Component

4-Hydroxyphenylpyruvate

4-Hydroxyphenylpyruvate. Species, exposure and limitations are retained in each linked claim.

5 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What acts on it

  1. Recombinant human TAT catalyzed reversible tyrosine transamination, with the highest activity for the tyrosine/2-oxoglutarate substrate pair.

    Human tyrosine aminotransferase / TAT → 4-Hydroxyphenylpyruvate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Purified full-length and truncated human enzyme expressed in E. coli.
    limitations
    A reversible enzyme assay is not a measurement of net in vivo flux.
    nutrient_topic
    L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
    plain_language
    Tyrosine breakdown begins by moving its amino group.
    primary_references
    The narrow substrate specificity of human tyrosine aminotransferase--the enzyme deficient in tyrosinemia type II. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16640556/ · DOI 10.1111/j.1742-4658.2006.05202.x

    L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 204–210

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified full-length and truncated human enzyme expressed in E. coli. · source_derived_draft · unverified_draft

    ## l-tyrosine-tat-carbon Tyrosine breakdown begins by moving its amino group. Recombinant human TAT catalyzed reversible tyrosine transamination, with the highest activity for the tyrosine/2-oxoglutarate substrate pair. Model: Purified full-length and truncated human enzyme expressed in E. coli. Limitations: A reversible enzyme assay is not a measurement of net in vivo flux. Evidence access: Primary abstract The narrow substrate specificity of human tyrosine aminotransferase--the enzyme deficient in tyrosinemia type II. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16640556/ · DOI 10.1111/j.1742-4658.2006.05202.x
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. HPDL produced 4-hydroxymandelate in human cells.

    Human hydroxyphenylpyruvate dioxygenase-like protein / HPDL → 4-Hydroxymandelate / 4-HMA source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/coq10-research/34471290.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a3cbcc69203ace49d0451e55c2d4040109e16facb575f4d66a0396d375ba8956", "start_char": 0, "end_char": 1028, "text_sha256": "a3cbcc69203ace49d0451e55c2d4040109e16facb575f4d66a0396d375ba8956"}
    experimental_model
    Oxygen-isotope metabolomics and enzyme perturbation
    exposure
    18O2 labeling and HPDL activity
    limitations
    Cellular pathway; no evidence that additional tyrosine treats every CoQ deficiency.
    nutrient_topic
    Coenzyme Q10 research collection; topical membership is not evidence of a direct dietary effect. · Coenzyme Q10 / CoQ10 redox system
    organism
    Human cell lines
    plain_language
    A separate enzyme helps make the head of the CoQ molecule.
    primary_references
    [coq10-p34471290] The polar oxy-metabolome reveals the 4-hydroxymandelate CoQ10 synthesis pathway. (2021). https://pubmed.ncbi.nlm.nih.gov/34471290/ DOI: 10.1038/s41586-021-03865-w
    tissue_or_cell_type
    Tyrosine-derived CoQ head-group precursor

    Coenzyme Q10: biosynthesis, electron transfer, antioxidant recycling and nutrient interactions (2026-09-17) · lines 164–175

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Oxygen-isotope metabolomics and enzyme perturbation · source_derived_draft · unverified_draft

    ### coq10-hpdl-hma HPDL produced 4-hydroxymandelate in human cells. Condition category: normal nutrient_topic: Coenzyme Q10 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A separate enzyme helps make the head of the CoQ molecule. organism: Human cell lines tissue_or_cell_type: Tyrosine-derived CoQ head-group precursor experimental_model: Oxygen-isotope metabolomics and enzyme perturbation limitations: Cellular pathway; no evidence that additional tyrosine treats every CoQ deficiency. exposure: 18O2 labeling and HPDL activity evidence_span: {"source_cache": "artifacts/coq10-research/34471290.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a3cbcc69203ace49d0451e55c2d4040109e16facb575f4d66a0396d375ba8956", "start_char": 0, "end_char": 1028, "text_sha256": "a3cbcc69203ace49d0451e55c2d4040109e16facb575f4d66a0396d375ba8956"} [coq10-p34471290] The polar oxy-metabolome reveals the 4-hydroxymandelate CoQ10 synthesis pathway. (2021). https://pubmed.ncbi.nlm.nih.gov/34471290/ DOI: 10.1038/s41586-021-03865-w
    Complete structured claim and evidence

  2. Human HPD converts 4-hydroxyphenylpyruvate to homogentisate; substrate-binding-site mutations altered catalytic efficiency.

