Component

Propionylcarnitine

Propionylcarnitine. Species, exposure and limitations are retained in each linked claim.

4 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 it acts on

  1. Four patients with propionic or methylmalonic aciduria had low plasma free carnitine and elevated short-chain acylcarnitine excretion; muscle carnitine was low in two biopsied patients.

    Propionylcarnitine → Human free carnitine pools in organic acidemias source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Two PA and two MMA cases; plasma, urine and selected muscle measurements.
    limitations
    Export-driven tissue depletion is the authors' mechanism; these inherited conditions are not synonymous with dietary B12 deficiency.
    nutrient_topic
    L-Carnitine collection; isomer, preparation, species, exposure and manipulation remain explicit. · L-Carnitine
    plain_language
    A metabolic block can tie up carnitine and lead to its loss in urine.
    primary_references
    Propionylcarnitine excretion in propionic and methylmalonic acidurias: a cause of carnitine deficiency. · 1984 · https://pubmed.ncbi.nlm.nih.gov/6723070/ · DOI 10.1016/0009-8981(84)90187-6
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    L-Carnitine: synthesis, acyl-group transport, fuel selection and nutrient interactions (2026-09-19) · lines 258–264

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Two PA and two MMA cases; plasma, urine and selected muscle measurements. · source_derived_draft · unverified_draft

    ## l-carnitine-organic-acid-loss A metabolic block can tie up carnitine and lead to its loss in urine. Four patients with propionic or methylmalonic aciduria had low plasma free carnitine and elevated short-chain acylcarnitine excretion; muscle carnitine was low in two biopsied patients. Model: Two PA and two MMA cases; plasma, urine and selected muscle measurements. Limitations: Export-driven tissue depletion is the authors' mechanism; these inherited conditions are not synonymous with dietary B12 deficiency. Evidence access: Primary abstract Propionylcarnitine excretion in propionic and methylmalonic acidurias: a cause of carnitine deficiency. · 1984 · https://pubmed.ncbi.nlm.nih.gov/6723070/ · DOI 10.1016/0009-8981(84)90187-6
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Carnitine repletion of doubly deficient HepG2 cells increased acetylcarnitine, propionylcarnitine and 3-hydroxyisovalerylcarnitine each by more than 50-fold.

    L-Carnitine → HepG2 acylcarnitine response to carnitine repletion source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_span
    {"source_cache": "artifacts/biotin-research/25527659.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4a368eb2fa2020bb1cabc99b31a3420870a8256886d5934d3d834c90b078238f", "start_char": 0, "end_char": 2372, "text_sha256": "4a368eb2fa2020bb1cabc99b31a3420870a8256886d5934d3d834c90b078238f"}
    experimental_model
    Two-factor biotin/carnitine depletion and carnitine repletion in human HepG2 cells
    exposure
    Separate and combined biotin and carnitine depletion
    limitations
    This is a cell-culture demonstration of marker masking; it does not validate a diagnostic correction formula in pregnancy or the general population.
    nutrient_topic
    Biotin research collection; topical membership is not evidence of a direct dietary effect. · Biotin
    organism
    Homo sapiens
    plain_language
    Restoring carnitine exposed the unresolved biotin-related bottleneck.
    primary_references
    [b7-p25527659] In HepG2 cells, coexisting carnitine deficiency masks important indicators of marginal biotin deficiency. (2015). https://pubmed.ncbi.nlm.nih.gov/25527659/ DOI: 10.3945/jn.114.201343
    tissue_or_cell_type
    HepG2 hepatoma cells
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Biotin: carboxylases, recycling, deficiency and nutrient interactions (2026-09-17) · lines 975–986

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Two-factor biotin/carnitine depletion and carnitine repletion in human HepG2 cells · source_derived_draft · unverified_draft

