2-heptylquinolin-4(1H)-one

naturalproductmech:mibig-182e475a70 REVIEW_NEEDED SEEDED antibacterial

Grounding review: This structure matches more than one 3-star ChEBI entry: CHEBI:62219, CHEBI:75306. ChEBI keeps such entries separate on purpose — a compound and its zwitterion share an InChIKey — so the identity is not picked here. A curator decides which term this record is.

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REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record.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	UYRHHBXYXSYGHA-UHFFFAOYSA-N
SMILES	CCCCCCCC1=CC(=O)C2=CC=CC=C2N1
Stereochemistry	fully defined
Cross-references	npatlas:NPA026460

Filing pathway

Alkaloids — 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
Pseudomonas aeruginosa PAO1 NCBITaxon:208964	SOURCE_ASSERTION	mibig:BGC0000922	DOI:10.1016/j.chembiol.2013.09.021

Occurrences 7

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
Haplophyllum griffithianum NCBITaxon:1006075	LOTUS	DOI:10.1007/S10600-010-9661-Y
Streptomyces NCBITaxon:1883	LOTUS	DOI:10.3390/MD17020133
Pseudomonas aeruginosa NCBITaxon:287	LOTUS	DOI:10.1016/S0021-9258(17)41580-8
Pseudomonas aeruginosa NCBITaxon:287	LOTUS	DOI:10.1016/S0040-4039(01)83977-0
Ruta graveolens NCBITaxon:37565	LOTUS	DOI:10.1007/PL00010251
Ruta graveolens NCBITaxon:37565	LOTUS	DOI:10.1007/S007060050230
Pseudoalteromonas NCBITaxon:53246	LOTUS	DOI:10.3390/MD15110336

Biosynthetic gene clusters 1

Accession	Host	Locus evidence	Genome
mibig:BGC0000922	Pseudomonas aeruginosa PAO1 NCBITaxon:208964	CLUSTER_UNSTATED	genbank:AE004091.2

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.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 7 nodes, 6 edges

PAO1 PqsB/PqsC native references, their co-purified complex and net HHQ formation. Protein references are distinguished from expression constructs. The graph does not assign independent PqsB catalysis or enzyme-catalyzed ring closure, and does not curate antimicrobial targets.

Subject	Predicate	Object	Notes	Evidence
2-heptyl-4(1H)-quinolone synthase subunit PqsB	is_subunit_of	PqsBC complex from Pseudomonas aeruginosa PAO1	Subunit association in the PAO1-derived preparation; not independent subunit catalysis or a physiological stoichiometry claim.	DOI:10.1074/jbc.M115.708453 https://www.uniprot.org/uniprotkb/Q9I4X2/entry https://www.ncbi.nlm.nih.gov/protein/AAG04386.1 https://doi.org/10.2210/pdb5DWZ/pdb reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes Co-purification and gel filtration support association; structural analysis used PqsC C129A. snippet form a tight complex reference https://www.uniprot.org/uniprotkb/Q9I4X2/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed PAO1 entry version 108; PA0997, 283 aa, linked GenPept AAG04386.1. reference https://www.ncbi.nlm.nih.gov/protein/AAG04386.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Native reference chosen after exact CDS translation, GenPept and UniProt comparison; accession does not denote the tagged assay construct. reference https://doi.org/10.2210/pdb5DWZ/pdb evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes PqsB deposited sequence matches its 283-aa native reference. PqsC has SAG plus native residues 2-348 with C129A. Several residues are unmodeled. The mmCIF has older A0A accession mappings and tetrameric assemblies; neither is silently substituted for the audited native references or physiological oligomerization.
2-heptyl-4(1H)-quinolone synthase subunit PqsC	is_subunit_of	PqsBC complex from Pseudomonas aeruginosa PAO1	Subunit association in the PAO1-derived preparation; not independent subunit catalysis or a physiological stoichiometry claim.	DOI:10.1074/jbc.M115.708453 https://www.uniprot.org/uniprotkb/Q9I4X1/entry https://www.ncbi.nlm.nih.gov/protein/AAG04387.1 https://doi.org/10.2210/pdb5DWZ/pdb reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes Co-purification and gel filtration support association; structural analysis used PqsC C129A. snippet form a tight complex reference https://www.uniprot.org/uniprotkb/Q9I4X1/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed PAO1 entry version 132; PA0998, 348 aa, linked GenPept AAG04387.1. reference https://www.ncbi.nlm.nih.gov/protein/AAG04387.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Native reference chosen after exact CDS translation, GenPept and UniProt comparison; accession does not denote the tagged assay construct. reference https://doi.org/10.2210/pdb5DWZ/pdb evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes PqsB deposited sequence matches its 283-aa native reference. PqsC has SAG plus native residues 2-348 with C129A. Several residues are unmodeled. The mmCIF has older A0A accession mappings and tetrameric assemblies; neither is silently substituted for the audited native references or physiological oligomerization.
PqsBC complex from Pseudomonas aeruginosa PAO1	supports_net_conversion	PqsBC-dependent net conversion to HHQ	Wild-type-derived preparation assayed with both substrates at 25 C in HEPES pH 8.2; not the crystallized C129A variant.	DOI:10.1074/jbc.M115.708453 reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes HPLC product quantification and spectroscopic turnover assays; PqsC was expressed with an N-terminal His8/TEV/linker fusion and purified with tag-cleavage steps.
2-Aminobenzoylacetate (2-ABA, assay substrate)	is_substrate_in	PqsBC-dependent net conversion to HHQ		DOI:10.1074/jbc.M115.708453 reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes 2-ABA was supplied with octanoyl-CoA in the purified-complex assay.
Octanoyl-CoA (assay substrate)	is_substrate_in	PqsBC-dependent net conversion to HHQ		DOI:10.1074/jbc.M115.708453 reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes Octanoyl-CoA was supplied with 2-ABA in the purified-complex assay.
PqsBC-dependent net conversion to HHQ	yields_detected_product	2-heptylquinolin-4(1H)-one	Net assay outcome only. Condensation followed by ring closure is not proof that both occur within the enzyme active site.	DOI:10.1074/jbc.M115.708453 reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes HHQ was measured as product; no rate, yield or physiological sufficiency is generalized here. snippet quantification of HHQ by HPLC