    Human 4-hydroxyphenylpyruvate dioxygenase / HPD → Homogentisate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human enzyme mutagenesis, binding assays and structural simulation.
    limitations
    HPD must not be merged with HPDL, which has a different product.
    nutrient_topic
    L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
    plain_language
    The carbon skeleton passes through a separate oxygen-dependent enzyme.
    primary_references
    Functional role of residues involved in substrate binding of human 4-hydroxyphenylpyruvate dioxygenase. · 2021 · https://pubmed.ncbi.nlm.nih.gov/34047349/ · DOI 10.1042/BCJ20210005

    L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 228–234

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human enzyme mutagenesis, binding assays and structural simulation. · source_derived_draft · unverified_draft

    ## l-tyrosine-hpd-hga The carbon skeleton passes through a separate oxygen-dependent enzyme. Human HPD converts 4-hydroxyphenylpyruvate to homogentisate; substrate-binding-site mutations altered catalytic efficiency. Model: Human enzyme mutagenesis, binding assays and structural simulation. Limitations: HPD must not be merged with HPDL, which has a different product. Evidence access: Primary abstract Functional role of residues involved in substrate binding of human 4-hydroxyphenylpyruvate dioxygenase. · 2021 · https://pubmed.ncbi.nlm.nih.gov/34047349/ · DOI 10.1042/BCJ20210005
    Complete structured claim and evidence

  3. During nitisinone treatment in SONIA 2, urinary derivatives upstream of homogentisate increased and tracked treatment-associated hypertyrosinemia.

    Nitisinone → Human alkaptonuria alternative urinary tyrosine metabolites source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    biomarker_context Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    AKU trial samples at baseline, 24 and 48 months; 47 treated serum and 53 treated urine sample series, with untreated comparisons.
    limitations
    Metabolite associations do not identify every conjugating enzyme or prove the proposed clearance benefit. This exposure is pharmacological.
    nutrient_topic
    L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
    plain_language
    Blocking one step changes the distribution of metabolites across other routes.
    primary_references
    Comprehensive Biotransformation Analysis of Phenylalanine-Tyrosine Metabolism Reveals Alternative Routes of Metabolite Clearance in Nitisinone-Treated Alkaptonuria. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36295829/ · DOI 10.3390/metabo12100927
    trigger_kind
    biomarker_context Imported condition classification; unverified.

    L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 308–314

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · AKU trial samples at baseline, 24 and 48 months; 47 treated serum and 53 treated urine sample series, with untreated comparisons. · source_derived_draft · unverified_draft

    ## l-tyrosine-nitisinone-network Blocking one step changes the distribution of metabolites across other routes. During nitisinone treatment in SONIA 2, urinary derivatives upstream of homogentisate increased and tracked treatment-associated hypertyrosinemia. Model: AKU trial samples at baseline, 24 and 48 months; 47 treated serum and 53 treated urine sample series, with untreated comparisons. Limitations: Metabolite associations do not identify every conjugating enzyme or prove the proposed clearance benefit. This exposure is pharmacological. Evidence access: Primary abstract Comprehensive Biotransformation Analysis of Phenylalanine-Tyrosine Metabolism Reveals Alternative Routes of Metabolite Clearance in Nitisinone-Treated Alkaptonuria. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36295829/ · DOI 10.3390/metabo12100927
    Complete structured claim and evidence

  4. Human TAT is PLP dependent, with spectroscopic analysis of its cofactor-linked aldimine.

    PLP → Human tyrosine aminotransferase / TAT source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Recombinant human enzyme spectroscopy and kinetics.
    limitations
    Enzyme dependence does not establish dietary B6 limitation or that adding B6 treats TAT genetic deficiency.
    nutrient_topic
    L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Tyrosine
    plain_language
    The active B6 form participates in tyrosine breakdown.
    primary_references
    The narrow substrate specificity of human tyrosine aminotransferase--the enzyme deficient in tyrosinemia type II. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16640556/ · DOI 10.1111/j.1742-4658.2006.05202.x

    L-Tyrosine: catecholamines, thyroid chemistry, pigment, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 212–218

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human enzyme spectroscopy and kinetics. · source_derived_draft · unverified_draft

    ## l-tyrosine-tat-b6 The active B6 form participates in tyrosine breakdown. Human TAT is PLP dependent, with spectroscopic analysis of its cofactor-linked aldimine. Model: Recombinant human enzyme spectroscopy and kinetics. Limitations: Enzyme dependence does not establish dietary B6 limitation or that adding B6 treats TAT genetic deficiency. Evidence access: Primary abstract The narrow substrate specificity of human tyrosine aminotransferase--the enzyme deficient in tyrosinemia type II. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16640556/ · DOI 10.1111/j.1742-4658.2006.05202.x
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards