L-Cysteine

CHEBI:17561 chemically defined MAPPED CHEBI EXACT_MATCH

Ontology mapping

Primary identifier
CHEBI:17561
Ontology label
L-cysteine
kg-microbe node
CHEBI:17561

Nutritional roles

Synonyms (19)

SynonymTypeSourceOccurrences
Cross-references: KEGG:cys-L RAW_TEXT CultureMech
Role: Nitrogen source; Properties: Defined component, Organic compound, Simple component RAW_TEXT CultureMech
Role: Nitrogen source; Properties: Defined component, Simple component, Organic compound RAW_TEXT CultureMech
Role: Nitrogen source; Properties: Simple component, Defined component, Organic compound RAW_TEXT CultureMech
(2R)-2-amino-3-mercaptopropanoic acid EXACT_SYNONYM kg_microbe
(2R)-2-amino-3-sulfanylpropanoic acid EXACT_SYNONYM kg_microbe
(2R)-2-ammonio-3-mercaptopropanoate EXACT_SYNONYM kg_microbe
(2R)-2-ammonio-3-sulfanylpropanoate EXACT_SYNONYM kg_microbe
(R)-2-amino-3-mercaptopropanoic acid EXACT_SYNONYM kg_microbe
E 920 EXACT_SYNONYM kg_microbe
E-920 EXACT_SYNONYM kg_microbe
E920 EXACT_SYNONYM kg_microbe
FREE CYSTEINE EXACT_SYNONYM kg_microbe
L-2-Amino-3-mercaptopropionic acid EXACT_SYNONYM kg_microbe
L-Cystein EXACT_SYNONYM kg_microbe
L-Zystein EXACT_SYNONYM kg_microbe
Role: Nitrogen source; Properties: Organic compound, Defined component, Simple component RAW_TEXT CultureMech
CYSTEINE EXACT_SYNONYM chebi_synonym_review
L-cysteine (Sigma) CATALOG_VARIANT culturemech:output/ingredient_occurrences.tsv

Rejected enrichment labels (2)

Provenance-only candidates: these are not synonyms and do not resolve to this record.

Rejected labelDispositionSourceOccurrences
Cysteine-HCl∙H2O REJECTED_LABEL kg_microbe
L-cysteine zwitterion REJECTED_LABEL kg_microbe

Chemical properties

Cas rn
52-90-4
Data source
CultureBotHT compounds_to_cas.csv
Retrieval date
2026-04-05T21:48:45.250014+00:00
Molecular formula
C3H7NO2S
Inchi
InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6)/t2-/m0/s1
Smiles
N[C@@H](CS)C(=O)O

Evidence (1)

DATABASE_MATCH via CultureMech

Imported from CultureMech pipeline, quality=DIRECT_MATCH

Occurrence statistics

Total occurrences
129
Distinct media
128

Curation history

TimestampCuratorActionNew statusChanges
2026-03-09T06:54:18.022301+00:00 import_from_culturemech IMPORTED MAPPED Initial import from CultureMech pipeline
2026-04-05T21:48:45.250016+00:00 fetch_cas_rn_from_culturebot_csv ADDED_CAS_RN MAPPED Added CAS-RN:52-90-4 from CultureBotHT compounds_to_cas.csv (matched: L-Cysteine)
2026-04-05T21:48:45.251906+00:00 fetch_cas_rn_from_culturebot_csv ADDED_CAS_RN MAPPED Added CAS-RN:52-90-4 from CultureBotHT compounds_to_cas.csv (matched: L-cysteine)
2026-04-18T00:00:00+00:00 cbclaw_kg_microbe_sweep LLM ADDED_SYNONYMS MAPPED Added 14 synonyms from kg-microbe P4.4 enrichment: (2R)-2-amino-3-mercaptopropanoic acid, (2R)-2-amino-3-sulfanylpropanoic acid, (2R)-2-ammonio-3-mercaptopropanoate, (2R)-2-ammonio-3-sulfanylpropanoate, (R)-2-amino-3-mercaptopropanoic acid, ... (9 more)
2026-04-19T07:39:23.955331+00:00 audit_mim_merge MERGED_FROM_DUPLICATES MAPPED Absorbed 1 duplicate MIM record(s) into this one: L-cysteine_2.yaml. Synonyms, curation_history, and occurrence counts were unioned/summed; winner selected by highest occurrence count with preferred_term readability tie-break.
2026-05-01T07:35:34.314716+00:00 auto_classify_ingredient_type AUTO_CLASSIFY_INGREDIENT_TYPE set ingredient_type=SINGLE_INGREDIENT (CHEBI primary)
2026-05-01T08:08:30.320142+00:00 auto_classify_ingredient_type AUTO_BACKFILL_CHEBI_CHEMISTRY molecular_formula=C3H7NO2S; inchi=InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,; smiles=N[C@@H](CS)C(=O)O
2026-05-02T03:12:15.467989+00:00 auto_classify_ingredient_type AUTO_CLASSIFY_INGREDIENT_TYPE set ingredient_type=SINGLE_INGREDIENT (chemical structure populated (molecular_formula))
2026-05-29T23:35:36.111612+00:00 extract_roles_from_synonyms ANNOTATED Added media role: NITROGEN_SOURCE (confidence: 1.00)
2026-06-09T05:23:46.784426+00:00 correct_stale_ontology_labels.py CORRECTED ontology_label 'L-Cysteine' -> 'L-cysteine': synced to canonical CHEBI label (preferred_term 'L-Cysteine' unchanged).
2026-07-20T00:00:00+00:00 migrate_media_roles_to_facets ANNOTATED Migrated legacy media_roles to role facets (#128): NITROGEN_SOURCE -> nutritional_roles.NITROGEN_SOURCE
2026-08-27T03:16:39.519123+00:00 refresh_occurrence_statistics CORRECTED occurrence_statistics 51/68 -> 128/129 (media_count/total_occurrences), derived from distinct CultureMech recipe ids in the #337 occurrence table. The prior values came from the importer retired in #453, whose media_count counted a list truncated to 50 examples (#449). [source=ingredient_occurrences.tsv culturemech_rev=15a4da5c08 rows=194137 distinct_recipes=15257]
2026-08-30T04:48:06.233536+00:00 claude_culturemech_alias_backfill ADDED_SYNONYMS Added 1 CultureMech recipe surface form(s) that folded onto this record's published label but were absent from MIM's label index, so CultureMech could not resolve them: 'L-cysteine (Sigma)' (x1 CultureMech mentions). Source: culturemech:output/ingredient_occurrences.tsv.
2026-09-10T06:14:55Z mediaingredientmech-agentic-curation LLM CORRECTED Marked hydrate/salt synonym Cysteine-HCl∙H2O non-resolving for free L-cysteine; the monohydrate resolves to CHEBI:91248 (#521).
2026-09-24T07:48:22.690313+00:00 claude LLM REJECTED_WRONG_SUBSTANCE_SYNONYMS MAPPED Retyped REJECTED_LABEL: 'L-cysteine zwitterion' (EXACT_SYNONYM): the zwitterion CHEBI:35235 has its own record; the record is neutral L-cysteine CHEBI:17561 (#669). Kept as provenance only; it must not resolve, be exported, or enter the SSSOM other column.