108451-25-8Relevant academic research and scientific papers
Enzymatic synthesis of 4-amino-3,5-diethylphenyl sulfate, a rodent metabolite of alachlor
Logusch, Sherry J.,Feng, Paul C. C.,Fujiwara, Hideji,Hutton, William C.,Wratten, Stephen J.
, p. 2125 - 2129 (1999)
Rat liver tissue homogenates were utilized for in vitro enzymatic conversion of 2,6-diethylaniline (DEA) to the important alachlor metabolite 4-amino-3,5-diethylphenyl sulfate (ADEPS), which was also generated as a radiolabeled standard for use in metabolism studies. ADEPS formation in rodents is associated with the production of other reactive metabolites implicated in alachlor rodent carcinogenesis, making dependable access to an ADEPS standard highly desirable. 14C-DEA was oxidized by rat liver microsomes to 14C-4-amino-3,5-diethylphenol, which was further converted to ADEPS via addition of the phosphosulfate transferase cofactor adenosine-3'- phosphate-5'-phosphosulfate. Microprobe NMR was used in conjunction with high-resolution mass spectrometry to fully characterize the resulting 14C- ADEPS and confirm its structure. Because microgram quantities sufficed for full characterization, the enzymatic transformation provides a viable alternative to radiosynthesis of 14C-ADEPS.
Hapten design in the development of competitive enzyme-linked immunosorbent assays for genotoxic metabolites of alachlor
Tessier,Clark
, p. 3925 - 3933 (2007/10/03)
The acetanilide compounds 2-chloro-2',6'-diethylacetanilide (CDA) and 2- hydroxy-2',6'-diethylacetanilide (HDA) are environmental degradative products of the chloroacetanilide herbicide alachlor. CDA, HDA, and alachlor are ground and surface water contaminants. CDA and HDA are genotoxic in bacterial and mammalian test systems. This paper reports hapten design in the development of two competitive enzyme-linked immunosorbent assays (cELISA) for the detection of CDA and HDA. Chloroacetanilide herbicides and other alachlor metabolites that may be present in environmental samples do not cross-react with the detection of CDA and HDA. Solid-phase extraction of CDA and HDA residues from aqueous samples results in a 1000-fold concentration factor, resulting in an effective detection limit of 15 pg/mL for both assays. The specificity of the cELISAs required preservation of the degree of substitution of the acetanilide moiety in the hapten design. The hapten synthesis strategies are suitable for metabolites of other chloroacetanilide herbicides (i.e., acetochlor, butachlor, metolachlor, and propachlor).
Dialkylquinoneimine metabolites of chloroacetanilide herbicides induce sister chromatid exchanges in cultured human lymphocytes
Hill, Anna B.,Jefferies, Phillip R.,Quistad, Gary B.,Casida, John E.
, p. 159 - 171 (2007/10/03)
Some of the most widely-used herbicides are the chloroacetanilides exemplified by alachlor and butachlor (derived from 2,6-diethylaniline) and metolachlor and acetochlor (synthesized from 2-ethyl-6-methylaniline). This investigation tests the hypothesis that the previously-observed oncogenicity of these herbicides is due to genotoxic intermediates such as diethylbenzoquinoneimine, a purported alachlor metabolite. Syntheses are reported here for the corresponding 2,6-dialkylbenzoquinoneimines, selected chloroacetyldialkylbenzoquinoneimines and several other candidate or known metabolites. The possible mutagenicity of diethylbenzoquinoneimine was tested in Salmonella typhimurium strains TA98 and TA100 with a weakly-positive response in the TA100 strain indicating induction of base-pair substitution mutations. The frequency of sister chromatid exchange (SCE) in Chinese hamster ovary cells was increased by alachlor at 10 μM and diethylaniline but not ethylmethylaniline at 30 and 3 μM. Isolated and cultured peripheral lymphocytes (mostly T cells) were used from two human donors to study the effects of the chloroacetanilides and their metabolites on primary human cells. In tests at 10 μM, the SCE frequency was increased by alachlor and possibly acetochlor but not by butachlor, metolachlor, dimethachlor (a 2,6-dimethyl analog) and dimethenamid (an analog based on 2,4-dimethyl-3-thienylamine). At 0.3 μM in cultured human lymphocytes, alachlor, the corresponding chloroacetanilide (N-dealkyl-alachlor) and aniline metabolites (and their 4-hydroxy derivatives), and diethylbenzoquinone were inactive or active in only one of the two donors whereas at 0.1-0.3 μM the SCE ratio for treated cells divided by the controls was always higher for diethylbenzoquinoneimine than for ethylmethyl- and dimethylbenzoquinoneimines. All the tested compounds were toxic to lymphocytes, but the depression of the mitotic index and increased duration of the cell cycle were not directly linked with SCE induction. Previous investigations have suggested that chloroacetanilide herbicides such as alachlor derived from 2,6-dialkylanilines are metabolized to 2,6-dialkylbenzoquinoneimines and the present study provides the first direct evidence that these metabolites are genotoxic in human lymphocytes.
