oxacillin

CHEBI:7809 ·resolve ·ANTIBACTERIAL ·EXACT SEEDED

A penicillin antibiotic carrying a 5-methyl-3-phenylisoxazole-4-carboxamide group at position 6β. — 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

penicillin beta-lactamARO:3000008

Strictly broader compounds or drug classes this molecule belongs to.

CHEBI:17334 CHEBI:17334
ARO:3000008 ARO:3000008

Chemical structure

Computed structure properties
Molecular formula	C19H19N3O5S
Charge	0
Average mass	401.444 Da
Monoisotopic mass	401.10454 Da
Source	ChEBI
InChIKey	UWYHMGVUTGAWSP-JKIFEVAISA-N

SMILES

[H][C@]12SC(C)(C)[C@H](C(=O)O)N1C(=O)[C@H]2NC(=O)c1c(-c2ccccc2)noc1C

InChI

InChI=1S/C19H19N3O5S/c1-9-11(12(21-27-9)10-7-5-4-6-8-10)15(23)20-13-16(24)22-14(18(25)26)19(2,3)28-17(13)22/h4-8,13-14,17H,1-3H3,(H,20,23)(H,25,26)/t13-,14+,17-/m1/s1

Also called

2,2-dimethyl-6β-(5-methyl-3-phenyl-1,2-oxazole-4-carboxamido)penam-3α-carboxylic acid (EXACT_SYNONYM)— chebi
(2S,5R,6R)-3,3-dimethyl-6-{[(5-methyl-3-phenylisoxazol-4-yl)carbonyl]amino}-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid (EXACT_SYNONYM)— chebi
(5-methyl-3-phenyl-4-isoxazolyl)penicillin (EXACT_SYNONYM)— chebi
5-methyl-3-phenyl-4-isoxazolyl-penicillin (EXACT_SYNONYM)— chebi
6β-(5-methyl-3-phenylisoxazol-4-yl)penicillanic acid (EXACT_SYNONYM)— chebi
Oxacillin (EXACT_SYNONYM)— chebi
oxazocillin (EXACT_SYNONYM)— chebi
MPI-penicillin (EXACT_SYNONYM)— aro
Ossacillina (EXACT_SYNONYM)— aro
Oxacilina (EXACT_SYNONYM)— aro
Oxacilline (EXACT_SYNONYM)— aro
Oxacillinum (EXACT_SYNONYM)— aro
Oxazocillin (EXACT_SYNONYM)— aro
Oxazocilline (EXACT_SYNONYM)— aro
Prostaphlin (EXACT_SYNONYM)— aro
Prostaphlyn (EXACT_SYNONYM)— aro

Cross-references

Equivalent identifiers for this same structure in other resources.

ARO:0000056
cas:66-79-5
drugbank:DB00713
drugcentral:2006
hmdb:HMDB0014851
kegg.compound:C07334
kegg.drug:D08307
lincs.smallmolecule:LSM-6005
patent:US2996501
reaxys:1093589
wikipedia.en:Oxacillin
chembl:CHEMBL819
pubchem.compound:6196

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:0000056`	oxacillin	`antibioticmech:aro-42474d1716`	2026-08-30
CHEBI	`CHEBI:7809`	oxacillin	`antibioticmech:chebi-1162e9b95e`	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:0000056 (oxacillin); database assertion, not a primary citation.)

Resistance mechanisms

5 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 3

ANTIBIOTIC_EFFLUX
Determinant	ARO ID	Organism	Gene families	Evidence
Corynebacterium striatum tetA	ARO:3004639	not organism-specific	—	ARO:3004639 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000056 (oxacillin); database assertion, not a primary citation.)
MdtEF-TolC	ARO:3000788	not organism-specific	—	ARO:3000788 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000056 (oxacillin); database assertion, not a primary citation.)
mdeA	ARO:3007011	not organism-specific	—	ARO:3007011 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000056 (oxacillin); database assertion, not a primary citation.)

ANTIBIOTIC_INACTIVATION 2

ANTIBIOTIC_INACTIVATION
Determinant	ARO ID	Organism	Gene families	Evidence
OXA beta-lactamase	ARO:3000017	not organism-specific	—	ARO:3000017 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000056 (oxacillin); database assertion, not a primary citation.)
blaS1	ARO:3005111	not organism-specific	—	ARO:3005111 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:0000056 (oxacillin); 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

Provenance

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