Enantioselective degradation and chiral stability of malathion in environmental samples

The dissipation behaviors of the two enantiomers of the organophosphorus pesticide malathion (MA) in environment samples were elucidated using a normal-phase high-performance liquid chromatography with a cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) chiral column. A validated chiral residue analysis method in soil and water was established; the average recoveries for the two enantiomers were 88-102% in soil and 81-99% in water. Racemic and enantiopure R-(+)- and S-(-)-MA were incubated in five soil and water systems. The results of the degradation of racemate in all of the environment samples showed the inactive S-(-)-enantiomer degraded more rapidly than the active R-(+)-enantiomer, resulting in a relative enrichment of the R-form. Moreover, when the enantiopure S-(-)- and R-(+)-MA were incubated in three well-chosen soil and water samples, respectively, inversion from one enantiomer to another was found, indicating that using the optically pure enantiomer will not help to increase the bioactivity and reduce the environmental pollution.     

Enantiomeric resolution and growth-retardant activity in rice seedlings of uniconazole

The increasing application of chiral pesticides has enhanced interest in their enantioselectivity. However, little relevant information is currently available for enantioselective activity of chiral plant growth regulators. In an attempt to screen active enantiomers of uniconazole, this work investigated enantiomeric separation and the enantioselective effect of uniconazole on the growth of rice seedlings and cyanobacteria. Baseline resolution of uniconazole enantiomers was achieved on a Chiralpak AD column by chiral high-performance liquid chromatography (HPLC). The relationship among circular dichroism (CD), optical rotation (OR), and absolute configuration was successfully established by coupling of CD and OR detection. The t test at the 95% level of confidence indicated significant differences between the enantiomers in their retardant activity toward growth of rice seedlings and stimulation effect on growth of cyanobacteria, the natural biofertilizers in rice paddy fields. The S-(+)-enantiomer was more active than the R-(-)-enantiomer in retarding growth of rice seedlings and stimulating growth of Microcystis aeruginosa . This special enantiomeric selectivity was further elucidated by probing the binding mode of enantiomers to gibberellin (GA) 20-oxidase by molecular docking. The S-(+)-enantiomer was found to bind tightly with GA 20-oxidase. The results suggested that the S-(+)-enantiomer instead of a racemate of uniconazole should be used to improve rice seedling quality.     

Single and joint acute toxicity of isocarbophos enantiomers to Daphnia magna

Although enantioselectivity in the toxicity of chiral pesticides has received considerable attention over recent years, how coexisting enantiomers interact with each other during their toxic action remains unknown. In this study, we attempted to resolve the enantiomers of a chiral organophosphate insecticide, isocarbophos, and investigated the acute toxicity of individual enantiomers and various enantiomer mixtures. Baseline enantiomeric separation of isocarbophos was achieved on a Chiralcel OD column with the mobile phase of n-hexane/isopropanol (90/10, v/v) at a flow rate of 0.8 mL/min. The resolved enantiomers were differentiated by their responses on a circular dichroism detector. The median lethal concentrations (LC 50) of racemate, (+)-enantiomer, and (-)-enantiomer of isocarbophos toward Daphnia magna were 13.9, 7.08, and 353 microg/L, respectively, after 48 h of static exposure, displaying a 50-fold difference between the enantiomers. Toxic unit (TU) analysis was employed to evaluate the joint toxicity of isocarbophos enantiomer mixtures. The calculated TU mix for the acute toxicity (48 h test) of various binary mixtures ranged from 0.83 to 1.04, suggesting a mode of additive effect. Further evaluation of available literature data for chiral organophosphorus insecticides showed that the joint toxicity of enantiomers may be additive, synergistic, and antagonistic. Therefore, when significant enantioselectivity exists for a chiral pesticide, it is important to also evaluate the interaction of enantiomers in the joint toxicity effect when enantiomers are present in a mixture.     

