Barnyard grass extract and application thereof

Abstract

The invention belongs to the field of pesticides, and particularly relates to a barnyard grass extract and application thereof in barnyard grass inhibition. The barnyard grass extract is extracted by taking barnyard grass as a raw material, and the extract contains a series of compounds with barnyard grass inhibition activity. Active compounds contained in the barnyard grass extract have inhibitory activity on barnyard grass, and the barnyard grass extract can be mixed with agriculturally acceptable solvents and / or auxiliary materials to form a barnyard grass inhibitor.

Description

Technical Field

[0001] The invention belongs to the field of pesticides, and particularly relates to a barnyard grass extract and application of the extract in preparing a barnyard grass inhibitor. Background Art

[0002] Echinochloa plants belong to the Poaceae family, native to Europe and India, and distributed in tropical and temperate regions. They are annual or perennial herbs. Most of them are field weeds, causing serious damage to crops. Echinochloa weeds are also widely distributed in my country, causing serious damage to crops such as rice. Among the malignant weeds that cause serious damage to farmland in my country, Echinochloa ranks first.

[0003] Echinochloa weeds are particularly harmful to rice and have become the number one malignant weed in rice-producing areas, seriously affecting rice yield and quality. They belong to the same family as rice and are closely related. Their growth cycle, plant type, and requirements for light, water, and fertilizer are very similar. Echinochloa weeds grow alongside rice in paddy fields, causing allelopathic effects, and fiercely competing for water, fertilizer, light, and growth space, inhibiting the normal growth and development of rice and causing rice yield reductions. At the same time, Echinochloa weeds have a strong ability to spread, and their reproductive capacity and resistance are stronger than rice. Their appearance is very similar to rice, so the prevention and control of Echinochloa weeds is very difficult.

[0004] Weed control is mainly divided into physical control, agricultural control, chemical control and biological control. Physical control includes manual weeding, electric and microwave weeding, film covering and weed suppression, etc.; agricultural control is to optimize the current farmland cultivation methods, cultivation techniques and field management methods. Chemical control is to use herbicides to control weeds; biological control is to use biological natural enemies to control weeds. However, physical weeding and agricultural control consume a lot of human resources and are expensive. Biological control has just started, and chemical control has the characteristics of high efficiency, fast and convenient. Therefore, herbicides are currently mainly used for weed control. The high efficiency and convenience of chemical herbicides have made them widely used around the world, and the amount of use has been increasing. Long-term use and irregular management have seriously affected the ecological environment and have an impact on human health, and the resistance of Echinochloa genus weeds to them has also been increasing. Echinochloa genus weeds have been found to be resistant to 9 types of herbicides, including urea / amide type propanil, hormone type dichloroquine acid, and dual ALS inhibitor bispyribac-sodium.

[0005] Compared with chemical herbicides, botanical herbicides often have the characteristics of low toxicity and low environmental harm, so the research and development of botanical extracts in weed control has been ongoing: for example, the ethanol extracts of Vitex truncatula and Acer palmatum can inhibit the growth of barnyard grass seedlings, the ethyl acetate extract and n-butanol extract of Erigeron can inhibit the germination of barnyard grass seeds and the growth of seedlings, the ethanol extract of Artemisia annua leaves can inhibit the germination of barnyard grass seeds, the chloroform extract, ethyl acetate extract and water part of rice husk ethanol extract inhibit barnyard grass growth to varying degrees, the extract of Eupatorium adenophorum can inhibit the germination of barnyard grass seeds and the growth and development of the root system, the ethanol extract of Abelia grandiflora and its extract can inhibit the germination of barnyard grass seeds and the growth of seedlings, and the water extract of tall fescue can inhibit the growth of barnyard grass, etc. However, the first of all, the plants developed for botanical extracts are limited; the second is that the plants currently developed are all exogenous plants, and their extracts contain many exogenous substances that barnyard grass itself does not have.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] In view of the problems existing in the prior art, a barnyard grass extract and use thereof in preparing a barnyard grass inhibitor are provided.

[0008] To achieve the above purpose, the present invention adopts the following technical solution:

[0009] A barnyard grass extract is obtained by extracting barnyard grass as a raw material.

[0010] The barnyard grass extract is obtained by taking barnyard grass as a raw material and extracting with an organic solvent.

