Metabolism of isopropyl-3-chlorocarbanilate by cucumber plants

Abstract

Root-treated cucumber plants absorb, translocate, and metabolize 14C-labeled isopropyl-3chlorocarbanilate (chlorpropham-14C). Polar products and solid residues are found in the roots, stems, and leaves after a 3-day treatment period. Pulse time-course experiments demonstrate a precursor-product relationship between chlorpropham, soluble polar products, and solid residual materials. The polar metabolites are not translocated once they are formed in either the roots or shoots. The radiocarbon distribution pat-terns of phenyl-14C and isopropyl-14C-labeled chlorpropham were similar in all comparative experiments. Polar metabolites were isolated and partly purified, and the chlorpropham oxidized moiety was characterized. Cucumber tissues rapidly convert chlorpropham to isopropyl-4-hydroxy-3-chlorocarbanilate, which is conjugated with unknown plant components. These chlorpropham metabolites were found in both root and shoot tissues.

Uptake, Translocation, and Metabolism of Propham by Wheat(Triticum aestivum), Sugarbeet(Beta vulgaris), and Alfalfa(Medicago sativa)

“…A similar trend concerning the concentration of extractable and inextractable propham and chlorpropham has been observed in two other species (25,27). The decrease in ex tractable 1 4 C and the increase in inextractable 1 4 C was ap parently due to increased conjugation and binding of the her bicide as treatment time increased.…”

“…The proposed pathway for the metabolism of propham in wheat, sugarbeet, and alfalfa ( Figure 2) is based upon the re sults obtained in the present investigation and other work con cerning plant metabolism of propham and chlorpropham (10,23,24,25,26,27,28,29). In all species propham and chlor propham were ring hydroxylated in either the ortho or para position and rapidly conjugated to form polar metabolites.…”

“…This informa tion, however, neither coincides with the results of the work mentioned previously (25,28) nor the work on the metabo lism of chlorpropham (isopropyl w-chlorocarbanilate) in two other plant species. The major aglycones isolated from soy bean and cucumber were isopropyl-2-hydroxy-m-chlorocarbanilate (23,24) and isopropyl-4-hydroxy-w-chlorocarbanilate, respectively (27).…”

Organic Toxicants and Plants

“…Thus, in alfalfa plant absorbed isopropyl carbanilate is transformed with the formation of the main component isopropyl-4-hydroxycarbanilate (Still and Mansager, 1975b). Among wheat, sugar beet, and alfalfa plants cultivated in nutrient solution and in soil, formation of isopropyl-4-hydroxycarbanilate was observed only in wheat, and, in addition, 4-hydroxy and 2-hydroxy derivatives were formed (Burt and Corbin, 1978).…”

“…Among wheat, sugar beet, and alfalfa plants cultivated in nutrient solution and in soil, formation of isopropyl-4-hydroxycarbanilate was observed only in wheat, and, in addition, 4-hydroxy and 2-hydroxy derivatives were formed (Burt and Corbin, 1978). Isopropyl-3-chlorocarbanilate is hydroxylated with the formation of isopropyl-3-chloro-2-hydroxycarbanilate or isopropyl-3-chloro-4-hydroxycarbanilate (Still and Mansager, 1975b).…”