Development of new sustainable pyridinium ionic liquids: From reactivity studies to mechanism-based activity predictions.

CONTEXT: This study addresses the development of sustainable pyridinium ionic liquids (ILs) because of their potential applications in agriculture and pharmaceuticals. Pyridinium-based ILs are known for their low melting points, high thermal stability, and moderate solvation properties. We synthesized three novel pyridinium-based ILs: 1-(2-(isopentyloxy)-2-oxoethyl)pyridin-1-ium chloride, 1-(2-(hexyloxy)-2-oxoethyl)pyridin-1-ium chloride, and 1-(2-(benzyloxy)-2-oxoethyl)pyridin-1-ium chloride. The biological activities of these compounds were evaluated through plant growth promotion, herbicidal, and insecticidal assays. Our results show that the benzyloxy derivative significantly enhances wheat and cucumber growth, whereas the isopentyloxy compound has potent herbicidal effects. Computational methods, including DFT calculations and molecular docking, were applied to understand the structure‒activity relationships (SARs) and mechanisms of action. METHODS: The computational techniques involved dispersion-corrected density functional theory (DFT) with the B3LYP functional and the 6-311G** basis set. Grimme's D3 corrections were included to account for dispersion interactions. The calculations were performed via GAMESS-US software. Quantum descriptors of reactivity, such as ionization potential, electron affinity, chemical potential, and electrophilicity index, were derived from the HOMO and LUMO energies. Molecular docking studies were conducted via the CB-Dock server via AutoDock Vina software to predict binding affinities to cancer-related proteins. Petra/Osiris/Molinspiration (POM) analysis was used to predict the drug likeness and other pharmaceutical properties of the synthesized ILs.

Colchicine, Caffeine, Gramine, and Their Derivatives as Potential Herbicides, Fungicides, and Insecticides.

A preliminary in silico screening of 94 compounds, including colchicine, caffeine, gramine, and their derivatives, was conducted to identify potential herbicides, insecticides, and fungicides. Among the compounds tested, only gramine and its 13 derivatives exhibited potential activity. These compounds were further tested against eight species of insects, three species of weeds, and four species of fungi. All of the tested alkaloids were found to be ineffective as herbicides and insecticides, but they did exhibit some fungicidal activity. Four gramine derivatives showed some activity against Phytophthora infestans, Botrytis cinerea, Zymoseptoria tritici, and Fusarium culmorum.

Optimized Ginkgo leaf biochar: An efficient adsorbent for 2,4-D herbicide removal from wastewater.

This research exploited biochar, sourced from Ginkgo leaves (GLs), to facilitate the adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous environments. The results reveal that GL biochar, activated with ZnCl2 at a temperature of 500°C (500-ZGBC), demonstrated the greatest specific surface area (SBET) of 536.0 m2 g-1 for 2,4-D adsorption. The biochar's properties, including specific surface area, morphology, structure, thermal stability, and functional groups, were analyzed. Additionally, studies of kinetic and isotherm profiles were conducted, yielding the highest recorded adsorption capacity of 281.8 mg g-1. Pore filling, hydrogen bonding, π-π interactions, surface complexation with Zn groups, and electrostatic interactions contribute significantly to the adsorption performance of 500-ZGBC for 2,4-D. Optimal adsorption was determined to occur at pH 2.117, with a dose of 0.4230 g L-1 of 500-ZGBC, and an initial concentration of 2,4-D at 294.7 mg L-1, as evidenced by the application of the response surface method (RSM). PRACTITIONER POINTS: Premium pharmaceutical-grade biochar, derived from Ginkgo leaves, boasting a SBET of 536.0 m2 g-1 was produced. An absorption capacity reaching 281.8 mg g-1 was observed in Ginkgo leaf biochar for 2,4-dichlorophenoxyacetic acid (2,4-D) adsorption. The adsorption procedure was refined through the employment of response surface methodology.

Study of Amino Acid-Derived 3-Acyltetramic Acids as Herbicidal Agents.