[0011] The "extract" described in the present invention is a substance formed by using barnyard grass as raw material, through a physical and chemical extraction and separation process, to obtain and / or concentrate one or more target components (i.e., components with barnyard grass inhibitory effect) in the raw material. It includes extraction methods known in the art and combinations of extraction methods known in the art; extraction methods include but are not limited to solvent treatment, solid phase extraction, supercritical CO2, heat, ultrasonic extraction, pressure or centrifugal force, or other chemical and / or mechanical process to obtain target components from raw materials. Therefore, the "extract" described in the present invention includes crude extracts, active components and active monomers.

[0012] The "crude extract" and "crude extract" mentioned in the present invention both refer to a mixture obtained after extracting and separating the raw materials with a solvent.

[0013] The "active component" of the present invention refers to an extract (relative to the crude extract) having a higher concentration of anti-barnyardgrass effect obtained by further processing the crude extract with the inhibitory activity of barnyardgrass as the guide, such as extraction, chromatography, distillation, sublimation, crystallization and precipitation, ion exchange, chromatographic separation, centrifugal separation, electrodialysis, electrolytic separation, electromagnetic separation, adsorption separation, magnetic separation, etc. In the present invention, the "active component" can be an extract, a purified product, an eluate, a separated product, etc.

[0014] The "active monomer" mentioned in the present invention refers to a certain target compound in the "active component" (ie, the active compound having barnyard grass inhibitory effect).

[0015] The "analogues" mentioned in the present invention refer to compounds that use one or more active monomers (i.e., active compounds with barnyard grass inhibitory effects) obtained from the extract as the parent compound, (1) compounds that are similar to the parent compound in chemical structure; (2) compounds that have the core structural characteristics of the parent compound; (3) new compounds that retain the basic structure of the parent compound and replace carbon atoms or other atoms in the structure of the parent compound with similar atoms or groups.

[0016] The barnyard grass extract is obtained by using barnyard grass as raw material through solvent extraction; or, after solvent extraction, through organic solvent extraction; or, the extract is further purified and eluted to obtain an eluate; or, the eluate is further separated by HPLC to prepare an active monomer.

[0017] The barnyard grass extract is prepared by using barnyard grass as a raw material and extracting with an organic solvent to obtain a crude extract; or, the crude extract is subjected to solvent extraction to obtain an extract; or, the extract is further purified and eluted by silica gel column chromatography to obtain eluate 1; or, eluate 1 is further purified and eluted by MCI column to obtain eluate 2; or, eluate 2 is further purified and eluted by glucose gel column to obtain eluate 3; or, eluate 3 is further separated by HPLC to obtain an active monomer.

[0018] The extraction method can be one or more of pressing, leaching, supercritical extraction, water extraction, and solvent extraction.

[0019] The extraction method comprises the following steps: adding barnyard grass into a solvent for leaching to obtain a crude extract.

[0020] Furthermore, the crude extract is suspended in water, and extracted with petroleum ether and ethyl acetate in sequence to obtain a petroleum ether extract, an ethyl acetate extract and an aqueous phase extract, respectively.

[0021] Furthermore, the ethyl acetate extract was chromatographed on a silica gel column with a gradient elution of dichloromethane-methanol (volume ratio of 100:1, 50:1, 20:1, 10:1, 5:1, 2:1), and detected on TLC with vanillin sulfuric acid solution as a color developer. The results were combined to obtain active components Fr.A to Fr.E.

[0022] Furthermore, the active component Fr.B was separated by MCI column, gradient eluted with methanol-water (volume ratio 1:9, 3:7, 5:5, 7:3, 10:0), and detected on TLC with vanillin sulfuric acid solution as a color developer, and the results were combined to obtain Fr.B.1 to Fr.B.8.

[0023] Furthermore, the Fr.B.3 is separated by dextran gel column chromatography and isocratically eluted with methanol. The eluted components are detected on TLC using vanillin sulfuric acid solution as a color developer. The results are combined to obtain Fr.B.3-1, Fr.B.3-2 and Fr.B.3-3.

[0024] Furthermore, Fr.B.3-3 was separated and prepared by HPLC, using octadecylsilane bonded silica gel as the stationary phase, methanol and water (25 / 75, v / v) as the mobile phase, a flow rate of 2.0 mL / min, and a detection wavelength of 210 nm to separate and prepare the active monomer.

