Acrylaldehyde

Biotransformation and kinetics

Administrative data

Endpoint:

biotransformation and kinetics

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Basic data given, meets basic scientific principles

Data source

Reference

Reference Type:

publication

Title:

METABOLISM OF [14C]ACROLEIN (MAGNACIDE H® HERBICIDE): NATURE AND MAGNITUDE OF RESIDUES IN FRESHWATER FISH AND SHELLFISH

Author:

Nordone AJ, Dotson TA, Kovacs MF, Doane R, Biever RC

Year:

1998

Bibliographic source:

Environmental Toxicology and Chemistry, Vol. 17, No. 2, pp. 276-281

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

assessment of metaboIism of acrolein and its residues in edible tissues of fish and shellfish

GLP compliance:

not specified

Type of medium:

aquatic

Test material

Test material information

Constituent 1

Reference substance name:

Acrolein

IUPAC Name:

Acrolein

Details on test material:

- Name of test material (as cited in study report): Acrolein
- Radiochemical purity (if radiolabelling): 92.2 %
- Specific activity (if radiolabelling): 648,980 dpm/µg
- Locations of the label (if radiolabelling): 2,3-14C-acrolein

Results and discussion

Transformation products:

yes

Any other information on results incl. tables

Total 14-C and acrolein water concentration
The estimated half-live of acrolein during the first 24 h was
L. macrochirus: 11.3 h
I. punctatus: 2.9 h.
Clam: 27.1 h
Crayfish: 27.8 h.

Total 14-C concentrations in tissue
L. macrochirus:
The mean total 14-C residue concentrations (mg/kg as acrolein equivalents) measured in the tissues of bluegill was 0.25 ± 0.05. Recovery was 123% of the oxidized tissue values. The high recovery was likely due to a combination of variability in compositing and initial tissue processing procedure and in concentration of total 14-C residues due to partial dehydration of tissue during storage.

I. punctatus:
The mean total 14-C residue concentrations (mg/kg as acrolein equivalents) measured in the tissues of catfish was0.22 ± .0.03. Recovery was 151% of the oxidized tissue values. The high recovery was likely due to a combination of variability in compositing and initial tissue processing procedure and in concentration of total 14-C residues due to partial dehydration of tissue during storage.

Crayfish:
The mean total 14-C residue concentrations (mg/kg as acrolein equivalents) measured in the tissues of crayfish was 0.42 ± 0.02. Recovery was 117% of the oxidized tissue values. The high recovery was likely due to a combination of variability in compositing and initial tissue processing procedure and in concentration of total 14-C residues due to partial dehydration of tissue during storage.

Clam:
The mean total 14-C residue concentrations (mg/kg as acrolein equivalents) measured in the tissues of clam was 5.34 ± 1.31. Recovery was 127% of the oxidized tissue values. The high recovery was likely due to a combination of variability in compositing and initial tissue processing procedure and in concentration of total 14-C residues due to partial dehydration of tissue during storage.

Metabolite identification and quantification
I. punctatus:
Glycidol was the major acrolein metabolite found in the channel catfish tissue, accounting for 54-57% of the total radioactive residue.

L. macrochirus:
The major acrolein metabolites found in the tissues of bluegill were 1,3-propanedio1 and glyceric acid, which accounted for 28 -40% and 14 -24%, respectively, of the tissue total radioactive residue.

Crayfish:
Glycerol and lactic acid were the major acrolein metabolites found in the crayfish tissue, accounting for 45-61% and 11-19% of the tissue total radioactive residue, respectively.

Clam:
Unidentified carbohydrates constituted the major 14C components in the clam tissue, at 27-34% of the tissue total radioactive residue.

Table: Metabolite residues found in the tissues of test species (expressed as mg/kg acrolein equivalents)

Melabolite	L. macrochirus	I. punctatus	Clam	Crayfish
Total water extractable [14C] residues	0.22	0,17	4.7	0.35
Glycidol	<0.01	0.12	0.05	0.02
Malonic acid	0.02	0,03	--	0.07
Lactic acid	--	0.03	0.48	0.05
Oxalic acid	0.01	<0.01	--	0,01
1,3-Propanediol	0.10	<0,01	0.11	--
Glycerol	<0.01	<0.01	--	0.21
Glyceric acid	0.04	--	1.18	--
Propiolic acid	0.03	--	0.80	--
HCO3	0.01	--	--	--
Propanol	--	--	0.05	--
Propionic acid	--	--	0,37	--
Carbohydrates	--	--	l,76	--
Unknowns	--	--	0.05	0.01
Total NaOH extractable [14.C] residues	0.02	0.04	0,64	0.06
Unknowns	0.02	0.04	0.64	0.06

Neither acrolein, acrylic acid, nor allyl alcohol were detected in the tissues of any of the test species. Metabolites of acrolein found in the water-extracted tissues were primarily alcohols and organic acids. These results suggest that the rapid biodegradation of acrolein in aquaria water is followed by the rapid and complete metabolism of the parent and water-borne metabolites in the tissues of all four species tested.

Glyceric acid, propanol, oxalic acid, und propionic acid were the only metabolites common to the fish, clam and crayfish tissue. These latter four acrolein metabolites could have been either directly assimilated from the test system or metabolic products produced by the test organisms. All other acrolein metabolites identified in the fish, clam and crayfish tissue, 1,3-propanediol, malonic acid, lactic acid, propiolic acid, glycidol, and glycerol, were likely metabolic products generated by the test species.

Conclusion:
Bluegill, channel catfish, crayfish, and clams, when continuously exposed to 14C-acrolein and its residues are able to further metabolize these compounds in their tissues to 10 identified metabolites, with a number of polar and nonpolar compounds being generally characterized as carbohydrates, amino acids, and peptides. The metabolism of 14C-acrolein is so rapid in these species that neither acrolein nor its major oxidative and reductive metabolites acrylic acid and allyl alcohol, respectively, were detected in the tissues examined.
The results demonstrated that the potential of acrolein to enter and persist in aquatic food chains is low.

Applicant's summary and conclusion

Executive summary:

The fish species Lepomis macrochirus and Ictalurus punctatus, the clam Elliptio complanata and the crayfish Orconectes virilis were exposed to nominal concentration of 20.2 µg/L (fish) and 101µg/L (clam, crayfish) in static exposure test systems, with two applications of acrolein made at 7-d intervals. Exposure was terminated on day 8, 1 d after the second acrolein application. Test organisms were killed and their edible tissues were used for metabolite identification. Neither acrolein, acrylic acid, nor allyl alcohol were detected in the tissues of any of the test species. Metabolites of acrolein found in the water-extracted tissues were primarily alcohols and organic acids. These results suggest that the rapid biodegradation of acrolein in aquaria water is followed by the rapid and complete metabolism of the parent and water-borne metabolites in the tissues of all four species tested. They are able to further metabolize these compounds in their tissues to 10 identified metabolites, with a number of polar and nonpolar compounds being generally characterized as carbohydrates, amino acids, and peptides.
The results demonstrated that the potential of acrolein to enter and persist in aquatic food chains is low.