Component

Menaquinone-8 / MK-8

2 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. Isotope-labeled methionine contributed carbon to E. coli MK-8 in the historical labeling experiment.

    L-Methionine → Menaquinone-8 / MK-8 source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary indexed abstract reviewed; full results, tables and supplements not independently extracted.
    experimental_model
    E. coli 1966 isotope tracing; shikimate ring carbon versus methionine methyl carbon.
    interpretation_status
    Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.
    limitations
    Carbon incorporation, not complete enzymatic sequence, human MK-7 production or oral vitamin-K efficacy.
    plain_language
    Isotope-labeled methionine contributed carbon to E. coli MK-8 in the historical labeling experiment.
    primary_references
    Biosynthesis of ubiquinone in Escherichia coli K-12: biochemical and genetic characterization of a mutant unable to convert chorismate into 4-hydroxybenzoate. | 1974 | DOI 10.1128/jb.118.1.41-45.1974 | PMID 4595202 | https://pubmed.ncbi.nlm.nih.gov/4595202/ | https://doi.org/10.1128/jb.118.1.41-45.1974 | https://pmc.ncbi.nlm.nih.gov/articles/PMC246637/
    primary_references
    The role of shikimic acid in the biosynthesis of vitamin K2. | 1966 | DOI 10.1042/bj1000001 | PMID 5337721 | https://pubmed.ncbi.nlm.nih.gov/5337721/ | https://doi.org/10.1042/bj1000001 | https://pmc.ncbi.nlm.nih.gov/articles/PMC1265084/
    source_locator
    Reviewed reference lines 27-27; exact primary location described in quoted passage where extracted.

    Shikimic acid: detailed mechanisms of action (reviewed 5 October 2026) · lines 27–27

    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. · supports · E. coli 1966 isotope tracing; shikimate ring carbon versus methionine methyl carbon. · source_derived_draft · unverified_draft

    **The K and Q branches are organism-specific.** Isotope experiments in E. coli traced shikimate carbon into the benzene ring of menaquinone-8 (MK-8), and methionine-derived methyl carbon into that product. This does not establish increased human MK-7, vitamin-K function or an oral shikimate dose response. Separately, an E. coli ubiC mutant failed to convert chorismate to 4-hydroxybenzoate and produced little ubiquinone unless supplied with 4-hydroxybenzoate. UbiC therefore identifies a branch-specific supply bottleneck; bacterial ubiquinone production is not synonymous with human mitochondrial CoQ10 synthesis. [The role of shikimic acid in the biosynthesis of vitamin K2.](https://pubmed.ncbi.nlm.nih.gov/5337721/) [Biosynthesis of ubiquinone in Escherichia coli K-12: biochemical and genetic characterization of a mutant unable to convert chorismate into 4-hydroxybenzoate.](https://pubmed.ncbi.nlm.nih.gov/4595202/)
    Complete structured claim and evidence

  2. Isotope-labeled shikimate contributed carbon to E. coli MK-8 in the historical labeling experiment.

    Shikimate anion → Menaquinone-8 / MK-8 source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary indexed abstract reviewed; full results, tables and supplements not independently extracted.
    experimental_model
    E. coli 1966 isotope tracing; shikimate ring carbon versus methionine methyl carbon.
    interpretation_status
    Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.
    limitations
    Carbon incorporation, not complete enzymatic sequence, human MK-7 production or oral vitamin-K efficacy.
    plain_language
    Isotope-labeled shikimate contributed carbon to E. coli MK-8 in the historical labeling experiment.
    primary_references
    Biosynthesis of ubiquinone in Escherichia coli K-12: biochemical and genetic characterization of a mutant unable to convert chorismate into 4-hydroxybenzoate. | 1974 | DOI 10.1128/jb.118.1.41-45.1974 | PMID 4595202 | https://pubmed.ncbi.nlm.nih.gov/4595202/ | https://doi.org/10.1128/jb.118.1.41-45.1974 | https://pmc.ncbi.nlm.nih.gov/articles/PMC246637/
    primary_references
    The role of shikimic acid in the biosynthesis of vitamin K2. | 1966 | DOI 10.1042/bj1000001 | PMID 5337721 | https://pubmed.ncbi.nlm.nih.gov/5337721/ | https://doi.org/10.1042/bj1000001 | https://pmc.ncbi.nlm.nih.gov/articles/PMC1265084/
    source_locator
    Reviewed reference lines 27-27; exact primary location described in quoted passage where extracted.

    Shikimic acid: detailed mechanisms of action (reviewed 5 October 2026) · lines 27–27

    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. · supports · E. coli 1966 isotope tracing; shikimate ring carbon versus methionine methyl carbon. · source_derived_draft · unverified_draft

    **The K and Q branches are organism-specific.** Isotope experiments in E. coli traced shikimate carbon into the benzene ring of menaquinone-8 (MK-8), and methionine-derived methyl carbon into that product. This does not establish increased human MK-7, vitamin-K function or an oral shikimate dose response. Separately, an E. coli ubiC mutant failed to convert chorismate to 4-hydroxybenzoate and produced little ubiquinone unless supplied with 4-hydroxybenzoate. UbiC therefore identifies a branch-specific supply bottleneck; bacterial ubiquinone production is not synonymous with human mitochondrial CoQ10 synthesis. [The role of shikimic acid in the biosynthesis of vitamin K2.](https://pubmed.ncbi.nlm.nih.gov/5337721/) [Biosynthesis of ubiquinone in Escherichia coli K-12: biochemical and genetic characterization of a mutant unable to convert chorismate into 4-hydroxybenzoate.](https://pubmed.ncbi.nlm.nih.gov/4595202/)
    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.