CN111789120B

CN111789120B - Bactericide imazalil ionic liquid, and preparation method and application thereof

Info

Publication number: CN111789120B
Application number: CN202010744758.1A
Authority: CN
Inventors: 谭新球; 张卓; 陈岳; 满益龙; 曹永松; 郑立敏; 欧阳超; 刘思珍; 史晓斌; 李成刚; 张德咏; 刘勇
Original assignee: HUNAN PLANT PROTECTION INSTITUTE
Current assignee: HUNAN PLANT PROTECTION INSTITUTE
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2022-04-01
Anticipated expiration: 2040-07-29
Also published as: CN111789120A

Abstract

The invention relates to the field of pesticides, in particular to imazalil ionic liquid as a bactericide, and a preparation method and application thereof. The imazalil ionic liquid is prepared by respectively carrying out acid-base neutralization reaction on the ligands of imazalil and organic acid, more specifically fatty acid and acid containing benzene ring. Experimental results show that the experimental imazalil ionic liquid shows different synergistic bacteriostatic activities on test strains by taking colletotrichum capsici, rice blast, fusarium and phytophthora capsici as the test strains, the highest synergistic effect reaches 47.19%, and the application prospect is wide.

Description

Bactericide imazalil ionic liquid, and preparation method and application thereof

Technical Field

The invention belongs to the field of chemical pesticides in plant protection, and particularly relates to an imazalil bactericide ionic liquid, and a preparation method and application thereof.

Background

The ionic liquid is salt which is completely composed of organic ions and has a melting point lower than 100 ℃, is generally in a molten state at room temperature, is different from the traditional molten salt, and is salt which is always in a liquid state and has relatively low viscosity at low temperature. The ionic liquid can optimize the physical and chemical properties of the matrix, such as melting point, solubility, surface tension and the like, by selecting different cation and anion pairing ions (different alkyl chain lengths, different ion types and the like). In recent years, scientists have taken active ingredients of medicines as the basis and matched with different types of paired anions/cations, so that the activity of the original medicine is ensured, the physicochemical properties of the defects of the original medicine are improved, and the influence of natural ionic liquid on the sustainable development of green chemistry causes enthusiasm attention of academics, thereby becoming one of the research hotspots.

In the field of agriculture, after the medicine is prepared into the ionic liquid, the permeability of the membrane can be improved, and the medicine release speed can be accelerated; in the field of agricultural chemistry, an appropriate ligand is selected to prepare an ionic liquid with hydrophobic property, so that the rain wash resistance is improved, the drift amount of active substances is reduced, the drug effect is enhanced, the usage amount of pesticides is reduced, and the movement of active ingredients in plants is promoted. Such as Rogers topic group [ Hough W L, Rogers R D. Ionic liquids the n and now: from solvents to materials to active pharmaceutical ingredients [ J ]. Bulletin of the Chemical Society of Japan,2007,80(12):2262-2269] by synthesizing ionic liquids, improving the hydrophobic, controlled release and conductive transport properties of the original drug to enhance the biological activity of the original drug; doherty et al [ Doherty K M, Kulpa Jr C F. selectivity and antibacterial activity of imidazolium and pyridinium ionic liquids [ J ]. Green Chemistry,2005,7(4):185-189] synthesized imidazolium and pyridinium ionic liquids with increased antibacterial properties as the paired ionic alkyl chain grows; however, the current research on related ionic liquids is mainly limited to the improvement of the characteristics of the herbicide, such as stability, leaching property and the like, so that the control efficiency of the herbicide is improved, and the research on bactericides and other chemical pesticides is relatively low.

