ethambutol
CHEBI:4877
·resolve ·ANTIMYCOBACTERIAL
·EXACT
SEEDED
An ethylenediamine derivative that is ethane-1,2-diamine in which one hydrogen attached to each of the nitrogens is sutstituted by a 1-hydroxybutan-2-yl group (S,S-configuration). It is a bacteriostatic antimycobacterial drug, effective against Mycobacterium tuberculosis and some other mycobacteria. It is used (as the dihydrochloride salt) in combination with other antituberculous drugs in the treatment of pulmonary and extrapulmonary tuberculosis; resistant strains of M. tuberculosis are readily produced if ethambutol is used alone. — ChEBI
Machine-generated and unreviewed. Identity, structure and
cross-references come straight from ChEBI's and CARD's own data; no curator has
signed off on this record yet.
Classification
polyamine antibioticARO:3000527
Strictly broader compounds or drug classes this molecule belongs to.
Chemical structure
Computed structure properties
| Molecular formula | C10H24N2O2 |
|---|
| Charge | 0 |
|---|
| Average mass | 204.314 Da |
|---|
| Monoisotopic mass | 204.18378 Da |
|---|
| Source | ChEBI |
|---|
| InChIKey | AEUTYOVWOVBAKS-UWVGGRQHSA-N |
|---|
SMILES
CC[C@@H](CO)NCCN[C@@H](CC)CO
InChI
InChI=1S/C10H24N2O2/c1-3-9(7-13)11-5-6-12-10(4-2)8-14/h9-14H,3-8H2,1-2H3/t9-,10-/m0/s1
Also called
- etambutol (INN)— chebi
- ethambutolum (INN)— chebi
- (2S,2'S)-2,2'-(ethane-1,2-diyldiimino)dibutan-1-ol (EXACT_SYNONYM)— chebi
- (+)-2,2'-(ethylenediimino)di-1-butanol (EXACT_SYNONYM)— chebi
- (+)-N,N'-bis(1-(hydroxymethyl)propyl)ethylenediamine (EXACT_SYNONYM)— chebi
- (+)-S,S-ethambutol (EXACT_SYNONYM)— chebi
- (+)-ethambutol (EXACT_SYNONYM)— chebi
- (2S,7S)-2,7-diethyl-3,6-diazaoctane-1,8-diol (EXACT_SYNONYM)— chebi
- (S,S)-ethambutol (EXACT_SYNONYM)— chebi
- EMB (EXACT_SYNONYM)— chebi
- Ethambutol (EXACT_SYNONYM)— chebi
- S,S-Ethambutol (EXACT_SYNONYM)— chebi
Cross-references
Equivalent identifiers for this same structure in other resources.
Activity roles
Every antimicrobial role a source asserts for this compound — the
unreduced evidence behind its antimicrobial_class.
Source concepts
Every upstream concept that resolved to this record. The merge is
the product: this is what shows ChEBI and CARD are describing the same structure.
Upstream concepts merged into this record
| Source | Native ID | Label | Minted CURIE | Version |
|---|
| ARO |
ARO:3000497 |
ethambutol |
antibioticmech:aro-a472e0292c |
2026-08-30 |
| CHEBI |
CHEBI:4877 |
ethambutol |
antibioticmech:chebi-8ef15eb8e0 |
2026-08-30 |
Molecular targets
The molecular entity or process this compound acts on. Each target
carries evidence — this is a mechanistic claim, not a classification.
antibiotic sensitive aftA PROTEIN DIRECT_BINDING_TARGET
ARO:3000725
CARD/ARO database assertion; target organism, strain, and assay are not specified. AftA is asserted as the antibiotic-sensitive enzyme. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).
- ARO:3000725 (CARD/ARO asserts targeted_by_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
antibiotic sensitive embC PROTEIN DIRECT_BINDING_TARGET
ARO:3000763
CARD/ARO database assertion; target organism, strain, and assay are not specified. EmbC is asserted as the antibiotic-sensitive enzyme. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).
- ARO:3000763 (CARD/ARO asserts targeted_by_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
antibiotic sensitive embA PROTEIN DIRECT_BINDING_TARGET
ARO:3000764
CARD/ARO database assertion; target organism, strain, and assay are not specified. EmbA is asserted as the antibiotic-sensitive enzyme. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).