Enantioselective environmental behavior of the chiral herbicide fenoxaprop-ethyl and its chiral metabolite fenoxaprop in soil

The enantioselective degradation behavior of fenoxaprop-ethyl (FE) and its chiral metabolite fenoxaprop (FA) in three soils under native conditions was investigated. Two pairs of enantiomers were analyzed by high-performance liquid chromatography (HPLC) with an amylose tri-(3,5-dimethylphenylcarbamate) (ADMPC) chiral column. The degradation of racemic FE in three soils showed the herbicidally inactive S-(-)-enantiomer degraded faster than the active R-(+)-enantiomer. FE was configurationally stable in soils because no interconversion to the respective antipodes was observed during incubation of the enantiopure S-(-)- or R-(+)-FE. The main metabolites of FE were confirmed as FA and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB), and the formation of the chiral metabolite FA showed enantioselectivity in soils. The degradation of rac-FA was also enantioselective with the S-(-)-FA preferentially degraded: the half-life (t(1/2)) of the S-form in the three soils ranged from 2.03 to 5.17 days, and that of R-form ranged from 2.42 to 20.39 days. The inversion of the S-(-)-enantiomer into the R-(+)-enantiomer occurred in two of the three soils when the enantiopure S-(-)- and R-(+)-FA were incubated. The data from sterilized control experiments indicated that the enantioselectivity of FE and FA was attributed to microbially mediated processes.     

Enantioselective residue dissipation of hexaconazole in cucumber (Cucumis sativus L.), head cabbage (Brassica oleracea L. var. caulorapa DC.), and soils

In this study, the enantioselective dissipation behavior of hexaconazole was investigated in cucumber fruit, head cabbage, and two different types of agricultural soils. The dissipation kinetics was determined by reverse-phase liquid chromatography-tandem mass spectrometry on a cellulose tris (3-chloro-4-methylphenylcarbamate) chiral column. Dissipation rates of hexaconazole enantiomers followed first-order kinetics; the residues of (+)-enantiomer decreased more rapidly than (-)-enantiomer in cucumber and head cabbage, resulting in relative enrichment of the (-)-form, while the two enantiomers showed similar degradation rates in the tested soils. These results indicate substantial enantioselectivity in the residue dissipation of hexaconazole enantiomers in cucumber and head cabbage; however, nonenantioselective dissipation was observed in the tested soils.     

Different enantioselective degradation of pyraclofos in soils

This study investigated the enantioselective degradation behavior of pyraclofos in three soils (NC, HZ, and ZZ) under native and sterilized conditions. The absolute configuration of pyraclofos enantiomers has been determined by the combination of experimental and calculated electronic circular dichroism spectra. S-(+)- and R-(-)-Pyraclofos were separated and determined on a cellulose tri-(4-chloro-3-methylphenylcarbamate) (Lux Cellulose-4) chiral column by reversed-phase high-performance liquid chromatography-tandem mass spectrometry. Pyraclofos enantiomers were configurationally stable in three soils and no interconversion was observed during the incubation of enantiopure S-(+)- or R-(-)-pyraclofos under native conditions. The enantioselective degradation behavior of chiral pyraclofos was dramatically different in three soils under native conditions, with half-lives (t(1/2)) of pyraclofos in NC, HZ, and ZZ soils of 2.6, 13.4, and 7.8 days for S-(+)-pyraclofos and 9.2, 9.3, and 8.2 days for R-(-)-pyraclofos. Compared to the half-lives (t(1/2)) of rac-pyraclofos of 21.5, 55.9, and 14.4 days in sterilized NC, HZ and ZZ soils, the degradation velocity was greatly improved in native soils, indicating that degradation was greatly attributed to microbially mediated processes in agricultural cultivating soils.     

Enantiomeric resolution and biotoxicity of methamidophos

Despite the fact that the biological processes of chiral pesticides are enantioselective, the biotoxicity of methamidophos with respect to enantioselectivity has so far received limited research. In this study, the enantiomeric separation and biotoxicity of the two enantiomers of methamidophos were investigated. Successful enantioseparation of methamidophos using high-performance liquid chromatography on a Chiralcel OD column was achieved. As indicated by the optical rotation and circular dichroism detection, (+)-methamidophos was eluted prior to (-)-methamidophos. The t test at the 95% level of confidence indicated significant differences between the enantiomers in their in vitro inhibition toward acetylcholinesterases of bovine erythrocytes and Electrophorus electricus and in vivo acute aquatic toxicity to Daphnia magna. The in vitro assays showed that (-)-methamidophos was about 8.0-12.4 times more potent to the enzymes than its (+)-form. In contrast, the (+)-enantiomer was 7.0 times more toxic to D. magna in 48 h tests. The toxicity of racemic methamidophos was intermediate in both in vitro and in vivo bioassays. These results suggest that the biotoxicity of chiral OPs to nontargeted organisms is enantioselective and therefore should be reevaluated with their pure enantiomers.     

