Chemical substance record

Nalidixic acid

389-08-2C₁₂H₁₂N₂O₃232.239 g/mol

Organic/Inorganic Small MoleculeChEBI source record

A monocarboxylic acid comprising 1,8-naphthyridin-4-one substituted by carboxylic acid, ethyl and methyl groups at positions 3, 1, and 7, respectively. An orally administered antibacterial, it is used in the treatment of lower urinary-tract infections due to Gram-negative bacteria, including the majority of E. coli, Enterobacter, Klebsiella, and Proteus species. — ChEBI

Safety references

Safety documents & references

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Identity & molecular properties

Source-linked values

CAS number	389-08-2	ChEBI ↗
Molecular formula	C₁₂H₁₂N₂O₃	ChEBI ↗
Molar mass	232.239 g/mol	ChEBI ↗
Monoisotopic mass	232.08479 Da	ChEBI ↗
Formal charge	0	ChEBI ↗
ChEBI identifier	CHEBI:100147	ChEBI ↗

Cross-source molecular data

PubChem

Molar mass	232.23 g/mol	PubChem ↗
Exact mass	232.08479225 Da	PubChem ↗
Computed XLogP	1.4	PubChem ↗
Topological polar surface area (Å²)	70.5	PubChem ↗
H-bond donors	1	PubChem ↗
H-bond acceptors	5	PubChem ↗
Rotatable bonds	2	PubChem ↗

PubChem computed values are shown separately from the ChEBI record. An exact InChIKey match was used to connect the records. Molecular descriptors do not describe a supplied product’s purity, particle size or performance.

Names & structural identifiers

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Source preferred name

nalidixic acid

IUPAC name

1-ethyl-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid

InChIKey

MHWLWQUZZRMNGJ-UHFFFAOYSA-N

SMILES

CCn1cc(C(=O)O)c(=O)c2ccc(C)nc21

InChI

InChI=1S/C12H12N2O3/c1-3-14-6-9(12(16)17)10(15)8-5-4-7(2)13-11(8)14/h4-6H,3H2,1-2H3,(H,16,17)

Names & synonyms

1-ethyl-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acidacide nalidixiqueacido nalidixicoacidum nalidixicum

Names are supplied by ChEBI. Trade names and related synonyms may describe a broader product context.

Classification & relationships

ChEBI ontology

monocarboxylic acidChEBI parent class · 25384 ↗1,8-naphthyridine derivativeChEBI parent class · 73537 ↗quinolone antibioticChEBI parent class · 86324 ↗

carboxylic acid organic heterocyclic compound organic molecular entity

Roles recorded in ChEBI

antimicrobial agentantibacterial agentantibacterial drugDNA synthesis inhibitor

Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.

Mass ↔ amount of substance

Calculated from sourced mass

Amount

Input unit

Equivalent amount

0.00430591 mol

Uses 232.239 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.

Elemental composition

Theoretical mass fractions

C

Carbon · 12 atoms

62.06%

O

Oxygen · 3 atoms

20.67%

N

Nitrogen · 2 atoms

12.06%

H

Hydrogen · 12 atoms

5.21%

Calculated theoretical mass fractions from the reported formula and PubChem periodic-table atomic masses. These are not assay or purity results.

Research & patent references

Selected source associations

Nalidixic acid is still the drug of choice for shigellosis in Pakistan. ↗JPMA. The Journal of the Pakistan Medical Association · 2001 Feb · PMID 11321869

Antibiotic resistance and sero-groups of shigella among paediatric out-patients in southwest Ethiopia. ↗East African medical journal · 2001 Jun · PMID 12002106

BE612258 · Patent reference ↗Patent cross-reference supplied by ChEBI. Association alone does not establish claim scope.

US3590036 · Patent reference ↗Patent cross-reference supplied by ChEBI. Association alone does not establish claim scope.

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Sources & record history

Checked 27 Sep 2026

Identity, formula, mass, synonyms & ontologyEMBL-EBI ChEBI · CHEBI:100147

Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0

Additional molecular descriptorsNCBI PubChem · CID 4421 · retrieved 2026-09-27

PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.

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