Pirlimycin hydrochloride

Pirlimycin hydrochloride	Last updated: 12/09/2025
(Also known as: PNU-57930E; pirimycin; U-57930E)

GENERAL INFORMATION

Description

A lincosamide antibiotic active against gram-positive bacteria

Examples of veterinary uses

Used in the treatment of subclinical mastitis in lactating cows

Examples of species treated

Cattle

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

Pirlimycin hydrochloride displays optical isomerism due to multiple chiral centres in its structure, which define its three-dimensional configuration and biological activity. As a lincosamide antibiotic, its therapeutic effect hinges on the precise stereochemistry that enables it to bind effectively to the 50S subunit of bacterial ribosomes, thereby inhibiting protein synthesis.

Chemical formula

C₁₇H₃₁ClN₂O₅S

Canonical SMILES

CCC1CCNC(C1)C(=O)NC(C2C(C(C(C(O2)SC)O)O)O)C(C)Cl

Isomeric SMILES

CC[C@@H]1CCN[C@@H](C1)C(=O)N[C@@H]([C@@H]2[C@@H]([C@@H]([C@H]([C@H](O2)SC)O)O)O)[C@H](C)Cl

International Chemical Identifier key (InChIKey)

HBJOXQRURQPDEX-MHXMMLMNSA-N

International Chemical Identifier (InChI)

InChI=1S/C17H31ClN2O5S/c1-4-9-5-6-19-10(7-9)16(24)20-11(8(2)18)15-13(22)12(21)14(23)17(25-15)26-3/h8-15,17,19,21-23H,4-7H2,1-3H3,(H,20,24)/t8-,9+,10-,11+,12-,13+,14+,15+,17+/m0/s1

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Antimicrobial, Antibacterial, Antibiotic, Medicinal drug

Substance groups

Lincosamide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Acts by inhibiting bacterial protein synthesis

Molecular targets

[50S rRNA, Antagonist]

CAS RN

79548-73-5

EC number

CIPAC number

US EPA chemical code

PubChem CID

Therapeutic Class

Antiinfectants for systemic use: Antibacterials for intramammary use

ATCvet Code

QJ51FF90

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed substance (Table 1: Bovine)

Molecular mass

447.42

PIN (Preferred Identification Name)

IUPAC name

methyl(2S-cis)-7-chloro-6,7,8-trideoxy-6[[(4-ethyl-2-piperidinyl) carbonyl]amino]-1-thio-L-threo-a-D-galacto-octopyranoside

CAS name

L-threo-α-D-galacto-octopyranoside, methyl 7-chloro-6,7,8-trideoxy-6(((4-ethyl-2-piperidinyl)carbonyl)amino)-1-thio-, monohydrochloride

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

White crystalline powder

Related substances & organisms

lincomycin

clindamycin

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Circa 1990, introduced

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

Zoetis UK Ltd

Example products using this active

Pirsue Intramammary Solution

Formulation and application details

Supplied as a solution for intramammary infusion

Commercial production

The production of pirlimycin hydrochloride involves a multi-step synthetic process that begins with the condensation of 4-ethylpyridine-2-carboxylic acid with methyl-6-amino-7-chloro-6,7,8-trideoxy-1-thio-L-threo-α-D-galacto-octopyranoside. This reaction is facilitated by isobutyl chloroformate and triethylamine in acetonitrile, forming an amide intermediate. The intermediate is then subjected to hydrogenation using platinum oxide in a mixture of methanol, water, and hydrochloric acid, which reduces the compound and yields pirlimycin. Finally, the product is converted into its hydrochloride salt form to enhance stability and solubility for pharmaceutical use.

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)

70000

at pH 4.5

High

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

Melting point (°C)

211

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

Log P

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

Max @ >220nm

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

6.7

Non-persistent

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)

Slightly mobile

K_oc (mL g⁻¹)

2119

Notes and range

Literature data: K_oc range 278-566 mL g⁻¹

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)

13.2

Low potential

CT₅₀ (days)

Known soil and groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

pirlimycin sulfoxide

Rat (Urine, Liver)

pirlimycin sulfone

Rat (Liver)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2524

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)

> 1000

Low

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)

> 970

Oncorhynchus mykiss

Low

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

190

Oncorhynchus mykiss

Low

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)

> 100

Daphnia magna

Low

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) (NOEC)

0.014

Raphidocelis subcapitata

Moderate

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)

2524

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

Some metabolism occurs, with around 60% eliminated in the faeces and around 5% in the urine.

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

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

May cause gastric irritation
Possible stomach and kidney toxicant

Handling issues

Property

Value and interpretation

General

No 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

pirlimycin hydrochloride

French

pirlimycine

German

Danish

Italian

Spanish

pirlimycina

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	12/09/2025
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