Toxicity of (+)- and (-)-gossypol to the plant pathogen,Rhizoctonia solani

The dimeric sesquiterpene gossypol occurs naturally in cottonseed and other parts of the cotton plant. Gossypol exists as enantiomers because of the restricted rotation around the central binaphthyl bond. The (-)-enantiomer is toxic to nonruminant animals while the (+)-enantiomer exhibits little, if any, toxicity to these animals. Developing cotton plants with low levels of the (-)-gossypol could expand the use of cottonseed as a feed source. Gossypol also may play a role in protecting the plant from pathogens. The relative toxicity of (+)- and (-)-gossypol to plant pathogens has not been reported. We measured the concentration of (+)- and (-)-gossypol in roots from cotton seedlings that were treated with the biocontrol agent Trichoderma virens that induces biosynthesis of gossypol and related terpenoids in cotton roots. (-)-Gossypol was the minor enantiomer in control and treated roots, but levels were slightly higher in roots from T. virens-treated seed. We also determined the toxicity of the gossypol enantiomers and the racemate to the seedling disease pathogen Rhizoctonia solani. The (+)- and (-)-enantiomers of gossypol and the racemate are equally effective in inhibiting growth of this pathogen. The lethal doses of the gossypols required to kill the pathogen appeared to be similar, but their toxicities are significantly less than those of related cotton and kenaf sesquiterpenes. The results indicate that altering the enantiomeric ratio in cotton roots will not adversely affect the resistance of seedlings to the seedling pathogen R. solani.     

Enantioselective degradation and ecotoxicity of the chiral herbicide diclofop in three freshwater alga cultures

Aryloxyphenoxypropanoates are a class of chiral herbicides. They have a pair of enantiomers, only the R(+) form of which is herbicidally active. Diclofop, the model compound of these herbicides, is commercialized as the racemate of the ester form, diclofop-methyl, consisting of a 1:1 mixture of the enantiomers. This study evaluated the enantioselectivity in aquatic toxicity and biodegradation of diclofop and diclofop-methyl. The herbicidally inactive S(-) enantiomers of both diclofop-methyl and diclofop were similar to or higher than the corresponding R(+) forms in toxicity to algae, depending on specific species. Although no enantiomeric conversion occurred for diclofop-methyl and diclofop, the difference in the enantioselective degradation of these herbicides observed in algae cultures suggested that their application forms were an important factor determining their enantioselective environmental behavior. The cell permeability and heat treatment of algae revealed that the enantioselective degradation of diclofop in algae cultures was governed primarily by the facilitated uptake by algae, whereas the enantioselective toxicity was primarily governed by the passive uptake. These results suggested that the acute toxicity test such as the 96 h EC 50 was insufficient to assess the ecological risk of chiral pesticides because of the differential degradation as well as possibly differential action sites of enantiomers. From this study, it was concluded that the enantioselective degradation and toxicity of chiral herbicides may result in their ecotoxicological effects being difficult to predict and that specific attention should thus be paid to currently used racemic pesticides as less active or inactive enantiomers may pose higher ecological risks.     

Enantioselective separation and phytotoxicity on rice seedlings of paclobutrazol

The environmental significance of enantioselectivity in chiral insecticides and herbicides has been widely studied. However, little information is currently available on the enantioselective behavior of chiral plant growth regulators. In this study, paclobutrazol enantiomers were resolved and prepared by chiral high-performance liquid chromatography with a Sino-chiral OJ column. The relationship among absolute configuration, optical activity and circular dichroism of paclobutrazol enantiomers was established. The enantioselective behavior of paclobutrazol, including enantioselective effect of paclobutrazol on the growth of rice seedlings and cyanobacteria and enantioselective loss of paclobutrazol in rice seedling growth media, in rice culture system was studied. The (2S,3S)-(-)-enantiomer was almost 3.1 times more active than the (2R,3R)-(+)-enantiomer toward shoot growth as measured by 7 day EC50 values. Enantioselectivity could not be determined with respect to root growth of rice seedlings because a typical dosage response was not observed in the range of the concentrations studied. The dissipation of paclobutrazol in rice growth medium is not enantioselective. Enantiomers and diastereoisomer of paclobutrazol all facilitated the growth of cyanobacteria, which increase the effectiveness of rice biofertilizers. The (2S,3S)-(-)-enantiomer showed stronger stimulatory activity on Microcystis aeruginosa cyanobacteria than the (2R,3R)-(+)-enantiomer, whereas the latter was a more potent stimulator of Anabaena sp. growth. These observations indicate that application of the (2S,3S)-(-)-enantiomer of paclobutrazol and Microcystis aeruginosa in rice cultivation is a good strategy for improving rice seedling performance.     

