Chitosan chlorine-containing salicylamide derivative and preparation method thereof

Abstract

The invention relates to the technical field of chemical synthesis, and discloses a chitosan chlorine-containing salicylamide derivative and a preparation method thereof, and the chitosan amide derivative containing different substituent groups is prepared by reacting two kinds of chitosan with different molecular weights with different kinds of chlorine-containing salicylic acid. The substitution degree of the chitosan chlorphenyl-containing amide derivative synthesized by the preparation method disclosed by the invention reaches 29.90 to 44.10 percent. By utilizing the excellent characteristics of a special structure, biocompatibility and the like of chitosan, an active group, namely chlorosalicylic acid, of a pesticide is effectively combined with chitosan molecules, so that a synergistic effect can be generated, and the specific biological activities of bacteriostasis, disease resistance induction and the like of the chitosan are remarkably enhanced. The novel chitosan chlorophenyl-containing amide compound is formed by carrying out an amidation reaction on carboxyl containing chlorosalicylic acid and amino on chitosan molecules, a novel green pesticide with low toxicity and high efficiency is developed, the specific biological activities of bacteriostasis, disease resistance induction and the like of chitosan are remarkably enhanced, and the toxicity of effective groups is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chemical synthesis, and particularly relates to a chitosan chloro-salicylamide derivative and a preparation method thereof. BACKGROUND

[0002] In the development history of agriculture in China, pesticides, including fungicides, insecticides, herbicides and plant growth regulators, play an important role in agricultural production. As a relatively efficient pesticide in fungicides, organochlorine pesticide has high toxicity and strong persistence, and can kill pests and pathogenic fungi to achieve the purpose of crop protection. However, it is difficult to degrade and will accumulate in the environment while enriching in the food chain, seriously endangering human health. When using pesticides in the field, it is easy to absorb pesticides through skin contact, respiratory inhalation and other ways. Long-term contact with high-toxicity pesticides can cause chronic poisoning, damage the nervous system, cause headache, dizziness, fatigue, memory loss and affect the human immune system, increase the risk of disease, and even cause cancer and other major diseases. The residues of organochlorine pesticides can also destroy the ecological structure of soil, affect the activity of soil microorganisms, reduce soil fertility, and thus affect the growth and quality of crops. After entering the water body, pesticides can pollute the water source and destroy the balance of the aquatic ecosystem. Many aquatic organisms are extremely sensitive to pesticides, and organochlorine pesticides can cause the death of aquatic animals such as fish and shrimp, affecting the stability of the aquatic ecosystem. In addition, organochlorine pesticides can also be transmitted through the food chain and accumulate and amplify in the organism. Therefore, it is urgent to develop a new type of green and non-toxic pesticide, which can regulate plant growth and resist pests and diseases on the one hand, and degrade in the soil and has no toxic side effects on the environment on the other hand.

[0003] Chitosan is a high-molecular-weight linear polysaccharide, which has good biodegradability and biocompatibility, and has no toxic side effects on the human body, and is a green and natural environmental-friendly polymer material. Chitosan has a large number of free amino groups and hydroxyl groups in its molecular structure, which endow chitosan with unique reaction characteristics and can combine with different functional groups to exhibit different properties.

[0004] Organochlorine pesticides have significant fungicidal effect, but have serious impact on the environment. The structure of chitosan has good affinity to the tissues and cells of organisms, so it can be combined with chloro-containing functional groups to develop a new type of green pesticide with low toxicity and high efficiency, which can produce synergistic effect and further improve the plant stress resistance, and has great potential and broad prospects in agriculture.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] To solve the above technical problems, the basic idea of the technical scheme of the present application is as follows:

[0007] A chitosan chlorosalicylamide derivative, the derivative is a compound of formula (1):

[0008]

[0009] Formula (1)

[0010] wherein, n=15-25 and 1200-1300; R is:

[0011] , , .

