College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Sci Total Environ. 2018 Jun 1;626:860-866. doi: 10.1016/j.scitotenv.2018.01.140. Epub 2018 Feb 19.
Amide herbicides, which are used extensively worldwide, are often chiral. Enantiomeric selectivity comes from the different effects of the enantiomers on target and non-target organisms. In this study, the enantiomers of three amide herbicides were purified by the semi-preparative column and were used to investigate the enantioselective effects on target Echinochloa crusgalli (lowland rice weeds), and non-target Microcystis aeruginosa, and the yeast transformed with the human TRβ plasmid organisms. The results showed that (i) the R-enantiomers of the three amide herbicides exhibited the strongest activity toward weed inhibition and the lowest toxicity toward non-target organisms; (ii) napropamide was better suited for controlling root growth, while acetochlor and propisochlor were better for leaves control; (iii) herbicides at certain low concentrations (0.01 mg L for acetochlor and propisochlor) could be utilized to promote plant growth. These findings encourage the use of R-amide herbicides instead of their racemates to increase the efficiency of weed control and reduce the risk to non-target organisms. On the other hand, the adverse effects are caused mostly by S-enantiomer, using R-enantiomer-enriched products may offer great environmental/ecological benefits.
酰胺类除草剂在世界范围内广泛使用，通常具有手性。对映体选择性来自对映体对靶标和非靶标生物的不同影响。在这项研究中，通过半制备柱对三种酰胺类除草剂的对映体进行了纯化，并用于研究对靶标稗草（稻田杂草）和非靶标铜绿微囊藻以及转化了人 TRβ 质粒的酵母的对映体选择性影响。结果表明：（i）三种酰胺类除草剂的 R-对映体对杂草抑制活性最强，对非靶标生物毒性最低；（ii）napropamide 更适合控制根生长，而 acetochlor 和 propisochlor 则更适合控制叶片；（iii）在一定低浓度（acetochlor 和 propisochlor 为 0.01mg/L）下，除草剂可被用于促进植物生长。这些发现鼓励使用 R-酰胺类除草剂代替其外消旋体，以提高杂草控制效率并降低对非靶标生物的风险。另一方面，不利影响主要是由 S-对映体引起的，使用 R-对映体富集产品可能会带来巨大的环境/生态效益。