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

Causal graph — biosynthesis 12 nodes, 11 edges

UniProt-annotated PAO1 PqsA/PqsD/PqsE precursor chemistry, connected to the separately inspected net PqsBC HHQ assay. The upstream reactions are database assertions, not primary assays inspected here. Native protein references are not experimental constructs. This is not a balanced reaction diagram, a reconstituted complete pathway or an essentiality claim; cofactors and byproducts are described in evidence notes.

Subject	Predicate	Object	Notes	Evidence
Anthranilate--CoA ligase	is_annotated_to_catalyze	Annotated anthranilate activation	Native PAO1 reference, not an audited expression construct. Primary PqsA/PqsD/PqsE assay methods were not inspected in this pass.	https://www.uniprot.org/uniprotkb/Q9I4X3/entry https://www.ncbi.nlm.nih.gov/protein/AAG04385.1 reference https://www.uniprot.org/uniprotkb/Q9I4X3/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed entry version 115; PA0996, 517 aa. UniProt annotates anthranilate activation with ATP and CoA, releasing AMP and diphosphate. snippet Catalyzes the formation of anthraniloyl-CoA reference https://www.ncbi.nlm.nih.gov/protein/AAG04385.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Native accession selected after exact PAO1 CDS translation, deposited translation, GenPept and UniProt sequence comparison. This does not establish the sequence of any experimental plasmid or mutant.
Anthraniloyl-CoA anthraniloyltransferase	is_annotated_to_catalyze	Annotated 2-ABA-CoA formation	Native PAO1 reference, not an audited expression construct. Primary PqsA/PqsD/PqsE assay methods were not inspected in this pass.	https://www.uniprot.org/uniprotkb/P20582/entry https://www.ncbi.nlm.nih.gov/protein/AAG04388.1 reference https://www.uniprot.org/uniprotkb/P20582/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed entry version 147; PA0999, 337 aa. UniProt annotates condensation of anthraniloyl-CoA with malonyl-CoA to form 2-ABA-CoA; no DHQ production claim is added. snippet to form 2-aminobenzoylacetyl-CoA reference https://www.ncbi.nlm.nih.gov/protein/AAG04388.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Native accession selected after exact PAO1 CDS translation, deposited translation, GenPept and UniProt sequence comparison. This does not establish the sequence of any experimental plasmid or mutant.
2-aminobenzoylacetyl-CoA thioesterase	is_annotated_to_catalyze	Annotated 2-ABA-CoA hydrolysis	Native PAO1 reference, not an audited expression construct. Primary PqsA/PqsD/PqsE assay methods were not inspected in this pass.	https://www.uniprot.org/uniprotkb/P20581/entry https://www.ncbi.nlm.nih.gov/protein/AAG04389.1 reference https://www.uniprot.org/uniprotkb/P20581/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed entry version 129; PA1000, 301 aa. UniProt annotates hydrolysis of 2-ABA-CoA to 2-ABA and CoA; catalytic annotation is not a genetic-essentiality claim. snippet to form 2-aminobenzoylacetate (2-ABA) reference https://www.ncbi.nlm.nih.gov/protein/AAG04389.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Native accession selected after exact PAO1 CDS translation, deposited translation, GenPept and UniProt sequence comparison. This does not establish the sequence of any experimental plasmid or mutant.
Anthranilate	is_annotated_substrate_in	Annotated anthranilate activation		https://www.uniprot.org/uniprotkb/Q9I4X3/entry reference https://www.uniprot.org/uniprotkb/Q9I4X3/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Anthranilate is the aromatic substrate; ATP and CoA are additional reactants in the cited annotation.