Soil pH on mobility of imazaquin in oxisols with positive balance of charges

The influence of soil pH on the leaching potential of the ionizable herbicide imazaquin was assessed on the profile of two highly weathered soils having a net positive charge in the B horizon, in contrast to a soil having a net negative charge in the whole profile, using packed soil column experiments. Imazaquin leached to a large extent and faster at Kd values lower than 1.0 L kg(-1), a much more lenient limit than usually proposed for pesticides in the literature (Kd < 5.0 L kg(-1)). The amount of imazaquin leached increased with soil pH. As the soil pH increased, the percentage of imazaquin in the anionic forms, the negative surface potential of the soils, as well as imazaquin water solubility also increased, thus reducing sorption because of repulsive electrostatic forces (hydrophilic interactions). For all surface samples (0-0.2 m), imazaquin did not leach at soil pH values lower than pKa (3.8) and more than 80% of the applied amount was leached at pH values higher than 5.5. For subsurface samples from the acric soils, imazaquin only began to leach at soil pH values > zero point of salt effects (ZPSE > 5.7). In conclusion, the use of surface K(oc) values to predict the amount of imazaquin leached within soil profiles having a positive balance of charges may greatly overestimate its actual leaching potential.     

Determination of enantiomers of synthetic pyrethroids in water by solid phase microextraction - enantioselective gas chromatography

Solid phase microextraction (SPME) is an ideal sample preparation technique because of its speed and solvent-free features. Sampling by SPME is selective and only the dissolved concentration is measured, which allows measurement of the bioavailable fraction of a contaminant in aqueous media. One potential application of SPME is for analysis of enantiomers of chiral contaminants in environmental samples. In this study, a method was developed for determining enantiomers of (Z)-cis-bifenthrin and cis-permethrin in water using coupled SPME and enantioselective gas chromatography (GC). Following SPME sampling, enantiomers of (Z)-cis-bifenthrin and cis-permethrin were separated at the baseline on a beta-cyclodextrin-based enantioselective column, and analyte enrichment onto the SPME fiber was not enantioselective. The GC response increased as sampling time was increased from 0 to 240 min, and as sampling temperature was increased from 20 to 40 degrees C. Organic solvents such as methanol, acetone, and acetonitrile enhanced, while soil extracts slightly decreased, the GC response. The integrated SPME-enantioselective GC method was used to analyze surface runoff samples. The analysis showed preferential degradation of the 1S-3S enantiomer over the 1R-3R enantiomer for both (Z)-cis-bifenthrin and cis-permethrin. The concentrations detected by SPME-GC were substantially smaller than those determined following solvent extraction, suggesting that SPME-enantioselective GC analysis selectively measured the dissolved fraction.     

Enantiomer resolution and assay of propionic acid-derived herbicides in formulations by using chiral liquid chromatography and achiral gas chromatography

Enantiomers of 6 propionic acid-derived herbicides in the form of their esters were resolved using liquid chromatography with a chiral column. Free acids are converted to methyl esters by means of a BF3-catalyzed reaction. Chromatographic resolutions for 6 of 8 herbicides investigated were in the range of 2 to 4. The method was applied for the simultaneous determination of mecoprop and 2,4-D content and individual mecoprop enantiomers in 2 formulations containing racemic and R-mecoprop in mixture with 2,4-D. Precision and accuracy of content determination was comparable to standard methods, and enantiomer contents were in good agreement with declared values. The enantiomers of dichlorprop and mecoprop were also resolved as diastereomeric menthyl esters by achiral high resolution gas chromatography (HRGC). HRGC data on enantiomer composition were in good agreement with those from the LC method and other data.     

Potent enantioselective auxin: indole-3-succinic acid.

