{"id":"91ac7aa2-c318-5145-bc0f-f5c2435c4922","stable_key":"ec987f3e-0b3c-55cc-b304-c703a738e35d:egcg-sult1a1-substrate","predicate":"sulfates","statement":"The 2022 study assigned hepatic EGCG sulfation to SULT1A1.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"863aa45a-2221-5842-b937-d7a3600827bf","mechanism_event_label":"One study identifies this enzyme as a route for processing EGCG.","subject":{"id":"77a2330c-c4ad-59f2-9c0e-67a508bfe20d","slug":"sult1a1","display_name":"Human sulfotransferase 1A1 / SULT1A1","entity_type_key":"protein"},"object":{"id":"22e1b8eb-f35f-5afa-be20-b0534df9f6be","slug":"egcg","display_name":"Epigallocatechin-3-gallate (EGCG)","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"863aa45a-2221-5842-b937-d7a3600827bf","stable_key":"ec987f3e-0b3c-55cc-b304-c703a738e35d:egcg-sult1a1-substrate-event","event_type":"observed_relationship","label":"One study identifies this enzyme as a route for processing EGCG.","description":"The 2022 study assigned hepatic EGCG sulfation to SULT1A1.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"77a2330c-c4ad-59f2-9c0e-67a508bfe20d","slug":"sult1a1","display_name":"Human sulfotransferase 1A1 / SULT1A1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"22e1b8eb-f35f-5afa-be20-b0534df9f6be","slug":"egcg","display_name":"Epigallocatechin-3-gallate (EGCG)","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"0d47b6ae-dd61-5f07-918d-689e33248822","slug":"egcg-4-double-prime-sulfate","display_name":"EGCG-4″-sulfate","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Human liver/intestinal cytosol, enzyme assignment and a human ingestion pharmacokinetic study.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Formation rate and metabolite exposure do not prove identical biological effects of free and conjugated EGCG.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"EGCG collection; comparator and shared-pathway records retain their actual intervention.","comparator":null,"unit":null,"notes":"","entity":{"slug":"egcg","display_name":"Epigallocatechin-3-gallate (EGCG)","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"One study identifies this enzyme as a route for processing EGCG.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"4″-Sulfation Is the Major Metabolic Pathway of Epigallocatechin-3-gallate in Humans: Characterization of Metabolites, Enzymatic Analysis, and Pharmacokinetic Profiling. · 2022 · https://pubmed.ncbi.nlm.nih.gov/35786898/ · DOI 10.1021/acs.jafc.2c02150","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"ea1d14e9-4a05-5f7d-832e-82bcf1d2a30e","evidence_kind":"source_excerpt","locator":"Lines 276-282","start_line":276,"end_line":282,"excerpt":"## egcg-sult1a1-substrate\nOne study identifies this enzyme as a route for processing EGCG.\nThe 2022 study assigned hepatic EGCG sulfation to SULT1A1.\nModel: Human liver/intestinal cytosol, enzyme assignment and a human ingestion pharmacokinetic study.\nLimitations: Formation rate and metabolite exposure do not prove identical biological effects of free and conjugated EGCG.\nEvidence access: primary abstract.\n4″-Sulfation Is the Major Metabolic Pathway of Epigallocatechin-3-gallate in Humans: Characterization of Metabolites, Enzymatic Analysis, and Pharmacokinetic Profiling. · 2022 · https://pubmed.ncbi.nlm.nih.gov/35786898/ · DOI 10.1021/acs.jafc.2c02150","model_system":"Human liver/intestinal cytosol, enzyme assignment and a human ingestion pharmacokinetic study.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Primary-abstract paraphrase; no full-text methods verification claimed.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"1f6d09e8-3aae-5c41-9ea7-15d0d1cab72d","stable_key":"import-ec987f3e-0b3c-55cc-b304-c703a738e35d","title":"EGCG: receptor signaling, metabolism, nutrient interactions and discovery questions (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"b101c8d4d96ee03ff97eb1922c7bb0f96943295af473fdc3ef98b0dbd62fe8c7","revision_id":"e19bc5b2-ee3c-5f67-b5c5-9dc3b7d5f850","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[{"id":"78a00c8f-c7f2-5f2a-835d-8559d029b387","title":"EGCG and SULT1A1: opposing substrate assignments","kind":"contradiction","status":"open","why":"The 2016 paper explicitly reports EGCG is not a SULT1A1 substrate; the 2022 paper assigns hepatic sulfation to SULT1A1. These are competing published substrate assignments, not an authoring correction.","resolution":"Unresolved at this curation level. Compare enzyme/cofactor conditions and product identification. Substrate recognition and allosteric inhibition can coexist, but that alone does not resolve the opposing substrate assignments.","created_at":"2026-09-18 22:58:13","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/78a00c8f-c7f2-5f2a-835d-8559d029b387","sides":[{"conflict_id":"78a00c8f-c7f2-5f2a-835d-8559d029b387","ordinal":0,"label":"2016 enzyme study","revision_id":"e19bc5b2-ee3c-5f67-b5c5-9dc3b7d5f850","start_line":300,"end_line":306,"quote":"## egcg-sult-not-substrate\nAn earlier enzyme study gives a different substrate assignment.\nThe 2016 SULT1A1 allostery study explicitly reported that EGCG was not a SULT1A1 substrate but was sulfonated by SULT2A1.\nModel: Equilibrium binding and pre-steady-state human SULT enzyme experiments.\nLimitations: This differs from the later SULT1A1 assignment; assay and product-identification differences require comparison.\nEvidence access: primary abstract.\nIsozyme Specific Allosteric Regulation of Human Sulfotransferase 1A1. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27356022/ · DOI 10.1021/acs.biochem.6b00401","source_key":"import-ec987f3e-0b3c-55cc-b304-c703a738e35d","source_title":"EGCG: receptor signaling, metabolism, nutrient interactions and discovery questions (2026-09-18)","claim_ids":["b1e946aa-cf52-5973-9a9d-77c0dc020e2e"]},{"conflict_id":"78a00c8f-c7f2-5f2a-835d-8559d029b387","ordinal":1,"label":"2022 metabolism study","revision_id":"e19bc5b2-ee3c-5f67-b5c5-9dc3b7d5f850","start_line":276,"end_line":282,"quote":"## egcg-sult1a1-substrate\nOne study identifies this enzyme as a route for processing EGCG.\nThe 2022 study assigned hepatic EGCG sulfation to SULT1A1.\nModel: Human liver/intestinal cytosol, enzyme assignment and a human ingestion pharmacokinetic study.\nLimitations: Formation rate and metabolite exposure do not prove identical biological effects of free and conjugated EGCG.\nEvidence access: primary abstract.\n4″-Sulfation Is the Major Metabolic Pathway of Epigallocatechin-3-gallate in Humans: Characterization of Metabolites, Enzymatic Analysis, and Pharmacokinetic Profiling. · 2022 · https://pubmed.ncbi.nlm.nih.gov/35786898/ · DOI 10.1021/acs.jafc.2c02150","source_key":"import-ec987f3e-0b3c-55cc-b304-c703a738e35d","source_title":"EGCG: receptor signaling, metabolism, nutrient interactions and discovery questions (2026-09-18)","claim_ids":["91ac7aa2-c318-5145-bc0f-f5c2435c4922"]}]}],"corrections":[],"research":null}