Influence of the herbicides hexazinone and chlorsulfuron on the metabolism of isolated soybean leaf cells

The effects of the herbicides hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] and chlorsulfuron (2-chloro-N-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]benzenesulfonamide) on the metabolism of enzymatically isolated leaf cells from soybean [Glycine max (L.) Merr., cv. ‘Essex’] were examined. Photosynthesis, protein, ribonucleic acid (RNA), and lipid syntheses were assayed by the incorporation of specific radioactive substrates into the isolated soybean leaf cells. These specific substrates were NaH¹⁴CO₃, [¹⁴C]leucine, [¹⁴C]uracil, and [¹⁴C]acetate, respectively. Time-course and concentration studies included incubation periods of 30, 60, and 120 min and concentrations of 0.1, 1, 10, and 100 μM of both herbicides. Photosynthesis was the most sensitive and first metabolic process inhibited by hexazinone. RNA and lipid syntheses were also inhibited significantly by hexazinone whereas the effect of this herbicide on protein synthesis was less. The most sensitive and first metabolic process inhibited by chlorsulfuron was lipid synthesis. Photosynthesis, RNA, and protein syntheses were affected significantly only by the highest concentration of this herbicide and longest exposure. Although these two herbicides may exert their herbicidal action by affecting other plant metabolic processes not examined in this study, hexazinone appears to be a strong photosynthetic inhibitor, while the herbicidal action of chlorsulfuron appeared to be related to its effects on lipid synthesis.     

Localizing the action of two thiadiazolyl herbicidal derivatives

Enzymatically isolated leaf cells from navy beans (Phaseolus vulgaris L., cv. “Tuscola”) were used to study the effect of buthidazole (3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone) and tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea) on photosynthesis, protein, ribonucleic acid (RNA), and lipid synthesis. The incorporation of NaH¹⁴CO₃, [¹⁴C]leucine, [¹⁴C]uracil, and [¹⁴C]acetic acid as substrates for the respective metabolic process was measured. Time-course and concentration studies included incubation periods of 30, 60, and 120 min and concentrations of 0.1, 1, 10, and 100 μM of both herbicides. Photosynthesis was very sensitive to both buthidazole and tebuthiuron and was inhibited in 30 min by 0.1 μM concentrations. RNA and lipid syntheses were inhibited 50 and 87%, respectively, by buthidazole and 42 and 64%, respectively, by tebuthiuron after 120 min at 100 μM concentration. Protein synthesis was not affected by any herbicide at any concentration or any exposure time period. The inhibitory effects of buthidazole and tebuthiuron on RNA and lipid syntheses may be involved in the ultimate herbicidal action of these herbicidal chemicals.     

Inhibition of fatty acid biosynthesis in isolated bean and maize chloroplasts by herbicidal phenoxy-phenoxypropionic acid derivatives and structurally related compounds

The effects of nine phenoxy-phenoxypropionic acid derivatives and structurally related compounds on the incorporation of [¹⁴C]-acetate into free fatty acids in isolated bean and maize chloroplasts were studied. The compounds tested were esters and the corresponding free acids, OH-diclofop, a nonherbicidal metabolite of diclofop in plants, and d and l enantiomers of diclofop. Fatty acid biosynthesis in bean chloroplasts was not affected by all compounds. OH-Diclofop had a weak inhibitory effect on fatty acid synthesis in maize chloroplasts, while free acids were stronger inhibitors than the corresponding esters in the same system. Uptake studies with diclofop-methyl and diclofop indicated that the esters showed higher uptake rates in chloroplasts suspension. d-Diclofop (I₅₀, 9 × 10^?8M) was a more potent inhibitor than l-diclofop (I₅₀, 4 × 10^?6M). This agrees with the low herbicidal activity of the l enantiomer in vivo. The results suggest that the mode of action in this type of herbicide may be closely linked with the inhibition of fatty acid biosynthesis. The tolerance of beans could be based on an insensitivity of the target site.     

