Format

Send to:

Choose Destination
See comment in PubMed Commons below
Sci Total Environ. 2014 Feb 15;472:582-9. doi: 10.1016/j.scitotenv.2013.11.068. Epub 2013 Dec 6.

Studies on the anoxic dissipation and metabolism of pyribambenz propyl (ZJ0273) in soils using position-specific radiolabeling.

Author information

  • 1Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture of PRC, Zhejiang University, Hangzhou 310029, China.
  • 2Shanghai Institute of Organic Chemistry, Chinese Academy of Science, Shanghai 200032, China.
  • 3Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture of PRC, Zhejiang University, Hangzhou 310029, China. Electronic address: qfye@zju.edu.cn.

Abstract

Pyribambenz propyl (ZJ0273) is a polycyclic herbicide with increasing use, although studies show that it tends to be persistent in soil and pose phytotoxicity to rotational crops. This study employed an improved ring-specific (14)C labeling method to characterize its anoxic metabolism, with (14)C positioned on the benzoate, pyrimidyl or benzyl rings. Separation and identification of the metabolites were achieved by liquid chromatography (LC), ultralow-level liquid scintillation spectrometry, and LC-mass spectrometry (MS). Results show that the anoxic degradation follows first-order kinetics and the half-lives are approximately 38.7, 50.2 and 70.7d for loamy, saline and clayey soils, respectively. A total of five radioactive intermediates (M1-M5) were detected, and due to the loss of radiolabels, different radiochromatograms were obtained from different labels, i.e., radioactive M5 was only detected for pyrimidinyl-(14)C; M3 and M4 were only detected for pyrimidinyl-(14)C and benzyl-(14)C, while M1 and M2 were detected for all labels. Based on their appearance pattern and fragmentations from LC-MS, the structures of M1-M5 were identified, and they were proposed to form by reactions such as de-estering, hydrolysis, acylation, CN cleavage, and demethylation. All metabolites have been previously detected in aerobic soils except M4, which is a demethylation product from M3, and identified as 2-(4-hydroxy-6-methoxypyrimidin-2-yloxy)benzoic acid. The results show that ZJ0273 is more persistent in anoxic soils, and its degradation pathways and intermediates are different from aerobic metabolism and differ with the soil types, suggesting that soil-specific and farming practices may be important considerations in the use of this herbicide. The ring-specific labeling provides full molecular information about the referred compound and guarantees the reliability of the results, and can be used as an effective tool for metabolite profiling of polycyclic compounds.

Copyright © 2013 Elsevier B.V. All rights reserved.

KEYWORDS:

Anoxic degradation; Herbicide; Metabolites; Pyribambenz propyl (ZJ0273); Ring-specific (14)C labeling

PMID:
24317166
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk