{"id":"cc6b0658-860d-5d27-9d86-e9bd23d5ae60","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:ver-ubiquinol-regeneration","predicate":"regenerates","statement":"Ubiquinol-10 reduced alpha-tocopheroxyl to alpha-tocopherol in stopped-flow solution experiments, with second-order rate constants of 3.74 × 10^5 M^-1 s^-1 in benzene and 2.15 × 10^5 M^-1 s^-1 in ethanol at 25 °C.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"4571725a-ed09-5059-9752-6b9311c0bd9d","mechanism_event_label":"Reduced CoQ10 recycled the vitamin E radical in these chemical assays.","subject":{"id":"64fbe9b3-bf24-5b66-9611-8b78262d6ffc","slug":"reduced-coq10","display_name":"Reduced CoQ10","entity_type_key":"small_molecule"},"object":{"id":"40a6525a-76b8-576e-b73d-1e11aecf5f8d","slug":"alpha-tocopherol","display_name":"Alpha-tocopherol","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"4571725a-ed09-5059-9752-6b9311c0bd9d","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:ver-ubiquinol-regeneration-event","event_type":"biochemical_relationship","label":"Reduced CoQ10 recycled the vitamin E radical in these chemical assays.","description":"Ubiquinol-10 reduced alpha-tocopheroxyl to alpha-tocopherol in stopped-flow solution experiments, with second-order rate constants of 3.74 × 10^5 M^-1 s^-1 in benzene and 2.15 × 10^5 M^-1 s^-1 in ethanol at 25 °C.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ec585435-0fdf-5f6f-97d9-6fff230d405e","slug":"alpha-tocopheroxyl-radical","display_name":"Alpha-tocopheroxyl radical","entity_type_key":"chemical_species"},"role":"electron/hydrogen acceptor","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"64fbe9b3-bf24-5b66-9611-8b78262d6ffc","slug":"reduced-coq10","display_name":"Reduced CoQ10","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"40a6525a-76b8-576e-b73d-1e11aecf5f8d","slug":"alpha-tocopherol","display_name":"Alpha-tocopherol","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Stopped-flow spectrophotometry","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"25 °C; reduced CoQ10.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"No direct tissue flux or oral CoQ10 effect was measured.","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":"Cell-free","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Reduced CoQ10 recycled the vitamin E radical in these chemical assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ver-mukai1990] Stopped-flow kinetic study of the regeneration reaction of tocopheroxyl radical by reduced ubiquinone-10 in solution. (1990). https://pubmed.ncbi.nlm.nih.gov/2383582/ DOI: 10.1016/0304-4165(90)90176-w","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Benzene or ethanol solution","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"84eb55b3-ce4f-5172-afa8-231b00b233df","evidence_kind":"source_excerpt","locator":"Lines 508-520","start_line":508,"end_line":520,"excerpt":"### ver-ubiquinol-regeneration\nUbiquinol-10 reduced alpha-tocopheroxyl to alpha-tocopherol in stopped-flow solution experiments, with second-order rate constants of 3.74 × 10^5 M^-1 s^-1 in benzene and 2.15 × 10^5 M^-1 s^-1 in ethanol at 25 °C.\nCondition category: normal\nnutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Reduced CoQ10 recycled the vitamin E radical in these chemical assays.\norganism: Cell-free\ntissue_or_cell_type: Benzene or ethanol solution\nexperimental_model: Stopped-flow spectrophotometry\nlimitations: No direct tissue flux or oral CoQ10 effect was measured.\nexposure: 25 °C; reduced CoQ10.\ncross_nutrient: true\nevidence_location: Primary abstract\n[ver-mukai1990] Stopped-flow kinetic study of the regeneration reaction of tocopheroxyl radical by reduced ubiquinone-10 in solution. (1990). https://pubmed.ncbi.nlm.nih.gov/2383582/ DOI: 10.1016/0304-4165(90)90176-w","model_system":"Stopped-flow spectrophotometry","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [ver-mukai1990] Stopped-flow kinetic study of the regeneration reaction of tocopheroxyl radical by reduced ubiquinone-10 in solution. (1990). https://pubmed.ncbi.nlm.nih.gov/2383582/ DOI: 10.1016/0304-4165(90)90176-w","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3ac41dba-4727-5116-a556-ac3bbb0dc41c","stable_key":"import-e0ea2d6a-7429-5e9f-b774-41e5e3288da3","title":"Vitamin E: transport, membrane protection and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. 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