Registration Dossier
Registration Dossier
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EC number: 433-730-7 | CAS number: 23926-51-4 L-THREONINETHYLESTER
Endpoint summary
Administrative data
Link to relevant study record(s)
Description of key information
No studies are available. Based on the molecular structure, molecular weight, water solubility, and octanol-water partition coefficient of L-TEE it can be expected that the oral and inhalational absorption rates maybe high and the dermal absorption rate is considered moderate. No data on distribution is available, but based on the effects seen in the 28-day study and physical/chemical data, L-TEE is expected to be distributed though the body. L-TEE is an ester formed by L-threonine and ethanol, both of which are substances that are readily metabolized in the body. A high degree of endogenous hydrolysation into these substances is expected due to the activity of normally occurring esterases. However, no specific data on the hydrolysation rates are available.
Based on the antipicated metabolic fate and the resulting formation of L-threonine and ethanol, it is considered relevant to consider data on these substances when evaluating L-TEE.
Key value for chemical safety assessment
- Bioaccumulation potential:
- no bioaccumulation potential
- Absorption rate - oral (%):
- 100
- Absorption rate - dermal (%):
- 10
- Absorption rate - inhalation (%):
- 100
Additional information
In a 28 days oral toxicological study rats were exposed to L-TEE at 250, 500 or 1000 mg/kg bw/day.No adverse findings were observed, however, minimal/slight cortico-medullary mineralisation in the kidneys and increased lymphocyte counts were observed in females treated at all dose levels. From this, it can be deduced that L-TEE is absorbed from the gastro-intestinal tract. Due to lack of specific data on absorption rates, an oral absorption rat of 100% is therefore anticipated.
As no adequate data on inhalation is available, an absorption of 100% is antipicated.
L-TEE is a small molecule with a very high water solubilty so some dermal absorption may be expected. Having some liphophilic properties ethanol is considered to have a higher potential for dermal absorption as L-TEE and a s an worst case assumption the same absorption rate for ethanol may be used for L-TEE. For dermal absorption of ethanol, an absorption rate of 10% has been found (Pendlington et al. 2001, Food and Chemical Toxicology 39 (2001) 169–174), thus the aborption rate of 10% is applied for L-TEE.
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