[0025] The active monomer is 1,3,5-trimethoxybenzene.

[0026] The solvent in the extraction method is one or more of water, alcohol, dichloromethane, chloroform, ethyl acetate, ether, benzene, petroleum ether and / or acetone; preferably alcohol; more preferably ethanol. The mass ratio of barnyard grass to the extraction solvent is 1:(3-20); specifically, it can be 1:5, 1:8, 1:10, 1:12, 1:15, 1:18.

[0027] The mass ratio of the crude extract to water in the suspension is 1:(1-10); specifically, it can be 1:1, 1:2, 1:5, 1:7, or 1:9.

[0028] The barnyard grass is the whole plant of barnyard grass.

[0029] The use of the barnyard grass extract in preparing an anti-barnyard grass agent.

[0030] The anti-barnyard grass agent contains an extract obtained by extracting barnyard grass as a raw material (including a crude extract, active components and / or active monomers) and one or more of the active monomer analogs in the extract.

[0031] The "inhibition of barnyard grass" or "barnyard grass inhibition" mentioned in the present invention means reducing the activity of barnyard grass, specifically refers to slowing down the growth and development of barnyard grass, and reducing the flowering rate, pollen amount, fruit setting rate and / or seed germination rate by some means.

[0032] The barnyard grass inhibitor is used for reducing barnyard grass harm.

[0033] A barnyard grass inhibitor, the active ingredients of which include one or more of an extract obtained by extracting barnyard grass itself as a raw material, an extract (including a crude extract, an active component and / or an active monomer), and an active monomer analogue in the extract.

[0034] The barnyard grass inhibitor is a mixture of active ingredients and agriculturally acceptable solvents, wherein the active ingredients account for 0.00001-99.9% of the weight of the inhibitor; the agriculturally acceptable solvent is one or more of water or organic solvents.

[0035] The barnyard grass inhibitor is a mixture of active ingredients and agriculturally acceptable solvents, and may also include agriculturally acceptable adjuvants; wherein the active ingredients account for 0.001-99.9% of the weight of the barnyard grass inhibitor.

[0036] The active ingredient preferably accounts for 0.01-50% by weight of the barnyard grass inhibitor, more preferably 0.01-40%, and even more preferably 0.1-30%. The active ingredient may specifically account for 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, etc. by weight of the barnyard grass inhibitor.

[0037] Furthermore, the auxiliary materials include agriculturally acceptable adjuvants and / or carriers.

[0038] Furthermore, the auxiliary agent includes a wetting agent, a dispersant, a thickener, an antifreeze agent, a defoaming agent, a film former, a preservative and / or an emulsifier.

[0039] The preparation can be a spray, a fumigant or a nano preparation, etc.

[0040] A composition for inhibiting the growth of barnyard grass comprises an active component A and an active component B, wherein the active component A and the active component B are mixed in a weight ratio of 1:100-100:1; the active component A is one or more of a crude extract obtained by extracting barnyard grass itself as a raw material, an active component, and an active monomer; and the active component B is one or more of other herbicides, insecticides, miticides, and fungicides.

[0041] Use of 1,3,5-trimethoxybenzene and its analogs in the preparation of barnyard grass inhibitors.

[0042] The 1,3,5-trimethoxybenzene can be homemade or commercially available.

[0043] A barnyard grass inhibitor, the active ingredient of which contains 1,3,5-trimethoxybenzene.

[0044] The barnyard grass inhibitor is a mixture of active ingredients and agriculturally acceptable solvents, wherein the active ingredients account for 0.001-99.9% of the weight of the barnyard grass inhibitor; the agriculturally acceptable solvent is one or more of water or organic solvents.

[0045] The barnyard grass inhibitor is a mixture of active ingredients and agriculturally acceptable solvents, and may also include agriculturally acceptable adjuvants; wherein the active ingredients account for 0.001-99.9% of the weight of the barnyard grass inhibitor.

[0046] Furthermore, the auxiliary materials include agriculturally acceptable adjuvants and / or carriers.

[0047] Furthermore, the auxiliary agent includes a wetting agent, a dispersant, a thickener, an antifreeze agent, a defoaming agent, a film former, a preservative and / or an emulsifier.

[0048] The preparation can be a spray, a fumigant or a nano preparation, etc.

