nectriapyrone C

naturalproductmech:mibig-1b7d91c87a MINTED SEEDED

Grounding review: No 3-star ChEBI entry shares this structure, so the record keeps a content-hashed identifier.

What these status tags mean

Curation status describes a workflow state. SEEDED means the record entered through the source-seeding workflow; it does not imply that no later curation occurred. PROPOSED marks an addition awaiting review; REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record. These are workflow decisions, not independently verified human review. Agent-assisted contributions may appear in the record history.

Grounding describes the identifier mapping: EXACT uses an ontology identity asserted by the source; MINTED keeps a local identifier when no defensible ontology identity is available; REVIEW_NEEDED flags an exact structure whose ontology identity needs adjudication. The grounding note retains any unresolved alternatives. These tags do not establish the strength of producer or activity evidence.

Structure

Standard InChIKey	HTXMLHOTNKOVND-UHFFFAOYSA-N
SMILES	CC=C(CO)C1=CC(OC)=C(C)C(=O)O1
Stereochemistry	fully defined
Cross-references	pubchem:156580352, npatlas:NPA002130

Filing pathway

Polyketides — computed by NPClassifier npclassifier.gnps2.org@2026-09-07, which is why it is pinned rather than recomputed. The gene cluster's asserted class is pks, from MIBiG.

Producer organisms 1

A claim that this taxon makes the compound. The basis says what the evidence addressed — a knockout and a database assertion are not the same claim.

Taxon	Basis	Cluster	Evidence
Pyricularia oryzae 70-15 NCBITaxon:242507	BGC_CHARACTERIZED	mibig:BGC0002155	PMID:30443971

Occurrences 2

Somebody found the compound in this organism and cited it. That is not a claim that the organism makes it, and nothing here promotes one to the other.

Taxon	Source	Reference
Pyricularia oryzae NCBITaxon:1274781	LOTUS	DOI:10.1002/CBIC.201800620
Nectria NCBITaxon:5133	LOTUS	DOI:10.1080/10286020.2015.1040778

Biosynthetic gene clusters 1

Accession	Host	Locus evidence	Genome
mibig:BGC0002155	Pyricularia oryzae 70-15 NCBITaxon:242507	CLUSTER_DEMONSTRATED	genbank:CM001235.1

A locus claim and a taxon claim are different questions. Heterologous expression settles the first and leaves the second where the isolation report left it.

Biosynthesis curated

Written by a curator with claim-level evidence on each step; not derived from a source. This is what the rest of the record exists to support.

Step	Enzyme	Reaction	Substrate → product	Evidence
1	NEC2 O-methyltransferase UniProtKB:G4NEA9	RHEA:58748	CHEBI:142640 → CHEBI:142639	DOI:10.1002/cbic.201800620

Step 1: NEC2 methylates desmethylnectriapyrone to the 4-O-methyl 2-pyrone nectriapyrone; this single step records the NEC2/RHEA:58748 tailoring reaction in Pyricularia oryzae 70-15 (mibig:BGC0002155) and leaves upstream NEC1 polyketide assembly and downstream conversion to nectriapyrone C unexpanded.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 4 nodes, 3 edges

Pyricularia oryzae 70-15 NEC2 O-methylates desmethylnectriapyrone to form nectriapyrone upstream of nectriapyrone C.

