F9775A

naturalproductmech:mibig-1a2493f8d7 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REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record.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	KEHZWGZVOZXIKE-UHFFFAOYSA-N
SMILES	CC1=CC2=C(C(=C1)O)OC3=C(O2)C4(C5C(=CC(=O)C5(C(=O)C4=C(C3=O)O)O)C)C
Stereochemistry	undefined stereocentres — the InChIKey does not distinguish this compound from its stereoisomers
Cross-references	pubchem:9843671

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
Aspergillus nidulans FGSC A4 NCBITaxon:227321	BGC_CHARACTERIZED	mibig:BGC0000057	PMID:20174687

Occurrences 3

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
Aspergillus nidulans NCBITaxon:162425	LOTUS	DOI:10.1039/B904541D
Aspergillus nidulans NCBITaxon:162425	LOTUS	DOI:10.1073/PNAS.0901870106
Escherichia coli NCBITaxon:562	LOTUS	DOI:10.1073/PNAS.0901870106

Biosynthetic gene clusters 1

Accession	Host	Locus evidence	Genome
mibig:BGC0000057	Aspergillus nidulans FGSC A4 NCBITaxon:227321	CLUSTER_DEMONSTRATED	genbank:AACD01000135.1

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	OrsA UniProtKB:Q5AUX1	RHEA:62973	ungrounded → CHEBI:16162	DOI:10.1039/b904541d
2	OrsB/OrsC F-9775 tailoring module		ungrounded → naturalproductmech:mibig-1a2493f8d7	DOI:10.1039/b904541d

Step 1: This curates the Aspergillus nidulans FGSC A4 non-reducing polyketide synthase OrsA from the BGC0000057/AACD01000135.1 route; OrsA condenses acetyl-CoA with three malonyl-CoA units to form o-orsellinate, the branch precursor for F-9775 A biosynthesis.

Step 2: This curates the genetically supported OrsB/OrsC branch that diverts the OrsA orsellinic acid product toward F-9775 A and B. The exact isolated substrate, intermediates and individual OrsB and OrsC reactions remain unresolved, so this two-protein step is marked proposed and leaves enzyme_id empty.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 8 nodes, 7 edges

Partial Aspergillus nidulans F-9775 A biosynthesis graph for OrsA orsellinate formation and the OrsB/OrsC-dependent F-9775 branch.