- ARO:3000764 (CARD/ARO asserts targeted_by_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
antibiotic sensitive embB PROTEIN DIRECT_BINDING_TARGET
ARO:3000765
CARD/ARO database assertion; target organism, strain, and assay are not specified. EmbB is asserted as the antibiotic-sensitive enzyme. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).
- ARO:3000765 (CARD/ARO asserts targeted_by_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
Antibiotic sensitive embR PROTEIN SUSCEPTIBILITY_DETERMINANT
ARO:3003473
CARD/ARO database assertion; target organism, strain, and assay are not specified. ARO states only that wild-type embR is antibiotic-sensitive; direct binding is not asserted. Evidence status: DATABASE_ASSERTION_ONLY. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).
- ARO:3003473 (CARD/ARO asserts targeted_by_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
Mechanism summary
- Mode of action
- CELL_WALL_SYNTHESIS_INHIBITION microbial target — CURATOR: Confirmed as inhibition of mycobacterial Emb arabinosyltransferases and cell-wall arabinan synthesis after primary ethambutol mechanism review. PMID:2817850; PMID:8876238; PMID:19596878; PMID:32327601.
Resistance mechanisms
19 known routes by which microbes
resist this compound, grounded in ARO where CARD models them. Grouped by mechanism
type — expand a group to see its determinants.
ANTIBIOTIC_TARGET_ALTERATION 19
ANTIBIOTIC_TARGET_ALTERATION
| Determinant | ARO ID | Organism | Gene families | Evidence |
|---|
| Ethambutol resistant iniB |
ARO:3004136 |
not organism-specific |
— |
- ARO:3004136 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Ethambutol resistant iniC |
ARO:3003450 |
not organism-specific |
— |
- ARO:3003450 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis Rv1258c mutations confer resistance to ethambutol and capreomycin |
ARO:3007185 |
not organism-specific |
— |
- ARO:3007185 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis aftA mutations confer resistance to ethambutol |
ARO:3004951 |
not organism-specific |
— |
- ARO:3004951 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis embA mutant conferring resistance to ethambutol |
ARO:3003453 |
not organism-specific |
— |
- ARO:3003453 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis embB with mutation conferring resistance to ethambutol |
ARO:3003326 |
not organism-specific |
— |
- ARO:3003326 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis embC mutant conferring resistance to ethambutol |
ARO:3003327 |
not organism-specific |
— |
- ARO:3003327 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis embR mutant conferring resistance to ethambutol |
ARO:3003455 |
not organism-specific |
— |
- ARO:3003455 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis iniA mutant conferring resistance to ethambutol |
ARO:3003448 |
not organism-specific |
— |
- ARO:3003448 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis iniB with mutation conferring resistance to ethambutol |
ARO:3004135 |
not organism-specific |
— |
- ARO:3004135 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis iniC mutant conferring resistance to ethambutol |
ARO:3003451 |
not organism-specific |
— |
- ARO:3003451 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis ubiA mutations confer resistance to ethambutol |
ARO:3004950 |
not organism-specific |
— |
- ARO:3004950 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| Mycobacterium tuberculosis variant bovis embB with mutation conferring resistance to ethambutol |
ARO:3003325 |
not organism-specific |
— |
- ARO:3003325 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| ethambutol resistant aftA |
ARO:3002876 |
not organism-specific |
— |
- ARO:3002876 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| ethambutol resistant embA |
ARO:3003452 |
not organism-specific |
— |
- ARO:3003452 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| ethambutol resistant embB |
ARO:3000235 |
not organism-specific |
— |
- ARO:3000235 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| ethambutol resistant embC |
ARO:3002706 |
not organism-specific |
— |
- ARO:3002706 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| ethambutol resistant embR |
ARO:3003454 |
not organism-specific |
— |
- ARO:3003454 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
| ethambutol resistant iniA |
ARO:3003447 |
not organism-specific |
— |
- ARO:3003447 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000497 (ethambutol); database assertion, not a primary citation.)
|
Causal graphs
Evidence-backed mechanism graphs: how the compound reaches its
target, what the target does, and how the effect propagates to growth inhibition
or death.
