3,3'-diflaviolin

naturalproductmech:mibig-8dfce2dc21 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REVIEWED records curator sign-off on identity, structure, filing class and producer claims; DEPRECATED retains a superseded or out-of-scope record.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	GXAIIEQOZICWEL-UHFFFAOYSA-N
SMILES	O=C1C=C(O)C(C2=CC(O)=C(C3=C(O)C=C(C(C(O)=CC4=O)=O)C4=C3O)C(O)=C21)=O
Stereochemistry	fully defined

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, saccharide, 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
Saccharopolyspora erythraea NCBITaxon:1836	BGC_CHARACTERIZED	mibig:BGC0000285	PMID:12028378

Occurrences 0

None cited.

Biosynthetic gene clusters 1

Accession	Host	Locus evidence	Genome
mibig:BGC0000285	Saccharopolyspora erythraea NCBITaxon:1836	CLUSTER_DEMONSTRATED	genbank:AY078067.1

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	RppA UniProtKB:Q8KQM3		ungrounded → CHEBI:18365	DOI:10.1046/j.1365-2958.2002.02975.x

Step 1: This curates the Saccharopolyspora erythraea BGC0000285/AY078067.1 RppA type III PKS as the knockout-supported scaffold enzyme in the red-brown pigment locus upstream of flaviolin and 3,3'-diflaviolin. The record does not assert direct biochemical characterization of purified S. erythraea RppA or a single-enzyme reaction from RppA to 3,3'-diflaviolin.

Mechanism & Biosynthesis Overview

Causal graph — biosynthesis 7 nodes, 6 edges

Partial Saccharopolyspora erythraea RppA type III PKS graph for formation of 1,3,6,8-tetrahydroxynaphthalene and flaviolin upstream of 3,3'-diflaviolin.