[0012] A preparation method of a chitosan chlorosalicylamide derivative, a 2-morpholinoethanesulfonic acid hydroalcoholic solution is configured, chlorosalicylic acid is added to dissolve, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride (EDC) is added and stirred for 1 hour, then N-hydroxysuccinimide (NHS) is added for activation (the molar ratio of chlorosalicylic acid, EDC and NHS is 1:3:5), stirring for 2 hours (ice water bath), then mixed with chitosan (n=1240) dissolved in acetic acid solution, stirred at room temperature for 48 hours, then added with anhydrous ethanol for alcohol precipitation, centrifuged after cold storage for 12 hours, to obtain orange yellow precipitate; centrifuged after cold storage for 12 hours, to obtain orange yellow precipitate; after washing with ethanol for multiple times, filtering and drying, a chlorosalicyloyl high molecular chitosan is obtained.

[0013] As a preferred embodiment of the present application, the chlorosalicylic acid is dissolved in a small amount of ethanol, mixed with a morpholinoethanesulfonic acid aqueous solution containing 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride (EDC), after stirring for 1h, N-hydroxysuccinimide (NHS) is added for activation of the carboxyl group (the molar ratio of chlorosalicylic acid, EDC and NHS is 1:3:5), continue to stir for 2h (ice water bath), add chitosan (n=18), react for 24h, concentrate to 100ml by rotary evaporation at 50℃, load into a 1KDa dialysis bag and dialyze for 48h, transfer to a-80℃ refrigerator and cold storage for 12h, freeze-dry for 48h.

[0014] As a preferred embodiment of the present application, the mass of the chitosan is 0.5-2.5g.

[0015] As a preferred embodiment of the present application, the volume of the 2-morpholinoethanesulfonic acid buffer solution is 100-300mL.

[0016] As a preferred embodiment of the present application, the chlorosalicylic acid can be 5-chlorosalicylic acid, 3,5-dichlorosalicylic acid, 3,5,6-trichlorosalicylic acid.

[0017] As a preferred embodiment of the present application, the 2-morpholinoethanesulfonic acid buffer solution has a pH of 5-6.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] The present application uses two different molecular weight chitosan to react with different chlorine-containing salicylic acid to prepare chitosan amide derivatives with different substituents. The substitution degree of the chitosan chlorine-containing phenyl amide derivative synthesized by the preparation method of the present application is 29.90-44.10%. The special structure and biocompatibility of chitosan are used to effectively combine the active groups of the pesticide, chlorine-containing salicylic acid, and chitosan molecules, which can produce a synergistic effect, significantly enhance the unique biological activity of chitosan itself, such as bacteriostasis and disease induction. The carboxyl group of chlorine-containing salicylic acid reacts with the amino group on the chitosan molecule to form a new type of chitosan chlorine-containing phenyl amide compound, which develops a new type of low-toxicity and high-efficiency green pesticide, significantly enhances the unique biological activity of chitosan itself, such as bacteriostasis and disease induction. The toxicity of the active group is effectively reduced, a synergistic effect is produced, the plant stress resistance is further improved, and the potential and prospect in the field of agriculture are huge.

[0020] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0021] In the drawings:

[0022] Figure 1 The present application is a chitosan (n=1200-1300) raw material infrared spectrum;

[0023] Figure 2 The present application is a chitosan (n=15-25) raw material infrared spectrum;

[0024] Figure 3 The present application is a 5-chlorosalicyloyl chitosan (n=1200-1300) derivative infrared spectrum;

[0025] Figure 4 The present application is a 5-chlorosalicyloyl chitosan (n=15-25) derivative infrared spectrum;

[0026] Figure 5 The present application is a 3,5-dichlorosalicyloyl chitosan (n=1200-1300) derivative infrared spectrum;

[0027] Figure 6 The present application is a 3,5-dichlorosalicyloyl chitosan (n=15-25) derivative infrared spectrum;

