Salicylic acid analogue, preparation method thereof and application of salicylic acid analogue as crop safener

Abstract

The invention belongs to the technical field of crop safeners, and particularly relates to a salicylic acid analogue, a preparation method thereof and application of the salicylic acid analogue as a crop safener. The invention provides a salicylic acid analogue which has a chemical structural general formula as shown in a formula I. The salicylic acid analogue with the chemical structural general formula as shown in the formula I provided by the invention can improve the protection effect on rice seedlings and relieve or eliminate the phytotoxicity of herbicides on rice, so that the sustainability of agricultural production is guaranteed; meanwhile, the salicylic acid analogue provided by the invention is low in toxicity and good in stability, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of crop safety agent technology, specifically relating to a salicylic acid analogue, its preparation method, and its application as a crop safety agent. Background Technology

[0002] In modern agriculture, the use of herbicides has greatly improved agricultural production efficiency, but it can also harm crop growth. In particular, the use of herbicides in rice paddies often causes phytotoxicity to rice seedlings, affecting yield and quality.

[0003] While existing agrochemical safeners have mitigated this damage to some extent, their effectiveness in protecting rice from herbicide damage is limited, and they cannot effectively eliminate the adverse effects of herbicide damage on rice growth. Summary of the Invention

[0004] The purpose of this invention is to provide a salicylic acid analogue, its preparation method, and its application as a crop safety agent. The salicylic acid analogue provided by this invention, as a crop safety agent, can improve the protection of rice seedlings, reduce or eliminate the phytotoxicity of herbicides to rice, thereby ensuring the sustainability of agricultural production. At the same time, the salicylic acid analogue provided by this invention has low toxicity, good stability, and good application prospects.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a salicylic acid analog having the general chemical structure shown in Formula I:

[0007]

[0008] In Formula I: R group is one or more of halogen, nitro and C1-10 alkyl, and n is 1-4.

[0009] Preferably, the R group is one or more of Cl, nitro, and methyl.

[0010] Preferably, the R group is located at at least one substitution site at the 3, 4, and 5 positions of the benzene ring structure.

[0011] Preferably, it is any one of the following chemical structures:

[0012]

[0013] This invention provides a method for preparing the salicylic acid analogue described in the above technical solution, comprising the following steps:

[0014] The compound with the structure shown in Formula II, matrine, and an organic solvent were mixed and reacted to obtain the salicylic acid analogue.

[0015]

[0016] In Formula II: R group is one or more of halogen, nitro and C1-10 alkyl, and n is 1-4.

[0017] Preferably, the organic solvent is an alcohol solvent; the reaction temperature is 50–65°C, and the reaction time is 30–40 min.

[0018] This invention provides the application of salicylic acid analogues described in the above technical solutions or salicylic acid analogues prepared by the above technical solutions as crop safety agents.

[0019] Preferably, the crop is rice.

[0020] Preferably, the application includes the following steps:

[0021] Herbicides and safeners are applied together to crop seedlings.

[0022] Preferably, the herbicide includes metolachlor.

[0023] This invention provides a salicylic acid analog having the general chemical structure shown in Formula I. The salicylic acid analog of Formula I provided by this invention can enhance the protection of rice seedlings, reduce or eliminate herbicide damage to rice, thereby ensuring the sustainability of agricultural production. Simultaneously, the salicylic acid analog provided by this invention has low toxicity and good stability, showing promising application prospects. The results of the examples show that the salicylic acid analog of this invention can significantly improve the resistance of rice seedlings to S-metolachlor herbicide. Compounds I3, I5, and I6 provided in the examples have significant effects in mitigating the effects of S-metolachlor on rice, especially in terms of root length and fresh weight. Among them, compound I3 has the best safener activity against relative plant height, relative root length, and relative fresh weight of rice seedlings, at 65.11%, 98.51%, and 92.09%, respectively. Detailed Implementation

[0024] This invention provides a salicylic acid analog having the general chemical structure shown in Formula I:

[0025]

[0026] In Formula I: R group is one or more of halogen, nitro and C1-10 alkyl, and n is 1-4.