Ethambutol inhibits mycobacterial arabinan synthesis MECHANISTIC
Ethambutol inhibits Emb arabinosyltransferase complexes, reducing arabinan addition to arabinogalactan and lipoarabinomannan in the mycobacterial cell envelope.
Nodes — ethambutol_emb_arabinan_inhibition
| Node | Label | Type | Grounding |
|---|
ethambutol |
ethambutol |
COMPOUND |
CHEBI:4877 |
embab_complex |
mycobacterial EmbA-EmbB arabinosyltransferase complex |
GENE_OR_PROTEIN |
REVIEWED_LABEL_ONLY |
embc_complex |
mycobacterial EmbC arabinosyltransferase complex |
GENE_OR_PROTEIN |
REVIEWED_LABEL_ONLY |
arabinogalactan_arabinan |
mycobacterial arabinogalactan arabinan |
CHEMICAL |
REVIEWED_LABEL_ONLY |
lipoarabinomannan_arabinan |
mycobacterial lipoarabinomannan arabinan |
CHEMICAL |
REVIEWED_LABEL_ONLY |
cell_wall_arabinan_synthesis |
mycobacterial cell-wall arabinan synthesis |
BIOLOGICAL_PROCESS |
REVIEWED_LABEL_ONLY |
mycobacterial_cell_wall_integrity |
mycobacterial cell-wall integrity |
CELL_STRUCTURE |
REVIEWED_LABEL_ONLY |
Edges — ethambutol_emb_arabinan_inhibition
| Subject | Predicate | Object | Evidence |
|---|
ethambutol |
binds |
embab_complex |
- PMID:32327601 (Zhang and colleagues resolved mycobacterial EmbA-EmbB structures with ethambutol and donor and acceptor substrates.)
|
ethambutol |
binds |
embc_complex |
- PMID:32327601 (Zhang and colleagues also resolved ethambutol with mycobacterial EmbC complexes and assayed drug inhibition of Emb transferase activity.)
|
embab_complex |
participates in |
arabinogalactan_arabinan |
- PMID:8876238 (Belanger and colleagues linked embA and embB to mycobacterial cell-wall arabinan biosynthesis and ethambutol susceptibility.)
- PMID:32327601 (The ethambutol-bound EmbA-EmbB structures captured the substrate binding sites used for arabinofuranose transfer.)
|
embc_complex |
participates in |
lipoarabinomannan_arabinan |
- PMID:19596878 (Goude and colleagues showed that ethambutol inhibits EmbC-dependent lipoarabinomannan synthesis in Mycobacterium tuberculosis.)
|
arabinogalactan_arabinan |
participates in |
cell_wall_arabinan_synthesis |
- PMID:2817850 (Takayama and Kilburn observed that ethambutol blocked transfer of glucose-derived label into arabinogalactan arabinose in Mycobacterium smegmatis.)
|
lipoarabinomannan_arabinan |
participates in |
cell_wall_arabinan_synthesis |
- PMID:19596878 (The EmbC inhibition study traced ethambutol-sensitive arabinan synthesis into mycobacterial lipoarabinomannan.)
|
cell_wall_arabinan_synthesis |
supports |
mycobacterial_cell_wall_integrity |
- PMID:9142129 (Telenti and colleagues identified the M. tuberculosis embCAB cluster through ethambutol resistance and placed Emb activity in mycobacterial cell-wall biosynthesis.)
|
Curation history
-
SEEDED_FROM_SOURCES
2026-08-30 · seed_from_sources
Seeded from data/raw/ inventories (ARO, CHEBI)
-
RESEEDED_FROM_SOURCES
2026-08-30 · seed_from_sources
Re-seeded from updated data/raw/ inventories
-
RESEEDED_FROM_SOURCES
2026-08-30 · seed_from_sources
Re-seeded from updated data/raw/ inventories
-
RESEEDED_FROM_SOURCES
2026-08-31 · seed_from_sources
Re-seeded from updated data/raw/ inventories
-
CURATED_CAUSAL_GRAPH
2026-09-04 · codex · LLM-assisted
Added a PMID-supported causal graph for ethambutol inhibition of Emb-dependent mycobacterial cell-wall arabinan synthesis.
Provenance
Seeded by scripts/seed_from_sources.py from the committed
inventories in data/raw/.
View the record.