2-heptyl-3-hydroxy-4-quinolone

CHEBI:29472 EXACT SEEDED

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REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record.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.

A quinolone consisting of quinolin-4(1H)-one carrying a heptyl substituent at position 2 and a hydroxy group at position 3.

Structure

Standard InChIKey	CEIUIHOQDSVZJQ-UHFFFAOYSA-N
SMILES	CCCCCCCC1=C(C(=O)C2=CC=CC=C2N1)O
Stereochemistry	fully defined
Cross-references	npatlas:NPA019649

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:10.1128/jb.184.23.6472-6480.2002

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
Pseudomonas aeruginosa NCBITaxon:287	LOTUS	DOI:10.1039/B803796P
Pseudomonas aeruginosa NCBITaxon:287	LOTUS	DOI:10.1073/PNAS.96.20.11229

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.

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	PqsH 2-heptyl-3-hydroxy-4(1H)-quinolone synthase UniProtKB:Q9I0Q0	RHEA:37871	CHEBI:62219 → CHEBI:29472	DOI:10.1128/JB.184.23.6472-6480.2002

Step 1: Pseudomonas aeruginosa PAO1 PqsH hydroxylates 2-heptyl-4(1H)-quinolone / HHQ to the Pseudomonas quinolone signal; upstream pqsABCD formation of HHQ is left unexpanded.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 3 nodes, 2 edges

Pseudomonas aeruginosa PAO1 PqsH hydroxylates HHQ to form 2-heptyl-3-hydroxy-4-quinolone.

Subject	Predicate	Object	Notes	Evidence
2-heptyl-4(1H)-quinolone	is hydroxylated by	PqsH	PqsH uses NADH and O2 in the RHEA:37871 hydroxylation of HHQ.	DOI:10.1128/JB.184.23.6472-6480.2002 https://www.uniprot.org/uniprotkb/Q9I0Q0 https://www.rhea-db.org/rhea/37871 reference DOI:10.1128/JB.184.23.6472-6480.2002 evidence type PRIMARY_EXPERIMENT notes Gallagher et al. named the unlinked Pseudomonas aeruginosa PAO1 PA2587 gene pqsH and showed that a pqsH transposon mutant was defective in Pseudomonas quinolone signal production by TLC. reference https://www.uniprot.org/uniprotkb/Q9I0Q0 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes Reviewed UniProtKB:Q9I0Q0 is the Pseudomonas aeruginosa PAO1 pqsH / PA2587 gene product and annotates the RHEA:37871 catalytic activity of 2-heptyl-3-hydroxy-4(1H)-quinolone synthase. reference https://www.rhea-db.org/rhea/37871 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes RHEA:37871 is the 2-heptyl-4(1H)-quinolone plus NADH plus O2 plus H(+) to 2-heptyl-3-hydroxy-4(1H)-quinolone plus NAD(+) plus H2O reaction.
PqsH	forms	2-heptyl-3-hydroxy-4-quinolone	PqsH is the PA2587 flavin monooxygenase in Pseudomonas aeruginosa PAO1.	DOI:10.1128/JB.184.23.6472-6480.2002 https://www.uniprot.org/uniprotkb/Q9I0Q0 https://www.rhea-db.org/rhea/37871 reference DOI:10.1128/JB.184.23.6472-6480.2002 evidence type PRIMARY_EXPERIMENT notes Gallagher et al. named the unlinked Pseudomonas aeruginosa PAO1 PA2587 gene pqsH and showed that a pqsH transposon mutant was defective in Pseudomonas quinolone signal production by TLC. reference https://www.uniprot.org/uniprotkb/Q9I0Q0 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes Reviewed UniProtKB:Q9I0Q0 is the Pseudomonas aeruginosa PAO1 pqsH / PA2587 gene product and annotates the RHEA:37871 catalytic activity of 2-heptyl-3-hydroxy-4(1H)-quinolone synthase. reference https://www.rhea-db.org/rhea/37871 evidence type DATABASE_ASSERTION retrieved on 2026-09-30 notes RHEA:37871 is the 2-heptyl-4(1H)-quinolone plus NADH plus O2 plus H(+) to 2-heptyl-3-hydroxy-4(1H)-quinolone plus NAD(+) plus H2O reaction.

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

Causal graph — biosynthesis 7 nodes, 6 edges

Database-annotated PAO1 PhnAB anthranilate supply for PQS. Subunit roles and complex assembly include by-similarity evidence. This is not a balanced reaction, a complete reconstituted pathway or a primary native-complex assay; no stoichiometry or genetic essentiality is asserted.

