{"id":"5c544a8f-19ac-57ad-8fc7-ab2a37c7f8ee","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:ve-transport-nadph-microsomal-oxidation","predicate":"enables","statement":"Rat liver microsomes formed initial alpha- and gamma-tocopherol side-chain oxidation products with NADPH but not without it.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"2af33f02-4eda-57bd-ba8b-8f7162db545d","mechanism_event_label":"The initial microsomal oxidation required a reducing cofactor.","subject":{"id":"4aba2a5e-8d06-5304-bb01-c0402b225a94","slug":"nadph","display_name":"NADPH","entity_type_key":"small_molecule"},"object":{"id":"fcbfe1cf-c9b7-5946-b75c-d0c4bfb57300","slug":"microsomal-tocopherol-omega-hydroxylation","display_name":"Microsomal tocopherol omega-hydroxylation","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"2af33f02-4eda-57bd-ba8b-8f7162db545d","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:ve-transport-nadph-microsomal-oxidation-event","event_type":"biochemical_relationship","label":"The initial microsomal oxidation required a reducing cofactor.","description":"Rat liver microsomes formed initial alpha- and gamma-tocopherol side-chain oxidation products with NADPH but not without it.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"4aba2a5e-8d06-5304-bb01-c0402b225a94","slug":"nadph","display_name":"NADPH","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"fcbfe1cf-c9b7-5946-b75c-d0c4bfb57300","slug":"microsomal-tocopherol-omega-hydroxylation","display_name":"Microsomal tocopherol omega-hydroxylation","entity_type_key":"cellular_process"},"role":"target","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":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"2de3a4d0-56b1-57f9-9e9d-934ba52a1753","slug":"gamma-tocopherol","display_name":"Gamma-tocopherol","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Cofactor omission/addition; Figure 6","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"0.5 mM NADPH; reaction followed for 80 minutes.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Direct NADPH dependence; no dietary niacin or riboflavin shortage, universal supplement combination or magnesium requirement was tested.","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":"Rattus norvegicus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The initial microsomal oxidation required a reducing cofactor.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[sontag2002] Cytochrome P450 omega-hydroxylase pathway of tocopherol catabolism. Novel mechanism of regulation of vitamin E status. (2002). https://pubmed.ncbi.nlm.nih.gov/11997390/ DOI: 10.1074/jbc.m201466200","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Liver microsomes","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"2203821a-2344-59bc-93d1-5eb484861116","evidence_kind":"source_excerpt","locator":"Lines 441-452","start_line":441,"end_line":452,"excerpt":"### ve-transport-nadph-microsomal-oxidation\nRat liver microsomes formed initial alpha- and gamma-tocopherol side-chain oxidation products with NADPH but not without it.\nCondition category: normal\nnutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The initial microsomal oxidation required a reducing cofactor.\norganism: Rattus norvegicus\ntissue_or_cell_type: Liver microsomes\nexperimental_model: Cofactor omission/addition; Figure 6\nlimitations: Direct NADPH dependence; no dietary niacin or riboflavin shortage, universal supplement combination or magnesium requirement was tested.\nexposure: 0.5 mM NADPH; reaction followed for 80 minutes.\ncross_nutrient: true\n[sontag2002] Cytochrome P450 omega-hydroxylase pathway of tocopherol catabolism. Novel mechanism of regulation of vitamin E status. (2002). https://pubmed.ncbi.nlm.nih.gov/11997390/ DOI: 10.1074/jbc.m201466200","model_system":"Cofactor omission/addition; Figure 6","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [sontag2002] Cytochrome P450 omega-hydroxylase pathway of tocopherol catabolism. Novel mechanism of regulation of vitamin E status. (2002). https://pubmed.ncbi.nlm.nih.gov/11997390/ DOI: 10.1074/jbc.m201466200","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. Not publisher full text.","file_path":"","sha256":"a90b6565e092c6a2da07f74cf758792c2cf63b40746260c8ff12bd64322c36f4","revision_id":"956793d1-23e4-5397-9291-25c1732a8e02","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}