[0028] Figure 7Infrared spectrum of 3,5,6-trichlorosalicyloyl chitosan (n=1200-1300) derivative of the present application;

[0029] Figure 8 Infrared spectrum of 3,5,6-trichlorosalicyloyl chitosan (n=15-25) derivative of the present application;

[0030] Figure 9 Chitosan (n=1200-1300) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0031] Figure 10 Chitosan (n=15-25) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0032] Figure 11 5-chlorosalicyloyl chitosan (n=1200-1300) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0033] Figure 12 5-chlorosalicyloyl chitosan (n=15-25) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0034] Figure 13 3,5-dichlorosalicyloyl chitosan (n=1200-1300) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0035] Figure 14 3,5-dichlorosalicyloyl chitosan (n=15-25) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0036] Figure 15 3,5,6-trichlorosalicyloyl chitosan (n=1200-1300) derivative of the present application 13 C nuclear magnetic resonance spectrum;

[0037] Figure 16 3,5,6-trichlorosalicyloyl chitosan (n=15-25) derivative of the present application 13 C nuclear magnetic resonance spectrum. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments will be described clearly and completely below with reference to the drawings in the embodiments of the present application, and the following embodiments are used to illustrate the present application.

[0039] A chitosan chlorosalicylamide derivative, the derivative is a compound of formula (1):

[0040]

[0041] Formula (1)

[0042] wherein, n=15-25 and 1200-1300; R is:

[0043]

[0044] A method for preparing a chitosan chlorosalicylamide derivative, a 2-morpholinoethanesulfonic acid water-alcohol solution is prepared, chlorosalicylic acid is added for dissolution, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride (EDC) is added for stirring for 1 hour, N-hydroxysuccinimide (NHS) is then added for activation (the molar ratio of chlorosalicylic acid, EDC, and NHS is 1:3:5), stirring is performed for 2 hours (ice water bath), and then chitosan (n=1240) dissolved in acetic acid solution is mixed, stirring is performed at room temperature for 48 hours, anhydrous ethanol is then added for alcohol precipitation, centrifugation is performed after cold storage for 12 hours, orange yellow precipitate is obtained, centrifugation is performed after cold storage for 12 hours, orange yellow precipitate is obtained, and the chlorosalicylamide high molecular chitosan is obtained after ethanol washing, filtration, and drying.

[0045] Chlorosalicylic acid is dissolved in a small amount of ethanol, mixed with a morpholinoethanesulfonic acid aqueous solution containing 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride (EDC), N-hydroxysuccinimide (NHS) is added after stirring for 1 hour for activation of the carboxyl group (the molar ratio of chlorosalicylic acid, EDC, and NHS is 1:3:5), stirring is continued for 2 hours (ice water bath), chitosan (n=18) is added, reaction is performed for 24 hours, rotary evaporation is performed at 50°C to concentrate to 100 ml, a 1KDa dialysis bag is filled for dialysis for 48 hours, and then transferred to a-80°C refrigerator for cold storage for 12 hours, and then freeze-dried for 48 hours.

[0046] The chitosan has a mass of 0.5-2.5 g, wherein the chitosan (n=1240 and 18) is purchased from Qingdao Yunzhu Biological Technology Co., Ltd., and DD>90%.

[0047] The volume of the 2-morpholinoethanesulfonic acid buffer solution is 100-300 mL.

[0048] The chlorosalicylic acid can be 5-chlorosalicylic acid, 3,5-dichlorosalicylic acid, or 3,5,6-trichlorosalicylic acid.

[0049] The 2-morpholinoethanesulfonic acid buffer solution has a pH of 5-6.

[0050] Example 1​​​

[0051] 0.5-2.5g chitosan (n=1200-1300) was dissolved in acetic acid and mixed with 100-300 mL 2-morpholinoethanesulfonic acid buffer solution, and reacted with 5-chlorosalicylic acid with activated carboxyl group at room temperature for 48 hours; after stirring at room temperature for 48 hours, anhydrous ethanol was added for alcohol precipitation, centrifuged after cold storage for 12 hours to obtain orange yellow precipitate. After multiple washing with ethanol, filtration and drying, 5-chlorosalicyloyl high molecular chitosan was obtained.

[0052] The structural formula is shown in formula (1), wherein R=

[0053] , n= n=1200-1300.

[0054] Infrared spectrum analysis shows that, compared with chitosan (n=1200-1300) (see Figure 3 ), 5-chlorosalicyloyl high molecular chitosan (see Figure 1 ) has the following characteristics: Figure 3 The characteristic wide peak of O-H and N-H at 3500-3200 cm -1 in the infrared spectrum is obviously shifted, indicating that N-H may have reacted; the characteristic absorption peak of -NH2 at 1530-1580 cm -1 is strengthened, indicating that -NH2 has reacted in amide reaction; Figure 3 The characteristic absorption peak of C=O appears at 1640.3 cm -1 , where the saturated -CH stretching vibration absorption peak is obviously saturated, 1218.2 cm -1 is the saturated -CH deformation vibration absorption peak, 823.1 cm -1 and 759.3 cm -1 are the benzene ring C-H out-of-plane bending vibration, 1200-950 cm -1 are the benzene ring C-H in-plane bending vibration. 13 C nuclear magnetic resonance spectrum (see Figure 11 ) analysis shows that: 176.4 ppm is the chemical shift of C=O carbon of amide bond; 100.3 (C1), 75.1 (C4), 71.4 (C5), 65.0 (C3), 57.3 (C6), 52.8 (C2) ppm are the chemical shifts of chitosan sugar ring; 160.3 ppm is the chemical shift of 5-chlorosalicylic acid C-O-H carbon chain. The above results can prove the formation of the target compound.

[0055] Example 2

[0056] 0.5-2.5 g chitosan (n=15-25) was dissolved in 100-300 mL 2-morpholinoethanesulfonic acid buffer solution, and reacted with chlorosalicylic acid containing activated carboxyl group at room temperature for 24 hours; after dialysis for 2-3 days with a dialysis bag with a molecular weight cut-off of 1 K Da, it was concentrated to 30-50 mL, and freeze-dried to obtain 5-chlorosalicyloyl low molecular chitosan. The structural formula is shown in formula 1,

[0057] wherein R=

[0058] n=15-25.

[0059] Infrared spectrum analysis showed that 5-chlorosalicyloyl low molecular chitosan (see Figure 4 ) compared with chitosan (n=15-25) (see Figure 2 ): Figure 4 the characteristic wide peak of O-H and N-H at 3500-3200 cm -1 in the spectrum was obviously shifted, indicating that N-H may have reacted; the characteristic absorption peak of -NH2 at 1571.7 cm -1 was strengthened, indicating that -NH2 had reacted to form an amide; Figure 5 a characteristic absorption peak of C=O appeared at 1631.5 cm -1 ; a clear saturated -CH stretching vibration absorption peak appeared at 2930.6 cm -1 , a saturated -CH deformation vibration absorption peak appeared at 1213.4 cm -1 , benzene ring C-H out-of-plane bending vibration appeared at 864.6 cm -1 and 763.3 cm -1 , and benzene ring C-H in-plane bending vibration appeared at 1200-950 cm -1 . 13 C nuclear magnetic resonance spectrum (see Figure 12 ) analysis showed that 177.1 ppm was the chemical shift of the C=O carbon of the amide bond; 98.1 (C1), 76.6 (C4), 74.8 (C5), 69.6 (C3), 64.0 (C6), and 52.5 (C2) ppm were the chemical shifts of the chitosan sugar ring; and 160.6 ppm was the chemical shift of the 5-chlorosalicylic acid C-O-H carbon chain. The above results can prove the formation of the target compound.