Subject	Predicate	Object	Notes	Evidence
PhnA (PAO1 native reference)	is_annotated_component_of	Annotated PhnAB anthranilate synthase complex	Complex membership and subunit division are database annotations, including by-similarity evidence; native oligomeric stoichiometry was not measured here.	https://www.uniprot.org/uniprotkb/P09785/entry https://www.ncbi.nlm.nih.gov/protein/AAG04390.1 reference https://www.uniprot.org/uniprotkb/P09785/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed entry version 151; PA1001, 530 aa. Native PAO1 protein; not a historical trpE/trpG paralog assignment or an experimental allele. snippet two-step biosynthesis of anthranilate reference https://www.ncbi.nlm.nih.gov/protein/AAG04390.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Exact agreement of genomic CDS-aware translation, deposited translation, GenPept and UniProt establishes the native reference, not an assay construct.
PhnB (PAO1 native reference)	is_annotated_component_of	Annotated PhnAB anthranilate synthase complex	Complex membership and subunit division are database annotations, including by-similarity evidence; native oligomeric stoichiometry was not measured here.	https://www.uniprot.org/uniprotkb/P09786/entry https://www.ncbi.nlm.nih.gov/protein/AAG04391.1 reference https://www.uniprot.org/uniprotkb/P09786/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Reviewed entry version 154; PA1002, 200 aa. Native PAO1 protein; not a historical trpE/trpG paralog assignment or an experimental allele. snippet glutamine amidotransferase activity reference https://www.ncbi.nlm.nih.gov/protein/AAG04391.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes Exact agreement of genomic CDS-aware translation, deposited translation, GenPept and UniProt establishes the native reference, not an assay construct.
Chorismate	is_annotated_substrate_of	Annotated PhnAB anthranilate synthase complex		https://www.uniprot.org/uniprotkb/P09785/entry https://www.uniprot.org/uniprotkb/P09786/entry reference https://www.uniprot.org/uniprotkb/P09785/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Chorismate is an annotated substrate of the overall complex reaction; this is not an independently inspected native-subunit assay. reference https://www.uniprot.org/uniprotkb/P09786/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Corroborating reviewed component annotation; includes by-similarity evidence, not a separately inspected primary experiment.
L-Glutamine	is_annotated_substrate_of	Annotated PhnAB anthranilate synthase complex		https://www.uniprot.org/uniprotkb/P09785/entry https://www.uniprot.org/uniprotkb/P09786/entry reference https://www.uniprot.org/uniprotkb/P09785/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes L-Glutamine is the annotated nitrogen donor. Subunit-specific chemistry is inferred by similarity in UniProt, not newly demonstrated here. reference https://www.uniprot.org/uniprotkb/P09786/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Corroborating reviewed component annotation; includes by-similarity evidence, not a separately inspected primary experiment.
Annotated PhnAB anthranilate synthase complex	is_annotated_to_produce	Anthranilate		https://www.uniprot.org/uniprotkb/P09785/entry https://www.uniprot.org/uniprotkb/P09786/entry reference https://www.uniprot.org/uniprotkb/P09785/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes The annotated overall reaction produces anthranilate, pyruvate, L-glutamate and a proton. The schematic omits byproduct nodes and does not assert native complex stoichiometry. reference https://www.uniprot.org/uniprotkb/P09786/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Corroborating reviewed component annotation; includes by-similarity evidence, not a separately inspected primary experiment.
Anthranilate	is_annotated_precursor_of	2-heptyl-3-hydroxy-4-quinolone		https://www.uniprot.org/uniprotkb/P09785/entry https://www.uniprot.org/uniprotkb/P09786/entry reference https://www.uniprot.org/uniprotkb/P09785/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes UniProt connects anthranilate supply to PQS through a multistep pathway; PhnAB does not directly convert anthranilate to PQS. No exclusive physiological dependence is asserted. reference https://www.uniprot.org/uniprotkb/P09786/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Corroborating reviewed component annotation; includes by-similarity evidence, not a separately inspected primary experiment.

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

Causal graph — bioactivity 3 nodes, 2 edges

PQS-stimulated, MvfR-associated pqsA promoter reporter response in PA14. The protein is a native reference; this graph does not identify an experimental construct or infer direct binding.

Subject	Predicate	Object	Notes	Evidence
2-heptyl-3-hydroxy-4-quinolone	increases_in_cellular_assay	MvfR-associated pqsA promoter reporter response (PA14)		DOI:10.1111/j.1365-2958.2006.05462.x reference DOI:10.1111/j.1365-2958.2006.05462.x evidence type PRIMARY_EXPERIMENT retrieved on 2026-10-11 notes PQS increased pqsA-lacZ reporter activity in the PA14 pqsA/pqsH mutant background; this is a cellular transcriptional readout. snippet stimulate MvfR-dependent
MvfR (PA14 native reference)	is_native_reference_for_regulator_in	MvfR-associated pqsA promoter reporter response (PA14)	Reference mapping, not a direct-binding or isolated-protein activity claim. PA14 and PAO1 native MvfR sequences differ at residue 314.	DOI:10.1111/j.1365-2958.2006.05462.x https://www.uniprot.org/uniprotkb/A0A0H2Z7A6/entry https://www.ncbi.nlm.nih.gov/protein/ABJ10167.1 reference DOI:10.1111/j.1365-2958.2006.05462.x evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes The study names MvfR in PA14. Native reference selection does not identify its plasmid, mutant or tagged fragment sequences. reference https://www.uniprot.org/uniprotkb/A0A0H2Z7A6/entry evidence type DATABASE_ASSERTION retrieved on 2026-10-11 notes Unreviewed entry version 57; PA14_51340, 332 aa, strain UCBPP-PA14 (NCBITaxon:208963). Exact strain takes priority over the PAO1 Swiss-Prot homolog. reference https://www.ncbi.nlm.nih.gov/protein/ABJ10167.1 evidence type CURATOR_INFERENCE retrieved on 2026-10-11 notes PA14 genomic CDS translation, deposited translation, GenPept and UniProt sequences agree exactly.

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

Explore across X-Mech

AntibioticMech (2-heptyl-3-hydroxy-4-quinolone) ↗ MediaIngredientMech (CHEBI:29472) ↗ TaxonMech: Pseudomonas aeruginosa PAO1 (NCBITaxon:208964) ↗ PathwayMech (mibig:BGC0000922) ↗

Open questions 1

curator-phnab-and-mvfr-evidence-boundaries — Which PhnAB primary functions and PA14 MvfR experimental sequences can be independently verified?

Provenance

Source concept	Source	Version
BGC0000922	MIBIG	5
CHEBI:29472	CHEBI	3-star

This page is generated from data/natural_products/alkaloids/2-heptyl-3-hydroxy-4-quinolone.yaml, which is generated from the committed inventories. Neither is edited by hand.