cefoxitin

CHEBI:209807 ·resolve ·ANTIBACTERIAL ·EXACT SEEDED

A semisynthetic cephamycin antibiotic which, in addition to the methoxy group at the 7α position, has 2-thienylacetamido and carbamoyloxymethyl side-groups. It is resistant to β-lactamase. — 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

cephalosporinARO:0000032

Strictly broader compounds or drug classes this molecule belongs to.

cephalosporin CHEBI:23066
cephamycin CHEBI:55429
Label unavailable CHEBI:72588
β-lactam antibiotic allergen CHEBI:88225
cephalosporin ARO:0000032

Chemical structure

Computed structure properties
Molecular formula	C16H17N3O7S2
Charge	0
Average mass	427.46 Da
Monoisotopic mass	427.05079 Da
Source	ChEBI
InChIKey	WZOZEZRFJCJXNZ-ZBFHGGJFSA-N

SMILES

[H][C@]12SCC(COC(N)=O)=C(C(=O)O)N1C(=O)[C@]2(NC(=O)Cc1cccs1)OC

InChI

InChI=1S/C16H17N3O7S2/c1-25-16(18-10(20)5-9-3-2-4-27-9)13(23)19-11(12(21)22)8(6-26-15(17)24)7-28-14(16)19/h2-4,14H,5-7H2,1H3,(H2,17,24)(H,18,20)(H,21,22)/t14-,16+/m1/s1

Also called

cefoxitina (INN)— chebi
cefoxitine (INN)— chebi
cefoxitinum (INN)— chebi
ceftoxitin (INN)— chebi
(6R,7S)-4-[(carbamoyloxy)methyl]-7-methoxy-8-oxo-7-[(thiophen-2-enyl)acetamido]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (EXACT_SYNONYM)— chebi
3-[(carbamoyloxy)methyl]-7α-methoxy-7β-[(thiophen-2-yl)acetamido]-3,4-didehydrocepham-4-carboxylic acid (EXACT_SYNONYM)— chebi
(6R,7S)-3-[(carbamoyloxy)methyl]-7-methoxy-8-oxo-7-[(2-thienylacetyl)amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (EXACT_SYNONYM)— chebi
CFX (EXACT_SYNONYM)— chebi
Cefoxitin (EXACT_SYNONYM)— chebi
Cephoxitin (EXACT_SYNONYM)— chebi
Rephoxitin (EXACT_SYNONYM)— chebi
FOX (EXACT_SYNONYM)— aro
Mefoxitin (EXACT_SYNONYM)— aro
mefoxin (EXACT_SYNONYM)— aro

Cross-references

Identifiers for this same structure in other resources. An accession that lands on two different structures in this corpus is withheld from both rather than shown here, since it names at most one of them.

Drug registries

Identifiers that name a drug rather than a structure. One of these can cover a parent compound, its salts and its stereoisomers, which this corpus keeps as separate records, so it is not an equivalence of structure.

Patents and articles

Documents about this compound. A patent covers a class and an article covers a topic; neither identifies a structure.

Activity roles

Every antimicrobial role a source asserts for this compound — the unreduced evidence behind its antimicrobial_class.

antimicrobial agent CHEBI:33281
antibacterial drug CHEBI:36047

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:0000008`	cefoxitin	`antibioticmech:aro-f8bb991f1c`	2026-08-30
CHEBI	`CHEBI:209807`	cefoxitin	`antibioticmech:chebi-b9a20bd574`	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.

beta-lactam sensitive penicillin-binding protein PROTEIN DIRECT_BINDING_TARGET

ARO:3000749

CARD/ARO database assertion; target organism, strain, and assay are not specified. Penicillin-binding proteins are asserted as inhibited transpeptidases. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).

ARO:3000749 (CARD/ARO asserts targeted_by_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)

Activity spectrum

Measured or curated activity against specific taxa. A number without a method is not an observation — every row here carries an assay.

