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Reference

Evidence

CompoundsSubstances with curated findings
OutcomesMeasured endpoints
ProteinsTransporters and enzymes
InteractionsPairs that share biology
PapersEvery paper a finding cites
ArticlesReadings of the evidence

Reference layer

PathwaysReactions grouped under one name
ProcessesWhat proteins are annotated as doing
AnatomyTissues, by what is expressed there
Cell typesCells, by what is expressed there
OrganismsSpecies a compound is prepared from
MaterialsSubstances that are not one molecule
AssessmentsRegulatory determinations, transcribed

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Atlas Graph Access Compounds Outcomes Proteins Interactions Papers Articles Pathways Processes Anatomy Cell types Organisms Materials Assessments

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Catalyst

The evidence graph for human biochemistry. Every edge carries its source, its study design, and a grade computed from both.

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A reference for what the literature reports. Not medical advice.

© 2026 CatalystPrivacy TermsReference data under the licences listed on the attribution page.

Reaction

(4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin(6R)-L-erythro-6,7-dihydrobiopterin+water

Direction not asserted · Balance undeterminable

Inferred

Reference data, not a finding. Evidence key

Catalysts

PCBD1
PCBD2

Rhea RHEA:11920·2026-08-19·CC BY 4.0Reference data