O,O′-二烃基 N-[α-芳氧乙(丙)酰基]硫代磷酰肼的合成与除草活性

通过芳氧乙(丙)酸与O,O'-二烃基硫代磷酰肼的缩合反应合成了8个未见报道的标题化合物,利用红外光谱、核磁共振、质谱和元素分析确定了化合物的结构。生物活性测试结果表明:目标化合物具有很好的选择性除草活性,其中化合物 3a、3b、3g和3h 对单子叶植物稗草和双子叶植物油菜均有较好的抑制作用,特别是对油菜的抑制作用尤为明显,其效果接近、有些甚至优于对照化合物2,4-D。     

A differential basis of antifungal activity of acylalanine fungicides and structurally related chloroacetanilide herbicides in Phytophthora megasperma f. sp. medicaginis

The acylalanine fungicides CGA 29212 and metalaxyl inhibit colony growth of Phytophthora megasperma f. sp. medicaginis at much lower concentrations than structurally related chloroacetanilide herbicides. Metolachlor, among the latter, shows the highest antifungal activity, followed by propachlor. Dimethachlor and alachlor are only weakly inhibitory. A metalaxyl- and CGA 29212-resistant strain of P. megasperma f. sp. medicaginis shows cross-resistance to metolachlor and propachlor, but levels of resistance are much lower than observed with CGA 29212 and metalaxyl. Cross-resistance does not occur to dimethachlor and alachlor. All compounds except metalaxyl inhibit uptake of [³H]uridine by mycelium, propachlor being most effective. Effects are similar with both a metalaxyl-sensitive and a -resistant strain. CGA 29212, metalaxyl, and metolachlor inhibit incorporation of [³H]uridine into RNA by mycelium of the sensitive strain at concentrations not inhibitory to uptake. Metalaxyl slightly affects incorporation by mycelium of the resistant strain; the other compounds have a more pronounced effect but only at concentrations inhibitory to uptake. Metalaxyl, CGA 29212, and propachlor do not induce leakage of radioactivity from mycelium of both strains when added at high concentrations to cultures previously incubated with [³H]uridine; under these conditions incorporation by mycelium of the metalaxyl-resistant strain is significantly more affected by CGA 29212 and propachlor than by metalaxyl. Endogenous RNA polymerase activity of isolated nuclei from a metalaxyl-sensitive strain is inhibited by CGA 29212, metalaxyl, and metolachlor but not by propachlor, dimethachlor, and alachlor. Neither compound has any effect on endogenous RNA polymerase activity of isolated nuclei from a metalaxyl-resistant strain. CGA 29212 and metolachlor evidently have a metalaxyl-type of action. The presence of cross-resistance of the metalaxyl-resistant strain to propachlor also indicates a metalaxyl-type of action for this compound, although this could not be confirmed by an inhibitory effect of propachlor on endogenous RNA polymerase activity. In addition to a metalaxyl-type of action, CGA 29212, metolachlor, and propachlor have a second one that is also present in dimethachlor and alachlor, which lack the metalaxyl-type of action. The second mechanism of action, involving inhibition of [³H]uridine uptake, is most prominent with propachlor and might be related to the primary mechanism of action in plants of the chloroacetanilide herbicides.     

丙炔氟草胺除草活性及对棉花的安全性

丙炔氟草胺是一种以原卟啉原氧化酶为作用标靶的N-苯基肽酰亚胺类除草剂。为探究其在棉花田的应用前景,通过温室盆栽法对丙炔氟草胺的杀草谱、除草活性及其对棉花的安全性进行了测定。结果表明:丙炔氟草胺对棉田常见阔叶杂草有较好防效,处理剂量为有效成分15 g/hm2时,对马齿苋Portulaca oleracea、反枝苋Amaranthus retroflexus、藜Chenopodium album、小藜Chenopodium serotinum和鳢肠Eclipta prostrata的鲜重防效均高于90%,对野油菜Rorippa indica、苣荬菜Sonchus arvensis、小飞蓬Conyza canadensis、龙葵Solanum nigrum、马唐Digitaria sanguinalis和牛筋草Eleusine indica等的鲜重防效高于80%;丙炔氟草胺对棉田4种常见阔叶杂草马齿苋、反枝苋、龙葵和藜的除草活性均显著高于二甲戊灵;丙炔氟草胺在鲁棉研28号与马齿苋、反枝苋、龙葵和藜之间的选择性指数依次为79.1、38.1、32.1和112.6,均显著高于二甲戊灵的12.0、9.9、5.8和9.2;鲁棉研37号、鑫秋4号与杂草间的选择性指数,与鲁棉研28号的相近。试验结果表明,丙炔氟草胺可作为棉田苗前防除阔叶杂草的候选药剂之一。     

Biochemical and physiological investigations into the delayed toxicity produced by O,O,S-trimethyl phosphorothioate in rats

Oral administration of O,O,S-trimethyl phosphorothioate (OOS), an impurity in several technical organophosphorus insecticides, causes delayed toxicity in rats with death occurring up to 28 days after the treatment. The oral LD₅₀ was determined to be 60 mg/kg. The effect of a single nonlethal dose of OOS (20 mg/kg) on in vivo protein synthesis in different organs was determined by measurement of the incorporation of [¹⁴C]leucine at 6 hr to 28 days after treatment. As early as 6 hr after OOS treatment the incorporation of [¹⁴C]leucine into the liver, lung, thymus, kidney, and spleen was elevated and remained elevated for up to 7 days. With the exception of the lung, organ weights were significantly decreased during the same time period. On Day 28 after treatment, the amount of [¹⁴C]leucine incorporation had decreased to the control level in all of the organs studied. Treatment with OOS at 20 mg/kg caused a significant increase in hematocrit on Days 3,5, and 7, and as early as 6 hr after treatment at 60 mg/kg. The clinical biochemistry of plasma indicated that there was no significant change from control values in the glutamic pyruvic transaminase, glutamic oxalic transaminase, lactate dehydrogenase, or alkaline phosphatase activities with the 20 mg/kg dose. The analysis of the intermediary metabolites indicated that the redox state of cytosol was more reduced on Day 5, whereas that of mitochondria was not affected by OOS. Data obtained at selected times after oral administration of a 60 mg/kg dose of OOS and that obtained from animals starved for 3 days are also discussed.     

N-(7-氟-3-氧-3,4-二氢-苯并噁嗪-6-基-)乙酰胺类化合物的合成及除草活性

为了寻找高效、安全的具有除草活性的新化合物,利用2-取代乙酰氯和2H苯并噁嗪-3-酮反应合成了9个N-(7-氟-3-氧-3,4-二氢苯并噁嗪-6-基-)乙酰胺类化合物,其结构经元素分析、IR、1H NMR确证。初步除草活性测试表明:在有效剂量75 g/hm2下,化合物 5d 芽后茎叶处理对刺苋Amaranthus spinosus等4种杂草显示出90%以上的抑制率。     

Influence of methabenzthiazuron on ATP-level and protein synthesis in wheat

Spring wheat (Triticum aestivum L. “Kolibri”) was grown in vermiculite treated with the photosynthesis inhibiting herbicide methabenzthiazuron (1-(benzothiazol-2-yl)-1,3-dimethylurea) either before germination or when the plants were 13 days old. The plants were analyzed from 2 days before until 11 days after treatment or up to a plant age of 23 days.The results are interpreted to fit the concept of a “shade adaptation reaction” caused by a herbicidal photosynthesis inhibition. Soluble reducing sugars have been found to decrease 4 hr after treatment and to stay at a low level throught the experiment. The ATP level was decreased 1 day after treatment but increased above control values 4 days later. This increase was accompanied by a decrease of the chlorophyll $\text{a}\text{b}$ ratio. The explanation is given that the ATP level was first decreased because of a lowered carbohydrate supply for substrate and oxidative phosphorylation, and was afterwords increased as a result of an increased cyclic photophosphorylation activity.The soluble protein content and the incorporation of [¹⁴C]leucine into protein were increased 4 days after herbicidal treatment. The total protein was slightly decreased beginning 1 day after treatment. The nitrate concentration and the in vitro nitrate reductase activity were both increased 1 day after treatment. The increase of the nitrate concentration occurred in two phases: a first increase by 50% 1 and 2 days after treatment and a second, much stronger increase beginning on the third day. The first increase is interpreted as the result of a decreased in vivo nitrate reductase activity. The second increase possibly was the result of an increased rate of nitrate uptake.     

Metalaxyl-induced changes in the antioxidant metabolism of Solanum nigrum L. suspension cells

The antioxidant responses of Solanum nigrum L. cell suspension cultures to metalaxyl exposure were investigated. An increase in lipid peroxidation and hydrogen peroxide content, for both concentrations tested (20 mg L⁻¹; 40 mg L⁻¹) revealed the response of oxidative metabolism of cell suspensions to metalaxyl. Superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and ascorbate peroxidase (APX; EC 1.11.1.11) activities increased, particularly in the highest concentration of metalaxyl used. An analysis by non-denaturing polyacrylamide gel (PAGE) followed by staining for enzyme activity, revealed seven SOD isoenzymes, two CAT isoenzymes, and nine APX isoenzymes. Metalaxyl levels were quantified in the culture medium and results suggest that suspension cells were able to accumulate and/or degrade the fungicide five hours after exposure. SOD, CAT and APX isoenzymes were differently affected by the metalaxyl treatment. Results suggest that the higher concentration of metalaxyl induced oxidative stress to cell suspension cultures of S. nigrum.     

A specific and sensitive assay to quantify the herbicidal activity of chloroacetamides

Based on a recently discovered property of chloroacetamide herbicides—the inhibition of the incorporation of oleic acid into sporopollenin of Scenedesmus acutus—a rapid quantitative test was developed for chloroacetamide-type herbicidal activity. In this test, algal cells are incubated for 3 h with [¹⁴C]oleic acid, saponified and the lipids (including non-saponifiable ones) extracted and discarded. The radioactivity incorporated into the residual non-lipid fraction is determined, and inhibition of this incorporation is used as a marker of chloroacetamide-type activity. Twenty-two agrochemical compounds were screened in this assay, which was found to be very sensitive, a 50% inhibition being reached with submicromolar herbicide concentrations. It is specific to chloroacetamides and related amides, since all these herbicides tested were potent inhibitors, while other herbicides were not. Highest inhibition was shown by cafenstrole followed by butachlor, fluthiamid, metazachlor, alachlor, dimethenamid, metolachlor and mefenacet. For these herbicides (with the exception of butachlor) sensitivity in the test was positively correlated (r=0·984) with their phytotoxic effect on the alga. © 1998 SCI     

Phytotoxicity of m-phenoxybenzamides: Inhibition of cell-free phytoene desaturation

Inhibition of carotenoid biosynthesis by herbicidal m-phenoxybenzamide derivatives has been investigated in a cell-free carotenogenic system from Aphanocapsa. Their target is the phytoenedesaturase reaction. Double-reciprocal plots of β-carotene biosynthesis (from ¹⁴C-labeled geranylgeranyl pyrophosphate) showed that 3-(2,5-dimethylphenoxy)-N-ethylbenzamide was a noncompetitive inhibitor of the phytoene-desaturase complex. The K_i value for cell-free inhibition of β-carotene formation was almost identical to the I₅₀ value of intact cells. Furthermore, the influence of certain substituents on herbicidal activity has been investigated. Inhibition increased with the length of the unbranched N-alkyl chains. In addition, substituents at the phenoxy group with higher lipophilicities showed greater inhibitory activities. The presence of a phenoxy or trifluoromethyl moiety at position 3 is essential.     

Characterization of herbicidal injury by acifluorfen-methyl in excised cucumber (Cucumis sativus L.) cotyledons