20 observations · Browse all observations · Complete record (JSON.gz)

Activity observations
Organism	Activity	MIC	Disk diffusion	Assay	Strain	Sample/genome	Evidence
Staphylococcus aureus NCBITaxon:1280	—	16.0 mg/L	—	In-house reference broth microdilution cefoxitin MIC; modal MIC from at least three tests; interpreted using CLSI M100 28th ed.	AR-0978	—	Evidence Page data (JSON.gz)
Staphylococcus aureus NCBITaxon:1280	—	8.0 mg/L	—	In-house reference broth microdilution cefoxitin MIC; modal MIC from at least three tests; interpreted using CLSI M100 28th ed.	AR-0979	—	Evidence Page data (JSON.gz)
Staphylococcus aureus NCBITaxon:1280	—	16.0 mg/L	—	In-house reference broth microdilution cefoxitin MIC; modal MIC from at least three tests; interpreted using CLSI M100 28th ed.	AR-0997	—	Evidence Page data (JSON.gz)
Klebsiella aerogenes NCBITaxon:548	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	0074	BioSample SAMN04014915	Evidence Page data (JSON.gz)
Escherichia coli NCBITaxon:562	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	0346	BioSample SAMN11953774	Evidence Page data (JSON.gz)
Escherichia coli NCBITaxon:562	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1305	BioSample SAMN46941623	Evidence Page data (JSON.gz)
Klebsiella pneumoniae NCBITaxon:573	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1149	BioSample SAMN34111336	Evidence Page data (JSON.gz)
Enterobacter cloacae complex NCBITaxon:354276	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1150	BioSample SAMN34111337	Evidence Page data (JSON.gz)
Enterobacter cloacae complex NCBITaxon:354276	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1151	BioSample SAMN34111338	Evidence Page data (JSON.gz)
Enterobacter cloacae complex NCBITaxon:354276	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1152	BioSample SAMN34111339	Evidence Page data (JSON.gz)
Klebsiella pneumoniae NCBITaxon:573	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1153	BioSample SAMN34111340	Evidence Page data (JSON.gz)
Klebsiella pneumoniae NCBITaxon:573	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1158	BioSample SAMN34111344	Evidence Page data (JSON.gz)
Enterobacter cloacae complex NCBITaxon:354276	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1160	BioSample SAMN34111346	Evidence Page data (JSON.gz)
Escherichia coli NCBITaxon:562	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1162	BioSample SAMN34111348	Evidence Page data (JSON.gz)
Klebsiella pneumoniae NCBITaxon:573	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1163	BioSample SAMN34111349	Evidence Page data (JSON.gz)
Staphylococcus aureus NCBITaxon:1280	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	0701	BioSample SAMN11953851	Evidence Page data (JSON.gz)
Staphylococcus aureus NCBITaxon:1280	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	0702	BioSample SAMN11953852	Evidence Page data (JSON.gz)
Citrobacter freundii NCBITaxon:546	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	0637	BioSample SAMN10055345	Evidence Page data (JSON.gz)
Enterobacter cloacae complex NCBITaxon:354276	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1329	BioSample SAMN50502208	Evidence Page data (JSON.gz)
Enterobacter cloacae complex NCBITaxon:354276	—	>16.0 mg/L	—	Broth microdilution cefoxitin MIC; modal MIC reported; interpreted using CLSI 2025 M100 S35.	1331	BioSample SAMN50502209	Evidence Page data (JSON.gz)

Resistance mechanisms

23 source-backed resistance determinants or associations, with ARO grounding where reported. Grouped by reported mechanism type.

ANTIBIOTIC_INACTIVATION 18

ANTIBIOTIC_INACTIVATION
Determinant	ARO ID	Organism	Gene families	Evidence
AMZ-1	ARO:3007694	not organism-specific	—	ARO:3007694 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
CAM-1	ARO:3004559	not organism-specific	—	ARO:3004559 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
CDA-1	ARO:3007650	not organism-specific	—	ARO:3007650 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
CMY-2	ARO:3002013	not organism-specific	—	ARO:3002013 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
CMY-42	ARO:3002053	not organism-specific	—	ARO:3002053 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
CTX-M-3	ARO:3001866	not organism-specific	—	ARO:3001866 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
CfxA	ARO:3003001	not organism-specific	—	ARO:3003001 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
LAQ-1	ARO:3007438	not organism-specific	—	ARO:3007438 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
NDM-5	ARO:3000467	not organism-specific	—	ARO:3000467 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
NmcA	ARO:3003589	not organism-specific	—	ARO:3003589 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
PDC-3	ARO:3002500	not organism-specific	—	ARO:3002500 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
PDC-5	ARO:3002502	not organism-specific	—	ARO:3002502 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
PJM-1	ARO:3007374	not organism-specific	—	ARO:3007374 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
PSZ-1	ARO:3007648	not organism-specific	—	ARO:3007648 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
SSA	ARO:3007442	not organism-specific	—	ARO:3007442 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
YRC-1	ARO:3005035	not organism-specific	—	ARO:3005035 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
blaC	ARO:3007182	not organism-specific	—	ARO:3007182 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
blaS1	ARO:3005111	not organism-specific	—	ARO:3005111 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)