    ### b7-carnitine-unmasking Carnitine repletion of doubly deficient HepG2 cells increased acetylcarnitine, propionylcarnitine and 3-hydroxyisovalerylcarnitine each by more than 50-fold. Condition category: nutrient_deficiency nutrient_topic: Biotin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Restoring carnitine exposed the unresolved biotin-related bottleneck. organism: Homo sapiens tissue_or_cell_type: HepG2 hepatoma cells experimental_model: Two-factor biotin/carnitine depletion and carnitine repletion in human HepG2 cells limitations: This is a cell-culture demonstration of marker masking; it does not validate a diagnostic correction formula in pregnancy or the general population. exposure: Separate and combined biotin and carnitine depletion evidence_span: {"source_cache": "artifacts/biotin-research/25527659.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4a368eb2fa2020bb1cabc99b31a3420870a8256886d5934d3d834c90b078238f", "start_char": 0, "end_char": 2372, "text_sha256": "4a368eb2fa2020bb1cabc99b31a3420870a8256886d5934d3d834c90b078238f"} [b7-p25527659] In HepG2 cells, coexisting carnitine deficiency masks important indicators of marginal biotin deficiency. (2015). https://pubmed.ncbi.nlm.nih.gov/25527659/ DOI: 10.3945/jn.114.201343
    Complete structured claim and evidence

  2. Human CPT2 had activity with C8-C18 acyl-CoAs but virtually none with short-chain acyl-CoAs or branched-chain amino-acid oxidation intermediates.

    Human carnitine palmitoyltransferase 2 / CPT2 → Propionyl-CoA source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Recombinant human CPT2 substrate panel.
    limitations
    No claim that every acylcarnitine originates from CPT2.
    nutrient_topic
    L-Carnitine collection; isomer, preparation, species, exposure and manipulation remain explicit. · L-Carnitine
    plain_language
    The long-chain shuttle is not the same enzyme system as short-chain buffering.
    primary_references
    Carnitine palmitoyltransferase 2: New insights on the substrate specificity and implications for acylcarnitine profiling. · 2010 · https://pubmed.ncbi.nlm.nih.gov/20538056/ · DOI 10.1016/j.bbadis.2010.06.002

    L-Carnitine: synthesis, acyl-group transport, fuel selection and nutrient interactions (2026-09-19) · lines 114–120

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human CPT2 substrate panel. · source_derived_draft · unverified_draft

    ## l-carnitine-cpt2-specificity The long-chain shuttle is not the same enzyme system as short-chain buffering. Human CPT2 had activity with C8-C18 acyl-CoAs but virtually none with short-chain acyl-CoAs or branched-chain amino-acid oxidation intermediates. Model: Recombinant human CPT2 substrate panel. Limitations: No claim that every acylcarnitine originates from CPT2. Evidence access: Primary abstract Carnitine palmitoyltransferase 2: New insights on the substrate specificity and implications for acylcarnitine profiling. · 2010 · https://pubmed.ncbi.nlm.nih.gov/20538056/ · DOI 10.1016/j.bbadis.2010.06.002
    Complete structured claim and evidence

  3. Giving L-carnitine to three patients with propionic acidemia increased urinary propionylcarnitine, verified by mass spectrometry.

    L-Carnitine → Human urinary propionylcarnitine excretion source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Small human metabolic intervention; three healthy comparison subjects excreted mainly acetylcarnitine.
    limitations
    Restoration of mitochondrial free CoA was a proposed mechanism, not directly measured.
    nutrient_topic
    L-Carnitine collection; isomer, preparation, species, exposure and manipulation remain explicit. · L-Carnitine
    plain_language
    Acyl-group disposal can consume and export carnitine.
    primary_references
    L-carnitine enhances excretion of propionyl coenzyme A as propionylcarnitine in propionic acidemia. · 1984 · https://pubmed.ncbi.nlm.nih.gov/6725560/ · DOI 10.1172/JCI111387

    L-Carnitine: synthesis, acyl-group transport, fuel selection and nutrient interactions (2026-09-19) · lines 250–256

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Small human metabolic intervention; three healthy comparison subjects excreted mainly acetylcarnitine. · source_derived_draft · unverified_draft

    ## l-carnitine-organic-acid-export Acyl-group disposal can consume and export carnitine. Giving L-carnitine to three patients with propionic acidemia increased urinary propionylcarnitine, verified by mass spectrometry. Model: Small human metabolic intervention; three healthy comparison subjects excreted mainly acetylcarnitine. Limitations: Restoration of mitochondrial free CoA was a proposed mechanism, not directly measured. Evidence access: Primary abstract L-carnitine enhances excretion of propionyl coenzyme A as propionylcarnitine in propionic acidemia. · 1984 · https://pubmed.ncbi.nlm.nih.gov/6725560/ · DOI 10.1172/JCI111387
    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