AntibioticMech

niclosamide

CHEBI:7553 ·resolve ·ANTIVIRAL ·EXACT SEEDED

A secondary carboxamide resulting from the formal condensation of the carboxy group of 5-chlorosalicylic acid with the amino group of 2-chloro-4-nitroaniline. It is an oral anthelmintic drug approved for use against tapeworm infections. — 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

Strictly broader compounds or drug classes this molecule belongs to.

Chemical structure

Computed structure properties
Charge
SourceChEBI
InChIKeyRJMUSRYZPJIFPJ-UHFFFAOYSA-N

SMILES

O=C(Nc1ccc([N+](=O)[O-])cc1Cl)c1cc(Cl)ccc1O

InChI

InChI=1S/C13H8Cl2N2O4/c14-7-1-4-12(18)9(5-7)13(19)16-11-3-2-8(17(20)21)6-10(11)15/h1-6,18H,(H,16,19)

Also called

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.

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
SourceNative IDLabelMinted CURIEVersion
CHEBI CHEBI:7553 niclosamide antibioticmech:chebi-7499d35beb 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.

Replicase polyprotein 1ab VIRAL_PROTEIN MEASURED_TARGET_ASSOCIATION

BindingDB quantitative measurement in the named target organism; source assay descriptions and identifiers are retained per measurement. Evidence status: PRIMARY_EVIDENCE. Source: BINDINGDB 2026-09 (retrieved 2026-08-31).

Severe acute respiratory syndrome coronavirus 2 NCBITaxon:2697049

Quantitative measurements
TypeReported valueAssayBindingDB IDsReference
IC50 280 nM DRC analysis by immunofluorescence
Ten-point DRCs were generated for each drug. Vero cells were seeded at 1.2 × 104 cells per well in DMEM, supplemented with 2% FBS and 1× antibiotic-antimycotic solution (Gibco), in black, 384-well μClear plates (Greiner Bio-One) 24 h prior to the experiment. Ten-point DRCs were generated, with compound concentrations ranging from 0.1 to 50 μM. For the viral infections, plates were transferred into the BSL3 containment facility and SARS-CoV-2 was added at a multiplicity of infection (MOI) of 0.0125. The cells were fixed at 24 hours postinfection (hpi) with 4% PFA and analyzed by immunofluorescence. The acquired images were analyzed using in-house software to quantify cell numbers and infection ratios, and antiviral activity was normalized to positive (mock) and negative (0.5% DMSO) controls in each assay plate. DRCs were fitted by sigmoidal dose-response models, with the following equation: Y = bottom + (top − bottom)/[1 + (IC50/X)Hillslope], using XLfit 4 software or Prism7. IC50 values were calculated from the normalized activity data set-fitted curves. All IC50 and 50% cytotoxic concentration (CC50) values were measured in duplicate, and the quality of each assay was controlled by Z -factor and the coefficient of variation in percent (%CV).		 RSID 874398
assay 8945_1
monomer 11242		 PMID:32366720
Organism-specific examples
ProteinGeneOrganismEntry
Replicase polyprotein 1ab UniProtKB:P0DTD1 — Severe acute respiratory syndrome coronavirus 2 REVIEWED

Replicase polyprotein 1ab VIRAL_PROTEIN MEASURED_TARGET_ASSOCIATION

BindingDB quantitative measurement in the named target organism; source assay descriptions and identifiers are retained per measurement. Evidence status: PRIMARY_EVIDENCE. Source: BINDINGDB 2026-09 (retrieved 2026-08-31).

Severe acute respiratory syndrome coronavirus NCBITaxon:2901879

Quantitative measurements
TypeReported valueAssayBindingDB IDsReference
IC50 >50000 nM SARS-CoV 3CL Protease Inhibition Assay
The effects of compound on enzyme activity were measured by using a fluorogenic peptide cleavage assay. Enhanced fluorescence caused by cleavage of the substrate peptide was monitored at 538 nm with excitation at 355 nm. The Ki measurements were performed at two fixed inhibitor concentrations and various substrate concentrations.		 RSID 19487
assay 1397_1
monomer 11242		 PMID:15974598
IC50 >50000 nM No assay is provided
This is a review article.		 RSID 868559
assay 8917_1
monomer 11242		 PMID:26878082
IC50 >50000 nM No assay is provided
This is a review article.		 RSID 868827
assay 8918_1
monomer 11242		 PMID:32852058
IC50 40000 nM Various Assay
This is a review article. Please point to the original journal.		 RSID 1074260
assay 10079_1
monomer 513089		 PMID:34798775
Organism-specific examples
ProteinGeneOrganismEntry
Replicase polyprotein 1ab UniProtKB:P0C6X7 — Severe acute respiratory syndrome coronavirus REVIEWED

Curation history

  1. SEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources

    Seeded from data/raw/ inventories (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.