K2HPO4 x 3 H2O

Ontology mapping

Primary identifier: kgmicrobe.compound:k2hpo4_x_3_h2o
Ontology term: CHEBI:131527 — dipotassium hydrogen phosphate
Ontology label: dipotassium hydrogen phosphate

Physicochemical roles

Role
BUFFER
Confidence
1.0
Evidence
- Reference text
  CultureMech database (118 occurrences as 'Buffer')
  Reference type
  DATABASE_ENTRY
  Url
  https://github.com/CultureBotAI/CultureMech
  Excerpt
  Role: Buffer; Properties: Defined component, Inorganic compound, Simple component
  Curator note
  Widespread use in media formulations (118 occurrences). High confidence based on 'Defined component' property.

Synonyms (8)

Synonym	Type	Source
Role: Buffer; Properties: Inorganic compound, Defined component, Simple component	RAW_TEXT	CultureMech
Role: Buffer; Properties: Simple component, Inorganic compound, Defined component	RAW_TEXT	CultureMech
K2HPO4 x 3H2O	HYDRATE_FORM	kg_microbe
K2HPO4 · 3 H2O	HYDRATE_FORM	kg_microbe
K2HPO4.3H2O	HYDRATE_FORM	kg_microbe
K2HPO4x 3 H2O	HYDRATE_FORM	kg_microbe
K2HPO4·3H2O	HYDRATE_FORM	kg_microbe
K2HPO4・3H2O	HYDRATE_FORM	kg_microbe

Chemical properties

Data source: PubChem (via CHEBI:131527)
Retrieval date: 2026-04-09T00:32:50.689620+00:00
Molecular formula: HO4P.2K.3H2O
Inchi: InChI=1S/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2
Smiles: O=P([O-])([O-])O.[K+].[K+]

Evidence (4)

DATABASE_MATCH via CultureMech

[HISTORICAL — superseded by the #321 re-grade below: this record is a hydrate of CHEBI:131527, not an exact match to it] Imported from CultureMech pipeline, quality=DIRECT_MATCH

DATABASE_MATCH via MIM curation (#321/#334)

identifier CHEBI:131527 -> kgmicrobe.compound:k2hpo4_x_3_h2o; mapping_quality EXACT_MATCH -> NARROW_MATCH. The record is a hydrate of CHEBI:131527 ('dipotassium hydrogen phosphate') and was sharing that term's identifier — the identity collapse MAPPING_SEMANTICS §3 forbids, which made a distinct substance indistinguishable from its anhydrous parent downstream. ChEBI has no term for this hydrate and the record carries no verified CAS, so steps 1 and 2 are unavailable and step 3 applies.

DATABASE_MATCH via MIM curation (#321)

molecular_formula 'HO4P.2K' -> 'HO4P.2K.3H2O'. The recorded value described the anhydrous salt while the label names a hydrate, understating the mass by 18 g/mol per water. Corrected because the label states 3 water(s) of hydration, and the recorded formula was byte-identical to the anhydrous parent CHEBI:131527's ChEBI formula ('HO4P.2K') — the mark of a value inherited from the parent rather than measured for this record. Water appended in ChEBI's own dot-separated notation.

DATABASE_MATCH via MIM curation (#342)

mapping_quality NARROW_MATCH -> CLOSE_MATCH, predicate skos:narrowMatch -> skos:closeMatch. narrowMatch asserts this record is *narrower in meaning* than CHEBI:131527 ('dipotassium hydrogen phosphate') — a subsumption ChEBI itself denies: it files hydrates under CHEBI:35505 'hydrate', never under the anhydrous compound, which is not an ancestor even transitively. A hydrate is a distinct substance containing the anhydrous form, not a specialization of it. closeMatch claims similarity without subsumption. The ontology_id and the record's own identifier are unchanged.