Annotated anthranilate activation	has_annotated_product	Anthraniloyl-CoA		https://www.uniprot.org/uniprotkb/Q9I4X3/entry reference https://www.uniprot.org/uniprotkb/Q9I4X3/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Anthraniloyl-CoA is the annotated activation product.
Anthraniloyl-CoA	is_annotated_substrate_in	Annotated 2-ABA-CoA formation		https://www.uniprot.org/uniprotkb/P20582/entry reference https://www.uniprot.org/uniprotkb/P20582/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Anthraniloyl-CoA is one annotated condensation substrate.
Malonyl-CoA	is_annotated_substrate_in	Annotated 2-ABA-CoA formation		https://www.uniprot.org/uniprotkb/P20582/entry reference https://www.uniprot.org/uniprotkb/P20582/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes This graph represents the malonyl-CoA annotation, not a separately audited malonyl-ACP assay.
Annotated 2-ABA-CoA formation	has_annotated_product	2-Aminobenzoylacetyl-CoA (2-ABA-CoA)		https://www.uniprot.org/uniprotkb/P20582/entry reference https://www.uniprot.org/uniprotkb/P20582/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes 2-ABA-CoA is the annotated product. Spontaneous cyclization and DHQ are not treated as HHQ formation.
2-Aminobenzoylacetyl-CoA (2-ABA-CoA)	is_annotated_substrate_in	Annotated 2-ABA-CoA hydrolysis		https://www.uniprot.org/uniprotkb/P20581/entry reference https://www.uniprot.org/uniprotkb/P20581/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes 2-ABA-CoA is the annotated thioesterase substrate.
Annotated 2-ABA-CoA hydrolysis	has_annotated_product	2-Aminobenzoylacetate (2-ABA)		https://www.uniprot.org/uniprotkb/P20581/entry reference https://www.uniprot.org/uniprotkb/P20581/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes The annotated hydrolysis releases 2-ABA. This does not establish exclusive physiological dependence on PqsE.
2-Aminobenzoylacetate (2-ABA)	is_assay_precursor_of	2-heptylquinolin-4(1H)-one	Separate net PqsBC assay: 2-ABA plus octanoyl-CoA gave detected HHQ. This is not a one-step conversion by PqsE or a reconstitution of the complete PqsA/D/E/BC route.	DOI:10.1074/jbc.M115.708453 reference DOI:10.1074/jbc.M115.708453 evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes The previously inspected PqsBC study supplied 2-ABA and octanoyl-CoA to the purified complex and quantified HHQ by HPLC. The existing pqsbc-pao1-net-hhq-formation graph retains the construct and cyclization limits.

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

Elsewhere in the fleet

AntibioticMech — CHEBI:62219 (same structure, same inchikey)
AntibioticMech — CHEBI:75306 (same structure, same inchikey)

Explore across X-Mech

AntibioticMech (2-heptylquinolin-4(1H)-one) ↗ MediaIngredientMech (naturalproductmech:mibig-182e475a70) ↗ TaxonMech: Pseudomonas aeruginosa PAO1 (NCBITaxon:208964) ↗ PathwayMech (mibig:BGC0000922) ↗

Open questions 2

curator-pqsbc-construct-and-reaction-boundaries — What remains unresolved beyond the PqsBC net HHQ formation assay?

curator-pqsade-annotation-and-primary-evidence — Which PqsA/PqsD/PqsE primary assays and constructs can be independently verified?

Provenance

Source concept	Source	Version
BGC0000922	MIBIG	5
CHEBI:62219	CHEBI	3-star
CHEBI:75306	CHEBI	3-star

This page is generated from data/natural_products/alkaloids/2-heptylquinolin-4-1h-one.yaml, which is generated from the committed inventories. Neither is edited by hand.