[0049] A composition for inhibiting the growth of barnyard grass comprises an active component A and an active component B, wherein the active component A and the active component B are mixed in a weight ratio of 1:100-100:1; the active component A is 1,3,5-trimethoxybenzene; and the active component B is one or more of other herbicides, insecticides, miticides and fungicides.

[0050] The 1,3,5-trimethoxybenzene can be homemade or commercially available.

[0051] The barnyard grasses are all weeds in the genus Echinochloa.

[0052] Furthermore, the barnyard grass is specifically barnyard grass (E.crusgalli) and its variants; the barnyard grass variants are specifically barnyard grass variant (E.crusgalli var.crusgalli), awnless barnyard grass (E.crusgalli var.mitis), western barnyard grass (E.crusgalli var.zelayensis), small barnyard grass (E.crusgalli var.austrojaponensis), short-awned barnyard grass (E.crusgalli var.breviseta), fine-leaved barnyard grass (E.crusgalli var.praticola), etc.

[0053] The beneficial effects of the present invention are:

[0054] (1) The barnyard grass extract (including crude extract, active components and active monomers) of the present invention is obtained by extracting the whole plant of barnyard grass, and is then used to inhibit barnyard grass (including inhibiting the germination of barnyard grass seeds and inhibiting the growth of barnyard grass plants). It is widely available and inexpensive, and does not contain any external additives or exogenous compounds. It is highly effective, safe and non-toxic, and is conducive to market promotion.

[0055] (2) The present invention applies the barnyard grass extract (including crude extract, active components and active monomers) to the prevention and treatment of barnyard grass, which expands the use of harmful weeds - barnyard grass and realizes waste utilization.

[0056] (3) The barnyard grass extract obtained by the present invention (including crude extract, active components and active monomers) can be directly applied to the barnyard grass itself by spraying, aerial spraying and other methods, which is convenient to use.

[0057] (4) The barnyard grass extract obtained by the present invention (including crude extract, active components and active monomers) can be used in dry land, paddy fields and other places where the growth of barnyard grass needs to be inhibited by spraying, aerial spraying and the like, and can effectively inhibit the germination of barnyard grass. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a flow chart for the extraction and separation of active components and active monomer 1,3,5-trimethoxybenzene from barnyard grass.

[0059] Figure 2 This is a graph showing the growth inhibition rate of barnyardgrass seeds after being treated with different concentrations of crude extracts in Example 1 for 3 days.

[0060] Figure 3 This is a graph showing the growth inhibition rate of barnyardgrass seeds after being treated with different extracts in Example 1 for 5 days.

[0061] Figure 4 This is a graph showing the growth inhibition rate of barnyardgrass seeds after 5 days of treatment with Fr.A-Fr.E in Example 2.

[0062] Figure 5 This is the high-resolution mass spectrum of 1,3,5-trimethoxybenzene.

[0063] Figure 6 1,3,5-trimethoxybenzene 1 H-NMR spectrum.

[0064] Figure 7 1,3,5-trimethoxybenzene 13 C-NMR spectrum.

[0065] Figure 8 This is a graph showing the growth inhibition rate of barnyardgrass seeds after being treated with different concentrations of 1,3,5-trimethoxybenzene for 5 days in Example 3. DETAILED DESCRIPTION

[0066] The technical solutions in the embodiments of the present invention are described clearly and completely below. The described embodiments are only a part of the present invention, not the whole of the invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] The preparation method of barnyard grass crude extract, active components and active monomers comprises the following steps:

[0068] (1) The whole plant of barnyard grass is dried and crushed to obtain barnyard grass powder;

[0069] (2) adding ethanol in a mass ratio of 1:(3-20) to barnyard grass powder, extracting for 1-5 times for 24-72 hours, and recovering the solvent until no solvent flows out, to obtain an extract, which is a crude barnyard grass extract;

[0070] (3) the crude extract of barnyard grass is suspended in water at a mass ratio of 1:(1-10), and then extracted with equal volumes of petroleum ether and ethyl acetate in sequence, the extraction times are 1-5 times, and the solvents are recovered after merging until no solvent flows out, thereby obtaining a petroleum ether extract, an ethyl acetate extract and a water extract of barnyard grass respectively;

[0071] (4) The ethyl acetate extract of barnyardgrass was chromatographed on a silica gel column with a gradient elution of dichloromethane-methanol (volume ratio of 100:1, 50:1, 20:1, 10:1, 5:1, 2:1), and detected on TLC with vanillin sulfuric acid solution as a colorimetric agent. The results were combined and chromatographed again with dichloromethane:methanol (volume ratio of 50:1) and HPLC was performed with octadecylsilane bonded silica gel as the stationary phase and methanol:water as the mobile phase (10:90-90:10, v / v) for gradient elution. The elution time was 30 min, the flow rate was 1 mL / min, and the detection wavelength was 254 nm. Similar components were combined according to the retention time of the main peak to obtain the active components Fr.A to Fr.E.

