ISSN:
1432-0703
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Medicine
Notes:
Abstract Carbaryl (1-naphthyl methylcarbamate), labeled with14C in the C1-naphthyl, carbonyl, orN-methyl position, was introduced into the culture medium of tobacco cells in suspension culture. Following incubation, cells were homogenized in water, centrifuged, and supernatants hydrolyzed withΒ-glucosidase or HCl. Organic moieties (moieties) were characterized by two-dimensional thin-layer chromatography (TLC), and many were subsequently identified by infrared and mass spectrometry. On the basis of the data obtained with14C1-naphthyl-labeled carbaryl, it appeared that 18.4% of the total characterized metabolites represented unconjugatedN-CH2OH- carbaryl [1-naphthylN-(hydroxymethyl)carbamate], excreted by the cells into the culture medium. The metabolites found in the cells primarily consisted of conjugates of 1-naphthol (73.6% of the total characterized metabolites) andN-CH2OH-carbaryl (2.5%). Conjugates of 7-hydroxycarbaryl (7-hydroxy-1-naphthyl methylcarbamate), 4-hydroxycarbaryl (4-hydroxy-1-naphthyl methylcarbamate), and 5-hydroxycarbaryl (5-hydroxy-1-naphthyl methylcarbamate) were also detected in small amounts. Of five unknown14C1-naphthyl-labeled carbaryl metabolites, three were tentatively characterized as:O-1-naphthylcholesterol (cholest-5-en-3Β-yl-1-naphthol; 3.0%); an unconjugated hydroxylated 1,4-dihydro-1,4-epiperoxynaphthalene (1.4%); and an acidlabile,Β-glucosidase-resistant conjugate of acis-dihydrodiol of 1-naphthol (0.3%; other than thetrans-5,6-dihydrodiol). The cholesterol derivative may represent a new “detoxification mechanism” in plants; the epiperoxide may help to elucidate plant oxidation mechanisms. A new TLC procedure was developed which successfully separated the acetate derivative ofN-hydroxycarbaryl (1-naphthylN-hydroxy-N-methylcarbamate) from 12 other common moieties of carbaryl metabolites and their acetate derivatives. A new two-dimensional TLC system was developed for the separation of underivatizedN-hydroxycarbaryl from 14 other moieties of carbaryl metabolites; two additional two-dimensional TLC systems were utilized for moiety separations. With these TLC procedures, no conjugated or unconjugatedN-hydroxycarbaryl could be detected in any tobacco cell culture fraction after incubation of cells in medium containing radiolabeled carbaryl. Authentic14C1-naphthyllabeledN-CH2OH-carbaryl was shown to be converted to desmethylcarbaryl (1-naphthylcarbamate) (97%) and 1-naphthol (3%) by 0.1N HCl hydrolysis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02221015
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