Tiamulin hydrogen fumarate

Tiamulin hydrogen fumarate	Last updated: 12/09/2025
(Also known as: tiamulin fumarate; dynamutilin )

GENERAL INFORMATION

Description

A semi-synthetic derivative of pleuromutilin active against gram-positive bacteria, mycoplasmas, and anaerobes

Examples of veterinary uses

Used in the treatment of dysentery, enzootic pneumonia and mycoplasmal infections

Examples of species treated

Pigs; Chicken; Turkeys

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

Tiamulin hydrogen fumarate exhibits stereoisomerism due to its complex, chiral structure derived from the pleuromutilin class of antibiotics. The tiamulin molecule contains multiple stereocentres, particularly within its rigid tricyclic diterpene core and the side chains, which give rise to diastereomers. The fumarate component also contributes geometric (E/Z) isomerism, as it exists in the (E)-but-2-enedioic acid form, meaning the two carboxylic acid groups are on opposite sides of the double bond.

Chemical formula

C₃₂H₅₁NO₈S

Canonical SMILES

CCN(CC)CCSCC(=O)OC1CC(C(C(C23CCC(C1(C2C(=O)CC3)C)C)C)O)(C)C=C.C(=CC(=O)O)C(=O)O

Isomeric SMILES

CCN(CC)CCSCC(=O)O[C@@H]1C[C@@]([C@H]([C@@H](C23CC[C@H](C1([C@H]2C(=O)CC3)C)C)C)O)(C)C=C.C(=C/C(=O)O)\C(=O)O

International Chemical Identifier key (InChIKey)

YXQXDXAHCSEVSD-QETAFFDQSA-N

International Chemical Identifier (InChI)

InChI=1S/C28H47NO4S.C4H4O4/c1-8-26(6)17-22(33-23(31)18-34-16-15-29(9-2)10-3)27(7)19(4)11-13-28(20(5)25(26)32)14-12-21(30)24(27)28;5-3(6)1-2-4(7)8/h8,19-20,22,24-25,32H,1,9-18H2,2-7H3;1-2H,(H,5,6)(H,7,8)/b;2-1+/t19-,20+,22-,24+,25+,26-,27-,28+;/m1./s1

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Antibiotic, Antimicrobial, Antibacterial, Feed Additive

Substance groups

Pleuromutilin

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Inhibition of ribosomal protein synthesis in sensitive bacteria

Molecular targets

[50S rRNA, Antagonist]

CAS RN

55297-96-6

EC number

259-581-6

CIPAC number

US EPA chemical code

PubChem CID

86280312

Therapeutic Class

Antiinfectants for systemic use: Antibacterials for systemic use

ATCvet Code

QJ01XQ01

Controlled Drug?

Regulation 37/2010 MRL Classification

Allowed substance (Table 1: Porcine, Chicken, Turkey, Rabbit)

Molecular mass

609.82

PIN (Preferred Identification Name)

IUPAC name

(E)-but-2-enedioic acid;[(1S,2R,3S,4S,6R,7S,8R,14R)-4-ethenyl-3-hydroxy-2,4,7,14-tetramethyl-9-oxo-6-tricyclo[5.4.3.01,8]tetradecanyl] 2-[2-(diethylamino)ethylsulfanyl]acetate

CAS name

14-deoxy-14-((2-diethylaminoethyl)-mercaptoacetoxy)-mutilin

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

White to yellow coloured crystalline powder

Commercial

Property

Value

Availability status

Introduction & key dates

early-1980s, first registrations

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

Novartis Animal Health UK Ltd
Abbey Laboratories Pty Ltd

Example products using this active

Denagard Premix for Medicated Feed
Denagard Concentrate Oral Solution
Tiamulabs Tiamulin Soluble Powder

Formulation and application details

Available as a medicated feed pre-mix or oral concentrations

Commercial production

Tiamulin hydrogen fumarate is produced through a semi-synthetic process that begins with the extraction of pleuromutilin, a diterpene antibiotic derived from the fermentation of the fungus Clitopilus passeckerianus. Once isolated, pleuromutilin undergoes chemical modification, starting with acetylation using acetic anhydride in the presence of a catalyst to alter its functional groups and enhance its pharmacological properties. This intermediate is then reacted with diethylaminoethyl thiol to introduce the side chain responsible for tiamulin’s antibacterial activity. Finally, the tiamulin base is combined with fumaric acid to form the stable salt, tiamulin hydrogen fumarate, which improves solubility and bioavailability for veterinary applications.

Impact on climate of production and use

As microbial-based products tend to use fermentation-based production processes rather than chemical synthesis, they typically have a lower fossil fuel input in formulation and active ingredient creation, and also have reduced downstream emissions due to biodegradability and minimal soil disruption, their life-cycle GHG emissions are expected to be low. Whilst hard and precise data is not available, broad estimates suggest that typically emissions are likely to be below 5 kg CO₂e/kg. However, the semi-synthetic nature of the production process for this substance is likely to increase emissions.

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)

147

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

1.26 X 10⁰²

Calculated

Log P

2.1

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

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

Substance may enter the environment via the urine faeces of treated animals or by leaching from spilt medicated feed.

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

DT₅₀ (lab at 20 °C)

106.5

Persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

USEPA data: lab studt DT₅₀ range 43-301 days, Soils=8

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)

841

Mouse

Moderate

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)

> 1860

Gallus domesticus

Moderate

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)

5.2

Unknown species

Moderate

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)

Daphnia magna

Moderate

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) (EC₅₀)

> 0.165

Raphidocelis subcapitata

Moderate

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)

841

Mouse

Moderate

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

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Subcutaneous LD₅₀ = 521 mg kg⁻¹

Mouse

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

Following absorption, it is rapidly metabolised and excreted

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 dermatitis or asthma
Possible liver and kidney toxicant

Handling issues

Property

Value and interpretation

General

Emits toxic fumes under fire conditions

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

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Name

English

tiamulin hydrogen fumarate

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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