The growing problem of herbicide resistance necessitates the development of novel herbicidal active ingredients, together with other integrated weed management approaches. Natural products are a major source of inspiration for novel actives. In previous research, we identified a 3-acyltetramic acid of microbial origin that inhibited algal growth in marine biofilms, at least in part through inhibition of photosystem II. In this work, we demonstrate the herbicidal effect of this lead compound and construct multiple libraries to test the impact of the different substituents of the central scaffold in order to study the structure-activity relationships. Among these analogues, the highest activities were found for medium- to long-chain acyl groups and apolar secondary amino acid residues. Finally, we provide first insights into the herbicidal mechanisms and present preliminary field-trial and ecotoxicological results for TA12-Pro, the most active analogue in our library. Together, this research shows the potential of 3-acyltetramic acids for herbicide development.

Persistence and degradation of tembotrione in loamy soil: Effect of various organic amendments, moisture regimes and temperatures.

In the present study, persistence and degradation of tembotrione, a triketone herbicide, was studied in loamy soil collected from maize field. Effects of organic amendments, moistures and temperatures on tembotrione dissipation were evaluated. Soil samples were processed according to the modified QuEChERS involving dichloromethane solvent and MgSO4 without PSA. Analysis using LC-MS/MS showed >95% recoveries of tembotrione its two metabolites TCMBA and M5 from fortified soils. Tembotrione residues dissipated with time and 85.55 to 98.53% dissipation was found on 90th day under different treatments. Tembotrione dissipation increased with temperature and moisture content of the soil. Among organic amendments, highest dissipation was observed in vermicompost amended soil. Minimum and maximum half-lives of tembotrione were recorded under 35 °C (15.7 days) and air-dry (33 days) conditions, respectively. Residues of tembotrione declined with time while that of TCMBA increased steadily up to 10-45th day in different treatments and declined thereafter. Residues of M5 were not detected in our experiments. Tembotrione persistence was negatively correlated with the organic carbon (%), moisture regimes, and temperature. A good correlation between soil microbial biomass carbon and degradation was found. A two-way ANOVA indicated significant differences between the treatments at 95% confidence level (p < 0.05).

Kinetics and sorption behavior of glyphosate and tricyclazole for their efficient retention in biomixtures.

The present investigation aims to study adsorption-desorption behavior of glyphosate and tricyclazole in rice straw-compost biomixtures. To enhance pesticide adsorption and performance of the bio-purification system, rice straw-compost (BM) biomixture was mixed with wheat straw biochar (WBC, 1% and 5%), and adsorption of both pesticides in control (BM) and WBCBM(1%) and WBCBM(5%) biomixtures was compared. The kinetics study suggested that the pseudo-second-order model best explained the time-dependent adsorption of both pesticides and intraparticle adsorption was not the rate-determining step. Tricyclazole was more sorbed than glyphosate in all biomixtures which can be attributed to its lower water solubility. The WBC increased the sorption of both pesticides, but the effect varied with the nature of pesticides and biochar content. The adsorption coefficient values in BM, WBCBM(1%), and WBCBM(5%) biomixtures were 26.74, 38.16, and 51.97 (glyphosate) and 38.07, 59.94, and 84.54 (tricyclazole), respectively. The adsorption data was subjected to the Freundlich, the Langmuir, and the Temkin isotherms, and among them, the Freundlich isotherm best explained pesticide adsorption behavior. Desorption results suggested that the adsorption of glyphosate was more irreversible than tricyclazole and depended upon initial pesticide concentration. This study suggested that biochar mixed rice straw-compost biomixtures can be exploited in bio-purification systems for glyphosate and tricyclazole.

Adsorption of imazamox in California agricultural soils and implications for branched broomrape (Phelipanche ramosa) management.

Results of previous research on chemigated imazamox for control of branched broomrape (Phelipanche ramosa) in processing tomatoes suggested potential soil-type differences in imazamox availability. Over two years, there were differences in crop-injury between two sites less than 30-km apart: imazamox-treated tomatoes in the Davis location had relatively minor early season injury while tomatoes at the Woodland location were severely injured or killed. The following study was conducted to investigate imazamox sorption in four California soils to determine if differences in herbicide adsorption played a role in variable crop-injury observed in the field trials. To determine the sorption capacity of imazamox of each soil, a batch-equilibrium study was conducted. There were significant differences in sorbed imazamox: the clay soil had the highest adsorption (Robert's Island: 742.5 pg µL-1 sorbed), followed by the sandy loam soil (Ripon: 723.9 pg µL-1 sorbed), while the loam soils from both trial sites (Davis: 704.2 pg µL-1 sorbed; Woodland: 699.9 pg µL-1 sorbed) had the lowest adsorption and were not significantly different from one another. Results from this study illustrate only minor differences in imazamox adsorption among the soils tested which suggests that soil type was likely not a major factor contributing to differences in crop-injury.

Biocompatible Nano-Cocrystal Engineering for Targeted Herbicide Delivery: Enhancing Efficacy through Stimuli-Responsive Release and Reduced Environmental Losses.

In addressing the critical challenges posed by the misuse and inefficiency of traditional pesticides, we introduce a Nano-Cocrystal material composed of the herbicide clopyralid and coformer phenazine. Developed through synergistic supramolecular self-assembly and mechanochemical nanotechnology, this Nano-Cocrystal significantly enhances pesticide performance. It exhibits a marked improvement in stability, with reductions in hygroscopicity and volatility by approximately 38%. Moreover, it intelligently modulates release according to environmental factors, such as temperature, pH, and soil inorganic salts, demonstrating decreased solubility by up to four times and improved wettability and adhesion on leaf surfaces. Importantly, the herbicidal activity surpasses that of pure clopyralid, increasing suppression rates of Medicago sativa L. and Oxalis corniculata L. by up to 27% at the highest dosage. This Nano-Cocrystal also shows enhanced crop safety and reduced genotoxicity compared to conventional formulations. Offering a blend of simplicity, cost-effectiveness, and robust stability, our findings contribute a sustainable solution to agricultural practices, favoring the safety of nontarget organisms.

Brassinosteroids Confer Resistance to Isoproturon through OsBZR4-Mediated Degradation Genes in Rice (Oryza sativa L.).

Plants have complex detoxification and metabolic systems that enable them to deal with environmental pollutants. We report accumulation of the pesticide isoproturon (IPU) in a BR signaling pathway for mutant bzr4-3/5 rice to be significantly higher than in wild-type (WT) rice controls and for exogenous 24-epibrassinolide to reverse toxic symptoms in WT rice but not in mutants. A genome-wide RNA sequencing study of WT/bzr4 rice is performed to identify transcriptomic changes and metabolic mechanisms under IPU exposure. Three differentially expressed genes in yeast cells increase the degradation rate of IPU in a growth medium by factors of 1.61, 1.51, and 1.29 after 72 h. Using UPLC/Q-TOF-MS/MS, five phase I metabolites and five phase II conjugates are characterized in rice grains, with concentrations generally decreasing in bzr4 rice grains. OsBZR4, a regulator of IPU degradation in rice, may eliminate IPU from edible parts of food crops by regulating downstream metabolic genes.

Unraveling the effects of acrylonitrile butadiene styrene (ABS) microplastic ageing on the sorption and toxicity of ionic liquids with 2,4-D and glyphosate herbicides.

Microplastics represent a novel category of environmental pollutants, and understanding their interactions with typical xenobiotics is crucial. In this study, we investigated the impact of ionic liquids (ILs) containing herbicidal anions, namely glyphosate [Glyph] and 2,4-dichlorophenoxyacetate [2,4-D], and the surfactant cation - dodecyltrimethylammonium [C12TMA] on acrylonitrile butadiene styrene (ABS) microplastics. The aim of the study was to assess the sorption capacity of microplastics that were present in both untreated and aged form using standard and modified Fenton methods. In addition, impact on toxicity and stress adaptation of the model soil bacterium Pseudomonas putida KT2440 was measured. Upon ageing, ABS microplastics underwent a fivefold increase in BET surface area and total pore volume (from 0.001 to 0.004 cm3/g) which lead to a dramatic increase in adsorption of the cations on ABS microplastics from 40 to 45% for virgin ABS to 75-80% for aged ABS. Toxicity was mainly attributed to hydrophobic cations in ILs (EC50 ∼ 60-65 mg/dm3), which was also mitigated by sorption on ABS. Furthermore, both cations and anions behaved similarly across different ILs, corresponding chlorides, and substrates used in the ILs synthesis. These findings highlight microplastics potential as hazardous sorbents, contributing to the accumulation of xenobiotics in the environment.

Enhanced Dechlorination of the Herbicide Acetochlor by an Anaerobic Consortium via Sulfate Acclimation.

Acetochlor residues can contaminate anoxic habitats where anaerobic microbial transformation dominates. Herein, a highly efficient anaerobic acetochlor-degrading consortium ACT6 was enriched using sulfate and acetochlor as selection pressures. The acclimated consortium ACT6 showed an 8.7-fold increase in its ability to degrade acetochlor compared with the initial consortium ACT1. Two degradation pathways of acetochlor were found: reductive dechlorination and thiol-substitution dechlorination in the chloroacetyl group, in which the latter dominated. Acclimation enhanced the abundances of Desulfovibrio, Proteiniclasticum, and Lacrimispora from 0.7 to 28.0% (40-fold), 4.7 to 18.1% (4-fold), and 2.3 to 12.3% (5-fold), respectively, which were positively correlated with sulfate concentrations and acetochlor degradation ability. Three acetochlor-degrading anaerobes were isolated from the acclimated consortium ACT6, namely Cupidesulfovibrio sp. SRB-5, Proteiniclasticum sp. BAD-10, and Lacrimispora sp. BAD-7. This study provides new insights into the anaerobic catabolism of acetochlor and the anaerobic treatment of acetochlor in wastewater.

Herbicidal Sorbicillinoid Analogs Cause Lignin Accumulation in Aspergillus aculeatus TE-65L.

Five new sorbicillinoid derivatives, including (±)-aspersorbicillin A [(±)-1], a pair of enantiomers at C-9, and aspersorbicillins B-D (2-4), together with two known analogs (5 and 6) were isolated from the endophytic fungus Aspergillus aculeatus TE-65L. Their structures including absolute configurations were determined by detailed spectroscopic analyses and electronic circular dichroism calculations. The herbicidal activity of sorbicillinoids on the germ and radicle elongation of various weed types was reported for the first time. Compound 1 displayed significant herbicidal activity against Eleusine indica germ elongation (IC50 = 28.8 µg/mL), while compound 6 inhibited radicle elongation (IC50 = 25.6 µg/mL). Both were stronger than those of glyphosate (66.2 and 30.9 µg/mL, respectively). Further transcriptomic and LC-MS/MS metabolomic analysis indicated that 6 induced the transcriptional expressions of genes related to the lignin biosynthetic pathway, resulting in lignin accumulation. Transmission electron microscopy confirmed the cell wall thickening of seeds treated with 6, suggesting weed growth inhibition. This study reveals new lead compounds for fabricating natural herbicides and expands the agricultural use of sorbicillinoid analogs.

Synthesis of Novel Propionamide-Methylpyrazole Carboxylates as Herbicidal Candidates.

Transketolase (TKL; EC 2.2.1.1) is a highly promising potential target for herbicidal applications. To identify novel TKL inhibitors, we designed and synthesized a series of 3-oxopropionamide-1-methylpyrazole carboxylate analogues and assessed their herbicidal activities. Ethyl 3-((1-((2,4-dichlorophenyl)amino)-1-oxopropan-2-yl)oxy)-1-methyl-1H-pyrazole-5-carboxylate (D15) and ethyl 1-methyl-3-((1-oxo-1-((thiophen-2-ylmethyl)amino)propan-2-yl)oxy)-1H-pyrazole-5-carboxylate (D20) exhibited superior growth inhibition activities against both the root and stem of Amaranthus retroflexus (A. retroflexus) compared to nicosulfuron and mesotrione. Additionally, D15 achieved an inhibition rate of more than 90% against the roots and stems of Digitaria sanguinalis (D. sanguinalis), outperforming the four control agents at a concentration of 200 mg/L using the small cup method. In the pre-emergence herbicidal activity test, D15 effectively inhibited D. sanguinalis by more than 90% at 150 g ai/ha, surpassing the efficacy of the control, mesotrione. Conversely, in the postemergence herbicidal activity test, D20 exhibited efficient inhibition of A. retroflexus by more than 90% at 150 g ai/ha, outperforming the control agents nicosulfuron, mesotrione, and metamifop. The results of the TKL enzyme activity test showed that the IC50 values of compounds D15 and D20 were 0.384 and 0.655 mg/L, respectively, which were close to those of the control agents. Furthermore, molecular docking and molecular dynamics simulation studies revealed that D15 and D20 interacted favorably with the TKL of Setaria viridis. Such findings highlight the promising potential of D15 and D20 as lead TKL inhibitors for the optimization of new herbicides.

Metproxybicyclone, a Novel Carbocyclic Aryl-dione Acetyl-CoA Carboxylase-Inhibiting Herbicide for the Management of Sensitive and Resistant Grass Weeds.

Postemergence control of grass weeds has become problematic due to the evolution of resistance to 5-enolpyruvylshikimate-3-phosphate synthase, acetyl-CoA carboxylase (ACCase), and acetolactate synthase-inhibiting herbicides. Herein we describe the invention and synthesis journey toward metproxybicyclone, the first commercial carbocyclic aryl-dione ACCase-inhibiting herbicide for the cost-effective management of grass weeds in dicotyledonous crops and in preplant burndown applications. Glasshouse and field experiments have shown that metproxybicyclone is safe for use on soybean, cotton, and sugar beet, among other crops. It is effective on a variety of key grass weeds including Eleusine indica, Digitaria insularis, Sorghum halepense, and Echinochloa crus-galli. Importantly, metproxybicyclone was more efficacious at killing resistant grass weed populations than current ACCase herbicides. Metproxybicyclone controlled the main ACCase target-site and nontarget site resistant mechanisms in characterized Lolium multiflorum and E. indica populations under glasshouse conditions. Excellent control of a broad resistance-causing D2078G target-site mutant E. indica population was also observed under field conditions.

A novel potato peels waste ß-cyclodextrin biocomposite for the efficient uptake of diuron and glyphosate herbicides.

A novel biocomposite (FPPW-ß-CD) was prepared by a simple and sustainable method involving fine potato peel waste, ß-cyclodextrin (ß-CD), and green citric acid through the crosslinking reaction. The polymer was characterized using SEM, FTIR, XRD, TGA, and DSC analyses. The adsorbent performance was evaluated about the glyphosate and diuron adsorption from the aqueous solution. Pesticide removal was investigated regarding the influence of solution pH, temperature, and initial concentration of contaminants. Also, it highlights the main interactions involved in the adsorption phenomenon based on the pH effect and characteristics of adsorbent and adsorbate molecules. The maximum adsorption capacity values according to the Sips model were higher than 2000 µg g-1. The pseudo-second-order and general-order models described the kinetic data well. Thermodynamic parameters indicated that pesticide removal was spontaneous and favorable. The magnitude of enthalpy variation values (27.37 kJ mol-1 and - 100.79 kJ mol-1) revealed that the glyphosate and diuron adsorption occurred through the physisorption and chemisorption, respectively. The novel biocomposite is a promising green adsorbent for the uptake of micropollutant pesticides in aqueous solutions at concentrations of µg L-1.

Microbial Biotransformation of 1-Methyl-L-tryptophan into Herbicidal Indole Alkaloids by Endophytic Fungus Nigrospora chinensis GGY-3.

Indole alkaloids are privileged secondary metabolites, and their production may be achieved by the microbial biotransformation of tryptophan analogues. By feeding 1-methyl-L-tryptophan (1-MT) into the culture of endophytic Nigrospora chinensis GGY-3, six novel (1-6) and seven known indole alkaloids (7-13) were generated. Their structures were elucidated by means of NMR spectroscopy, experimental electronic circular dichroism (ECD) spectra, and X-ray crystallography analysis. A Friedel-Crafts reaction was proposed as the key reaction responsible for the formation of the new compounds. Racemates 4 and 6 were separated into isomers by chiral HPLC, with their absolute configurations determined by X-ray and ECD calculation. Compounds 3, 4, and 8 display good herbicidal activity against dicotyledon weed Eclipta prostrata, of which 4 and 8 exhibited 88.50% and 100% inhibition rates on the radicle at 200 µg/mL, respectively, a similar effect compared to the positive control penoxsulam.

Multisite Mutagenesis of 4-Hydroxyphenylpyruvate Dioxygenase (HPPD) Enhances Rice Resistance to HPPD Inhibitors and Its Carotenoid Contents.

While frequently used herbicides display limited efficacy against herbicide-resistant weeds, it becomes imperative to explore novel herbicides that ensure both effective weed management and environmental safety. Though 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitory herbicides like mesotrione are prevalent in maize weed management, their integration into rice production is hindered due to the inherent sensitivity of rice HPPD (OsHPPD). In this study, a mutant allele of OsHPPD featuring six amino acid substitutions, termed OsHPPD-6M, maintains enzymatic activity in 200 µm mesotrione while the wild type can only withstand 1 µm. Enzymatic assays in vitro indicated that the HPPD activity of OsHPPD-6M surpassed that of the WT by 2-fold through enhanced substrate-binding. Its overexpression in transgenic rice conferred greater tolerance to mesotrione, topramezone, and isoxaflutole by 36.7-, 41.6-, and 37.1-fold relative to that in the WT rice. Interestingly, these 6M-OE plants demonstrated substantially elevated contents of carotenoids compared to WT plants without a significant impact on agronomic traits.