[0072] (5) The active component Fr.B was separated by MCI column, gradient eluted with methanol-water (volume ratio 1:9, 3:7, 5:5, 7:3, 10:0), and detected on TLC with vanillin sulfuric acid solution as the colorimetric agent. The results were combined and the plate was chromatographed again with dichloromethane:methanol (volume ratio 50:1) and sent to HPLC for detection. Octadecylsilane bonded silica gel was used as the stationary phase and methanol:water was used as the mobile phase (10:90-90:10, v / v) for gradient elution. The elution time was 30 min, the flow rate was 1 mL / min, and the detection wavelength was 254 nm. Similar components were combined according to the retention time of the main peak to obtain active components Fr.B.1 to Fr.B.8.

[0073] (6) Fr.B.3 was separated by dextran gel column chromatography and eluted isocratically with methanol. The eluted components were detected on TLC using vanillin sulfuric acid solution as a colorimetric agent and combined according to the results; the combined components were then analyzed by HPLC using octadecylsilane bonded silica gel as the stationary phase and methanol: water as the mobile phase (15:85-50:50, v / v) for gradient elution. The elution time was 30 min, the flow rate was 1 mL / min, and the detection wavelength was 254 nm. Similar components were combined according to the retention time of the main peak to obtain the active components Fr.B.3-1, Fr.B.3-2 and Fr.B.3-3;

[0074] (7) Fr.B.3-3 was separated and prepared by HPLC, using octadecylsilane bonded silica gel as the stationary phase, methanol and water (25 / 75, v / v) as the mobile phase for elution for 25 min, flow rate of 2.0 mL / min, detection wavelength of 210 nm, and separation to obtain the active monomer. Example 1 Experimental study on crude extracts of barnyard grass, extracts and their activity against barnyard grass

[0075] 1. Experimental Materials

[0076] Source of barnyard grass powder: The whole plant of barnyard grass is collected from Shenyang, dried and ground into powder before storage.

[0077] Source of barnyardgrass (E. crusgalli): mature barnyardgrass seeds harvested in autumn and grown in the laboratory.

[0078] 2. Crude Extract Preparation

[0079] Add 95% ethanol in an amount of 10 times the mass of barnyard grass powder, soak for 48 hours, extract 3 times, and recover the solvent under reduced pressure below 45°C to obtain an extract.

[0080] 3. Extract Preparation

[0081] Add twice the mass of water to the crude extract, then extract with petroleum ether and ethyl acetate three times in turn, and recover under reduced pressure at below 45°C until no solvent flows out, to obtain viscous petroleum ether extract, ethyl acetate extract and water extract (see the process for details). Figure 1 ).

[0082] 4. Experimental study on the activity of crude extract on barnyardgrass seeds

[0083] Select barnyard grass seeds that are uniform and plump.

[0084] Dissolve the crude extract with ethanol and add 0.1% Tween water to dilute it to 0.2g / mL, 0.1g / mL, and 0.05g / mL. Put 100 barnyard grass seeds in a centrifuge tube and add 2ml of the solution to soak for 24 hours. After 24 hours, transfer the seeds to a culture dish with double-layer filter paper + moist cotton balls for culture. Repeat 3 times for each treatment, and set up solvent controls (1% ethanol + 0.1% Tween water) and water controls. After treatment, put the culture dish into an incubator at 25±1℃ and 70% humidity to observe the germination. Observe the growth of barnyard grass seeds after 3 days, and count the root length and sprout length of barnyard grass seeds.

[0085] According to the statistical data, the growth inhibition rate of root length or shoot length of each treatment was calculated according to the following formula. The unit is percentage (%). The calculation result is rounded to two decimal places. The results are shown in Figure 2 .