[0027] In this invention, in Formula I, the R group is preferably one or more of F, Cl, Br, I, nitro and C1-5 alkyl.

[0028] In this invention, in Formula I, the R group is more preferably one or more of F, Cl, Br, I, nitro and C1-3 alkyl.

[0029] In this invention, in Formula I: the R group is most preferably one or more of Cl, nitro and methyl.

[0030] In this invention, in Formula I: the R group is preferably located at at least one substitution site at the 3rd, 4th and 5th positions of the benzene ring structure.

[0031] In an embodiment of the present invention, in Formula I: the R group can be Cl, nitro or methyl, and the R group is located at the 3rd, 4th or 5th position of the benzene ring structure.

[0032] In embodiments of the present invention, the salicylic acid analogue can be any one of the following chemical structures:

[0033]

[0034] This invention provides a method for preparing the salicylic acid analogue described in the above technical solution, comprising the following steps:

[0035] The compound with the structure shown in Formula II, matrine, and an organic solvent were mixed and reacted to obtain the salicylic acid analogue.

[0036]

[0037] In Formula II: R group is one or more of halogen, nitro and C1-10 alkyl, and n is 1-4.

[0038] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0039] In this invention, in Formula II: the R group is preferably one or more of F, Cl, Br, I, nitro and C1-5 alkyl.

[0040] In this invention, in Formula II, the R group is more preferably one or more of F, Cl, Br, I, nitro and C1-3 alkyl.

[0041] In this invention, in Formula II: the R group is most preferably one or more of Cl, nitro and methyl.

[0042] In this invention, in Formula II: the R group is preferably located at at least one substitution site at the 3rd, 4th and 5th positions of the benzene ring structure.

[0043] In an embodiment of the present invention, in Formula II: the R group can be Cl, nitro or methyl, and the R group is located at the 3rd, 4th or 5th position of the benzene ring structure.

[0044] In this invention, the R group in the compound with the structure shown in Formula II is the same as the R group in the salicylic acid analog with the structure shown in Formula I.

[0045] In this invention, the preferred mass ratio of the compound with the structure shown in Formula II to matrine is (0.5–3):(0.6–5.5), and in the examples it can be 1:1.439, 1:1.592, 0.5:0.69, 3:4.891, 1:1.592, or 3:5.474. The organic solvent is an alcohol solvent. The alcohol solvent is preferably ethanol or a mixture of ethanol and methanol. The alcohol solvent is preferably an anhydrous alcohol solvent. This invention does not have special requirements on the amount of the organic solvent used, as long as it ensures that the compound with the structure shown in Formula II and matrine are completely dissolved and react smoothly.

[0046] In this invention, the mixing preferably includes the following steps: dissolving the compound with the structure shown in Formula II in a portion of an organic solvent to obtain a solution of the compound with the structure shown in Formula II; dissolving matrine in the remaining organic solvent to obtain a matrine solution; and adding the matrine solution dropwise to the solution of the compound with the structure shown in Formula II and mixing thoroughly. The mixing method is preferably dropwise mixing. In this invention, the reaction temperature is preferably 50–65°C, and in practice, it can be 60°C. The reaction time is preferably 30–40 min, and in the examples, it can be 30 min. The reaction solution is obtained after the reaction is complete. This invention preferably performs post-treatment on the reaction solution to obtain the salicylic acid analogue.

[0047] The post-processing preferably includes: cooling the reaction solution obtained from the reaction to room temperature and allowing it to stand for natural evaporation, followed by solid-liquid separation to obtain the salicylic acid analogue. The standing time is preferably 1 to 1.5 days. The solid-liquid separation is preferably performed by vacuum filtration. During the standing process, a sealing film can be used for storage.

[0048] Alternatively, the post-processing preferably includes: cooling the reaction solution obtained from the reaction to room temperature and then filtering it, the resulting solid product being the salicylic acid analogue. The filtration is preferably vacuum filtration.

[0049] This invention provides the application of salicylic acid analogues described in the above technical solutions or salicylic acid analogues prepared by the above technical solutions as crop safety agents.

