Component

3-Hydroxyanthranilate

3-Hydroxyanthranilate

3 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

Where it participates (unsigned role)

  1. Human KYNU cleaves 3-hydroxykynurenine to 3-hydroxyanthranilate and alanine using PLP.

    Human kynureninase / KYNU → 3-Hydroxy-L-kynurenine source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    PLP-dependent KYNU follows the FAD-dependent KMO step, connecting B6 and B2 with tryptophan-niacin metabolism.
    existing_related_claim_ids
    ["5570a502-6ebf-5397-bf2a-0148727e7695"]
    experimental_model
    Recombinant human KYNU crystallography and biochemical characterization
    limitations
    KYNU does not directly make NAD; subsequent enzymes and dietary niacin also contribute.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    This B6-dependent step processes the product of upstream KMO chemistry.
    primary_references
    [b6-kynu-2007] Crystal Structure of Homo Sapiens Kynureninase (2007). https://pmc.ncbi.nlm.nih.gov/articles/PMC2531291/ DOI: 10.1021/bi0616697
    tissue_or_cell_type
    Purified recombinant protein; no intact tissue

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 885–896

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human KYNU crystallography and biochemical characterization · source_derived_draft · unverified_draft

    ### b6-met-kynu-hydrolysis Human KYNU cleaves 3-hydroxykynurenine to 3-hydroxyanthranilate and alanine using PLP. Condition category: normal nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: This B6-dependent step processes the product of upstream KMO chemistry. organism: Homo sapiens tissue_or_cell_type: Purified recombinant protein; no intact tissue experimental_model: Recombinant human KYNU crystallography and biochemical characterization limitations: KYNU does not directly make NAD; subsequent enzymes and dietary niacin also contribute. cross_nutrient: PLP-dependent KYNU follows the FAD-dependent KMO step, connecting B6 and B2 with tryptophan-niacin metabolism. existing_related_claim_ids: ["5570a502-6ebf-5397-bf2a-0148727e7695"] [b6-kynu-2007] Crystal Structure of Homo Sapiens Kynureninase (2007). https://pmc.ncbi.nlm.nih.gov/articles/PMC2531291/ DOI: 10.1021/bi0616697
    Complete structured claim and evidence

  2. Human HAAO expressed in HEK-293 cells was enzymatically active toward 3-hydroxyanthranilate, with an apparent substrate Km near 2 micromolar in the study of the quinolinate-producing pathway step.

    Human 3-hydroxyanthranilate 3,4-dioxygenase / HAAO → Quinolinic acid source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    This step follows the canonical PLP-dependent KYNU reaction and uses a nonheme iron enzyme.
    evidence_span
    {"source_cache": "artifacts/niacin-precursors-sources/haao1994.abstract.txt", "locator": "Indexed primary abstract", "start_char": 0, "end_char": 1874, "file_sha256": "a79697b138bcb2957b0eff9580266c7879a1c5853aba34898f891559b4e435f8", "text_sha256": "a79697b138bcb2957b0eff9580266c7879a1c5853aba34898f891559b4e435f8"}
    experimental_model
    Human HAAO cDNA from HepG2 library, expressed in HEK-293 cells and assayed biochemically
    exposure
    Biochemical or structural assay; no dietary intervention
    limitations
    The immediate HAAO product is ACMS, which cyclizes to quinolinate; the indexed abstract uses pathway-level quinolinate wording. This claim does not assert direct NAD+ synthesis.
    nutrient_topic
    Niacin research collection; topical membership is not evidence of a direct dietary effect. · Niacin (vitamin B3)
    organism
    Homo sapiens
    plain_language
    Expressed human HAAO processed the product made by B6-dependent KYNU.
    primary_references
    [b3-pre-haao1994] Molecular cloning and functional expression of human 3-hydroxyanthranilic-acid dioxygenase. (1994). https://pubmed.ncbi.nlm.nih.gov/7514594/ DOI: 10.1016/s0021-9258(17)36717-0 [b3-pre-haao2017] Crystal structures of human 3-hydroxyanthranilate 3,4-dioxygenase with native and non-native metals bound in the active site. (2017). https://pubmed.ncbi.nlm.nih.gov/28375145/ DOI: 10.1107/s2059798317002029
    supporting_evidence_spans
    [{"source_cache": "artifacts/niacin-precursors-sources/haao2017.paragraphs.txt", "locator": "Normalized full-text paragraphs 14–14 (0-based)", "start_char": 4395, "end_char": 7197, "file_sha256": "d02386a59595104ccae2e62943e69030930da86ec005769b469f2001e31a6eb5", "text_sha256": "3b52b56d1b671c24721b47204cd30d19cd004f8a461fecd4875e94d3f491dbf6"}]
    tissue_or_cell_type
    HEK-293 cells expressing human HAAO; biochemical activity assay

    Niacin: NAD metabolism, deficiency and nutrient interactions (2026-09-17) · lines 521–535

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human HAAO cDNA from HepG2 library, expressed in HEK-293 cells and assayed biochemically · source_derived_draft · unverified_draft