Low levels of synthetic auxins are used as root growth promoters for a wide variety of botanicals. When properly used, they can produce earlier and more prolific root growth. Indole-3-succinic acid (ISA) is a chiral compound that can be synthesized as a racemate. Its enantiomers were resolved by both chromatography and diastereomeric crystallization. The absolute configuration of each enantiomer was determined by X-ray crystallography and then tested for auxin activity. The relative effectiveness of the ISA enantiomers was determined and compared to the achiral synthetic auxin indole-3-butyric acid and to the natural auxin indole-3-acetic acid.     

Elucidation of the enantioselective enzymatic hydrolysis of chiral herbicide dichlorprop methyl by chemical modification

Up to 25% of the current pesticides are chiral, the molecules have chiral centers, but most of them are used as racemates. In most cases, enantiomers of chiral pesticides have different fates in the environment. Knowledge of the function of amino acids of enzymes involved in enantioselective behaviors contributes to the understanding of the enantioselectivity of chiral pesticides. In this work, Aspergillus niger lipase (ANL, EC3.1.1.3) was chemically modified using bromoacetic acid (BrAc), 2,3-butanedione (BD), N-bromosuccinimide (NBS), and methanal. The enantioselectivity of the enzymatic hydrolysis of 2,4-dichlorprop-methyl (DCPPM) was investigated by chiral GC. The results have suggested that histidine, arginine, and tryptophan are essential for lipase activity and might be involved in the catalytic site of ANL. In addition, histidine and lysine play an important role in determining the observed enantioselective hydrolysis of chiral herbicide dichlorprop methyl. The molecular modeling study revealed that the essential hydrogen bonds formed between DCPPM and catalytic residues of ANL might be responsible for the enantioselectivity of DCPPM. The loss of enantioselectivity can also arise from the fact that the modification of the amino acids may cause changes in both the nature of the ANL enzyme conformation and the binding pattern of DCPPM. Our study provides basic information for the exploration of the enantioselective interaction mechanism of enzymes with chiral pesticides.     

Determination of gossypol enantiomer ratio in cotton plants by chiral higher-performance liquid chromatography

A celulose tris(3,5-dimethylphenylcarbamate) coated onto APS silica (Nucleosil, particle size, 7 microm; pore size, 500 A) was used under a reversed-phase condition to measure the enantiomeric ratios of gossypol enantiomers in cottonseeds, flowers, and roots in a number of cultivars samples of different Gossipium species. While unidimensional chromatography was used for measuring the enantiomeric ratio of all the samples of G. hirsutum, G. mustelinum, and in the seeds of G. barbadense, multidimensional chromatography was necessary for the analysis of samples of roots and flowers of G. barbadense. In the latter case, an ODS Hypersil column was used in the first dimension for sample clean up, and the enantiomers were resolved on the second dimension by the chiral column. As expected, all the seed samples of G. hirsutum and G. mustelinum showed the (P)-(+)-enantiomer in excess, whereas the seeds of G. barbadense showed the (M)-(-)-enantiomer. However, (P)-(+)-gossypol was found in enantiomeric excess in three samples examined of roots and in one of flower of G. barbadense. These results are discussed in this paper.     

Enantioselective degradation and chiral stability of pyrethroids in soil and sediment

Synthetic pyrethroids contain two or three chiral centers, making them a family of chiral pesticides with a large number of stereoisomers. Recent studies showed significant differences in aquatic toxicity between enantiomers from the same diastereomers of pyrethroids. To better understand the ecotoxicological effect and fate of pyrethroid insecticides, chirality in biodegradation must also be considered. In this study, we examined enantiomer compositions of selected pyrethroids in field sediment samples taken from various locations in southern California. Enantioselective degradation was frequently observed for cis-bifenthrin, permethrin, and cyfluthrin under field conditions. We further conducted long incubation experiments under laboratory-controlled conditions using single enantiomers of cis-bifenthrin, cis-permethrin, and cypermethrin. The half-lives for individual enantiomers were calculated to be 277-770 days for cis-bifenthrin enantiomers, 99-141 days for cis-permethrin enantiomers, and 52-135 days for cypermethrin enantiomers, respectively. The direction and degree of enantioselectivity in degradation were found to closely depend on the specific compound as well as experimental conditions. Because no significant difference in degradation was observed after samples were sterilized, the observed enantioselectivity may be attributed to preferential biological transformations.     