Initial signs of herbicidal injury by several diphenyl ether herbicides were monitored by following the efflux of ⁸⁶Rb⁺ from treated cucumber (Cucumis sativis L.) cotyledons after exposure to light (600 μE m^?2 sec^?1; measured as PAR, i.e., photosynthetically active radiation between 400 and 700 nm). This very sensitive, rapid, and quantitative bioassay proved quite useful in (a) a structure-activity correlations study of the diphenyl ether compounds investigated and (b) an examination of herbicidal characteristics. The following diphenyl ether herbicides were analyzed: acifluorfen, sodium 5-[2-chloro-4-(trifluormethyl)phenoxy]-2-nitrobenzoate; acifluorfen-methyl (MC-10108), methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate; bifenox, methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate; nitrofen, 2,4-dichlorophenyl p-nitrophenyl ether; nitrofluorfen, 2-chloro-1-(4-nitrophenoxy)-4-(trifluoromethyl)benzene; oxyfluorfen, 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene; MC-7783, potassium 5-(2,4-dichlorophenoxy)-2-nitrobenzoate; and MC-10982, ethyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate. Of the compounds investigated, acifluorfen-methyl (AFM) had the greatest degree of herbicidal activity. Cucumber cotyledons placed in high light (600 μE m^?2 sec^?1; PAR) with 10 nM AFM showed a significant increase in the efflux of ⁸⁶Rb⁺ within 2 to 4 hr. Light was required for herbicidal activity by AFM, and when treated cotyledons were returned to darkness, no further damage to the tissue occurred. By decreasing the quantity of light, the effect of the compound was delayed, although the magnitudes of the responses at the different intensities (600, 300, 150, and 75 μE m^?2 sec^?1; PAR) were nearly equal. By increasing the length of time of dark pretreatment with 1 μM AFM, ⁸⁶Rb⁺ efflux could be detected as early as 10 to 15 min after exposure to light (600 μE m^?2 sec^?1; PAR). Following light activation of AFM there was a simultaneous efflux of ⁸⁶Rb⁺, ³⁶Cl^?, ⁴⁵Ca²⁺, 3-O-methyl-[¹⁴C]glucose, and [¹⁴C]methylamine⁺. These data suggest the initial response to the herbicidal activity of AFM is expressed as a general increase in membrane permeability.     

Synthesis and herbicidal potential of substituted aurones

BACKGROUND: With the objective of exploring the herbicidal activity of substituted aurones, a series of 4,6‐disubstituted and 4,5,6‐trisubstituted aurones were synthesised, and their herbicidal activities against Brassica campestris L. and Echinochloa crusgalli (L.) Beauv. were evaluated in laboratory bioassays. Effects of some of the compounds were evaluated on seed germination. The most active compounds in the laboratory were evaluated in the greenhouse. RESULTS: The compounds were characterised by ¹H NMR, ¹³C NMR and HRMS; some of them were further identified by IR. A (Z)‐configuration was assigned to the aurones, based on spectroscopic and crystallographic data. Bioassay results of root growth showed that the aurones had a moderate herbicidal activity against the dicotyledonous plant Brassica campestris. (Z)‐2‐Phenylmethylene‐4,6‐dimethoxy‐3(2H)‐benzofuranone(6o) was the most active compound, with 81.3 and 88.5% inhibition at 10 and 100 µg ml^?1 respectively, equal to the activity of mesotrione. Some of the aurones possessed some inhibition of germination on several plant species. For glasshouse tests, the substituted aurones had lower herbicidal activity than metolachlor and mesotrione. CONCLUSION: It is possible that aurone derivatives, which possess structures different from those of the commercial herbicides, may become novel lead compounds for the development of herbicides against dicotyledonous weeds with further structure modification. Copyright © 2012 Society of Chemical Industry     

吡唑酰胺基脲类化合物的合成及除草活性

根据活性结构拼接原理,以1-甲基-3-乙基-5-吡唑甲酰肼为起始原料,设计合成了19个新吡唑酰胺基脲类衍生物,其结构均经过核磁共振氢谱、红外光谱、质谱和元素分析确证。生物活性测试结果表明:大部分化合物对双子叶杂草苘麻Abutilon theophrasti、反枝苋Amaranthus retroflexus以及凹头苋A.ascedense显示出较好的除草活性及选择性,如在2 250 g/hm2的剂量下,3i在苗后和苗前处理时,对苘麻和反枝苋的抑制率都达到了100%。复筛的结果表明,在375 g/hm2下,3i对双子叶杂草表现出中等除草活性。     

Dimethoxypyrimidines as Novel Herbicides. Part 2. Synthesis and Herbicidal Activity of O-Pyrimidinylsalicylates and Analogues

A new series of the O-pyrimidinylsalicylates was synthesized and their herbicidal activity was examined. Some of these compounds showed very strong herbicidal activity under pre- and post-emergent treatment conditions against various kinds of grass and broadleaf weeds. Among these compounds, O-(4, 6-dimethoxypyrimidin-2-yl) salicylic acid and its methyl ester were found to exhibit the highest activity. The herbicidal symptoms observed after the treatments included early cessation of plant growth followed by chlorosis, necrosis and plant death. The symptoms were similar to those caused by sulfonylureas and imidazolinones, which inhibit branched-chain amino acid biosynthesis.     