[0060] Example 3

[0061] 0.5-2.5 g chitosan (n=1200-1300) was dissolved in acetic acid and mixed with 100-300 mL 2-morpholinoethanesulfonic acid buffer solution, and reacted with 3,5-dichlorosalicylic acid with activated carboxyl group at room temperature for 48 hours; after stirring at room temperature for 48 hours, anhydrous ethanol was added for alcohol precipitation, centrifuged after cold storage for 12 hours to obtain orange yellow precipitate. After multiple washing with ethanol, filtration and drying, 3,5-dichlorosalicyloyl high molecular chitosan was obtained. The structural formula is shown in formula 2, wherein R is

[0062] , n=1200-1300.

[0063] Infrared spectrum analysis shows that 3,5-dichlorosalicyloyl high molecular chitosan (see Figure 5 ) compared with chitosan (n=1200-1300) (see Figure 1 ): Figure 5 The characteristic wide peak of O-H and N-H at 3500-3200 cm -1 in the middle is obviously shifted, indicating that N-H may react; the characteristic absorption peak of -NH2 at 1553.3 cm -1 is strengthened, indicating that -NH2 has reacted with amide; Figure 7 The characteristic absorption peak of C=O appears at 1626.7 cm -1 in the middle; the obvious saturated-CH stretching vibration absorption peak appears at 2925.9 cm -1 , 1218.2 cm -1 is the saturated-CH deformation vibration absorption peak, and the benzene ring C-H out-of-plane bending vibration appears at 809.6 cm -1 and 754.5 cm -1 , the benzene ring C-H in-plane bending vibration appears at 1200-950 cm -1 . 13 C nuclear magnetic resonance spectrum (see Figure 13 ) analysis shows that 175.4 ppm is the chemical shift of C=O carbon of amide bond; 99.9 (C1), 75.2 (C4), 71.3 (C5), 64.9 (C3), 57.9 (C6), 52.3 (C2) ppm are the chemical shifts of chitosan sugar ring; 160.3 ppm is the chemical shift of 3,5-dichlorosalicylic acid carbon chain C-O-H. The above results can prove the formation of the target compound.

[0064] Example 4

[0065] 0.5-2.5 g chitosan (n=15-25) was dissolved in 100-300 mL 2-morpholinoethanesulfonic acid buffer solution, and reacted with chlorosalicylic acid containing activated carboxyl group at room temperature for 24 hours; after dialysis for 2-3 days with a dialysis bag with a molecular weight cut-off of 1 K Da, it was concentrated to 30-50 mL, and freeze-dried to obtain 3,5-dichlorosalicyloyl low molecular chitosan. The structural formula is shown in formula 2, wherein R=

[0066] , n=15-25.

[0067] Infrared spectrum analysis showed that 3,5-dichlorosalicyloyl low molecular chitosan (see Figure 6 ) compared with chitosan (n=15-25) (see Figure 2 ): Figure 6 the characteristic wide peak of O-H and N-H at 3500-3200 cm -1 in the spectrum was obviously shifted, indicating that N-H may have reacted; the characteristic absorption peak of -NH2 at 1562.3 cm -1 was strengthened, indicating that -NH2 had reacted to form an amide; Figure 6 a characteristic absorption peak of C=O appeared at 1645.2 cm -1 ; obvious saturated -CH stretching vibration absorption peak appeared at 2935.4 cm -1 , 1218.1 cm -1 was the saturated -CH deformation vibration absorption peak, and benzene ring C-H out-of-plane bending vibration appeared at 818.3 cm -1 and 759.3 cm -1 , benzene ring C-H in-plane bending vibration appeared at 1200-950 cm -1 . 13 C nuclear magnetic resonance spectrum (see Figure 14 ) analysis showed that 176.8 ppm was the chemical shift of C=O carbon of the amide bond; 97.9 (C1), 76.6 (C4), 74.8 (C5), 69.6 (C3), 63.9 (C6), 52.4 (C2) ppm were the chemical shifts of the chitosan sugar ring; and 160.6 ppm was the chemical shift of 3,5-dichlorosalicylic acid carbon chain C-O-H. The above results can prove the formation of the target compound.

[0068] Example 5

[0069] 0.5-2.5 g chitosan (n=1200-1300) was dissolved in acetic acid and mixed with 100-300 mL 2-morpholinoethanesulfonic acid buffer solution, and reacted with 3,5,6-trichlorosalicylic acid with activated carboxyl group at room temperature for 48 hours; after stirring at room temperature for 48 hours, anhydrous ethanol was added for alcohol precipitation, centrifuged after cold storage for 12 hours to obtain orange yellow precipitate. After multiple washing with ethanol, filtration and drying, 3,5,6-trichlorosalicyloyl chitosan was obtained. The structural formula is shown in formula 3, wherein R=

[0070] , n=1200-1300.

[0071] Infrared spectrum analysis showed that 3,5,6-trichlorosalicyloyl chitosan (see Figure 7 ) compared with chitosan (n=1200-1300) (see Figure 1 ): Figure 7 the characteristic wide peak of O-H and N-H at 3500-3200 cm -1 in the middle obviously shifted, indicating that N-H may react; the characteristic absorption peak of -NH2 at 1558.1 cm -1 was strengthened, indicating that -NH2 has undergone amide reaction; Figure 7 the characteristic absorption peak of C=O appeared at 1636.3 cm -1 , the obvious saturated-CH stretching vibration absorption peak appeared at 2934.4 cm -1 , the saturated-CH deformation vibration absorption peak appeared at 1213.4 cm -1 , the benzene ring C-H out-of-plane bending vibration appeared at 814.4 cm -1 and 768.1 cm -1 , and the benzene ring C-H in-plane bending vibration appeared at 1200-950 cm -1 . 13 C nuclear magnetic resonance spectrum (see Figure 15 ) analysis showed that 175.1 ppm was the chemical shift of C=O carbon of amide bond; 100.2 (C1), 75.2 (C4), 71.3 (C5), 65.2 (C3), 58.2 (C6), 56.3 (C2) ppm were the chemical shifts of chitosan sugar ring; 160.4 ppm was the chemical shift of 3,5,6-trichlorosalicylic acid carbon chain C-O-H. The above results can prove the formation of the target compound.

[0072] Example 6

[0073] 0.5-2.5 g chitosan (n=15-25) was dissolved in 100-300 mL 2-morpholinoethanesulfonic acid buffer solution, and reacted with chlorosalicylic acid containing activated carboxyl at room temperature for 24 hours; after dialysis for 2-3 days with a dialysis bag with a molecular weight cut-off of 1K Da, it was concentrated to 30-50 mL, and freeze-dried to obtain 3,5,6-trichlorosalicyloyl low molecular chitosan. The structural formula is shown in formula 3, wherein R=

[0074] , n=15-25.

[0075] Infrared spectrum analysis showed that 3,5,6-trichlorosalicyloyl low molecular chitosan (see Figure 8 ) compared with chitosan (n=15-25) (see Figure 2 ): Figure 8 the characteristic wide peak of O-H and N-H at 3500-3200 cm -1 in the infrared spectrum was obviously shifted, indicating that N-H may have reacted; the characteristic absorption peak of -NH2 at 1562.1 cm -1 was strengthened, indicating that -NH2 had undergone amide reaction; Figure 8 a characteristic absorption peak of C=O appeared at 1645.1 cm -1 ; a clear saturated -CH stretching vibration absorption peak appeared at 2929.4 cm -1 , a saturated -CH deformation vibration absorption peak appeared at 1213.4 cm -1 , benzene ring C-H out-of-plane bending vibration appeared at 869.4 cm -1 and 759.3 cm -1 , and benzene ring C-H in-plane bending vibration appeared at 1200-950 cm -1 . 13 C nuclear magnetic resonance spectrum (see Figure 16 ) analysis showed that 177.0 ppm was the chemical shift of the C=O carbon of the amide bond; 97.9 (C1), 76.5 (C4), 74.8 (C5), 71.9 (C3), 64.0 (C6), and 52.4 (C2) ppm were the chemical shifts of the chitosan sugar ring; and 160.6 ppm was the chemical shift of the C-O-H of the 3,5,6-trichlorosalicylic acid carbon chain. The above results can prove the formation of the target compound.

