Cell-free EXAFS study of the specified fulvic fraction.\nLimitations: Stomach-like acidity alone does not reproduce food, digestion, mucosal transport or human pharmacokinetics.\nEvidence access: Primary abstract\nEXAFS study on the reactions between iron and fulvic acid in acid aqueous solutions. · 2008 · https://pubmed.ncbi.nlm.nih.gov/18504967/ · DOI 10.1021/es072092z","model_system":"Cell-free EXAFS study of the specified fulvic fraction.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; 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