    ### b3-pre-haao-human-activity Human HAAO expressed in HEK-293 cells was enzymatically active toward 3-hydroxyanthranilate, with an apparent substrate Km near 2 micromolar in the study of the quinolinate-producing pathway step. Condition category: normal nutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Expressed human HAAO processed the product made by B6-dependent KYNU. organism: Homo sapiens tissue_or_cell_type: HEK-293 cells expressing human HAAO; biochemical activity assay experimental_model: Human HAAO cDNA from HepG2 library, expressed in HEK-293 cells and assayed biochemically limitations: The immediate HAAO product is ACMS, which cyclizes to quinolinate; the indexed abstract uses pathway-level quinolinate wording. This claim does not assert direct NAD+ synthesis. exposure: Biochemical or structural assay; no dietary intervention cross_nutrient: This step follows the canonical PLP-dependent KYNU reaction and uses a nonheme iron enzyme. evidence_span: {"source_cache": "artifacts/niacin-precursors-sources/haao1994.abstract.txt", "locator": "Indexed primary abstract", "start_char": 0, "end_char": 1874, "file_sha256": "a79697b138bcb2957b0eff9580266c7879a1c5853aba34898f891559b4e435f8", "text_sha256": "a79697b138bcb2957b0eff9580266c7879a1c5853aba34898f891559b4e435f8"} supporting_evidence_spans: [{"source_cache": "artifacts/niacin-precursors-sources/haao2017.paragraphs.txt", "locator": "Normalized full-text paragraphs 14–14 (0-based)", "start_char": 4395, "end_char": 7197, "file_sha256": "d02386a59595104ccae2e62943e69030930da86ec005769b469f2001e31a6eb5", "text_sha256": "3b52b56d1b671c24721b47204cd30d19cd004f8a461fecd4875e94d3f491dbf6"}] [b3-pre-haao1994] Molecular cloning and functional expression of human 3-hydroxyanthranilic-acid dioxygenase. (1994). https://pubmed.ncbi.nlm.nih.gov/7514594/ DOI: 10.1016/s0021-9258(17)36717-0 [b3-pre-haao2017] Crystal structures of human 3-hydroxyanthranilate 3,4-dioxygenase with native and non-native metals bound in the active site. (2017). https://pubmed.ncbi.nlm.nih.gov/28375145/ DOI: 10.1107/s2059798317002029
    Complete structured claim and evidence

  3. Crystallography and metal characterization identified iron in the active site of human HAAO, with spectroscopic behavior consistent with the ferrous preparation before air oxidation.

    Ferrous iron → Human 3-hydroxyanthranilate 3,4-dioxygenase / HAAO source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Nonheme iron participates in a downstream tryptophan/niacin pathway enzyme; nutritional iron restriction was not tested.
    evidence_span
    {"source_cache": "artifacts/niacin-precursors-sources/haao2017.paragraphs.txt", "locator": "Normalized full-text paragraphs 33–33 (0-based)", "start_char": 22514, "end_char": 24337, "file_sha256": "d02386a59595104ccae2e62943e69030930da86ec005769b469f2001e31a6eb5", "text_sha256": "4c47aa3f5cdc1fd3c776752c345f1d60e4833d0e3b7e8227c574ae086c3b1783"}
    experimental_model
    Purified human HAAO metal-containing crystal structures and ICP-MS/XRF/EPR characterization
    exposure
    Biochemical or structural assay; no dietary intervention
    limitations
    Purified-enzyme evidence does not establish dietary intake requirements or clinical outcomes.
    nutrient_topic
    Niacin research collection; topical membership is not evidence of a direct dietary effect. · Niacin (vitamin B3)
    organism
    Homo sapiens
    plain_language
    A second iron-containing enzyme acts farther along the tryptophan route.
    primary_references
    [b3-pre-haao2017] Crystal structures of human 3-hydroxyanthranilate 3,4-dioxygenase with native and non-native metals bound in the active site. (2017). https://pubmed.ncbi.nlm.nih.gov/28375145/ DOI: 10.1107/s2059798317002029
    tissue_or_cell_type
    Purified recombinant protein; no intact tissue

    Niacin: NAD metabolism, deficiency and nutrient interactions (2026-09-17) · lines 507–519

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human HAAO metal-containing crystal structures and ICP-MS/XRF/EPR characterization · source_derived_draft · unverified_draft

    ### b3-pre-haao-iron Crystallography and metal characterization identified iron in the active site of human HAAO, with spectroscopic behavior consistent with the ferrous preparation before air oxidation. Condition category: normal nutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect. plain_language: A second iron-containing enzyme acts farther along the tryptophan route. organism: Homo sapiens tissue_or_cell_type: Purified recombinant protein; no intact tissue experimental_model: Purified human HAAO metal-containing crystal structures and ICP-MS/XRF/EPR characterization limitations: Purified-enzyme evidence does not establish dietary intake requirements or clinical outcomes. exposure: Biochemical or structural assay; no dietary intervention cross_nutrient: Nonheme iron participates in a downstream tryptophan/niacin pathway enzyme; nutritional iron restriction was not tested. evidence_span: {"source_cache": "artifacts/niacin-precursors-sources/haao2017.paragraphs.txt", "locator": "Normalized full-text paragraphs 33–33 (0-based)", "start_char": 22514, "end_char": 24337, "file_sha256": "d02386a59595104ccae2e62943e69030930da86ec005769b469f2001e31a6eb5", "text_sha256": "4c47aa3f5cdc1fd3c776752c345f1d60e4833d0e3b7e8227c574ae086c3b1783"} [b3-pre-haao2017] Crystal structures of human 3-hydroxyanthranilate 3,4-dioxygenase with native and non-native metals bound in the active site. (2017). https://pubmed.ncbi.nlm.nih.gov/28375145/ DOI: 10.1107/s2059798317002029
    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