[0076] It is worth noting that Figure 1 infrared (cm -1 ): 3292.9, 2862.1, 1649.9, 1590.1, 1374.6, 1025.7.

[0077] Figure 2IR (cm -1 ): 3247.5, 2875.6, 1571.7, 1521.4, 1034.6.

[0078] Figure 3 IR (cm -1 ): 3316.1, 2921.1, 1640.3, 1558.1, 1218.2, 1034.6, 823.1, 759.3.

[0079] Figure 4 IR (cm -1 ): 3307.3, 2930.6, 1631.5, 1571.7, 1213.4, 1034.6, 823.1, 759.3.

[0080] Figure 5 IR (cm -1 ): 3279.4, 2925.9, 1626.7, 1553.3, 1218.2, 1061.7, 809.6, 754.5.

[0081] Figure 6 IR (cm -1 ): 3325.6, 2935.4, 1645.2, 1562.3, 1218.2, 1028.1, 818.3, 759.3.

[0082] Figure 7 IR (cm -1 ): 3302.5, 2939.4, 1636.3, 1558.1, 1213.4, 1066.5, 814.4, 768.1.

[0083] Figure 8 IR (cm -1 ): 3339.2, 2939.4, 1645.1, 1562.1, 1213.4, 1034.6, 869.4, 759.3.

[0084] Figure 9 Chemical shifts (ppm): 107.3, 99.2, 86.3, 75.6, 61.4, 58.4 ppm.

[0085] Figure 10 Chemical shifts (ppm): 98.0, 76.6, 74.8, 74.3, 72.0, 69.6, 55.9 ppm.

[0086] Figure 11Chemical shifts (ppm): 177.0, 160.6, 97.9, 76.5, 74.8, 71.9, 69.6, 64.0, 52.4 ppm.

[0087] Figure 12 Chemical shifts (ppm): 177.0, 160.6, 97.9, 76.5, 74.8, 71.9, 69.6, 64.0, 52.4 ppm.

[0088] Figure 13 Chemical shifts (ppm): 177.0, 160.6, 97.9, 76.5, 74.8, 71.9, 69.6, 64.0, 52.4 ppm.

[0089] Figure 14 Chemical shifts (ppm): 177.0, 160.6, 97.9, 76.5, 74.8, 71.9, 69.6, 64.0, 52.4 ppm.

[0090] Figure 15 Chemical shifts (ppm): 177.0, 160.6, 97.9, 76.5, 74.8, 71.9, 69.6, 64.0, 52.4 ppm.

[0091] Figure 16 Chemical shifts (ppm): 177.0, 160.6, 97.9, 76.5, 74.8, 71.9, 69.6, 64.0, 52.4 ppm.

[0092] The present application acylates chitosan with different molecular weights in 2-morpholinoethanesulfonic acid solution and different chloro-containing salicylic acids. The reaction temperature is 25℃, and the reaction time is 24-48 hours. The derivative is prepared by precipitation, filtration, washing, dissolution, dialysis and freeze-drying. The molar ratio of chitosan monomer to different chloro-containing salicylic acids in the preparation method is 1:3-1:5. Distilled water is used as the solvent for dissolution and dialysis.

