{"id":"393c454d-2ba6-5768-aa38-e8c4ff16ccd5","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-dietary-fad-hydrolysis","predicate":"hydrolyzed-to","statement":"Rat brush-border preparations released free riboflavin from FAD; inhibiting coenzyme hydrolysis reduced its competition with tracer riboflavin uptake.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"961d23c3-1534-5ab5-83ce-4cc6b1e43217","mechanism_event_label":"Dietary FAD can supply absorbable riboflavin after intestinal cleavage.","subject":{"id":"e2cd7179-f218-54e8-9ce9-7a836ae35fac","slug":"fad","display_name":"FAD","entity_type_key":"small_molecule"},"object":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"961d23c3-1534-5ab5-83ce-4cc6b1e43217","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-dietary-fad-hydrolysis-event","event_type":"biochemical_relationship","label":"Dietary FAD can supply absorbable riboflavin after intestinal cleavage.","description":"Rat brush-border preparations released free riboflavin from FAD; inhibiting coenzyme hydrolysis reduced its competition with tracer riboflavin uptake.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e2cd7179-f218-54e8-9ce9-7a836ae35fac","slug":"fad","display_name":"FAD","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"01532ed3-33c2-5652-8a5b-439d6501a481","slug":"intestinal-flavin-hydrolysis","display_name":"Intestinal flavin-coenzyme hydrolysis","entity_type_key":"cellular_process"},"role":"process","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_location","value_text":"Abstract; intestinal fractionation and EDTA competition experiments","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Rat mucosal fractionation, hydrolase assays and radiolabeled-riboflavin uptake in everted intestinal rings","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Flavin coenzymes with or without EDTA during tracer uptake.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Rat ex vivo evidence; molecular identities of the hydrolases were not established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Riboflavin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Rattus norvegicus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Dietary FAD can supply absorbable riboflavin after intestinal cleavage.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[transport-diet-1982] FMN phosphatase and FAD pyrophosphatase in rat intestinal brush borders: role in intestinal absorption of dietary riboflavin. (1982). https://doi.org/10.1093/jn/112.2.263 DOI: 10.1093/jn/112.2.263","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Small-intestinal mucosa","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"7e134bae-2b86-54f8-b25e-9fb13a42be68","evidence_kind":"source_excerpt","locator":"Lines 124-135","start_line":124,"end_line":135,"excerpt":"### transport-dietary-fad-hydrolysis\nRat brush-border preparations released free riboflavin from FAD; inhibiting coenzyme hydrolysis reduced its competition with tracer riboflavin uptake.\nCondition category: normal\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Dietary FAD can supply absorbable riboflavin after intestinal cleavage.\norganism: Rattus norvegicus\ntissue_or_cell_type: Small-intestinal mucosa\nexperimental_model: Rat mucosal fractionation, hydrolase assays and radiolabeled-riboflavin uptake in everted intestinal rings\nlimitations: Rat ex vivo evidence; molecular identities of the hydrolases were not established.\nexposure: Flavin coenzymes with or without EDTA during tracer uptake.\nevidence_location: Abstract; intestinal fractionation and EDTA competition experiments\n[transport-diet-1982] FMN phosphatase and FAD pyrophosphatase in rat intestinal brush borders: role in intestinal absorption of dietary riboflavin. (1982). https://doi.org/10.1093/jn/112.2.263 DOI: 10.1093/jn/112.2.263","model_system":"Rat mucosal fractionation, hydrolase assays and radiolabeled-riboflavin uptake in everted intestinal rings","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [transport-diet-1982] FMN phosphatase and FAD pyrophosphatase in rat intestinal brush borders: role in intestinal absorption of dietary riboflavin. (1982). https://doi.org/10.1093/jn/112.2.263 DOI: 10.1093/jn/112.2.263","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f7c9578-82bf-5e2d-b5c4-72a79fb4f6af","stable_key":"import-548ab9d6-3a9b-5bed-879c-17d03813b636","title":"Riboflavin: mechanisms, deficiency 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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