[0086]

[0087] Where:

[0088] R——growth inhibition rate;

[0089] L0——control root length (or shoot length);

[0090] L1 - Processing root length (or shoot length).

[0091] from Figure 2 It can be seen that different concentrations of crude extracts have an inhibitory effect on the growth of barnyard grass seeds after 3 days of application. It can be seen that there are active substances in the crude extracts of barnyard grass that can inhibit the growth of barnyard grass seeds, and the next step is to conduct separation experiments and activity experiments on them.

[0092] 5. Activity test of extracts on barnyardgrass seeds

[0093] Select barnyard grass seeds that are uniform and plump.

[0094] The petroleum ether extract was prepared into a 0.1 g / mL solution with petroleum ether, the ethyl acetate extract was prepared into a 0.1 g / mL solution with ethyl acetate, and the water extract was prepared into a 0.1 g / mL solution with water.

[0095] Take 2 ml of the three treatment solutions and drip them evenly into a culture dish covered with two layers of filter paper. Repeat 3 times for each treatment. Set up solvent control (petroleum ether, ethyl acetate) and water control at the same time. After treatment, put the solvent in a fume hood to evaporate thoroughly, then add 5 ml of water to each culture dish (the concentration of each treatment solution is 0.04 g / mL), put 100 barnyard grass seeds in it, cover it with a lid and put it in a constant temperature and humidity incubator (28°C, 70%). Observe the growth of barnyard grass seeds after 5 days, and count the root length and sprout length of barnyard grass seeds.

[0096] According to the statistical data, the growth inhibition rate of root length or shoot length of each treatment was calculated according to the following formula. The unit is percentage (%). The calculation result is rounded to two decimal places. The results are shown in Figure 3 .

[0097]

[0098] Where:

[0099] R——growth inhibition rate;

[0100] L0——control root length (or shoot length);

[0101] L1 - Processing root length (or shoot length).

[0102] Depend on Figure 3 It can be seen that the above three extracts all have a certain inhibitory effect on the growth of barnyard grass seeds, and the ethyl acetate extract has the most obvious inhibitory effect on the growth of barnyard grass seeds. It can be seen that the active substances that inhibit the growth of barnyard grass seeds are more concentrated in the ethyl acetate extract of barnyard grass, and the next step of separation experiment and activity experiment are carried out on it.

[0103] Example 2 Preparation of Fr.A, Fr.B, Fr.C, Fr.D, Fr.E and Experimental Study on Their Activity against Echinochloa crusgalli

[0104] The ethyl acetate extract of barnyardgrass was chromatographed on a silica gel column (column size: 15 cm × 23.5 cm) with a gradient elution of dichloromethane-methanol (volume ratio: 100:1, 50:1, 20:1, 10:1, 5:1, 2:1) to obtain 32 elution portions. 1-19 were chromatographed on a TLC plate using dichloromethane:methanol (volume ratio: 50:1), and 12-32 were chromatographed on a plate using dichloromethane:methanol (volume ratio: 30:1). The results were observed under a 254 nm ultraviolet lamp, and then coated with a solution of vanillin sulfuric acid and heated for color development. According to the results, 12 components were combined and the chromatography plate was developed again with dichloromethane:methanol (volume ratio 50:1) and HPLC detection was performed. Octadecylsilane bonded silica gel was used as the stationary phase and methanol:water was used as the mobile phase (10:90-90:10, v / v) for gradient elution. The elution time was 30 min, the flow rate was 1 mL / min, and the detection wavelength was 254 nm. Similar components were combined according to the main peak retention time. The main peak retention time was: Fr.A: 20.46 min, Fr.B: 13.23 min, Fr.C: 24.78 min, 25.99 min, Fr.D: 26.01 min, Fr.E: 25.40 min. The solvent was recovered under reduced pressure below 45°C until no solvent flowed out, and 5 fractions Fr.A to Fr.E were obtained.

[0105] Select barnyard grass seeds that are uniform and plump.

[0106] Fr.A to Fr.E were prepared into a 0.0125 g / mL solution using methanol.

[0107] Take 2 ml of the above five treatment solutions and evenly drop them into a culture dish covered with two layers of filter paper. Repeat each treatment 3 times. Set up a solvent control (methanol) and a blank control. After treatment, put the solvent in a fume hood to evaporate thoroughly. Then add 5 ml of water to each culture dish (the concentration of each treatment solution is 0.005 g / mL), put 50 barnyard grass seeds in it, cover it with a lid and put it in a constant temperature and humidity incubator (28°C, 70%). Observe the growth of barnyard grass seeds after 5 days, and count the root length and sprout length of barnyard grass seeds.

