Enantioselective degradation

Buser H-R, MD Muller, ME Balmer (2002) Environmental behavionr of the chiral acetamide pesticide metalaxyl enantioselective degradation and chiral stability in soil. Environ Sci Technol 36 221-226. 

Nickel K, MJ-F Suter, H-PE Kohler (1997) Involvement of two 3-ketoglutarate-dependent dioxygenases in enantioselective degradation of R)- and (S)-mecoprop by Sphingomonas herbicidovorans MH. Appl Environ Microbiol 63 6674-6679. 

Tett VA, AJ Willetts, HM Lappin-Scott (1994) Enantioselective degradation of the herbicide mecoprop [2-methyl-4-chlorophenoxypropionic acid] by mixed and pure bacterial cultures. FEMS Microbiol Ecol 14 191-200. 

Li Z, Zhang Z, Zhang L, Leng L (2009) Isomer- and enantioselective degradation and chiral stability of fenpropathrin and fenvalerate in soils. Chemosphere 76 509-516... 

Li ZY, Zhang ZC, Zhang L, Leng L (2008) Stereo and enantioselective degradation of /i-cypermethrin and -cyfluthrin in soil. Bull Environ Contam Toxicol 80 335-339... 

Qin S, Budd R, Bondarenko S, Liu W, Gan J (2006) Enantioselective degradation and chiral stability of pyrethroids in soil and sediment. J Agric Food Chem 54 5040-5045... 

Cai X, Liu W, Sheng G (2008) Enantioselective degradation and ecotoxicity of the chiral herbicide diclofop in three freshwater algae cultures. J Agric Food Chem 56 2139-2146... 

Metalaxyl Study of chiral separations to study microbial enantioselective degradation of metalaxyl in soil [535]... 

Alcaligenes sp. and Pseudomonas sp. have been used for the production of (R) or (5)-2,3-dichloro-l-propanol by the enantioselective degradation of (S) or (R) enantiomers, respectively (Figure 23(b)).24e-f The enantioselectivities were excellent but the yield did not exceed 50% in this case because half of the starting materials were degradated. 

Muller, M.D., Buser, H.-R. (1995) Environmental behavior of acetamide pesticide stereoisomers. 2. Stereo- and enantioselective degradation in sewage sludge and soil. Environ. Sci. Technol. 29, 2031-2037. 

The nonracemic compositions in the Arctic Ocean are due to microbial degradation of a-HCH both in tributary waters and within the oceanic water column. About 7% of a-HCH was enantioselectively degraded, with preferential elimination of the (-l-)-enantiomer, in streams draining into Amituk Lake on Cornwallis Island in the Canadian Archipelago [124]. In the lake itself, (—)-a-HCH was enriched (mean ER = 0.77) at 15-21 m depth [125]. 

Figure 4.13 Variability in enantiomer fractions (EFs) of cis-chlordane and trans-chlordane at plots In grassland (G) and woodlands (W1 and W2) In Scotland. Box plot defined as follows top and bottom of whiskers are maximum and minimum EFs, respectively top and bottom of box are 25 and 75% percentiles, respectively line in box is median EF. (Reproduced with permission from Environmental Science and Technology, Enantioselective Degradation of Organochlorine Pesticides In Background Soils Variability In Field and Laboratory Studies, by Perihan Binnur Kurt-Karakus, Jacqueline L. Stroud et af, 41(14), 4965-4971. Copyright (2007) American Chemical Society)...

While chirality is a powerful tool for detecting and understanding biochemical weathering processes in the environment, some caveats and precautions should be kept in mind. First, a compound must be asymmetric in order for chirality to be used. Thus, while extrapolations to structurally similar compounds may be plausible [194], such interpretations must be made cautiously in light of the variability in enantiomer behavior of even structurally similar chemicals. An example of such variability is the observation of enantioselective degradation of PCB 136 by rainbow trout, while structurally similar PCB 95 was not degraded [227,232]. 

Miiller, M.D. Buser, H.-R., Conversion reactions of various phenoxyalkanoic acid herbicides in soil. 1. Enantiomerization and enantioselective degradation of the chiral 2-phenoxypropionic acid herbicides Environ. Sci. Technol 1997, 31, 1953-1959. 

Pfaffenberger, B. Hiihnerfuss, H. Kallenborn, R. Kohler-Giinther, A. Konig, W.A. Kriiner, G., Chromatographic separation of the enantiomers of marine pollutants. Part 6 Comparison of the enantioselective degradation of a-hexachlorocyclohexane in marine biota and water Chemosphere 1992, 25, 719-725. 

Kurt-Karakus, P.B. Stroud, J.L. Bidleman, T. Semple, K.T. Jantunen, L. Jones, K.C., Enantioselective degradation of organochlorine pesticides in background soils Variability in field and laboratory studies Environ. Sci. Technol. 2007, 41, 4965-4971. 

Ludwig, P., W. Gunkel, and H. Huhnerfuss. 1992. Chromatographic separation of the enantiomers of marine pollutants. Part 5 Enantioselective degradation of phe-noxycarboxylic acid herbicides by marine organisms. Chemosphere 24 1423-1429. 

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