Occurrence statistics

Total occurrences: 198
Distinct media: 198

Curation history

Timestamp	Curator	Action	New status	Changes
2026-03-09T06:54:18.022301+00:00	import_from_culturemech	IMPORTED	MAPPED	Initial import from CultureMech pipeline
2026-04-09T00:32:50.689620+00:00	enrich_mim_cas_rn_batch	CAS_RN_ADDED	MAPPED	Added CAS-RN 7758-11-4 from PubChem (via CHEBI:131527)
2026-04-18T00:00:00+00:00	cbclaw_kg_microbe_sweep LLM	ADDED_SYNONYMS	MAPPED	Added 6 synonyms from kg-microbe P4.4 enrichment: K2HPO4 x 3H2O, K2HPO4 · 3 H2O, K2HPO4.3H2O, K2HPO4x 3 H2O, K2HPO4·3H2O, ... (1 more)
2026-05-01T07:35:34.154443+00:00	auto_classify_ingredient_type	AUTO_CLASSIFY_INGREDIENT_TYPE		set ingredient_type=SINGLE_INGREDIENT (CHEBI primary)
2026-05-01T08:08:30.151204+00:00	auto_classify_ingredient_type	AUTO_BACKFILL_CHEBI_CHEMISTRY		molecular_formula=HO4P.2K; inchi=InChI=1S/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*; smiles=O=P([O-])([O-])O.[K+].[K+]
2026-05-02T03:12:15.236661+00:00	auto_classify_ingredient_type	AUTO_CLASSIFY_INGREDIENT_TYPE		set ingredient_type=SINGLE_INGREDIENT (chemical structure populated (molecular_formula))
2026-05-29T23:35:36.111489+00:00	extract_roles_from_synonyms	ANNOTATED		Added media role: BUFFER (confidence: 1.00)
2026-06-09T05:23:46.780086+00:00	correct_stale_ontology_labels.py	CORRECTED		ontology_label 'K2HPO4 x 3 H2O' -> 'dipotassium hydrogen phosphate': synced to canonical CHEBI label (preferred_term 'K2HPO4 x 3 H2O' unchanged).
2026-07-20T00:00:00+00:00	migrate_media_roles_to_facets	ANNOTATED		Migrated legacy media_roles to role facets (#128): BUFFER -> physicochemical_roles.BUFFER
2026-08-13T00:00:00+00:00	mint_hydrate_registry_terms	MINTED_REGISTRY_FOR_HYDRATE		identifier CHEBI:131527 -> kgmicrobe.compound:k2hpo4_x_3_h2o; mapping_quality EXACT_MATCH -> NARROW_MATCH (#321/#334); §3 step 3.
2026-08-13T00:00:00+00:00	add_water_of_hydration	ADDED_WATER_OF_HYDRATION		molecular_formula 'HO4P.2K' -> 'HO4P.2K.3H2O' (#321); the label states 3 water(s) of hydration, and the recorded formula was byte-identical to the anhydrous parent CHEBI:131527's ChEBI formula ('HO4P.2K') — the mark of a value inherited from the parent rather than measured for this record. Water appended in ChEBI's own dot-separated notation.
2026-08-13T00:00:00+00:00	regrade_hydrate_to_close_match	REGRADED_HYDRATE_TO_CLOSE_MATCH		mapping_quality NARROW_MATCH -> CLOSE_MATCH (#342); a hydrate is not subsumed by its anhydrous form, and ChEBI does not model it as such.
2026-08-27T03:16:39.519050+00:00	refresh_occurrence_statistics	CORRECTED		occurrence_statistics 50/118 -> 198/198 (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]
2026-08-29T04:18:06.717834+00:00	hydrate_family_cas	CORRECTED		cas_rn 7758-11-4 REMOVED, not replaced: it is the anhydrous K2HPO4 CAS, and this record names a hydrate -- a different substance with a different formula weight. ChEBI has no term for this hydration state, so no authoritative value can be substituted. The grounding is separately wrong (#321); this corrects only the CAS (#334).
2026-10-12T03:21:01.216411+00:00	claude LLM	REMOVED_PARENT_IDENTITY	MAPPED	Removed kg_microbe_node_id CHEBI:131527, the anhydrous dipotassium hydrogen phosphate identity. The record keeps its distinct trihydrate identifier kgmicrobe.compound:k2hpo4_x_3_h2o, minted under §3 step 3 (#321/#334) because ChEBI has no term for this hydration state, and only a CLOSE_MATCH parent annotation (#342). The stale KG node field contradicted that ruling and kept the unified mapping publishing the anhydrous parent as the identity (#808, culturebotai-claw#571). No replacement KG node is asserted.