{"id":"c68cbf44-297f-523b-8e3e-9da658aacf09","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:e-sig-delta-acid-cox1","predicate":"competitively-inhibits","statement":"Delta-tocopherol-13′-carboxychromanol competitively inhibited purified ovine COX-1 cyclooxygenase activity with a reported Ki of 3.9 µM, measured by initial oxygen consumption while varying arachidonic acid.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"d5315dc5-bf9d-592a-a4e2-d8922f294445","mechanism_event_label":"The long-chain delta-tocopherol metabolite interfered with this purified enzyme’s use of arachidonic acid.","subject":{"id":"692528ac-5680-5d1e-bf48-d8ffd17cb97e","slug":"delta-13-carboxychromanol","display_name":"Delta-tocopherol-13′-carboxychromanol","entity_type_key":"small_molecule"},"object":{"id":"2a03770f-5849-5c0f-b5aa-2f352afc83ff","slug":"ptgs1-ovine","display_name":"Ovine cyclooxygenase-1","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"d5315dc5-bf9d-592a-a4e2-d8922f294445","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:e-sig-delta-acid-cox1-event","event_type":"biochemical_relationship","label":"The long-chain delta-tocopherol metabolite interfered with this purified enzyme’s use of arachidonic acid.","description":"Delta-tocopherol-13′-carboxychromanol competitively inhibited purified ovine COX-1 cyclooxygenase activity with a reported Ki of 3.9 µM, measured by initial oxygen consumption while varying arachidonic acid.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"39f9446f-52a6-502d-b507-91137726f82c","slug":"arachidonic-acid","display_name":"AA","entity_type_key":"small_molecule"},"role":"varied substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"692528ac-5680-5d1e-bf48-d8ffd17cb97e","slug":"delta-13-carboxychromanol","display_name":"Delta-tocopherol-13′-carboxychromanol","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"2a03770f-5849-5c0f-b5aa-2f352afc83ff","slug":"ptgs1-ovine","display_name":"Ovine cyclooxygenase-1","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified-enzyme oxygen-electrode kinetics","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"13′-COOH 0, 7.5, 15 or 25 µM; arachidonic acid 6–200 µM in Tris pH 8 with 1 µM hematin, phenol and EDTA.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Purified enzyme kinetics do not establish human anti-inflammatory benefit. Cyclooxygenase and peroxidase activities must not be conflated.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin E research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-e","display_name":"Vitamin E","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Ovis aries","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The long-chain delta-tocopherol metabolite interfered with this purified enzyme’s use of arachidonic acid.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[jiang2008] Long-chain carboxychromanols, metabolites of vitamin E, are potent inhibitors of cyclooxygenases. (2008). https://pubmed.ncbi.nlm.nih.gov/19074288/ DOI: 10.1073/pnas.0810962106","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"d0510bd1-e778-5fab-9d5f-1b0938b2d99d","evidence_kind":"source_excerpt","locator":"Lines 855-866","start_line":855,"end_line":866,"excerpt":"### e-sig-delta-acid-cox1\nDelta-tocopherol-13′-carboxychromanol competitively inhibited purified ovine COX-1 cyclooxygenase activity with a reported Ki of 3.9 µM, measured by initial oxygen consumption while varying arachidonic acid.\nCondition category: normal\nnutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The long-chain delta-tocopherol metabolite interfered with this purified enzyme’s use of arachidonic acid.\norganism: Ovis aries\ntissue_or_cell_type: Cell-free enzyme\nexperimental_model: Purified-enzyme oxygen-electrode kinetics\nlimitations: Purified enzyme kinetics do not establish human anti-inflammatory benefit. Cyclooxygenase and peroxidase activities must not be conflated.\nexposure: 13′-COOH 0, 7.5, 15 or 25 µM; arachidonic acid 6–200 µM in Tris pH 8 with 1 µM hematin, phenol and EDTA.\ncross_nutrient: false\n[jiang2008] Long-chain carboxychromanols, metabolites of vitamin E, are potent inhibitors of cyclooxygenases. (2008). https://pubmed.ncbi.nlm.nih.gov/19074288/ DOI: 10.1073/pnas.0810962106","model_system":"Purified-enzyme oxygen-electrode kinetics","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [jiang2008] Long-chain carboxychromanols, metabolites of vitamin E, are potent inhibitors of cyclooxygenases. 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