Effects of the phenylamide fungicides, mefenoxam and metalaxyl, on the microbiological properties of a sandy loam and a sandy clay soil

The objective of the study was to compare ecotoxicological data obtained from laboratory experiments on the side-effects of three phenylamide fungicides, pure metalaxyl (racemic mixture of R- and S-enantiomers), formulated metalaxyl and mefenoxam (only active R-enantiomer) on the chemical and biochemical parameters of two soils of different type and origin. The purpose of the comparison was to determine to what extent mefenoxam, developed as alternative to metalaxyl, can affect the activity of soil micro-organisms and their processes, and to elucidate the differences between the effects of pure and formulated metalaxyl. The dynamics of the quantitative changes in biochemical parameters induced by the addition of these fungicides at their recommended field rate were determined in a sandy clay soil from Cameroon and a sandy loam soil from Germany, during a 120-day incubation experiment. The type of soil significantly influenced the effect of these fungicides on the soil parameters studied. Incorporation of these fungicides generally stimulated the activity of phosphatases and ß-glucosidase, mineralization and the availability of N and most plant nutrients in soils. The activity of dehydrogenase and the availability of NO₃^- were generally adversely affected. Among the fungicides tested, the stimulation was more pronounced with mefenoxam followed by formulated metalaxyl.     

Simultaneous gas chromatographic determination of carbofuran, metalaxyl, and simazine in soils

A method for extraction, cleanup, and simultaneous gas chromatographic detection of carbofuran, metalaxyl, and simazine in soils has been developed. Pesticide residues were extracted from soil with acetone containing 10% 0.2M HCl-KCl buffer (pH 2.0), cleaned up with methylene chloride-carbonate buffer (pH 10.7) solvent partitioning and solid-phase extraction on disposable silica gel columns, and quantitated with gas chromatography using a Supelcowax 10 megabore capillary column and a nitrogen-selective detector. Method limits of detection were 0.02 microgram/g for the 3 pesticides in surface soils (0-30 cm depths) and 0.02, 0.02, and 0.005 microgram/g in soils below 30 cm (subsoils) for carbofuran, metalaxyl, and simazine, respectively. Recoveries for carbofuran, metalaxyl, and simazine were 92.6 +/- 5.5, 93.6 +/- 5.0, and 88.4 +/- 6.7%, respectively, when soil samples were spiked with pesticide concentrations ranging from 0.02 to 2.0 micrograms/g.     

Effect of the addition of wine distillery wastes to vineyard soils on the adsorption and mobility of fungicides

In the present work, a study was made of the effect of the addition of liquid and solid wine distillery wastes (WLW and WSW) to vineyard soils on the adsorption and leaching of penconazole and metalaxyl, two fungicides of different hydrophobic character that are widely used in vine cultivation. The study of these processes is of great interest, since currently the green filter system is implemented simultaneously in vine cultivation and as an alternative to classic purification methods of such organic wastes. Three vineyard soils selected from the La Rioja region (NW Spain) were used. Adsorption isotherms of the 14C-labeled fungicides by the soils in aqueous medium and in WLW medium were obtained, together with the percolation curves of the fungicides in packed soil columns under saturated flow conditions. The adsorption and leaching of metalaxyl in a soil amended with WSW were also studied. The Freundlich Kf constants indicated an increase in the adsorption of both fungicides by the soils in WLW medium as compared to aqueous medium. The amounts of penconazole leached in the three soils when they were washed with water and WLW ranged between 3.18 and 39.3% and between 2.00 and 10.4%, respectively, of the total fungicide added to the columns. In the case of metalaxyl, these amounts represented 69.1-100 and 91.6-117%. Variations were also observed in the shape and parameters of the breakthrough curves obtained in both systems and in the presence of WSW. The soluble organic compounds of WLW must be retained by the soil components, creating new adsorbent hydrophobic surfaces, which increase the retention in the soil of the highly hydrophobic compound penconazole. In the case of metalaxyl, which is very water soluble, the soluble organic compounds of WLW seem to contribute to the increase in its leaching, whereas the WSW favors the opposite effect. The results obtained, indicating modifications in the adsorption and leaching of penconazole and metalaxyl in the presence of WLW and WSW, show that further studies should be carried out on the adsorption and mobility of the fungicides in soils from the vineyard zone, which in turn are used as a green filter purification system of wine wastes.