2,3-bis((2-mercaptoethyl)thio)-1-propanethiol

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Expert judgement is combined with the prediction of metabolism provided by the OECD QSAR Application Toolbox (Version 1.1.02).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Objective of study:

toxicokinetics

Principles of method if other than guideline:

No existing guideline covers this type of assessment.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,3-bis((2-mercaptoethyl)thio)-1-propanethiol

EC Number:

411-290-7

EC Name:

2,3-bis((2-mercaptoethyl)thio)-1-propanethiol

Cas Number:

131538-00-6

Molecular formula:

C7 H16 S5

IUPAC Name:

2,3-bis[(2-sulfanylethyl)sulfanyl]propane-1-thiol

Details on test material:

Not applicable

Test animals

Species:

other: not applicable

Details on test animals or test system and environmental conditions:

Not applicable

Administration / exposure

Route of administration:

other: oral and dermals routes are considered

Details on exposure:

Not applicable

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on absorption:

DMPT is predicted to be readily bioavailable via the oral route, while the dermal uptake will be very limited.

Details on distribution in tissues:

DMPT is predicted to be metabolised to molecules with hydrophilic groups (see figure 3 in the attached document), which are expected to be excreted rapidly via the urine. None of the molecules are expected to show a bioaccumulative potential.

Details on excretion:

The metabolites of DMPT have molecular weights lower than 500 g/mol and have hydrophilic groups. The molecules are likely to be excreted via the urine.

Metabolite characterisation studies

Metabolites identified:

not measured

Details on metabolites:

One or several of the thiol groups of DMPT will probably be oxidised in a stepwise manner, to sulfonic acid groups. These molecules are hydrophilic and are therefore likely to be eliminated via the urine.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): no bioaccumulation potential based on study results
2,3-bis((2-mercaptoethyl)thio)-1-propanethiol is predicted to be bioavailable via the oral route and have a low absorption potential via the dermal route.
2,3-bis((2-mercaptoethyl)thio)-1-propanethiol is expected to undergo stepwise oxidation of one or several of the thiol groups.
2,3-bis((2-mercaptoethyl)thio)-1-propanethiol is predicted to be readily metabolised. Its metabolites are hydrophilic and wil be readily excreted via the urine. Therefore, bioaccumulation in the tissues is unlikely.

Executive summary:

The toxicokinetic behaviour of 2,3 -bis((2 -mercaptoethyl)thio)-1 -propanethiol was assessed. The OECD QSAR Application Toolbox (version 1.1.02) was used to simulate the metabolites likely to be formed in the liver, skin and gastrointestinal tract. The charge of the molecule at the pH-level found in the intestine was simulated with the QSAR

tool SPARC to assess the oral bioavailability, while the QSAR-based tool DERMWIN (v2.00) was used to predict dermal absorption potential. By combining the results of the simulations and results from oral and dermal toxicity studies, and applying expert judgement, an assessment of the toxicokinetic properties of 2,3-bis((2-mercaptoethyl)thio)-1-propanethiol and its metabolites is made. 2,3-bis((2-mercaptoethyl)thio)-1-propanethiol is predicted to be bioavailable via the oral route and have a low absorption potential via the dermal route. 2,3-bis((2-mercaptoethyl)thio)-1-propanethiol is expected to undergo stepwise oxidation of one or several of the thiol groups, giving the corresponding sulfonic acid. These metabolites are hydrophilic and wil be readily excreted via the urine. Therefore, bioaccumulation in the tissues is unlikely.