[0050] In this invention, the crop can be rice.

[0051] In this invention, the application preferably includes the following steps:

[0052] The herbicide and safener are applied together to crop seedlings, wherein the safener includes the salicylic acid analogue described in the above technical solution or the salicylic acid analogue prepared by the preparation method described in the above technical solution.

[0053] In this invention, the herbicide preferably includes S-metolachlor. When the safener and herbicide are applied, the concentration of the safener in the agrochemical seedling culture medium is preferably 5–10 mg / L. -1 In the examples, the concentration can be 8 mg·L. -1 The preferred mass concentration of the herbicide is 0.07–0.075 g / L, and in the example it can be 0.073 g / L.

[0054] The salicylic acid analog of Formula I provided by this invention is a highly efficient and environmentally friendly rice herbicide safener that can improve the protection of rice seedlings, reduce or eliminate herbicide damage to rice, thereby ensuring the sustainability of agricultural production.

[0055] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0056] In the following embodiments and test cases:

[0057] Select plump, uniformly sized rice seeds (Huang Huazhan) free from pests, diseases, and rodents. Disinfect them with hypochlorous acid, then rinse them three times with deionized water. Soak the seeds in deionized water at 28°C for 24 hours, and then germinate them in the dark for 36 hours.

[0058] Rice was cultured using the agar medium method. Rice seedlings with uniform radicle germination were selected and transplanted into a medium containing 8 mg·L⁻¹ of agar. -1 Salicylic acid analogues (I1 prepared in Example 1, I2 prepared in Example 2, I3 prepared in Example 3, I4 prepared in Example 4, I5 prepared in Example 5, and I6 prepared in Example 6) or 8 mg·L -1 The salicylic acid analogues (I1-I6) and 0.073 g / L metolachlor mixture were placed in a small, round, transparent plastic box (6 cm inner diameter, 250 mL volume) on agar medium, and then transferred to a light incubator for incubation. Initially, the mixture was illuminated for 14 hours (light intensity 110-130 μE·m). -2 s -1 The plants were initially cultured at 30℃, then in the dark (at 25℃) for 10 hours. Data was collected after 10 days, and the activity of the salicylic acid analogue as a safener was determined using three indicators: plant height, root length, and fresh weight. All experiments were repeated three times. The formulas for calculating plant height, root length, and fresh weight are as follows:

[0059] Relative plant height = Average plant height of rice seedlings in the treatment group / Average plant height of rice seedlings in the control group;

[0060] Relative root length = Average root length of rice seedlings in the treatment group / Average root length of rice seedlings in the control group;

[0061] Relative fresh weight = average fresh weight of rice seedlings in the treatment group / average fresh weight of rice seedlings in the control group.

[0062] Example 1

[0063] In this embodiment, compound I1 was prepared using 3-chlorosalicylic acid and matrine.

[0064] 1 g of 3-chlorosalicylic acid and 1.439 g of matrine were dissolved in 10 mL of anhydrous ethanol. The two solutions were added dropwise and mixed well. The mixture was then stirred at 60 °C for 30 min. After cooling to room temperature and allowing to stand naturally for 1 day, crystals were precipitated. The yellow crystals were obtained by filtration, which is compound I1.

[0065] 1 HNMR(400MHz,Chloroform-d)δ(ppm)7.47(dd,1H),7.02(dd,1H),6.74(t,1H),4.48(dd,1H),3.82(s,1H),3.27(d,2H),3.0 9-2.97(m,3H),2.67(tdd,3H),2.45-2.13(m,4H),2.10-1.99(m,2H),1.98-1.72(m,6H),1.72-1.57(m,6H),1.50(dddd,1H).

[0066] IR(KBr)v(cm -1 )3491,3434,2941,1622,1460,1388,1302,1245.

[0067] Example 2

[0068] In this embodiment, compound I2 was prepared using 5-chlorosalicylic acid and matrine.

[0069] 1 g of 5-chlorosalicylic acid and 1.592 g of matrine were dissolved in 10 mL of anhydrous ethanol. The two solutions were added dropwise and mixed well. The mixture was then stirred at 60 °C for 30 min. After cooling to room temperature and allowing to stand naturally for 1 day, crystals were precipitated. The white crystals obtained by filtration were the compound I2.

