Enantioselective Phytoeffects of Chiral Pesticides

Abstract

Chirality exists extensively in nature. Synthetic chiral plant growth regulators and other pesticides usually behave enantioselectively in phyto-biochemical processes. Chiral plant growth regulators regulate the physiological processes of plants enantioselectively, and chiral pesticides cause enantioselective toxicities or ecotoxicities to plants. On the other hand, these chiral agrochemicals can be absorbed and enantioselectively metabolized by plants. This review summarizes the enantioselective effects of chiral plant growth regulators on plants and the phytotoxic and biotransformation effects of chiral herbicides and several persistent organic pollutants (POPs) on plants. Together, this information on the interactions between chiral agrochemicals and plants might shed light on studies on the chemical and biological behaviors of chiral chemicals, and direct research into the selection of plants, which can potentially decontaminate the environment.

Herbicides as Weed Control Agents: State of the Art: I. Weed Control Research and Safener Technology: The Path to Modern Agriculture

“…There are several excellent reviews and books on the MoAs of herbicides (Seitz et al, 2003;Liu et al, 2009;Dayan et al, 2010;Krämer at al, 2012) (Figs. 4 and 5).…”

Enantioselective Uptake and Translocation of a Novel Chiral Neonicotinoid Insecticide Cycloxaprid in Youdonger (Brassica campestris subsp. Chinensis)

“…After germination the seeds were sown in pots containing fluvio-marine yellow loamy soil (pH 6.50; OM 1.52%; CEC 6.4 cmol kg -1 ; clay 59.8%, silt 37.1%, sand 3.1%). After emergence the seedlings were transplanted into 20-ml glass pots containing 15 The seedlings of the Youdonger at the three-leaf stage were selected for treatment. The solution in the pots was replaced with 15 ml of fresh solution containing a total radioactivity of 1965 AE 47 Bq single stereoisomer of 14 C-cycloxaprid and the roots were completely submerged in solution.…”

“…15 On most occasions, the enantiomers of chiral chemicals exhibit different characteristics during environmental biological processes. The enantioselective biotransformation, residue, and metabolism of chiral herbicides, [15][16][17] ,insecticides, 15,[17][18][19][20] and organic pollutants 15,19,[21][22][23] has been found in the environment and biota. Consequently, environmental risk assessments of the two enantiomers ((1R;8S)-cycloxaprid (RS) and (1S;8R)-cycloxaprid (SR)) must be investigated separately.…”

Isomerization of chiral pesticides in the environment

“…In soil adsorption, different adsorption coefficients have been reported even for enantiomers when the stereoselective interactions occur with clay minerals and humic substances in soil. [16][17][18] The enantioselectivity in biological systems has been identified first in the efficacy and mammalian toxicity of chiral pesticides, 1,19) and recently in their environmental fate 2,21,23) and ecotoxicological effects. 4,6,9,11,20) Specific stereoisomer(s) would then be enriched in the natural environment by the different rates of degradation among them.…”

“…The ER and EF indices were first applied to monitor this change for organochlorine pesticides. 19,20) A similar approach has been taken to monitor pyrethroids in U.S. stream sediments. 126,127) The EF value of each stereoisomer in cis-bifenthrin (20) was kept almost constant around 0.5, while in cis-permethrin (13), the value varied with location of sediments and season of monitoring.…”