ofloxacin

antibioticmech:aro-2eea3233f3 ·ANTIBACTERIAL ·MINTED SEEDED

Ofloxacin is a 6-fluoro, 7-piperazinyl quinolone with a methyl-substituted oxazine ring. It has a broad spectrum of activity including many enterobacteria and mycoplasma but most anaerobes are resistant. — PMID:18159374

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

fluoroquinolone antibioticARO:0000001

Strictly broader compounds or drug classes this molecule belongs to.

ARO:0000001 ARO:0000001

Chemical structure

Computed structure properties
Molecular formula	C18H20FN3O4
Charge	0
Average mass	361.4 Da
Monoisotopic mass	361.14378429 Da
Source	PubChem · retrieved 2026-08-29
InChIKey	GSDSWSVVBLHKDQ-UHFFFAOYSA-N

SMILES

CC1COC2=C3N1C=C(C(=O)C3=CC(=C2N4CCN(CC4)C)F)C(=O)O

InChI

InChI=1S/C18H20FN3O4/c1-10-9-26-17-14-11(16(23)12(18(24)25)8-22(10)14)7-13(19)15(17)21-5-3-20(2)4-6-21/h7-8,10H,3-6,9H2,1-2H3,(H,24,25)

Also called

Tarivid (EXACT_SYNONYM)— aro
floxin (EXACT_SYNONYM)— aro

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.

CHEBI:33281 CHEBI:33281
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:3000663`	ofloxacin	`antibioticmech:aro-2eea3233f3`	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.

fluoroquinolone sensitive gyrA PROTEIN DIRECT_BINDING_TARGET

ARO:3000733

CARD/ARO database assertion; target organism, strain, and assay are not specified. ARO explicitly describes ligand binding to gyrase subunit A. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).

ARO:3000733 (CARD/ARO asserts targeted_by_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)

Fluoroquinolone sensitive parC PROTEIN DIRECT_BINDING_TARGET

ARO:3000735

CARD/ARO database assertion; target organism, strain, and assay are not specified. ParC is asserted as the fluoroquinolone-sensitive subunit. Evidence status: PRIMARY_EVIDENCE_NEEDED. Source: CARD_ARO 2026-08-30 (retrieved 2026-08-30).

ARO:3000735 (CARD/ARO asserts targeted_by_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)

Mechanism summary

Mode of action: NUCLEIC_ACID_SYNTHESIS_INHIBITION microbial target — Assigned from ChEBI role CHEBI:50750 (EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor), CHEBI:53559 (topoisomerase IV inhibitor), CHEBI:59517 (DNA synthesis inhibitor). ChEBI asserts the role on the compound. The role names a target specific to the microbe or virus — see mode_of_action_target_scope. Not a curator's mechanistic review.
Clinical status: APPROVED

Resistance mechanisms

35 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 27

ANTIBIOTIC_TARGET_ALTERATION
Determinant	ARO ID	Organism	Gene families	Evidence
Acinetobacter baumannii gyrA conferring resistance to fluoroquinolones	ARO:3003817	not organism-specific	—	ARO:3003817 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Acinetobacter baumannii parC conferring resistance to fluoroquinolones	ARO:3003818	not organism-specific	—	ARO:3003818 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Bartonella bacilliformis gyrA conferring resistance to fluoroquinolones	ARO:3003297	not organism-specific	—	ARO:3003297 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Clostridioides difficile gyrA conferring resistance to fluoroquinolones	ARO:3003995	not organism-specific	—	ARO:3003995 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Escherichia coli gyrA conferring resistance to fluoroquinolones	ARO:3003294	not organism-specific	—	ARO:3003294 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Escherichia coli parC conferring resistance to fluoroquinolones	ARO:3003308	not organism-specific	—	ARO:3003308 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Escherichia coli parE conferring resistance to fluoroquinolones	ARO:3003316	not organism-specific	—	ARO:3003316 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Morganella morganii gyrB conferring resistance to fluoroquinolones	ARO:3003306	not organism-specific	—	ARO:3003306 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium leprae gyrA conferring resistance to fluoroquinolones	ARO:3003298	not organism-specific	—	ARO:3003298 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium leprae gyrB conferring resistance to fluoroquinolones	ARO:3003304	not organism-specific	—	ARO:3003304 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium tuberculosis eccB5 conferring resistance to fluoroquinolones	ARO:3004918	not organism-specific	—	ARO:3004918 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium tuberculosis eccC5 conferring resistance to fluoroquinolones	ARO:3004919	not organism-specific	—	ARO:3004919 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium tuberculosis gyrA conferring resistance to fluoroquinolones	ARO:3003295	not organism-specific	—	ARO:3003295 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium tuberculosis gyrA mutations conferring resistance to ofloxacin	ARO:3007807	not organism-specific	—	ARO:3007807 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium tuberculosis gyrB mutations conferring resistance to ofloxacin	ARO:3007808	not organism-specific	—	ARO:3007808 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycobacterium tuberculosis gyrB with mutation conferring resistance to fluoroquinolones	ARO:3003459	not organism-specific	—	ARO:3003459 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Mycoplasma hominis parC conferring resistance to fluoroquinolones	ARO:3003310	not organism-specific	—	ARO:3003310 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Pseudomonas aeruginosa gyrA conferring resistance to fluoroquinolones	ARO:3003684	not organism-specific	—	ARO:3003684 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Pseudomonas aeruginosa parC conferring resistance to fluoroquinolones	ARO:3003702	not organism-specific	—	ARO:3003702 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Salmonella serovars gyrB conferring resistance to fluoroquinolones	ARO:3003307	not organism-specific	—	ARO:3003307 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Salmonella serovars parE conferring resistance to fluoroquinolones	ARO:3003317	not organism-specific	—	ARO:3003317 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Staphylococcus aureus gyrA conferring resistance to fluoroquinolones	ARO:3003296	not organism-specific	—	ARO:3003296 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Staphylococcus aureus parC conferring resistance to fluoroquinolones	ARO:3003312	not organism-specific	—	ARO:3003312 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Staphylococcus aureus parE conferring resistance to fluoroquinolones	ARO:3003315	not organism-specific	—	ARO:3003315 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Streptococcus pneumoniae parC conferring resistance to fluoroquinolones	ARO:3003311	not organism-specific	—	ARO:3003311 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Ureaplasma urealyticum gyrB conferring resistance to fluoroquinolones	ARO:3003305	not organism-specific	—	ARO:3003305 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Ureaplasma urealyticum parC conferring resistance to fluoroquinolones	ARO:3003309	not organism-specific	—	ARO:3003309 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)

