{"id":"10a453b9-9e3d-508b-8c56-fa2b8b8560f3","stable_key":"35ec55a7-323c-5c28-979e-3bdafe9d5769:metal-copper-binding-low","predicate":"reported_relationship","statement":"The tested cyanidin compounds and elderberry preparations had low copper-chelating activity despite their metal-reducing reactions.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"f116f881-2835-5b5d-9cd6-dee78010350b","mechanism_event_label":"The tested cyanidin compounds and elderberry preparations had low copper-chelating activity despite their metal-reducing reactions.","subject":{"id":"75149db0-02f7-5d32-8c7a-5c111d90d8ee","slug":"cyanidin-3-glucoside","display_name":"Cyanidin 3-O-beta-D-glucopyranoside","entity_type_key":"small_molecule"},"object":{"id":"dce94bf2-b471-56e0-ae73-4d10db0b656a","slug":"copper-chelation-assay","display_name":"Copper complexation in cell-free chemical assays","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"f116f881-2835-5b5d-9cd6-dee78010350b","stable_key":"35ec55a7-323c-5c28-979e-3bdafe9d5769:metal-copper-binding-low-event","event_type":"experimental_observation","label":"The tested cyanidin compounds and elderberry preparations had low copper-chelating activity despite their metal-reducing reactions.","description":"**Iron binding and metal reduction are different reactions.** Purified cyanidin, C3G and standardized elderberry extracts chelated iron and reduced iron and copper in cell-free assays; copper-chelating activity was relatively low. Extract behavior varied and was not completely explained by pigment concentration. Binding a metal, changing its oxidation state and reducing intestinal absorption are three different endpoints. This does not establish removal of intracellular metals or protection from ferroptosis in people. [Mladěnka et al., 2016](https://doi.org/10.1016/j.phytol.2016.10.025).","status":"provisional","compartment":null,"participants":[{"entity":{"id":"75149db0-02f7-5d32-8c7a-5c111d90d8ee","slug":"cyanidin-3-glucoside","display_name":"Cyanidin 3-O-beta-D-glucopyranoside","entity_type_key":"small_molecule"},"role":"tested factor","stoichiometry":null,"state_label":"as reported","sequence_order":0,"notes":""},{"entity":{"id":"dce94bf2-b471-56e0-ae73-4d10db0b656a","slug":"copper-chelation-assay","display_name":"Copper complexation in cell-free chemical assays","entity_type_key":"cellular_process"},"role":"measured outcome","stoichiometry":null,"state_label":"not_reported","sequence_order":1,"notes":""},{"entity":{"id":"2a870bb5-05a0-5e51-a70c-a9a843a8b571","slug":"copper-ii","display_name":"Copper(II) ion","entity_type_key":"ion"},"role":"tested metal","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"e00a80c5-8b02-5a86-a3e7-c2acf829d870","slug":"elderberry-extracts-mladenka-2016","display_name":"Ten standardized elderberry fruit extracts in Mladenka 2016","entity_type_key":"botanical"},"role":"separate tested botanical preparations","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary article abstract read in indexed publisher/author-hosted result; publisher full text unavailable. Exact pH series and extract/metal ratios not extracted.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Cell-free standardized spectrophotometric comparisons.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Low is not zero. Does not establish a clinical copper-depleting effect; extract composition and pH matter.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The tested cyanidin compounds and elderberry preparations had low copper-chelating activity despite their metal-reducing reactions.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Fruit extracts of 10 varieties of elderberry (Sambucus nigra L.) interact differently with iron and copper | 2016 | DOI 10.1016/j.phytol.2016.10.025 | https://doi.org/10.1016/j.phytol.2016.10.025","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 88-88; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"c9f86f68-f492-5ec0-83ac-02b94308fd73","evidence_kind":"source_excerpt","locator":"Lines 88-88","start_line":88,"end_line":88,"excerpt":"**Iron binding and metal reduction are different reactions.** Purified cyanidin, C3G and standardized elderberry extracts chelated iron and reduced iron and copper in cell-free assays; copper-chelating activity was relatively low. Extract behavior varied and was not completely explained by pigment concentration. Binding a metal, changing its oxidation state and reducing intestinal absorption are three different endpoints. This does not establish removal of intracellular metals or protection from ferroptosis in people. [Mladěnka et al., 2016](https://doi.org/10.1016/j.phytol.2016.10.025).","model_system":"Cell-free standardized spectrophotometric comparisons.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Exact excerpt of the retained AI-assisted reviewed reference; primary sources are cited in primary_references and access scope is retained. 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