3D structure of acetolactate synthase explains why the Asp-376-Glu point mutation does not give the same resistance level to different imidazolinone herbicides.

Resistance to ALS-inhibiting herbicides has dramatically increased worldwide due to the persisting evolution of target site mutations that reduce the affinity between the herbicide and the target. We evaluated the effect of the well-known ALS Asp-376-Glu target site mutation on different imidazolinone herbicides, including imazamox and imazethapyr. Greenhouse dose response experiments indicate that the Amaranthus retroflexus biotype carrying Asp-376-Glu was fully controlled by applying the field recommended dose of imazamox, whereas it displayed high level of resistance to imazethapyr. Likewise, Sorghum halepense, carrying Asp-376-Glu showed resistance to field recommended doses of imazethapyr but not of imazamox. Biochemical inhibition and kinetic characterization of the Asp-376-Glu mutant enzyme heterologously expressed using different plant sequence backbones, indicate that the Asp-376-Glu shows high level of insensitivity to imazethapyr but not to imazamox, corroborating the greenhouse results. Docking simulations revealed that imazamox can still inhibit the Asp-376-Glu mutant enzyme through a chalcogen interaction between the oxygen of the ligand and the sulfur atom of the ALS Met200, while imazethapyr does not create such interaction. These results explain the different sensitivity of the Asp-376-Glu mutation towards imidazolinone herbicides, thus providing novel information that can be exploited for defining stewardship guidelines to manage fields infested by weeds harboring the Asp-376-Glu mutation.

Validation of shikimate dehydrogenase as the herbicidal target of drupacine and screening of target-based compounds with high herbicidal activity.

The discovery of new targets and lead compounds is the key to developing new pesticides. The herbicidal target of drupacine has been identified as shikimate dehydrogenase (SkDH). However, the mechanism of interaction between them remains unclear. This study found that drupacine specifically binds to SkDH with a dissociation equilibrium constant (KD) of 8.88 µM and a Kd value of 2.15 µM, as confirmed by surface plasmon resonance and microscale thermophoresis. Site-directed mutagenesis coupled with fluorescence quenching analysis indicated that residue THR431 was the key amino acid site for drupacine binding to SkDH. Nine compounds with the best binding ability to SkDH were identified by virtual screening from about 120,000 compounds. Among them, compound 8 showed the highest inhibition rate with values of 41.95% against SkDH, also exhibiting the strongest herbicidal activity. This research identifies a novel potential target SkDH and a candidate lead compound with high herbicidal activity for developing new herbicides.

Insights into the enhanced adsorption of glyphosate by dissolved organic matter in farmland Mollisol: effects and mechanisms of action.

Dissolved organic matter (DOM) is easy to combine with residual pesticides and affect their morphology and environmental behavior. Given that the binding mechanism between DOM and the typical herbicide glyphosate in soil is not yet clear, this study used adsorption experiments, multispectral techniques, density functional theory, and pot experiments to reveal the interaction mechanism between DOM and glyphosate on Mollisol in farmland and their impact on the environment. The results show that the adsorption of glyphosate by Mollisol is a multilayer heterogeneous chemical adsorption process. After adding DOM, due to the early formation of DOM and glyphosate complex, the adsorption process gradually became dominated by single-layer chemical adsorption, and the adsorption capacity increased by 1.06 times. Glyphosate can quench the endogenous fluorescence of humic substances through a static quenching process dominated by hydrogen bonds and van der Waals forces, and instead enhance the fluorescence intensity of protein substances by affecting the molecular environment of protein molecules. The binding of glyphosate to protein is earlier, of which affinity stronger than that of humic acid. In this process, two main functional groups (C-O in aromatic groups and C-O in alcohols, ethers and esters) exist at the binding sites of glyphosate and DOM. Moreover, the complexation of DOM and glyphosate can effectively alleviate the negative impact of glyphosate on the soil. This study has certain theoretical guidance significance for understanding the environmental behavior of glyphosate and improving the sustainable utilization of Mollisol.