[0093] In the present application, different chloro-containing salicylic acids mainly react with the amino group (-NH2) at the C2 position of chitosan to form chitosan chloro-containing salicylamide derivatives, wherein the degree of substitution of the chloro-containing salicylic acid is 29.90-44.10%.

[0094] The prepared chitosan chlorophenylamide derivative is orange yellow or dark brown powder. The compound is analyzed and confirmed by infrared spectrum, carbon nuclear magnetic resonance spectrum and element analysis, and the chitosan molecules are effectively combined with the groups to form the chitosan chlorosalicylamide derivative, wherein the reacted amino groups account for 29.90-44.10% of the total groups in the chitosan.

[0095] The present application combines the chitosan with the effective groups of the chloro type to develop a new type of green pesticide with low toxicity and high efficiency, which can produce synergistic effect, has the characteristics of high efficiency in inhibiting bacteria and green low toxicity, and further adjusts the plant growth and other biological activities.

[0096] It can be understood that the present application is described through some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to the features and embodiments without departing from the spirit and scope of the present application. In addition, the features and embodiments can be modified to adapt to specific conditions and materials under the guidance of the present application without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope of protection of the present application.

Claims

1. A chitosan-containing chlorinated salicylamide derivative, characterized in that, Derivatives are compounds of formula (1): Formula (1) wherein n = 15-25 and 1200-1300; R is: ， ， 。 2. A method for preparing a chitosan chlorosalicylamide derivative, characterized by, The 2-morpholinoethanesulfonic acid aqueous solution is configured, chlorinated salicylic acid is added to dissolve, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride (EDC) is added and stirred for 1 hour, N-hydroxysuccinimide (NHS) is then added for activation (the molar ratio of chlorinated salicylic acid, EDC, and NHS is 1:3:5), stirring is continued for 2 hours (ice water bath), and then the mixture is mixed with chitosan (n=1240) dissolved in acetic acid solution, stirring is continued at room temperature for 48 hours, anhydrous ethanol is then added for alcohol precipitation, centrifugation is performed after cold storage for 12 hours, and an orange yellow precipitate is obtained; centrifugation is performed after cold storage for 12 hours, and an orange yellow precipitate is obtained; After multiple washing, filtering, and drying in ethanol, chlorinated salicyloyl high molecular chitosan is obtained.

3. The method for preparing chitosan-containing chlorinated salicylamide derivatives according to claim 2, characterized in that, Chlorinated salicylic acid is dissolved in a small amount of ethanol, mixed with a morpholinoethanesulfonic acid aqueous solution containing 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride (EDC), N-hydroxysuccinimide (NHS) is added after stirring for 1 hour to activate the carboxyl group (the molar ratio of chlorinated salicylic acid, EDC, and NHS is 1:3:5), stirring is continued for 2 hours (ice water bath), chitosan (n=18) is added, and the reaction is continued for 24 hours, 50°C rotary evaporation is performed to concentrate to 100ml, a 1KDa dialysis bag is used for dialysis for 48 hours, the dialysis bag is transferred to a-80°C refrigerator for cold storage for 12 hours, and freeze drying is performed for 48 hours.

4. The method for preparing chitosan-containing chlorinated salicylamide derivatives according to claim 3, characterized in that, The chitosan has a mass of 0.5-2.5g.

5. The method for preparing chitosan-containing chlorinated salicylamide derivatives according to claim 4, characterized in that, The 2-morpholinoethanesulfonic acid buffer solution has a volume of 100-300 mL.

6. The method for preparing chitosan-containing chlorinated salicylamide derivatives according to claim 5, characterized in that, The chlorinated salicylic acid can be 5-chlorosalicylic acid, 3,5-dichlorosalicylic acid, or 3,5,6-trichlorosalicylic acid.

7. The method for preparing chitosan-containing chlorinated salicylamide derivatives according to claim 2, characterized in that, The 2-morpholinoethanesulfonic acid buffer solution has a pH of 5-6.

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