Cefquinome

Cefquinome	Last updated: 15/09/2025
(Not known by any other names)

GENERAL INFORMATION

Description

Used for the treatment of bacterial infections in animals caused by some gram-positive and gram-negative micro-organisms. It is usually formulated using the sulphate variant.

Examples of veterinary uses

Used, generally as the sulphate, for the treatment of mastitis, respiratory disease, septicaemia, digital dermatitis. Also used for respiratory tract infections caused by Pasteurella multocida and Mannheimia haemolytica.

Examples of species treated

Cattle; Pigs

Approval status

VMR 2013/2033 approval status (GB/UK)

Approved - usually available as a prescription only medicine to be authorised by a veterinarian (POM-V)

EU Regulatory approval status

Approved

Chemical structure

Isomerism

Cefquinome exhibits geometrical (cis-trans or E/Z) isomerism and stereoisomerism, owing to its complex cephalosporin structure. One key site of geometrical isomerism is the methoxyimino group in its acyl side chain, which can exist in either the E- or Z-configuration. The biologically active form of cefquinome is the Z-isomer, which ensures optimal binding to bacterial penicillin-binding proteins and contributes to its potent antibacterial activity. Additionally, cefquinome contains chiral centres, notably at positions 6 and 7 of the beta-lactam ring system, giving rise to stereoisomers. The therapeutic compound is synthesised and used in its specific stereoisomeric form to maintain efficacy and minimize toxicity.

Chemical formula

C₂₃H₂₄N₆O₅S₂

Canonical SMILES

CON=C(C1=CSC(=N1)N)C(=O)NC2C3N(C2=O)C(=C(CS3)C[N+]4=CC=CC5=C4CCCC5)C(=O)[O-]

Isomeric SMILES

CO/N=C(\C1=CSC(=N1)N)/C(=O)N[C@H]2[C@@H]3N(C2=O)C(=C(CS3)C[N+]4=CC=CC5=C4CCCC5)C(=O)[O-]

International Chemical Identifier key (InChIKey)

YWKJNRNSJKEFMK-KJXIDEHUSA-N

International Chemical Identifier (InChI)

InChI=1S/C23H24N6O5S2/c1-34-27-16(14-11-36-23(24)25-14)19(30)26-17-20(31)29-18(22(32)33)13(10-35-21(17)29)9-28-8-4-6-12-5-2-3-7-15(12)28/h4,6,8,11,17,21H,2-3,5,7,9-10H2,1H3,(H3-,24,25,26,30,32,33)/b27-16+/t17-,21-/m1/s1

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Antibacterial, Antibiotic, Medicinal drug

Substance groups

Cephalosporin

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Short lived, broad-spectrum drug that acts by inhibition of the cell wall synthesis

Molecular targets

[Beta-lactamase, Agonist]

CAS RN

84957-30-2

EC number

CIPAC number

US EPA chemical code

PubChem CID

5464355

Therapeutic Class

Antiinfectants for Systemic use: Antibacterials for systemic use; Antibacterials for intramammary use

ATCvet Code

QJ01DE90; QJ51DA92

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed substance (Table 1: Bovine, Porcine, Equidae)

Molecular mass

528.60

PIN (Preferred Identification Name)

IUPAC name

(6R,7R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-methoxyiminoacetyl]amino]-8-oxo-3-(5,6,7,8-tetrahydroquinolin-1-ium-1-ylmethyl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

CAS name

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Pale yellow crystals

Related substances & organisms

cefquinome sulphate

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Late 1980s, first synthesised; Early 1990s, first veterinary USE

Example manufacturers & suppliers of products using this active now or historically

Santa Cruz Biotechnology
BOC Sciences
Shandong Perfect Biotechnology China
MSD Animal Health

Example products using this active

Cobactan

Formulation and application details

Available in a variety of formulations including solutions & suspensions for injection and ointments for topical application

Commercial production

Cefquinome is synthesized through a multi-step chemical process starting from 7-aminocephalosporanic acid (7-ACA), the core structure of cephalosporins. In the first step, 7-ACA reacts with tetrahydroquinoline under the influence of trimethyliodosilane, forming an intermediate known as 7-ACQ. This intermediate is then oxidised using hydrogen peroxide to enhance its reactivity. Next, 7-ACQ undergoes acylation with an AE-active ester, introducing the methoxyimino side chain that confers resistance to beta-lactamases. The final product, cefquinome, is obtained after purification and conversion into its sulphate salt for pharmaceutical use. This synthetic route is favoured for its mild reaction conditions, stable yields, and suitability for veterinary formulations.

Impact on climate of production and use

Published GHG data is not available for most pharmaceuticals. However, according to industry, global averages suggest producing 1 kg of a typical active pharmaceutical ingredient can range from 10 to 100 kg CO₂e for small molecule drugs and potentially up to 1000 kg CO₂e for complex biologicals such as vaccines, depending on the drug type, its formulation, complexity of synthesis, solvent recovery, and energy sources used.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

Octanol-water partition coefficient at pH 7, 20 °C

3.24 X 10^-02

Calculated

Log P

-1.49

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Surface tension (mN m⁻¹)

Refractive Index

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 3000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic

Notes

Bumblebees (Bombus spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Other bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Aquatic Plants (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

High (class III)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 3000

Rat

Low

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Excreted predominately in the faeces, when intermammarily administered substance is excreted in breast milk

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

No further information available

Handling issues

Property

Value and interpretation

General

No further information available

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

cefquinome

French

German

Danish

Italian

Spanish

cefquinoma

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	15/09/2025
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242