D-Glucopyranose, oligomeric, heptyl glycosides

Endpoint summary

Additional information

There is only limited data available on the genetic toxicity of D-Glucopyranose, oligomeric, heptyl glycoside. In order to fulfil the standard information requirements set out in Annex VII and VIII, 8.4, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances is conducted.

A detailed justification for the grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Sections 7.1 and 13).

In vitro

For genetic toxicity in vitro, one key study on gene mutation in bacteria is available for D-Glucopyranose, oligomeric, heptyl glycoside. However, no studies on the induction of genetic mutation in mammalian cells and chromosome aberration exist for D-Glucopyranose, oligomeric, heptyl glycoside. To cover these endpoints, results of studies on the category members D-Glucopyranose, oligomers, decyl octyl glycosides (CAS 68515-73-1) and D-Glucopyranose, oligomeric, C10-16-alkyl glycosides were used for read-across based on the category approach.

- Gene mutation in bacteria

A bacterial gene mutation assay (Ames test) was conducted with D-Glucopyranose, oligomeric, heptyl glycoside in compliance with OECD guideline 471 and under GLP conditions (Vivotecnia Research, 2012). In two independent experiments, S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 (pKM 101) were exposed to concentrations ranging from 0.06 to 5 mg/plate with and without metabolic activation. No increase in the mean number of revertants per plate was observed in any tester strain at the indicated concentrations. Furthermore, no cytotoxicity was observed in the experiments up to the limit concentration of 5000 µg/plate. The vehicle controls were within the spontaneous mutation ranges of the historical controls, and the positive controls induced the expected increase in the number of reverse mutants. Under the conditions of this experiment, the test substance did not show mutagenicity in the selected strains of S. typhimurium in the presence and absence of metabolic activation.

- Gene mutation in mammalian cells

The genotoxic potential of D-Glucopyranose, oligomers, decyl octyl glycoside was assessed using a gene mutation assay in cultured mammalian cells (mouse lymphoma L5178Y cells), which was equivalent or similar to OECD guideline 476 and in compliance with GLP (Microbiological Associates, 1991). Based on a preliminary toxicity study, ten doses of the non-activated and the activated cultures were selected for cloning. In the first experiment, the non-activated cultures that were cloned were treated with test substance concentrations ranging from 7.5 to 101 µg/mL, whereas activated cultures were treated with concentrations ranging from 13 to 179 µg/mL. In a second experiment, the activated cultures that were cloned were treated with 161-234 µg/mL of the test substance. No increase in mutant frequency was observed at any of the concentrations tested in both experiments. Therefore, it was concluded that under the conditions used in the study, the test material was not mutagenic at the TK-locus of mouse lymphoma L5178Y cells in the absence and presence of metabolic activation.

- Chromosome aberrations

D-Glucopyranose, oligomeric, C10-16-alkyl glycosides was assayed in an in vitro mammalian chromosome aberration test conducted according to OECD guideline 473 and in compliance with GLP (Henkel, 1995). In this experiment, Chinese hamster lung fibroblasts (V79) were treated with the test substance at concentrations up to 160 µg/mL in the presence of metabolic activation and up to 16 µg/mL without. Continuous treatment for 4 h was performed with and without S9-mix followed by culture periods of 7, 20 and 28 h, respectively. For chromosome analysis, concentrations ranging from 2 to 80 µg/mL were selected. The test substance did not induce chromosomal aberrations at any of the concentrations tested, neither in the presence nor absence of metabolic activation. Under the conditions of this assay, the test substance did not show clastogenic activity in vitro.

In vivo

No studies are available investigating the genetic toxicity of D-Glucopyranose, oligomeric, heptyl glycoside in vivo. Thus, a study performed with the structurally related substance D-Glucopyranose, oligomeric, C10-16-alkyl glycosides was used to cover this endpoint based on the category approach.

The category member D-Glucopyranose, oligomeric, C10-16-alkyl glycosides was tested in an in vivo mammalian chromosome aberration test according to OECD guideline 474 and in compliance with GLP (SafePharm, 2000). In this micronucleus assay, 7 male mice per group were intraperitoneally administered with the test substance at 62.5, 125 and 250 mg/kg bw or vehicle (distilled water). After a 24 or 48-h period bone marrow was extracted, and polychromatic and normochromatic erythrocytes were scored for the presence of miocronuclei. No biologically relevant increase in the frequency of micronucleated polychromatic erythrocytes was observed within the treatment groups. Thus, the test substance was considered to be not clastogenic in mice in vivo under the conditions of this Mammalian Erythrocyte Micronucleus assay.

Based on the negative results of the available studies on the substance itself and category members with alkyl chain lengths ranging from C8 to C16, it may be concluded that D-Glucopyranose, oligomeric, heptyl glycoside does not induce genetic toxicity in vitro and in vivo.

Justification for selection of genetic toxicity endpoint
Hazard assessment is conducted based on an Ames test with the substance itself and by means of read-across based on a category approach with structurally related substances according to the criteria laid down in Annex XI, 1.5 of Regulation (EC) No 1907/2006. The substances of the Category are generated by the reaction of D-glucose with alcohols of varying chain length and share identical structural characteristics only differing by the alkyl chain length of the respective alcohol and varying degree of oligomerisation. Upon hydrolysis they are degraded into glucose and fatty alcohols again which can be further metabolised by common endogenous pathways like glycolysis and, in case of the alcohols, degraded in the endogenous pathway of beta-oxidation subsequently to their oxidation into fatty acids. No specific study was selected, since three different endpoints are addressed by genetic toxicity in vitro: mutagenicity in bacteria, chromosomal aberration in mammalian cells and mutagenicity in mammalian cells; genetic toxicity in vivo is no mandatory endpoint according to Regulation (EC) No 1907/2006. However, all available in vitro and in vivo genetic toxicity studies were negative. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between source and target substance and overall quality assessment (refer to the endpoint discussion for further details).

Short description of key information:
In vitro:
OECD 471 (Ames): negative
RA-C, OECD 476 (Mouse lymphoma assay): negative
RA-C, OECD 473 (Chromosome aberration): negative

In vivo:
RA-C, OECD 474 (Micronucleus test in mice): negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The available data on genetic toxicity of D-Glucopyranose, oligomeric, heptyl glycoside and structurally related substances according to the criteria laid down in Regulation (EC) No 1907/2006, Annex XI, 1.5, do not meet the criteria for classification according to Regulation (EC) No 1272/2008 or Directive 67/548/EEC; therefore, D-Glucopyranose, oligomeric, heptyl glycoside is not considered to exert genetic toxicity, either, and the data are conclusive but not sufficient for classification.