AntibioticMech

cloxacillin

CHEBI:49566 ·resolve ·ANTIBACTERIAL ·EXACT SEEDED

A semisynthetic penicillin antibiotic carrying a 3-(2-chlorophenyl)-5-methylisoxazole-4-carboxamido group at position 6. — ChEBI

Classification

penicillin beta-lactamARO:3000008

Strictly broader compounds or drug classes this molecule belongs to.

• CHEBI:17334 CHEBI:17334
• CHEBI:72588 CHEBI:72588
• CHEBI:88187 CHEBI:88187
• ARO:3000008 ARO:3000008

Chemical structure

Computed structure properties

Molecular formula	C19H18ClN3O5S
Charge	0
Average mass	435.889 Da
Monoisotopic mass	435.06557 Da
Source	ChEBI
InChIKey	LQOLIRLGBULYKD-JKIFEVAISA-N

SMILES

[H][C@]12SC(C)(C)[C@H](C(=O)O)N1C(=O)[C@H]2NC(=O)c1c(-c2ccccc2Cl)noc1C

InChI

InChI=1S/C19H18ClN3O5S/c1-8-11(12(22-28-8)9-6-4-5-7-10(9)20)15(24)21-13-16(25)23-14(18(26)27)19(2,3)29-17(13)23/h4-7,13-14,17H,1-3H3,(H,21,24)(H,26,27)/t13-,14+,17-/m1/s1

Also called

• cloxacilina (INN)— chebi
• cloxacilline (INN)— chebi
• cloxacillinum (INN)— chebi
• 2,2-dimethyl-6β-({[5-methyl-3-(2-chlorophenyl)isoxazol-4-yl]carbonyl}amino)penam-3α-carboxylic acid (EXACT_SYNONYM)— chebi
• (2S,5R,6R)-6-({[3-(2-chlorophenyl)-5-methylisoxazol-4-yl]carbonyl}amino)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid (EXACT_SYNONYM)— chebi
• (3-(o-chlorophenyl)-5-methyl-4-isoxazolyl)penicillin (EXACT_SYNONYM)— chebi
• 6-(3-(o-chlorophenyl)-5-methyl-4-isoxazolecarboxamido)penicillanic acid (EXACT_SYNONYM)— chebi
• CLOXACILLIN (EXACT_SYNONYM)— chebi
• Cloxacillin (EXACT_SYNONYM)— chebi
• Chloroxacillin (EXACT_SYNONYM)— aro
• Clossacillina (EXACT_SYNONYM)— aro
• Cloxacilina (EXACT_SYNONYM)— aro
• Cloxacilline (EXACT_SYNONYM)— aro
• Cloxacillinum (EXACT_SYNONYM)— aro
• Cloxapen (EXACT_SYNONYM)— aro
• Methocillin S (EXACT_SYNONYM)— aro
• Orbenin (EXACT_SYNONYM)— aro
• Syntarpen (EXACT_SYNONYM)— aro
• Tegopen (EXACT_SYNONYM)— aro

Cross-references

Equivalent identifiers for this same structure in other resources.

• ARO:0000011
• beilstein:1232834
• cas:61-72-3
• drugbank:DB01147
• drugcentral:720
• hmdb:HMDB0015278
• kegg.compound:C06923
• kegg.drug:D07733
• lincs.smallmolecule:LSM-15183
• patent:US2996501
• pdb-ccd:CXN
• reaxys:1232834
• vsdb:1859
• wikipedia.en:Cloxacillin
• chembl:CHEMBL891
• pubchem.compound:6098

Activity roles

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

• CHEBI:33281 CHEBI:33281
• CHEBI:33282 CHEBI:33282
• CHEBI:36047 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:0000011	cloxacillin	antibioticmech:aro-0542d0dd3d	2026-08-30
CHEBI	CHEBI:49566	cloxacillin	antibioticmech:chebi-a59d504bdb	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:0000011 (cloxacillin); database assertion, not a primary citation.)

Resistance mechanisms

1 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_EFFLUX 1

ANTIBIOTIC_EFFLUX

Determinant	ARO ID	Organism	Gene families	Evidence
MdtEF-TolC	ARO:3000788	not organism-specific	—	ARO:3000788 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000011 (cloxacillin); database assertion, not a primary citation.)

Curation history

1. SEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources

   Seeded from data/raw/ inventories (ARO, CHEBI)

2. RESEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources

   Re-seeded from updated data/raw/ inventories

3. RESEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources

   Re-seeded from updated data/raw/ inventories

4. RESEEDED_FROM_SOURCES 2026-08-31 · seed_from_sources

   Re-seeded from updated data/raw/ inventories

Provenance

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