24-epibrassinolide

24-epibrassinolide	Last updated: 19/02/2021
(Also known as: epibrassinolide)

GENERAL INFORMATION

Description

An activator that enhances the plants ability to protect against abiotic stresses and to improve plant health. Although it is effective against some fungal infections it has no direct fungicidal or antagonistic effects.

Example pests controlled

Grey mould; Downy mildew; Bottom rot; Leaf spot; Salt stress

Example applications

Wine and table grapes; Leafy vegetables e.g. endive, chicory, spinach; Pumpkin; Lettuce; Cucumber; Sugarbeet

Efficacy & activity

Effectiveness demonstrated in plant trials. Disease severity and incidence tend to be reduced rather than cured.

Availability status

Current

Introduction & key dates

UK regulatory status

UK COPR regulatory status

Pending

Date COPR inclusion expires

UK LERAP status

No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Pending

Dossier rapporteur/co-rapporteur

Austria

Date EC 1107/2009 inclusion expires

EU Candidate for substitution (CfS)

Listed in EU database

Yes

Approved for use (✓) under EC 1107/2009 in the following EU Member States

ATAustria	BEBelgium	BGBulgaria	CYCyprus	CZCzech Republic	DEGermany	DKDenmark	EEEstonia	ELGreece

ESSpain	FIFinland	FRFrance	HRCroatia	HUHungary	IEIreland	ITItaly	LTLithuania	LULuxembourg

LVLatvia	MTMalta	NLNetherlands	PLPoland	PTPortugal	RORomania	SESweden	SISlovenia	SKSlovakia

Also used in

USA (pending)

Chemical structure

Isomerism

A brassinosteroid isomer

Chemical formula

C₂₈H₄₈O₆

Canonical SMILES

CC(C)C(C)C(C(C(C)C1CCC2C1(CCC3C2COC(=O)C4C3(CC(C(C4)O)O)C)C)O)O

Isomeric SMILES

International Chemical Identifier key (InChIKey)

IXVMHGVQKLDRKH-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C28H48O6/c1-14(2)15(3)24(31)25(32)16(4)18-7-8-19-17-13-34-26(33)21-11-22(29)23(30)12-28(21,6)20(17)9-10-27(18,19)5/h14-25,29-32H,7-13H2,1-6H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Elicitor and Plant activator; Fungicide

Substance group

Plant hormone

Minimum active substance purity

900 g kg⁻¹

Known relevant impurities

EU dossier 2018: None declared

Substance origin

Natural

Mode of action

An elicitor of the plant’s self-defence mechanisms against fungal diseases

CAS RN

78821-43-9

EC number

CIPAC number

US EPA chemical code

PubChem CID

Molecular mass

480.68

PIN (Preferred Identification Name)

(22R,23R,24R)-2a,3a,22,23-tetrahydroxy-24-methyl-ß-homo-7-oxa-5-cholestan-6-one

IUPAC name

(22R,23R,24R)-2α,3α,22,23-tetrahydroxy-24-methyl-β-homo-7-oxa-5-cholestan-6-one

CAS name

24-epibrassinolide

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

White to cream coloured powdery solid

Related substances & organisms

brassinolide

Formulations

Property

Value

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

Sunergist

Example products using this active

Suntton

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

3.8

at pH 4.5

Low

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

28700

Methanol

3.1

n-Heptane

5500

Ethyl acetate

18000

Acetone

Melting point (°C)

254.6

Boiling point (°C)

>400

Degradation point (°C)

>400

Flashpoint (°C)

Not expected to self-ignite; Not highly flammable

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

1.00 X 10⁰²

Calculated

Log P

2.0

at 30 °C

Low

Bulk density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

No dissociation

Vapour pressure at 20 °C (mPa)

1.9 X 10^-12

Estimated

Low volatility

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

2.40 X 10^-13

Non-volatile

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

pH 5.5: 205nm=183, 215nm=91.0
pH 0.6: 200nm=245
pH 13.4: 219nm=67

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Nor readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

34.4

Moderately persistent

DT₅₀ (lab at 20 °C)

34.4

Moderately persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier 2018: Dark aerobic conditions normalised Lab DT₅₀ range 22.17-69.55 days, Soils=3

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

19.6

at 25 °C

Non-persistent

Note

pH sensitive: 24.1 days at pH 5, 16.4 days at pH 9, all at 25 °C

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Value

Cannot be calculated

Note

Potential for particle bound transport index

Potential for loss via drain flow

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

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)

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 5.0

Danio rerio

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

> 2.86

Daphnia magna

Moderate

Aquatic invertebrates - Chronic 21 day NOEC (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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

Non-target plants

Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Honeybees (Apis spp.)

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

> 10

Apis mellifera solubility limit

Moderate

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

> 92.2

Apis mellifera

Moderate

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

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 pollinators (1)

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

Mode of exposure

Other pollinators (2)

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

Mode of exposure

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

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

0.69

>
Aphidius rhopalosiphi

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

0.28

>
Typhlodrumus pyri

% Effect

Soil micro-organisms

Mesocosm study data

NOEAEC mg l⁻¹

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 1.08

Rat 4 hr

Other Mammal toxicity endpoints

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

None allocated

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

None allocated

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

None allocated

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

None allocated

Dermal penetration studies (%)

0.01

Dangerous Substances Directive 76/464

Exposure Routes

Public

As the substance displays no biologically or toxicologically relevant hazard risks are consider negligible

Occupational

As the substance displays no biologically or toxicologically relevant hazard risks are consider negligible

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Decrease in food consumption and loss of body weight may occur if ingested

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising

CLP classification 2013

Environment: H413

EC Risk Classification

EC Safety Classification

WHO Classification

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

24-epibrassinolide

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Polish

Swedish

Hungarian

Dutch

Record last updated:	19/02/2021
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