2-杂环基-1,3,4-噁二嗪酮类化合物的合成及其除草活性

以取代杂环羧酸为起始原料,在1,3,4-噁二嗪-5-酮的2-位上分别引入呋喃环、吡啶环及氯代噻吩环,合成了31个未见报道的2-杂环基-1,3,4-噁二嗪酮化合物,其化学结构经核磁共振氢谱和元素分析确证。初步的生物活性测定结果表明,该类化合物具有良好的除草活性,如在质量浓度200 mg/L时,化合物 E14、E16、E20、E21 对马唐Digitaria sanguinalis的抑制率大于90%,化合物 E06、E07、E10、E14、E16、E20 对苋菜Ambrosia tricolor的抑制率也大于90%。     

Quantitative structure-activity relationships of herbicidal N′-substituted phenyl-N-methoxy-N-methylureas

Relationships between three types of herbicidal activity of N′-substituted phenyl-N-methoxy-N-methylureas and substitution at the benzene ring were analyzed by the Hansch-Fujita method. First, the Hill inhibitory activity was correlated with electronic (σ) as well as hydrophobic (π) substituent constants. The existence of an optimum value of hydrophobicity for substituents was suggested to reach the target site of action. Second, bliaching activity observed for the 3-substituted but not for 4-substituted compounds was correlated with π, σ, and steric substituent constant, E_s. Third, the postemergent herbicidal activity was shown to correlate linearly with the Hill inhibitory activity, pI₅₀, and hydrophobic parameter, π.     

含肟醚并取代异 NFDA1唑环的氨基甲酸酯类化合物的合成及生物活性

为寻找具有优异生物活性的氨基甲酸酯类化合物,根据活性亚结构拼接原理,将取代异 NFDA1 唑和肟醚基团引入多菌灵结构中,以取代苯甲醛 (1) 和2-氯苄胺(3) 为起始原料,经多步反应设计合成了10个未见文献报道的含肟醚并取代异 NFDA1 唑的氨基甲酸酯类化合物,其结构经 1H NMR 和 MS 确证。初步生物活性测定结果表明,部分目标化合物不仅具有一定的杀菌活性,同时还具有较好的除草活性。其中,活体盆栽试验结果表明,化合物11b对黄瓜霜霉病Pseudoperonospora cubensis 的相对防效为90%,对黄瓜白粉病Sphaerotheca fuliginea 的相对防效达95%,低于对照药剂多菌灵;除草活性皿测法表明,化合物11c和11j 200 mg/L下对靶标作物的根、茎抑制率均达80%以上,与对照药剂异丙酯草醚活性相当。盆栽法表明,150 g/hm2下,化合物11c和11j对繁缕Stellaria media苗前和苗后的抑制率均在70%以上,低于异丙酯草醚。此类化合物的构效关系有待进一步研究。     

棉籽壳中除草活性物质提取及鉴定

为了开发利用棉籽壳中的除草活性物质,分别以无水乙醇、正丁醇、石油醚和乙酸乙酯为溶剂,采用索氏提取法对棉籽壳中的活性物质进行了提取,并对各溶剂粗提物进行了除草活性测定。结果发现:用无水乙醇提取的粗提物对稗草生长的抑制活性最高,经气相色谱-质谱(GC-MS)联用分析,发现该粗提物中主要含有甘油、三环己基3-烯-6-辛酮、4-乙烯基-2-甲氧基苯酚、(邻甲基苯酚)-2-溴-2氯-乙酰酯、十四酸、十四酸乙酯、十六烷酸、辛酸异戊酯和亚油酸9种化合物。进一步的除草活性测定结果表明,亚油酸、辛酸异戊酯、4-乙烯基-2-甲氧基苯酚和(邻甲基苯酚)-2-溴-2氯-乙酰酯4种化合物对稗草表现出一定的除草活性,其中亚油酸活性最强,其IC₅₀值为14.5 mg/L。