{"id":"98632ec6-a777-5f64-a844-02f79a7d432c","stable_key":"00c24cfe-6189-5244-b81f-5d693e4e177d:chlorogenic_acid-comt-cga","predicate":"o_methylates","statement":"COMT-mediated O-methylation of CGA contributed to the coupled-assay response.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"f6f6dc40-8e87-51ca-8c58-d6ce9753e92c","mechanism_event_label":"Metabolizing a catechol connects it to methyl-group chemistry.","subject":{"id":"6b945a9f-6363-53b0-ac4f-5f0193752b21","slug":"comt-assay-preparation","display_name":"COMT preparation used in dietary-catechol methylation assay, organism not specified in abstract","entity_type_key":"protein_family"},"object":{"id":"705c7f84-5840-55e1-be69-383cc8793a06","slug":"chlorogenic-acid","display_name":"Chlorogenic acid / 5-O-caffeoylquinic acid","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"f6f6dc40-8e87-51ca-8c58-d6ce9753e92c","stable_key":"00c24cfe-6189-5244-b81f-5d693e4e177d:chlorogenic_acid-comt-cga-event","event_type":"biochemical_relationship","label":"Metabolizing a catechol connects it to methyl-group chemistry.","description":"COMT-mediated O-methylation of CGA contributed to the coupled-assay response.","status":"provisional","compartment":null,"participants":[{"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":0,"notes":""},{"entity":{"id":"049cdeae-4cd8-5eac-b3c5-5a24a235a945","slug":"caffeic-acid","display_name":"Caffeic acid","entity_type_key":"small_molecule"},"role":"also_tested_catechol","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"6b945a9f-6363-53b0-ac4f-5f0193752b21","slug":"comt-assay-preparation","display_name":"COMT preparation used in dietary-catechol methylation assay, organism not specified in abstract","entity_type_key":"protein_family"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"705c7f84-5840-55e1-be69-383cc8793a06","slug":"chlorogenic-acid","display_name":"Chlorogenic acid / 5-O-caffeoylquinic acid","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/chlorogenic_acid-research/16081510.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e93fafd7946f8a4aea30ff3ee9ef05e303f9154eb947410fca8e63c6521a4170\", \"start_char\": 0, \"end_char\": 2008, \"text_sha256\": \"e93fafd7946f8a4aea30ff3ee9ef05e303f9154eb947410fca8e63c6521a4170\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Coupled catechol-methylation/DNA-methylation assays and breast-cancer cell experiments","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"CGA DNMT1 IC50 0.9 micromolar in the coupled assay; compounds tested up to 20 micromolar","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"These concentrations and coupled-reaction conditions do not establish whole-body methyl-donor depletion, anticancer benefit or vitamin deficiency after food intake. COMT-mediated SAH generation is distinct from direct competitive binding to DNMT1.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Chlorogenic acid research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"chlorogenic-acid","display_name":"Chlorogenic acid / 5-O-caffeoylquinic acid","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Human DNMT1 and MCF-7/MDA-MB-231 cells; COMT preparation species unresolved in abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Metabolizing a catechol connects it to methyl-group chemistry.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[chlorogenic_acid-p16081510] Inhibition of DNA methylation by caffeic acid and chlorogenic acid, two common catechol-containing coffee polyphenols. (2006). https://pubmed.ncbi.nlm.nih.gov/16081510/ DOI: 10.1093/carcin/bgi206","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free methyltransferase reactions and cultured cancer cells","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"fcabfd73-67c6-5efe-bb87-d68079bd9de0","evidence_kind":"source_excerpt","locator":"Lines 776-787","start_line":776,"end_line":787,"excerpt":"### chlorogenic_acid-comt-cga\nCOMT-mediated O-methylation of CGA contributed to the coupled-assay response.\nCondition category: normal\nnutrient_topic: Chlorogenic acid research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Metabolizing a catechol connects it to methyl-group chemistry.\norganism: Human DNMT1 and MCF-7/MDA-MB-231 cells; COMT preparation species unresolved in abstract\ntissue_or_cell_type: Cell-free methyltransferase reactions and cultured cancer cells\nexperimental_model: Coupled catechol-methylation/DNA-methylation assays and breast-cancer cell experiments\nlimitations: These concentrations and coupled-reaction conditions do not establish whole-body methyl-donor depletion, anticancer benefit or vitamin deficiency after food intake. COMT-mediated SAH generation is distinct from direct competitive binding to DNMT1.\nexposure: CGA DNMT1 IC50 0.9 micromolar in the coupled assay; compounds tested up to 20 micromolar\nevidence_span: {\"source_cache\": \"artifacts/chlorogenic_acid-research/16081510.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e93fafd7946f8a4aea30ff3ee9ef05e303f9154eb947410fca8e63c6521a4170\", \"start_char\": 0, \"end_char\": 2008, \"text_sha256\": \"e93fafd7946f8a4aea30ff3ee9ef05e303f9154eb947410fca8e63c6521a4170\"}\n[chlorogenic_acid-p16081510] Inhibition of DNA methylation by caffeic acid and chlorogenic acid, two common catechol-containing coffee polyphenols. 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