Subject	Predicate	Object	Notes	Evidence
desmethylnectriapyrone	is O-methylated by	NEC2	NEC2 uses SAM to methylate the desmethylnectriapyrone oxygen and RHEA records this step as RHEA:58748.	DOI:10.1002/cbic.201800620 https://mibig.secondarymetabolites.org/repository/BGC0002155.3/BGC0002155.gbk https://www.uniprot.org/uniprotkb/G4NEA9 https://www.rhea-db.org/rhea/58748 reference DOI:10.1002/cbic.201800620 evidence type PRIMARY_EXPERIMENT snippet The nectriapyrone biosynthetic gene cluster consists of a polyketide synthase gene (NEC1) and an O-methyltransferase gene (NEC2). notes Motoyama et al. assigned the Pyricularia oryzae 70-15 nectriapyrone cluster and showed that NEC1 plus NEC2 overexpression induced overproduction of nectriapyrone and nectriapyrone analogues. reference https://mibig.secondarymetabolites.org/repository/BGC0002155.3/BGC0002155.gbk evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes MIBiG BGC0002155.3 places NEC2 locus tag MGG_14657 at GenBank CM001235.1 with protein_id EHA48592.1 in the Pyricularia oryzae 70-15 nectriapyrone BGC. reference https://www.uniprot.org/uniprotkb/G4NEA9 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes Reviewed UniProtKB:G4NEA9 resolves to the 265 aa Pyricularia oryzae strain 70-15 O-methyltransferase NEC2 / MGG_14657 gene product, cross-references EMBL CM001235 protein EHA48592.1, and annotates catalytic activity RHEA:58748. reference https://www.rhea-db.org/rhea/58748 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes RHEA:58748 is the desmethylnectriapyrone plus S-adenosyl-L-methionine to nectriapyrone plus S-adenosyl-L-homocysteine plus H(+) reaction; Rhea maps the master reaction to UniProtKB:G4NEA9 in Swiss-Prot.
NEC2	forms	nectriapyrone	NEC2 is the MGG_14657 O-methyltransferase in the BGC0002155 Pyricularia oryzae 70-15 cluster.	DOI:10.1002/cbic.201800620 https://mibig.secondarymetabolites.org/repository/BGC0002155.3/BGC0002155.gbk https://www.uniprot.org/uniprotkb/G4NEA9 https://www.rhea-db.org/rhea/58748 reference DOI:10.1002/cbic.201800620 evidence type PRIMARY_EXPERIMENT snippet The nectriapyrone biosynthetic gene cluster consists of a polyketide synthase gene (NEC1) and an O-methyltransferase gene (NEC2). notes Motoyama et al. assigned the Pyricularia oryzae 70-15 nectriapyrone cluster and showed that NEC1 plus NEC2 overexpression induced overproduction of nectriapyrone and nectriapyrone analogues. reference https://mibig.secondarymetabolites.org/repository/BGC0002155.3/BGC0002155.gbk evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes MIBiG BGC0002155.3 places NEC2 locus tag MGG_14657 at GenBank CM001235.1 with protein_id EHA48592.1 in the Pyricularia oryzae 70-15 nectriapyrone BGC. reference https://www.uniprot.org/uniprotkb/G4NEA9 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes Reviewed UniProtKB:G4NEA9 resolves to the 265 aa Pyricularia oryzae strain 70-15 O-methyltransferase NEC2 / MGG_14657 gene product, cross-references EMBL CM001235 protein EHA48592.1, and annotates catalytic activity RHEA:58748. reference https://www.rhea-db.org/rhea/58748 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes RHEA:58748 is the desmethylnectriapyrone plus S-adenosyl-L-methionine to nectriapyrone plus S-adenosyl-L-homocysteine plus H(+) reaction; Rhea maps the master reaction to UniProtKB:G4NEA9 in Swiss-Prot.
nectriapyrone	is an upstream precursor of	nectriapyrone C	Motoyama et al. assigned the Pyricularia oryzae 70-15 NEC1/NEC2 cluster (BGC0002155) to nectriapyrone and its oxidatively modified congener nectriapyrone C; the downstream tailoring step from nectriapyrone to nectriapyrone C is left unexpanded.	DOI:10.1002/cbic.201800620 https://mibig.secondarymetabolites.org/repository/BGC0002155.3/BGC0002155.gbk reference DOI:10.1002/cbic.201800620 evidence type PRIMARY_EXPERIMENT snippet The nectriapyrone biosynthetic gene cluster consists of a polyketide synthase gene (NEC1) and an O-methyltransferase gene (NEC2). notes Motoyama et al. assigned the Pyricularia oryzae 70-15 NEC1/NEC2 cluster (BGC0002155) to nectriapyrone and its oxidatively modified congener nectriapyrone C; the downstream tailoring step from nectriapyrone to nectriapyrone C is left unexpanded. reference https://mibig.secondarymetabolites.org/repository/BGC0002155.3/BGC0002155.gbk evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes MIBiG BGC0002155.3 records nectriapyrone C alongside nectriapyrone as a product of the Pyricularia oryzae 70-15 NEC1/NEC2 cluster on CM001235.1.

Every edge carries its own citation; an uncited edge is refused by the corpus tests.

Explore across X-Mech

AntibioticMech (nectriapyrone C) ↗ MediaIngredientMech (naturalproductmech:mibig-1b7d91c87a) ↗ TaxonMech: Pyricularia oryzae 70-15 (NCBITaxon:242507) ↗ PathwayMech (mibig:BGC0002155) ↗

Provenance

Source concept	Source	Version
BGC0002155	MIBIG	3

This page is generated from data/natural_products/polyketides/nectriapyrone-c.yaml, which is generated from the committed inventories. Neither is edited by hand.