[0108] According to the statistical data, the growth inhibition rate of root length or shoot length of each treatment was calculated according to the following formula. The unit is percentage (%). The calculation result is rounded to two decimal places. The results are shown in Figure 4 .

[0109]

[0110] Where:

[0111] R——growth inhibition rate;

[0112] L0——control root length (or shoot length);

[0113] L1 - Processing root length (or shoot length).

[0114] Depend on Figure 4 It can be seen that segments Fr.A to Fr.E all have a relatively obvious inhibitory effect on barnyard grass, among which Fr.B has the most obvious inhibitory effect on the growth of barnyard grass seeds. It can be seen that the active substances that inhibit the growth of barnyard grass seeds are more present in Fr.B, and the next step of separation experiment and activity experiment will be carried out on it.

[0115] Example 3 Extraction, separation, identification of 1,3,5-trimethoxybenzene and its activity test against barnyard grass

[0116] 1. Extraction, separation and identification of 1,3,5-trimethoxybenzene

[0117] Fr.B in Example 2 was separated by MCI column (chromatographic column size 50cm×3cm), and gradient eluted with methanol-water (volume ratio 1:9, 3:7, 5; 5, 7:3, 10:0) to obtain 30 elution parts, 1-30 of which were applied to TLC chromatographic plates with dichloromethane:methanol (volume ratio 50:1), and the results were observed under 254nm ultraviolet light, and then coated with vanillin sulfuric acid solution and heated for color development. According to the results, 21 components were combined, and the above components were passed through a 0.22 μm organic filter membrane and then subjected to HPLC detection. The HPLC detection results were initially combined into 9 samples, and the plates were chromatographed again with a ratio of dichloromethane: methanol (volume ratio 50:1) and sent for HPLC detection. Octadecylsilane bonded silica gel was used as the stationary phase, and methanol: water was used as the mobile phase (10:90-90:10, v / v / v) for gradient elution. The elution time was 30 min, the flow rate was 1 mL / min, and the detection wavelength was 254 nm. Similar components were combined according to the retention time of the main peak. Components, main peak retention time: Fr.B.1: 3.25min, Fr.B.2: 9.54min, Fr.B.3: 12.51min, Fr.B.4: 13.25min, 16.21min, Fr.B.5: 16.04min, Fr.B.6: 17.77min, Fr.B.7: 24.00min, Fr.B.8: 28.20min, the solvent was recovered under reduced pressure below 45°C until no solvent flowed out, and 8 subcomponents (Fr.B.1~Fr.B.8) were obtained.

[0118] Fr.B.3 was separated by chromatography on a Sephadex LH20 column (column size: 65cm×2.5cm), and eluted isocratically with methanol, maintaining a flow rate of 10-15s / drop, and one bottle was added every 8min, to obtain a total of 95 elution components. 1-48 were chromatographed on a TLC plate in a ratio of dichloromethane:methanol (volume ratio of 50:1), 48-80 were chromatographed on a plate in a ratio of dichloromethane:methanol (volume ratio of 10:1), 80-87 were chromatographed on a plate in a ratio of dichloromethane:methanol (volume ratio of 15:1), and 87-85 were chromatographed on a plate in a ratio of dichloromethane:methanol (volume ratio of 10:1). The results were observed under a 254nm ultraviolet lamp, and then coated with vanillin sulfuric acid solution and heated for color development. According to the results, 9 components were merged and then analyzed by HPLC with octadecylsilane bonded silica gel as the stationary phase and methanol: water as the mobile phase (15:85-50:50, v / v / v) for gradient elution. The elution time was 30 min, the flow rate was 1 mL / min, and the detection wavelength was 254 nm. The components were merged according to the main peak retention time. The main peak retention times were: Fr.B.3-1: 12.44 min, Fr.B.3-2: 14.09 min, Fr.B.3-3: 15.89 min, and 3 subcomponents (Fr.B.3-1, Fr.B.3-2, Fr.B.3-3) were obtained.