REDUCED_PERMEABILITY 4

REDUCED_PERMEABILITY
Determinant	ARO ID	Organism	Gene families	Evidence
Burkholderia pseudomallei Omp38	ARO:3004123	not organism-specific	—	ARO:3004123 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
Klebsiella pneumoniae OmpK35	ARO:3003966	not organism-specific	—	ARO:3003966 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
Klebsiella pneumoniae OmpK37	ARO:3004122	not organism-specific	—	ARO:3004122 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)
Serratia marcescens Omp1	ARO:3004128	not organism-specific	—	ARO:3004128 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)

ANTIBIOTIC_TARGET_ALTERATION 1

ANTIBIOTIC_TARGET_ALTERATION
Determinant	ARO ID	Organism	Gene families	Evidence
Staphylococcus aureus PBP4 mutant conferring resistance to nafcillin and cefoxitin	ARO:3009660	not organism-specific	—	ARO:3009660 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000008 (cefoxitin); database assertion, not a primary citation.)

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
RESEEDED_FROM_SOURCES 2026-09-10 · seed_from_sources
Re-seeded from updated data/raw/ inventories
CURATED_RESISTANT_TAXA 2026-09-12 · codex · LLM-assisted
Added three DOI-backed cefoxitin-resistant Staphylococcus aureus isolate MIC observations from Gargis et al. 2020.
CURATED_RESISTANT_TAXA 2026-09-12 · codex · LLM-assisted
Added one stable-URL CDC/FDA AR Isolate Bank cefoxitin-resistant Klebsiella aerogenes isolate MIC observation.
CURATED_RESISTANT_TAXA 2026-09-12 · codex · LLM-assisted
Fixes #286. Corrected the CDC/FDA AR Isolate Bank 0074 breakpoint context from CLSI 2024 M100 S34 to CLSI 2025 M100 S35.
CURATED_RESISTANT_TAXA 2026-09-12 · codex · LLM-assisted
Added one stable-URL CDC/FDA AR Isolate Bank cefoxitin-resistant Escherichia coli MIC observation from isolate 0346.
CURATED_RESISTANT_TAXA 2026-09-12 · codex · LLM-assisted
Added one stable-URL CDC/FDA AR Isolate Bank cefoxitin-resistant Escherichia coli isolate MIC observation for AR-1305.
CURATED_RESISTANT_TAXA 2026-09-12 · codex · LLM-assisted
Added 9 stable-URL CDC/FDA AR Isolate Bank cefoxitin-resistant Multi-Mechanism panel MIC observations for AR-1149, AR-1150, AR-1151, AR-1152, AR-1153, AR-1158, AR-1160, AR-1162, and AR-1163.
CURATED_RESISTANT_TAXA 2026-09-13 · codex · LLM-assisted
Added two stable-URL CDC/FDA AR Isolate Bank Panel 1125 cefoxitin-resistant Staphylococcus aureus activity observations for AR-0701 and AR-0702.
CURATED_RESISTANT_TAXA 2026-09-14 · codex · LLM-assisted
Added one stable-URL CDC/FDA AR Isolate Bank Panel 10 cefoxitin-resistant Citrobacter freundii MIC observation for AR-0637.
CURATED_RESISTANT_TAXA 2026-09-17 · codex · LLM-assisted
Added one stable-URL CDC/FDA AR Isolate Bank Panel 10 cefoxitin-resistant Enterobacter cloacae complex MIC observation for AR-1329.
CURATED_RESISTANT_TAXA 2026-09-17 · codex · LLM-assisted
Added one stable-URL CDC/FDA AR Isolate Bank Panel 10 cefoxitin-resistant Enterobacter cloacae complex MIC observation for AR-1331.
STRUCTURED_ACTIVITY_BIOSAMPLE_ACCESSIONS 2026-09-26 · codex · LLM-assisted
Structured BioSample accessions on 17 activity_spectrum observation(s) where evidence notes already named exactly one accession.

Provenance

Seeded by scripts/seed_from_sources.py from the committed inventories in data/raw/. View the record (YAML).

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