[0070] 1H NMR(400MHz,Chloroform-d)δ(ppm)7.72(d,1H),6.68-6.60(m,2H),4.51(dd,1H),3.86(ddd,1H),3.48-3.39(m,2H),3.36-3.24(m,1 H),3.06(t,1H),2.86(tdd,2H),2.44-2.30(m,3H),2.30-2.12(m,3H),2.08-1.55(m,12H),1.47(tdd,1H),1.31(s,1H),1.20(t,1H).

[0071] IR(KBr)v(cm -1 )3499,3437,2940,1621,1587,1423,1350,1259.

[0072] Example 3

[0073] In this embodiment, compound I3 was prepared using 3-nitrosalicylic acid and matrine.

[0074] 0.5 g of 3-nitrosalicylic acid and 0.69 g of matrine were dissolved in 6 mL of anhydrous ethanol and 2 mL of methanol. The matrine was dissolved in 2 mL of anhydrous ethanol. The two solutions were added dropwise and mixed well. The mixture was then stirred at 60 °C for 30 min to produce a yellow solid. After cooling to room temperature, the yellow solid was obtained by filtration, which is compound I3.

[0075] 1 H NMR(400MHz,Chloroform-d)δ(ppm)7.65(d,1H),7.14(dd,1H),6.73(d,1H),4.53(ddd,1H),3.84(ddd,1H),3.45(tdt,2H),3.30(t,1H),3.0 4(t,1H),2.88(tdd,2H),2.39(dtd,1H),2.31(dd,1H),2.26(s,3H),2.19(dtd,1H),2.13-2.01(m,2H),2.01-1.56(m,12H),1.49(dddd,1H).

[0076] IR(KBr)v(cm -1 )3480,3423,2946,1610,1480,1427,1353,1252.

[0077] Example 4

[0078] In this embodiment, compound I4 was prepared using 5-methylsalicylic acid and matrine.

[0079] 3g of 5-methylsalicylic acid and 4.891g of matrine were dissolved in 11mL of anhydrous ethanol, and the matrine was dissolved in 7mL of anhydrous ethanol. The two solutions were added dropwise and mixed well. Then, the mixture was stirred at 60℃ for 30min. The entire reaction solution was collected in a wide-mouthed Erlenmeyer flask, sealed with sealing film, allowed to evaporate naturally, and allowed to stand for 1 day to crystallize. The white crystals obtained by filtration were the compound I4.

[0080] 1 H NMR(400MHz,Methanol-d4)δ(ppm)7.81(dd 1H),7.56(dd,1H),7.39(dd,1H),7.02(td,1H),6.83(dd,1H),6.74(t,1H),4.61(dd,1H),4.17(ddd,1H),3.88-3.66(m,2H) ,3.31(t,1H),3.01(t,1H),2.64-2.42(m,3H),2.36-1.94(m,5H),1.94-1.77(m,2H),1.79-1.52(m,8H),1.52-1.17(m,1H).

[0081] IR(KBr)v(cm -1 )2933,1635,1454,1368,1278,744.

[0082] Example 5

[0083] In this embodiment, compound I5 was prepared using 4-chlorosalicylic acid and matrine.

[0084] 1 g of 4-chlorosalicylic acid and 1.592 g of matrine were dissolved in 10 mL of anhydrous ethanol. The two solutions were added dropwise and mixed well. The mixture was then stirred at 60 °C for 30 min. After natural evaporation and standing for 1 day, crystals were precipitated. The light pink crystals were obtained by filtration, which is compound I5.

[0085] 1 H NMR(400MHz,Chloroform-d)δ(ppm)8.01(d,1H),7.80-7.53(m,2H),4.64(dd,1H),4.18(td,1H),3.97-3.64(m,2H),3. 31(t,1H),3.12(d,1H),2.74-2.43(m,3H),2.38-1.97(m,7H),1.97-1.53(m,9H),1.53-1.31(m,1H),1.31-1.14(m,1H).

[0086] IR(KBr)v(cm -1)3318,3253,3166,2946,1583,1476,1389,1256.

[0087] Example 6

[0088] In this embodiment, compound I6 was prepared using 4-methylsalicylic acid and matrine.

[0089] 3g of 4-methylsalicylic acid and 5.474g of matrine were dissolved in 17mL of anhydrous ethanol, and 8mL of anhydrous ethanol were dissolved in matrine. The two solutions were added dropwise and mixed well. Then, the mixture was stirred at 60℃ for 30min. The entire reaction solution was collected in a wide-mouth Erlenmeyer flask, sealed with sealing film, allowed to evaporate naturally, and allowed to stand for 1 day to crystallize. The white crystals obtained by filtration were the compound I6.

[0090] 1 H NMR(400MHz,Methanol-d4)δ(ppm)7.63(dt,1H),7.15(ddd,1H),6.74(td,1H),4. 54(dd,1H),3.86(ddd,1H),3.57-3.46(m,1H),3.42(t,1H),3.10-2.91(m,1H),2.3 9(dtd,1H),2.33-2.15(m,2H),2.15-2.03(m,2H),2.01(d,1H),1.95(dt,1H),1.8 4(ddt,6H),1.77-1.70(m,3H),1.70-1.59(m,2H),1.59-1.42(m,2H),1.19(t,1H).

[0091] IR(KBr)v(cm -1 )3491,3419,1946,1628,1466,1383,1298,767.

[0092] The physicochemical data of the salicylic acid prepared in Examples 1 to 6 are shown in Table 1.

[0093] Table 1 Physicochemical data of compounds I1 to I6

[0094]

[0095]

[0096] Test Example 1

[0097] Rice was cultured using the agar solid medium method. The rice variety was Huanghuazhan. Based on the determination of the phytotoxicity of S-metolachlor to rice seedlings, 0.073 g / L was selected as the inhibitory concentration of S-metolachlor on rice seedlings.

[0098] 1. Preparation of nutrient solution

[0099] First, weigh out appropriate amounts of compounds I1 to I6, dissolve them thoroughly in DMSO, and set aside for later use.

[0100] S-metolachlor was added to the agar medium to make the concentration of S-metolachlor in the agar medium 0.073 g / L. Then, 6 groups of agar medium containing S-metolachlor were used as ion salt treatment groups 1-6, 1 group was used as the control group, and a blank group without drug was set up. Each group was set up with 3 parallel samples.

[0101] Ionic salt groups I1-I6: Ionic salt groups I1-I6 were used as experimental groups for compounds I1-I6, respectively. Compounds I1-I6 were added to the agar medium containing metolachlor in the corresponding treatment groups to obtain a medium with a final concentration of 8 mg / L for compounds I1-I6.

[0102] Control group: The agar medium contained only 0.073 g / L of metolachlor and did not contain compounds I1-I6.

[0103] Blank group: The agar medium does not contain metolachlor and compounds I1-I6.

[0104] 2. Rice germination methods:

[0105] Rice seeds were disinfected with hypochlorous acid and then rinsed three times with deionized water. They were then soaked in deionized water at 28°C for 24 hours, followed by germination in the dark for 36 hours. Before embryonic germination, rice seedlings with uniform radicle germination were selected and transplanted into small, round, transparent plastic boxes containing agar medium (specifications: outer diameter 14cm, inner diameter 12.5cm, height 9cm, 916mL). These boxes were then transferred to a light incubator for cultivation, initially under light conditions for 14 hours (light intensity 110–130 μE·m). -2 s -1 The seedlings were cultured at 30℃, followed by 10 hours in darkness at 25℃. Rice seedlings with shoot and root lengths of equal length were selected and evenly distributed on the agar medium surfaces of ion salt treatment groups 1-6 and the control and blank groups (shoots facing up, roots facing down). They were then transferred to a tissue culture room for further cultivation, with the light intensity controlled at 14 hours (light intensity 110–130 μE·m). -2 s -1The temperature was 30℃, and the time was 6:00-20:00, followed by 10 hours of darkness (temperature 25℃, time 20:00-6:00). Suitable humidity was maintained for the first few days. After the rice reached the three-leaf stage, the watering amount was increased (watering time was 8:00). Half a month later, the plant height, fresh weight, and root length of the rice were measured. All experiments were repeated three times. The formulas for calculating the three indicators of plant height, root length, and fresh weight are as follows:

[0106] Relative plant height = Average plant height of rice seedlings in the treatment group / Average plant height of rice seedlings in the control group;

[0107] Relative root length = Average root length of rice seedlings in the treatment group / Average root length of rice seedlings in the control group;

[0108] Relative fresh weight = average fresh weight of rice seedlings in the treatment group / average fresh weight of rice seedlings in the control group.

[0109] The test data is shown in Table 2.

[0110] Table 2. Effects of compounds I1-I6 on mitigating the damage caused by metolachlor to rice.

[0111] serial number Relative plant height (%) Relative root length (%) Relative fresh weight (%) Blank control (CK) 100 100 100 S-methylpropionate 48.46±0.98 67.23±2.85 55.81±0.40 I1 55.16±2.04 77.78±1.35 61.96±0.80 I2 52.31±2.01 74.80±1.30 58.88±0.80 I3 65.11±0.59 98.51±1.82 92.09±0.60 I4 58.96±0.43 47.13±0.66 55.48±0.50 I5 61.44±0.63 87.77±0.34 83.84±0.70 I6 62.57±0.60 87.75±0.51 91.67±0.80

[0112] Table 2 shows that of the six compounds I1-I6 prepared in Examples 1-6, only compound I4 failed to alleviate the effects of S-metolachlor on rice root length and fresh weight. Compounds I3, I5, and I6 showed significant effects in alleviating the effects of S-metolachlor on rice, especially on root length and fresh weight. This indicates that the activity is relatively high when the substituent at the 3-position of the salicylic acid benzene ring is a nitro group, and the activity is comparable when the substituent at the 4-position is a chlorine atom or a methyl group. Among them, compound I3 showed the best safety agent activity for rice seedling relative plant height, relative root length, and relative fresh weight, at 65.11%, 98.51%, and 92.09%, respectively.

[0113] As can be seen from the above embodiments, the salicylic acid analog provided by the present invention, as a crop safety agent, can improve the protection of rice seedlings, reduce or eliminate the phytotoxicity of herbicides to rice, thereby ensuring the sustainability of agricultural production; at the same time, the salicylic acid analog provided by the present invention has low toxicity and good stability, and has good application prospects.

[0114] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative intent, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A salicylic acid analogue, characterized in that, It has the general chemical structure shown in Formula I: In Formula I: R group is one or more of halogen, nitro and C1-10 alkyl, and n is 1-4.

2. The salicylic acid analogue according to claim 1, characterized in that, The R group is one or more of Cl, nitro, and methyl.

3. The salicylic acid analogue according to claim 2, characterized in that, The R group is located at at least one substitution site at the 3, 4, and 5 positions of the benzene ring structure.

4. The salicylic acid analogue according to claim 1 or 2, characterized in that, It can be any of the following chemical structures:

5. The method for preparing the salicylic acid analogue according to any one of claims 1 to 4, characterized in that, Includes the following steps: The compound with the structure shown in Formula II, matrine, and an organic solvent were mixed and reacted to obtain the salicylic acid analogue. In Formula II: R group is one or more of halogen, nitro and C1-10 alkyl, and n is 1-4.

6. The preparation method according to claim 5, characterized in that, The organic solvent is an alcohol solvent; the reaction temperature is 50–65°C and the reaction time is 30–40 min.

7. The application of the salicylic acid analogue according to any one of claims 1 to 4 or the salicylic acid analogue prepared by the preparation method according to claim 5 or 6 as a crop safety agent.

8. The application according to claim 7, characterized in that, The crop in question is rice.

9. The application according to claim 7 or 8, characterized in that, The application includes the following steps: Herbicides and safeners are applied together to crop seedlings.

10. The application according to claim 9, characterized in that, The herbicide includes S-metolachlor.

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