Subject	Predicate	Object	Notes	Evidence
malonyl-CoA(5-)	is condensed by	RppA	The S. erythraea RppA edge is proposed from the cloned rppA sequence, knockout of the pigment locus, and homology to biochemically characterized bacterial THN synthases.	DOI:10.1046/j.1365-2958.2002.02975.x https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html https://www.uniprot.org/uniprotkb/Q8KQM3 https://www.ncbi.nlm.nih.gov/protein/AAL78053.1 reference DOI:10.1046/j.1365-2958.2002.02975.x evidence type PRIMARY_EXPERIMENT snippet disrupt the red-brown pigment-producing (rpp) locus in S. erythraea, generating a mutant that displayed an albino phenotype notes Cortes et al. used rpp-locus disruption and vector recapture in Saccharopolyspora erythraea to connect the cloned chalcone-synthase-like rppA locus to diffusible red-brown flaviolin-derived pigment biosynthesis; the RppA-to-THN product assignment is proposed from type III PKS homology rather than an assay of purified S. erythraea RppA. reference https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes MIBiG BGC0000285.5 names flaviolin among products of the Saccharopolyspora erythraea AY078067.1 red-brown-pigment locus and annotates AAL78053.1/rppA as a knockout-supported Type III PKS scaffold-biosynthesis gene. reference https://www.uniprot.org/uniprotkb/Q8KQM3 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes Unreviewed UniProtKB:Q8KQM3 is the 367 aa Saccharopolyspora erythraea RppA/rppA protein and cross-references EMBL AY078067 protein AAL78053.1. reference https://www.ncbi.nlm.nih.gov/protein/AAL78053.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept AAL78053.1 is the AY078067.1 rppA CDS from the Saccharopolyspora erythraea red-brown-pigment locus and is sequence-identical to UniProtKB:Q8KQM3.
RppA	catalyzes proposed formation of	1,3,6,8-tetrahydroxynaphthalene	The edge stops at the proposed THN synthase product rather than assigning RppA to exact flaviolin, flaviolin rhamnoside, or 3,3'-diflaviolin formation.	DOI:10.1046/j.1365-2958.2002.02975.x https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html https://www.uniprot.org/uniprotkb/Q8KQM3 https://www.ncbi.nlm.nih.gov/protein/AAL78053.1 reference DOI:10.1046/j.1365-2958.2002.02975.x evidence type PRIMARY_EXPERIMENT snippet disrupt the red-brown pigment-producing (rpp) locus in S. erythraea, generating a mutant that displayed an albino phenotype notes Cortes et al. used rpp-locus disruption and vector recapture in Saccharopolyspora erythraea to connect the cloned chalcone-synthase-like rppA locus to diffusible red-brown flaviolin-derived pigment biosynthesis; the RppA-to-THN product assignment is proposed from type III PKS homology rather than an assay of purified S. erythraea RppA. reference https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes MIBiG BGC0000285.5 names flaviolin among products of the Saccharopolyspora erythraea AY078067.1 red-brown-pigment locus and annotates AAL78053.1/rppA as a knockout-supported Type III PKS scaffold-biosynthesis gene. reference https://www.uniprot.org/uniprotkb/Q8KQM3 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes Unreviewed UniProtKB:Q8KQM3 is the 367 aa Saccharopolyspora erythraea RppA/rppA protein and cross-references EMBL AY078067 protein AAL78053.1. reference https://www.ncbi.nlm.nih.gov/protein/AAL78053.1 evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes NCBI GenPept AAL78053.1 is the AY078067.1 rppA CDS from the Saccharopolyspora erythraea red-brown-pigment locus and is sequence-identical to UniProtKB:Q8KQM3.
1,3,6,8-tetrahydroxynaphthalene	spontaneously oxidizes through	THN oxidation	The non-enzymatic process captures THN oxidation without assigning an exact downstream tailoring enzyme in either cluster.	DOI:10.1046/j.1365-2958.2002.02975.x reference DOI:10.1046/j.1365-2958.2002.02975.x evidence type PRIMARY_EXPERIMENT snippet Flaviolin is a spontaneous oxidation product of 1,3,6,8-tetrahydroxynaphthalene notes Cortes et al. place flaviolin downstream of the THN synthase product; the BGC0000285 cluster also encodes RppB and ORF3 oxidases, but those tailoring enzymes are not assigned here to the exact flaviolin branch.
THN oxidation	forms	flaviolin	The exact flaviolin intermediate is supported by the spontaneous-oxidation statement and by the BGC0000285 MIBiG product assertion.	DOI:10.1046/j.1365-2958.2002.02975.x https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html reference DOI:10.1046/j.1365-2958.2002.02975.x evidence type PRIMARY_EXPERIMENT snippet Flaviolin is a spontaneous oxidation product of 1,3,6,8-tetrahydroxynaphthalene notes Cortes et al. place flaviolin downstream of the THN synthase product; the BGC0000285 cluster also encodes RppB and ORF3 oxidases, but those tailoring enzymes are not assigned here to the exact flaviolin branch. reference https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes MIBiG BGC0000285.5 names flaviolin among products of the Saccharopolyspora erythraea AY078067.1 red-brown-pigment locus and annotates AAL78053.1/rppA as a knockout-supported Type III PKS scaffold-biosynthesis gene.
flaviolin	dimerizes through	flaviolin dimerization	Cortes et al. detected 3,3'-diflaviolin alongside flaviolin as a pigment product of the Saccharopolyspora erythraea rpp locus; the exact dimerization tailoring enzyme in BGC0000285 is left unexpanded.	DOI:10.1046/j.1365-2958.2002.02975.x https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html reference DOI:10.1046/j.1365-2958.2002.02975.x evidence type PRIMARY_EXPERIMENT snippet The products detected were flaviolin (red pigment), a dimer of flaviolin (3,3'-diflaviolin), and the 2-O- and 5-O-rhamnosides of flaviolin notes Cortes et al. detected 3,3'-diflaviolin alongside flaviolin as a pigment product of the Saccharopolyspora erythraea rpp locus; the exact dimerization tailoring enzyme in BGC0000285 is left unexpanded. reference https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes MIBiG BGC0000285.5 names 3,3'-diflaviolin and flaviolin among products of the Saccharopolyspora erythraea AY078067.1 red-brown-pigment locus.
flaviolin dimerization	forms	3,3'-diflaviolin	Cortes et al. detected 3,3'-diflaviolin alongside flaviolin as a pigment product of the Saccharopolyspora erythraea rpp locus; the exact dimerization tailoring enzyme in BGC0000285 is left unexpanded.	DOI:10.1046/j.1365-2958.2002.02975.x https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html reference DOI:10.1046/j.1365-2958.2002.02975.x evidence type PRIMARY_EXPERIMENT snippet The products detected were flaviolin (red pigment), a dimer of flaviolin (3,3'-diflaviolin), and the 2-O- and 5-O-rhamnosides of flaviolin notes Cortes et al. detected 3,3'-diflaviolin alongside flaviolin as a pigment product of the Saccharopolyspora erythraea rpp locus; the exact dimerization tailoring enzyme in BGC0000285 is left unexpanded. reference https://mibig.secondarymetabolites.org/repository/BGC0000285.5/index.html evidence type DATABASE_ASSERTION retrieved on 2026-09-27 notes MIBiG BGC0000285.5 names 3,3'-diflaviolin and flaviolin among products of the Saccharopolyspora erythraea AY078067.1 red-brown-pigment locus.

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

Explore across X-Mech

AntibioticMech (3,3'-diflaviolin) ↗ MediaIngredientMech (naturalproductmech:mibig-8dfce2dc21) ↗ TaxonMech: Saccharopolyspora erythraea (NCBITaxon:1836) ↗ PathwayMech (mibig:BGC0000285) ↗

Provenance

Source concept	Source	Version
BGC0000285	MIBIG	5

This page is generated from data/natural_products/polyketides/3-3-diflaviolin.yaml, which is generated from the committed inventories. Neither is edited by hand.