[0119] Fr.B.3-3 was separated and prepared by HPLC, using octadecylsilane bonded silica gel as the stationary phase, methanol and water (25 / 75, v / v) as the mobile phase for elution for 25 min, a flow rate of 2.0 mL / min, and a detection wavelength of 210 nm to separate and prepare the active monomer (see the process). Figure 1 ).

[0120] According to its high-resolution mass spectrometry ( Figure 5 ), 1 H-NMR( Figure 6 )and 13 C-NMR( Figure 7 ), it can be determined that the active monomer is 1,3,5-trimethoxybenzene.

[0121] 2. Inhibitory effect of 1,3,5-trimethoxybenzene on barnyard grass

[0122] 1,3,5-Trimethoxybenzene (CAS: 621-23-8): AR, 98%, Rohn's reagent, commercially available.

[0123] Barnyard grass: Select barnyard grass seeds that are evenly distributed and full.

[0124] 1,3,5-Trimethoxybenzene was prepared with methanol to test concentrations of 2.5 mg / mL, 1.25 mg / mL, and 0.25 mg / mL for later use.

[0125] Take 2 mL of the above three treatment solutions and drip them evenly into a culture dish covered with two layers of filter paper. Repeat 3 times for each treatment. Set up a solvent control (methanol) and a blank control. After treatment, put the dish in a fume hood to evaporate the solvent thoroughly. Then add 5 ml of water to each dish (the final concentration of the treatment solution is 1 mg / mL, 0.5 mg / mL and 0.1 mg / mL, respectively), put 100 seeds of barnyard grass in it, cover it with a lid and put it in a constant temperature and humidity incubator (28°C, 70%). Observe the growth of barnyard grass seeds after 5 days, and count the root length and sprout length of barnyard grass seeds.

[0126] According to the statistical data, the growth inhibition rate of root length or shoot length of each treatment was calculated according to the following formula. The unit is percentage (%). The calculation result is rounded to two decimal places. The results are shown in Figure 8 .

[0127]

[0128] Where:

[0129] R——growth inhibition rate;

[0130] L0——control root length (or shoot length);

[0131] L1 - Processing root length (or shoot length).

[0132] Depend on Figure 8 It can be seen that when the concentration of the treatment solution reached 0.5 mg / mL and above, the growth of barnyard grass seeds was significantly inhibited.

Claims

1. A barnyard grass extract, characterized in that: The barnyard grass extract is obtained by extracting barnyard grass itself as a raw material.

2. The barnyard grass extract according to claim 1, characterized in that: The extract is obtained by using barnyard grass as a raw material through solvent extraction.

3. The barnyard grass extract according to claim 2, characterized in that: The extract is obtained by using barnyard grass as a raw material through solvent extraction; or, after solvent extraction, through further extraction; or, after further purification and elution of the extract.

4. The barnyard grass extract according to claim 3, characterized in that: The extract is one or more of a crude extract, an active component, and an active monomer.

5. A method for preparing the extract according to claim 1, characterized in that: The method is obtained by using barnyard grass as raw material through solvent extraction; or, after solvent extraction, it is obtained through further extraction; or, the extract is further purified and eluted to obtain it; or, the eluate is further separated and prepared by HPLC to obtain it.

6. Use of the barnyard grass extract according to claim 1 in the preparation of a barnyard grass inhibitor.

7. A barnyard grass inhibitor, characterized in that: The inhibitor is one or more of the extract obtained by extracting barnyard grass itself as a raw material as claimed in claim 1, the active components of the purified extract, and the active monomers.

8. The barnyard grass inhibitor according to claim 7, characterized in that: The inhibitor is a mixture of an active ingredient and an agriculturally acceptable solvent; wherein the active ingredient accounts for 0.001-99.9% of the weight of the inhibitor for inhibiting the growth of barnyard grass, and the active ingredient is one or more of the extract obtained by extracting barnyard grass itself as a raw material as described in claim 1, the active component after purification of the extract, and the active monomer.

9. A composition for inhibiting the growth of barnyard grass, characterized in that: The composition comprises an active component A and an active component B, wherein the active component A and the active component B are mixed in a weight ratio of 1:100-100:1; the active component A is one or more of a crude extract obtained by extracting barnyard grass itself as a raw material, an active component, and an active monomer; and the active component B is one or more of other herbicides, insecticides, miticides, and fungicides.

10. A barnyard grass inhibitor, characterized in that: The preparation contains 1,3,5-trimethoxybenzene.

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