NaturalProductMech

stemphyloxin I

CHEBI:145070 EXACT SEEDED

An octahydronaphthalene that is 2,4,5,7-tetramethyloctahydronaphthalen-1(2H)-one which is substituted by hydroxy groups at positions 2 and 7, a (2R)-1-hydroxybutan-2-yl group at position 3, and a (2Z)-3-hydroxyprop-2-enoyl group at position 4 (the 2S,3R,4R,4aS,5R,7R,8aS stereoisomer). Isolated from the endophytic fungus Stemphylium botryosum, it is the causal agent of leaf spot and foliage blight disease in tomatoes. Its phytotoxcity is at least 200 times greater than that of stemphyloxin II. It shows high affinity for Fe3+ (but not Fe2+) ions.

Structure

Standard InChIKeyYRECHDUAXCBBOZ-HOCCXODSSA-N
SMILES[H][C@]12[C@@](C[C@](C)(O)C[C@H]2C)([H])C([C@@](C)(O)[C@]([H])([C@H](CO)CC)[C@]1(C)C(/C=C\O)=O)=O
Stereochemistryfully 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, 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.

TaxonBasisClusterEvidence
Parastagonospora nodorum SN15
NCBITaxon:321614
SOURCE_ASSERTION mibig:BGC0002165 PMID:31553484

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.

TaxonSourceReference
Stemphylium botryosum
NCBITaxon:120510
LOTUS DOI:10.1016/S0031-9422(00)80518-X
Stemphylium botryosum
NCBITaxon:120510
LOTUS DOI:10.1126/SCIENCE.220.4601.1065
Stemphylium botryosum
NCBITaxon:120510
CHEBI PMID:16662165

Biosynthetic gene clusters 1

AccessionHostLocus evidenceGenome
mibig:BGC0002165 Parastagonospora nodorum SN15
NCBITaxon:321614
CLUSTER_UNSTATED genbank:CH445335.1

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.

Open questions 1

name-disagreement — ChEBI calls this structure 'stemphyloxin I' and MIBiG calls it 'compound 7'. They share a Standard InChIKey, so if the names denote different compounds then one upstream record has the wrong structure. Check which.

Provenance

Source conceptSourceVersion
BGC0002165MIBIG3
CHEBI:145070CHEBI3-star

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