{"id":"2788b159-bf8d-5cbd-9879-dc43f57238ef","stable_key":"35ec55a7-323c-5c28-979e-3bdafe9d5769:human-pca-formation","predicate":"reported_relationship","statement":"Labeled C3G produced circulating labeled PCA in humans; mean free PCA Cmax was 146 +/- 74 nM, n=8.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"e301f57a-cec2-56ca-ac95-642d5d3b835a","mechanism_event_label":"Labeled C3G produced circulating labeled PCA in humans; mean free PCA Cmax was 146 +/- 74 nM, n=8.","subject":{"id":"75149db0-02f7-5d32-8c7a-5c111d90d8ee","slug":"cyanidin-3-glucoside","display_name":"Cyanidin 3-O-beta-D-glucopyranoside","entity_type_key":"small_molecule"},"object":{"id":"f7042803-09ec-53d9-9d4c-9a0ce4042c00","slug":"protocatechuic-acid","display_name":"Protocatechuic acid / 3,4-dihydroxybenzoic acid","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"e301f57a-cec2-56ca-ac95-642d5d3b835a","stable_key":"35ec55a7-323c-5c28-979e-3bdafe9d5769:human-pca-formation-event","event_type":"biochemical_relationship","label":"Labeled C3G produced circulating labeled PCA in humans; mean free PCA Cmax was 146 +/- 74 nM, n=8.","description":"**Individual metabolites peak at different times.** A second analysis of the same tracer cohort reported the following selected serum values; these are means ± SEM, not universal target concentrations. The number of participants with quantifiable analyte differed by compound. [de Ferrars et al., 2014, Table 2](https://pmc.ncbi.nlm.nih.gov/articles/PMC4080980/).\n\n| Analyte | n | Peak, nM | Time to peak, hours |\n|---|---:|---:|---:|\n| C3G | 5 | 141 ± 70 | 1.8 ± 0.2 |\n| Protocatechuic acid (PCA) | 8 | 146 ± 74 | 3.3 ± 0.7 |\n| PCA sulfates, pooled isomers | 8 | 157 ± 116 | 11.4 ± 3.8 |\n| Vanillic acid | 2 | 1,845 ± 838 | 12.5 ± 11.5 |\n| Ferulic acid, B-ring label | 7 | 827 ± 371 | 8.2 ± 4.1 |\n| Hippuric acid | 8 | 1,962 ± 1,389 | 15.7 ± 4.1 |\n\nFree PCA and C3G therefore had similar mean peaks in this experiment. Vanillic acid's estimate came from only two participants. The values are distinct maxima, not a simultaneous mixture to be summed. Conjugated and unconjugated forms are separate exposures. A 50 µM PCA experiment is roughly 340 times this mean free-PCA peak; plasma comparisons still do not establish intestinal or intracellular concentrations. The two tracer publications are complementary analyses, not independent replications.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"75149db0-02f7-5d32-8c7a-5c111d90d8ee","slug":"cyanidin-3-glucoside","display_name":"Cyanidin 3-O-beta-D-glucopyranoside","entity_type_key":"small_molecule"},"role":"tested factor","stoichiometry":null,"state_label":"as reported","sequence_order":0,"notes":""},{"entity":{"id":"f7042803-09ec-53d9-9d4c-9a0ce4042c00","slug":"protocatechuic-acid","display_name":"Protocatechuic acid / 3,4-dihydroxybenzoic acid","entity_type_key":"small_molecule"},"role":"measured outcome","stoichiometry":null,"state_label":"not_reported","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Full text retrieved; relevant methods/results/figure text reviewed. No independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human 500 mg labeled C3G bolus; plasma chemical measurement, not a biological efficacy test.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Specific tracer-supported precursor/product relationship; does not assign every PCA effect to C3G or identify all microbial versus nonmicrobial formation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Labeled C3G produced circulating labeled PCA in humans; mean free PCA Cmax was 146 +/- 74 nM, n=8.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"The pharmacokinetics of anthocyanins and their metabolites in humans. | 2014 | DOI 10.1111/bph.12676 | PMID 24602005 | https://pubmed.ncbi.nlm.nih.gov/24602005/ | https://pmc.ncbi.nlm.nih.gov/articles/PMC4080980/ | https://doi.org/10.1111/bph.12676","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 19-30; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"cd505564-27a5-5b38-9957-9108a65d3a33","evidence_kind":"source_excerpt","locator":"Lines 19-30","start_line":19,"end_line":30,"excerpt":"**Individual metabolites peak at different times.** A second analysis of the same tracer cohort reported the following selected serum values; these are means ± SEM, not universal target concentrations. The number of participants with quantifiable analyte differed by compound. [de Ferrars et al., 2014, Table 2](https://pmc.ncbi.nlm.nih.gov/articles/PMC4080980/).\n\n| Analyte | n | Peak, nM | Time to peak, hours |\n|---|---:|---:|---:|\n| C3G | 5 | 141 ± 70 | 1.8 ± 0.2 |\n| Protocatechuic acid (PCA) | 8 | 146 ± 74 | 3.3 ± 0.7 |\n| PCA sulfates, pooled isomers | 8 | 157 ± 116 | 11.4 ± 3.8 |\n| Vanillic acid | 2 | 1,845 ± 838 | 12.5 ± 11.5 |\n| Ferulic acid, B-ring label | 7 | 827 ± 371 | 8.2 ± 4.1 |\n| Hippuric acid | 8 | 1,962 ± 1,389 | 15.7 ± 4.1 |\n\nFree PCA and C3G therefore had similar mean peaks in this experiment. Vanillic acid's estimate came from only two participants. The values are distinct maxima, not a simultaneous mixture to be summed. Conjugated and unconjugated forms are separate exposures. A 50 µM PCA experiment is roughly 340 times this mean free-PCA peak; plasma comparisons still do not establish intestinal or intracellular concentrations. The two tracer publications are complementary analyses, not independent replications.","model_system":"Human 500 mg labeled C3G bolus; plasma chemical measurement, not a biological efficacy test.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Exact excerpt of the retained AI-assisted reviewed reference; primary sources are cited in primary_references and access scope is retained. Not a verbatim quotation from a primary paper.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"b08e7f7d-4d34-56d7-a185-2124f8d72b3c","stable_key":"import-35ec55a7-323c-5c28-979e-3bdafe9d5769","title":"Anthocyanins: detailed mechanisms of action (reviewed 4 October 2026)","document_type":"imported_text","citation_label":"Original AI-assisted review of primary studies and, where relevant, official regulatory records. Access level is retained per claim. Corrections, null results and unresolved questions remain explicit. Not publisher full text or independent replication.","file_path":"","sha256":"7cff1a47fbd9c625412b84162b1c823004b4162b7c009f9a11d5807fb8e04ef9","revision_id":"1bd4fa42-bfeb-5148-8250-fc363d8c1de0","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}