{"id":"27120605-ea5b-519c-acf0-ea14823fb39d","stable_key":"a9dd23c6-978a-5755-8bd8-f29bd1fe0cda:b3-cons-nnmt-methyl-transfer","predicate":"produces","statement":"NNMT transfers a methyl group from SAM to nicotinamide, yielding N1-methylnicotinamide and S-adenosylhomocysteine.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"423e809e-296e-5b8a-bcf9-bc3f24acec5c","mechanism_event_label":"Nicotinamide methylation uses a methyl group from SAM.","subject":{"id":"68273ca3-19da-57e0-85bb-2f1245928df5","slug":"nnmt","display_name":"Human NNMT","entity_type_key":"protein"},"object":{"id":"b02a63e0-a972-53c5-8a3a-eea6b7578cd5","slug":"n1-methylnicotinamide","display_name":"N1-Methylnicotinamide","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"423e809e-296e-5b8a-bcf9-bc3f24acec5c","stable_key":"a9dd23c6-978a-5755-8bd8-f29bd1fe0cda:b3-cons-nnmt-methyl-transfer-event","event_type":"biochemical_relationship","label":"Nicotinamide methylation uses a methyl group from SAM.","description":"NNMT transfers a methyl group from SAM to nicotinamide, yielding N1-methylnicotinamide and S-adenosylhomocysteine.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"68273ca3-19da-57e0-85bb-2f1245928df5","slug":"nnmt","display_name":"Human NNMT","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"08c27a3f-552e-5c92-8688-321a9b64a0d6","slug":"nicotinamide","display_name":"Nicotinamide","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"role":"methyl_donor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"b02a63e0-a972-53c5-8a3a-eea6b7578cd5","slug":"n1-methylnicotinamide","display_name":"N1-Methylnicotinamide","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"e84829b1-0607-558e-8add-aaa3af4747e7","slug":"s-adenosylhomocysteine","display_name":"S-Adenosyl-L-homocysteine","entity_type_key":"small_molecule"},"role":"coproduct","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/niacin-consumption-sources/nnmt2013.txt\", \"locator\": \"Full text, normalized paragraph 8\", \"start_char\": 2396, \"end_char\": 4508, \"file_sha256\": \"7d88fd656ba772962185234a9bd021e40a9b83f9156db836f723eba06b68acca\", \"text_sha256\": \"fc5cdd48751fa59656f5c16e70c31ab3f36788c265267d7cb57f269bb1848fc6\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human cancer-cell enzyme activity and metabolomics study","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Nicotinamide substrate and NNMT expression/activity comparisons","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Engineered human cancer-cell culture, not healthy-human niacin repletion. SAM consumption does not establish systemic methyl depletion or a need for folate/B12 supplements.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Niacin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"niacin","display_name":"Niacin (vitamin B3)","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Human","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Nicotinamide methylation uses a methyl group from SAM.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b3-cons-nnmt2013] NNMT promotes epigenetic remodeling in cancer by creating a metabolic methylation sink. (2013). https://pubmed.ncbi.nlm.nih.gov/23455543/ DOI: 10.1038/nchembio.1204","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"769P, OVCAR3, MUM2C and comparison cell models","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"19c2a1f8-3f0e-560b-bcaf-211554bca275","evidence_kind":"source_excerpt","locator":"Lines 747-759","start_line":747,"end_line":759,"excerpt":"### b3-cons-nnmt-methyl-transfer\nNNMT transfers a methyl group from SAM to nicotinamide, yielding N1-methylnicotinamide and S-adenosylhomocysteine.\nCondition category: normal\nnutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Nicotinamide methylation uses a methyl group from SAM.\norganism: Human\ntissue_or_cell_type: 769P, OVCAR3, MUM2C and comparison cell models\nexperimental_model: Human cancer-cell enzyme activity and metabolomics study\nlimitations: Engineered human cancer-cell culture, not healthy-human niacin repletion. SAM consumption does not establish systemic methyl depletion or a need for folate/B12 supplements.\nexposure: Nicotinamide substrate and NNMT expression/activity comparisons\ncross_nutrient: true\nevidence_span: {\"source_cache\": \"artifacts/niacin-consumption-sources/nnmt2013.txt\", \"locator\": \"Full text, normalized paragraph 8\", \"start_char\": 2396, \"end_char\": 4508, \"file_sha256\": \"7d88fd656ba772962185234a9bd021e40a9b83f9156db836f723eba06b68acca\", \"text_sha256\": \"fc5cdd48751fa59656f5c16e70c31ab3f36788c265267d7cb57f269bb1848fc6\"}\n[b3-cons-nnmt2013] NNMT promotes epigenetic remodeling in cancer by creating a metabolic methylation sink. (2013). https://pubmed.ncbi.nlm.nih.gov/23455543/ DOI: 10.1038/nchembio.1204","model_system":"Human cancer-cell enzyme activity and metabolomics study","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b3-cons-nnmt2013] NNMT promotes epigenetic remodeling in cancer by creating a metabolic methylation sink. (2013). https://pubmed.ncbi.nlm.nih.gov/23455543/ DOI: 10.1038/nchembio.1204","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"a62b7b5b-786a-57e9-85e9-67c6912a5054","stable_key":"import-a9dd23c6-978a-5755-8bd8-f29bd1fe0cda","title":"Niacin: NAD metabolism, 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. Not publisher full text.","file_path":"","sha256":"a8cac59639322f74812ce12eef338c2f6c385c04cc4af6ab511fc7c972f0c2e6","revision_id":"bec8fc45-12e7-5f75-a814-5d72ed015d01","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}