{"id":"dd07a50a-ff8b-54be-ad10-527422c480f3","stable_key":"3279ff78-2460-5064-bfc0-3f2987af85a0:melatonin-cyp-2c19-demethylation","predicate":"demethylates_melatonin_to","statement":"Human CYP2C19 catalyzed melatonin O-demethylation.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"8ec0ba67-a453-5071-9a2e-a8ab30fd2d9c","mechanism_event_label":"Removing the methyl group returns a molecule with the identity of a synthetic precursor.","subject":{"id":"cc080b54-fd5d-5cc0-930e-2cb86c116c68","slug":"cyp2c19","display_name":"Human cytochrome P450 2C19","entity_type_key":"protein"},"object":{"id":"50dd19e0-6457-59d5-9c01-3a156c28ee7c","slug":"n-acetylserotonin","display_name":"N-Acetylserotonin","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"8ec0ba67-a453-5071-9a2e-a8ab30fd2d9c","stable_key":"3279ff78-2460-5064-bfc0-3f2987af85a0:melatonin-cyp-2c19-demethylation-event","event_type":"biochemical_relationship","label":"Removing the methyl group returns a molecule with the identity of a synthetic precursor.","description":"Human CYP2C19 catalyzed melatonin O-demethylation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"0f0bc1f1-d18d-5652-bc1d-98f61f7ab65c","slug":"melatonin","display_name":"Melatonin","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"4aba2a5e-8d06-5304-bb01-c0402b225a94","slug":"nadph","display_name":"NADPH","entity_type_key":"small_molecule"},"role":"reducing_equivalent_source","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"cc080b54-fd5d-5cc0-930e-2cb86c116c68","slug":"cyp2c19","display_name":"Human cytochrome P450 2C19","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"50dd19e0-6457-59d5-9c01-3a156c28ee7c","slug":"n-acetylserotonin","display_name":"N-Acetylserotonin","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/melatonin-research/15616152.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"482334074e10503323360f236e00b5b837c5b082a7cda4df000a23d491bff8a2\", \"start_char\": 0, \"end_char\": 1733, \"text_sha256\": \"482334074e10503323360f236e00b5b837c5b082a7cda4df000a23d491bff8a2\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant P450 screen and mouse brain comparisons","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Eleven P450 isozymes; NADPH-dependent 6-hydroxylation/O-demethylation","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Catalytic capacity in an enzyme assay is not whole-body contribution. CYP1B1 is an extrahepatic route; human proteins are not substituted for mouse knockout identity.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Melatonin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"melatonin","display_name":"Melatonin","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Human recombinant enzymes; separate mouse knockout experiment","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Removing the methyl group returns a molecule with the identity of a synthetic precursor.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[melatonin-p15616152] Metabolism of melatonin by human cytochromes p450. (2005). https://pubmed.ncbi.nlm.nih.gov/15616152/ DOI: 10.1124/dmd.104.002410","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Oxidative melatonin metabolism","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"b8d50252-5619-5a3e-9811-19ffb71be8bd","evidence_kind":"source_excerpt","locator":"Lines 604-615","start_line":604,"end_line":615,"excerpt":"### melatonin-cyp-2c19-demethylation\nHuman CYP2C19 catalyzed melatonin O-demethylation.\nCondition category: normal\nnutrient_topic: Melatonin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Removing the methyl group returns a molecule with the identity of a synthetic precursor.\norganism: Human recombinant enzymes; separate mouse knockout experiment\ntissue_or_cell_type: Oxidative melatonin metabolism\nexperimental_model: Recombinant P450 screen and mouse brain comparisons\nlimitations: Catalytic capacity in an enzyme assay is not whole-body contribution. CYP1B1 is an extrahepatic route; human proteins are not substituted for mouse knockout identity.\nexposure: Eleven P450 isozymes; NADPH-dependent 6-hydroxylation/O-demethylation\nevidence_span: {\"source_cache\": \"artifacts/melatonin-research/15616152.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"482334074e10503323360f236e00b5b837c5b082a7cda4df000a23d491bff8a2\", \"start_char\": 0, \"end_char\": 1733, \"text_sha256\": \"482334074e10503323360f236e00b5b837c5b082a7cda4df000a23d491bff8a2\"}\n[melatonin-p15616152] Metabolism of melatonin by human cytochromes p450. (2005). https://pubmed.ncbi.nlm.nih.gov/15616152/ DOI: 10.1124/dmd.104.002410","model_system":"Recombinant P450 screen and mouse brain comparisons","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [melatonin-p15616152] Metabolism of melatonin by human cytochromes p450. (2005). https://pubmed.ncbi.nlm.nih.gov/15616152/ DOI: 10.1124/dmd.104.002410","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"bab588de-d217-5038-9c8b-b41222eba08b","stable_key":"import-3279ff78-2460-5064-bfc0-3f2987af85a0","title":"Melatonin: synthesis, receptors, circadian timing 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":"ff4f279d263f95a69da8e7e8a6c6318ab6ba1b55254dbbda1bfa9ce437e1db80","revision_id":"0318eef8-ff38-513e-8ffa-458146ca5e77","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}