Subject	Predicate	Object	Notes	Evidence
acetyl-CoA(4-)	is condensed by	OrsA	RHEA:62973 selects acetyl-CoA as the starter unit in the OrsA o-orsellinate synthase reaction.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUX1 https://www.ncbi.nlm.nih.gov/protein/EAA59563.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUX1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUX1 is the Aspergillus nidulans FGSC A4 OrsA orsellinic acid synthase, length 2103 aa, annotates the left-to-right physiological RHEA:62973 reaction, and cross-references EMBL AACD01000135 protein EAA59563.1. reference https://www.ncbi.nlm.nih.gov/protein/EAA59563.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes NCBI GenPept EAA59563.1 is locus_tag AN7909.2 from the BGC0000057 AACD01000135.1 Aspergillus nidulans FGSC A4 locus and maps to reviewed UniProtKB:Q5AUX1.
malonyl-CoA(5-)	is condensed by	OrsA	RHEA:62973 consumes three malonyl-CoA units per o-orsellinate formed by OrsA.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUX1 https://www.ncbi.nlm.nih.gov/protein/EAA59563.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUX1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUX1 is the Aspergillus nidulans FGSC A4 OrsA orsellinic acid synthase, length 2103 aa, annotates the left-to-right physiological RHEA:62973 reaction, and cross-references EMBL AACD01000135 protein EAA59563.1. reference https://www.ncbi.nlm.nih.gov/protein/EAA59563.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes NCBI GenPept EAA59563.1 is locus_tag AN7909.2 from the BGC0000057 AACD01000135.1 Aspergillus nidulans FGSC A4 locus and maps to reviewed UniProtKB:Q5AUX1.
OrsA	forms	o-orsellinate	The curated Rhea reaction forms o-orsellinate, which enters the OrsB/OrsC-dependent F-9775 branch.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUX1 https://www.ncbi.nlm.nih.gov/protein/EAA59563.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUX1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUX1 is the Aspergillus nidulans FGSC A4 OrsA orsellinic acid synthase, length 2103 aa, annotates the left-to-right physiological RHEA:62973 reaction, and cross-references EMBL AACD01000135 protein EAA59563.1. reference https://www.ncbi.nlm.nih.gov/protein/EAA59563.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes NCBI GenPept EAA59563.1 is locus_tag AN7909.2 from the BGC0000057 AACD01000135.1 Aspergillus nidulans FGSC A4 locus and maps to reviewed UniProtKB:Q5AUX1.
o-orsellinate	feeds	OrsB/OrsC F-9775 tailoring	AN7911.4 and AN7912.4 deletions still produced orsellinic acid but failed to produce F-9775 A and B, placing the genetically supported OrsB/OrsC branch downstream of the OrsA product.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUW9 https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 https://www.uniprot.org/uniprotkb/Q5AUW8 https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUW9 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW9 is the Aspergillus nidulans FGSC A4 decarboxylase OrsB/F9775 biosynthesis cluster protein B, length 331 aa, gene orsB, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59565.1" notes NCBI GenPept EAA59565.1 is the AACD01000135.1 locus_tag AN7911.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsB. reference https://www.uniprot.org/uniprotkb/Q5AUW8 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW8 is the Aspergillus nidulans FGSC A4 tyrosinase-like protein OrsC/F9775 biosynthesis cluster protein C, length 369 aa, gene orsC, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59566.1" notes NCBI GenPept EAA59566.1 is the AACD01000135.1 locus_tag AN7912.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsC.
OrsB	is required for	OrsB/OrsC F-9775 tailoring	Deleting AN7911.4/orsB abolished F-9775 A and B production while leaving orsellinic acid production intact.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUW9 https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 https://www.uniprot.org/uniprotkb/Q5AUW8 https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUW9 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW9 is the Aspergillus nidulans FGSC A4 decarboxylase OrsB/F9775 biosynthesis cluster protein B, length 331 aa, gene orsB, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59565.1" notes NCBI GenPept EAA59565.1 is the AACD01000135.1 locus_tag AN7911.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsB. reference https://www.uniprot.org/uniprotkb/Q5AUW8 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW8 is the Aspergillus nidulans FGSC A4 tyrosinase-like protein OrsC/F9775 biosynthesis cluster protein C, length 369 aa, gene orsC, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59566.1" notes NCBI GenPept EAA59566.1 is the AACD01000135.1 locus_tag AN7912.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsC.
OrsC	is required for	OrsB/OrsC F-9775 tailoring	Deleting AN7912.4/orsC abolished F-9775 A and B production while leaving orsellinic acid production intact.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUW9 https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 https://www.uniprot.org/uniprotkb/Q5AUW8 https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUW9 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW9 is the Aspergillus nidulans FGSC A4 decarboxylase OrsB/F9775 biosynthesis cluster protein B, length 331 aa, gene orsB, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59565.1" notes NCBI GenPept EAA59565.1 is the AACD01000135.1 locus_tag AN7911.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsB. reference https://www.uniprot.org/uniprotkb/Q5AUW8 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW8 is the Aspergillus nidulans FGSC A4 tyrosinase-like protein OrsC/F9775 biosynthesis cluster protein C, length 369 aa, gene orsC, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59566.1" notes NCBI GenPept EAA59566.1 is the AACD01000135.1 locus_tag AN7912.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsC.
OrsB/OrsC F-9775 tailoring	forms	F9775A	Sanchez et al. genetically delimited the F-9775 A/B branch to OrsA plus OrsB and OrsC, but the exact F-9775 A-specific sequence of tailoring reactions remains unresolved.	DOI:10.1039/b904541d https://www.uniprot.org/uniprotkb/Q5AUW9 https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 https://www.uniprot.org/uniprotkb/Q5AUW8 https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 reference DOI:10.1039/b904541d evidence type PRIMARY_EXPERIMENT snippet only two additional genes notes Sanchez et al. used targeted deletions in Aspergillus nidulans and found that OrsA is sufficient for orsellinic acid biosynthesis, while the adjacent AN7911.4/orsB and AN7912.4/orsC genes are additionally required for F-9775 A and B synthesis. reference https://www.uniprot.org/uniprotkb/Q5AUW9 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW9 is the Aspergillus nidulans FGSC A4 decarboxylase OrsB/F9775 biosynthesis cluster protein B, length 331 aa, gene orsB, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59565.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59565.1" notes NCBI GenPept EAA59565.1 is the AACD01000135.1 locus_tag AN7911.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsB. reference https://www.uniprot.org/uniprotkb/Q5AUW8 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 notes Reviewed UniProtKB:Q5AUW8 is the Aspergillus nidulans FGSC A4 tyrosinase-like protein OrsC/F9775 biosynthesis cluster protein C, length 369 aa, gene orsC, and cross-references EMBL AACD01000135. reference https://www.ncbi.nlm.nih.gov/protein/EAA59566.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-28 snippet /protein_id="EAA59566.1" notes NCBI GenPept EAA59566.1 is the AACD01000135.1 locus_tag AN7912.2 coding sequence that maps to Aspergillus nidulans FGSC A4 OrsC.

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

Explore across X-Mech

AntibioticMech (F9775A) ↗ MediaIngredientMech (naturalproductmech:mibig-1a2493f8d7) ↗ TaxonMech: Aspergillus nidulans FGSC A4 (NCBITaxon:227321) ↗ PathwayMech (mibig:BGC0000057) ↗

Provenance

Source concept	Source	Version
BGC0000057	MIBIG	5

This page is generated from data/natural_products/polyketides/f9775a.yaml, which is generated from the committed inventories. Neither is edited by hand.