ANTIBIOTIC_EFFLUX 8

ANTIBIOTIC_EFFLUX
Determinant	ARO ID	Organism	Gene families	Evidence
MexCD-OprJ	ARO:3000797	not organism-specific	—	ARO:3000797 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
MexXY-OprA	ARO:3003038	not organism-specific	—	ARO:3003038 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
MexXY-OprM	ARO:3003032	not organism-specific	—	ARO:3003032 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
QepA3	ARO:3004378	not organism-specific	—	ARO:3004378 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Rv1877	ARO:3007662	not organism-specific	—	ARO:3007662 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
Staphylococcus aureus norA	ARO:3004667	not organism-specific	—	ARO:3004667 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
abeM	ARO:3000753	not organism-specific	—	ARO:3000753 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); database assertion, not a primary citation.)
putative nickel/cobalt transporter	ARO:3007659	not organism-specific	—	ARO:3007659 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3000663 (ofloxacin); 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.

Ofloxacin inhibits bacterial DNA gyrase supercoiling MECHANISTIC

Ofloxacin inhibits the DNA gyrase-catalyzed supercoiling reaction, disrupting bacterial chromosome topology control.

Nodes — ofloxacin_dna_gyrase_supercoiling_inhibition
Node	Label	Type	Grounding
`ofloxacin`	ofloxacin	COMPOUND	`antibioticmech:aro-2eea3233f3`
`dna_gyrase`	bacterial DNA gyrase	GENE_OR_PROTEIN	`ARO:3000733`
`dna_supercoiling`	ATP-dependent DNA supercoiling	BIOLOGICAL_PROCESS	REVIEWED_LABEL_ONLY
`dna_topology_control`	bacterial DNA topology control	BIOLOGICAL_PROCESS	REVIEWED_LABEL_ONLY

Edges — ofloxacin_dna_gyrase_supercoiling_inhibition
Subject	Predicate	Object	Evidence
`ofloxacin`	inhibits	`dna_supercoiling`	DOI:10.1128/AAC.31.2.325 (Imamura and colleagues compared the ability of optically active ofloxacin forms to inhibit Escherichia coli DNA gyrase.) PMID:3010848 (Zweerink and Edison included ofloxacin in comparative Micrococcus luteus DNA gyrase supercoiling assays.)
`dna_gyrase`	enables	`dna_supercoiling`	PMID:3010848 (The purified-enzyme assay measured quinolone inhibition of supercoiling by Micrococcus luteus DNA gyrase.)
`dna_supercoiling`	supports	`dna_topology_control`	PMID:3010848 (The in vitro comparison links quinolone-sensitive DNA gyrase activity to DNA supercoiling.)

Curation history

SEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources
Seeded from data/raw/ inventories (ARO)
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 2026-08-31 · 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 primary-literature support for a causal graph of ofloxacin inhibition of bacterial DNA gyrase supercoiling.

Provenance

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