Imazalil belongs to broad-spectrum, systemic and substituted benzimidazole bactericides, has structural characteristics of typical cations, and influences cell membrane permeability, physiological functions and lipid anabolism. The mechanism of action is related to the nitrogen-containing heterocycle, and the nitrogen atom on the heterocycle can be bonded with the heme region (heme-iron active center) of cytochrome P450 sterol 14-alpha-demethylase (sterol 14 alpha-demethylase P450, Cyp51) in a coordination bond, thereby inhibiting the activity of the enzyme [ Ji H, Zhang W, Zhang M, et al Ji, H.et al, Structure-based de novo design, synthesis, and biological evaluation of non-azo inhibitors specific for lanosterol 14-demethylase of funngi. J.Med.chem.46,474-485[ J ]. Journal of Medicinal Chemistry,2003,46 (4).: 485 ]. Ergosterol is an essential component of fungal cell membranes, Cyp51 is a key enzyme in the ergosterol biosynthetic pathway [ Yoshida Y, Aoyama Y, Noshiro M, et al, Sterol 14-demethylase P450(CYP51) provides a breakdown through for the discission on the evolution of the cytochrome P450 gene superior [ J ]. Biochemical & Biophysical Research Communications,2000,273(3):799-804], inhibition of enzyme activity leading to a retardation of ergosterol synthesis, the loss of which leads to a disruption and a loss of function of the membrane structure, and finally to fungal death [ prunus leaf, Schulverns, Song Aihuan ] antifungal CYP-sensitive vs. resistant Penicillium 51 gene sequence comparison [ J ] proceedings of fungi, 2003,22(1): 153-. Imazalil belongs to dmi bactericides, and the ergosterol biosynthesis inhibitor dmi bactericides are positioned as low-to-medium-resistance risk medicaments by a bactericide resistance action committee (FRAC), but certain plant pathogenic bacteria can generate higher-level resistance or drug resistance on part of dmi bactericides due to unreasonable long-term use, and particularly, the penicillium citrinum has obvious drug resistance.

Currently, imazalil is mainly applied to control of penicillium citrinum, crop anthracnose pathogen and the like, and researches report that pathogenic fungi such as anthrax from various hosts generate drug resistance to various bactericides such as DMIs and the like, so that the problem of how to overcome or delay the generation and development of the drug resistance of pathogenic bacteria to the pathogenic bacteria so as to prolong the service life of the pathogenic bacteria is an important problem in the problem of the drug resistance of plant pathogenic bacteria. Meanwhile, the development speed of the novel bactericide is greatly limited due to long drug development period and high cost. The ionic liquid has the characteristics of easy synthesis, various varieties and stable physicochemical properties, and simultaneously has the characteristic of reducing environmental pollution by selecting different counter ions to improve the physicochemical properties of the pesticide on the premise of not influencing the biological activity of the pesticide, thereby providing a new way for the efficient use of the traditional broad-spectrum bactericide.

Disclosure of Invention

Based on the above, the organic acid, specifically the organic acid with different carbon chain lengths and containing benzene rings and heterocycles, is selected as the anion ligand, and imazalil is taken as the matrix (taken as the alkali), the imazalil ionic liquid is prepared through acid-base neutralization reaction, the chemical characterization of the related ionic liquid is researched, the biological activity and the synergistic condition of the ionic liquid prepared by different ligands are compared, and the change of the antibacterial spectrum is determined. The method is used for explaining the improvement of the sensitivity of fungi to the ionized medicines so as to delay the generation of drug resistance of the fungi, and simultaneously screening the optimal ligand so as to provide scientific basis for the preparation and the efficient utilization of the bactericide ionic liquid, prolong the service life of the high-efficiency but easily-generated drug imazalil, and simultaneously realize the reduction of the use amount of pesticides in agricultural production.

Therefore, the invention firstly provides the ionic liquid of the bactericide imazalil, which is prepared by respectively carrying out acid-base neutralization reaction on imazalil and organic acid, more specifically fatty acid, acid containing benzene ring or ligand with heterocyclic acid. The invention takes the fungicide imazalil as a matrix and takes organic acid with different carbon chain lengths and containing benzene rings and heterocycles as anion ligand to carry out chemical reaction, and the ionic liquid of which the product is the corresponding fungicide is obtained.

In a preferred embodiment, the fatty acid is acetic acid, nonanoic acid or oleic acid; the acid containing benzene ring is benzoic acid or salicylic acid. Wherein, the ionic liquid has the following structural formula:

in a more preferred embodiment, the ligand is salicylic acid.

The invention also provides a bactericide containing the ionic liquid as an active ingredient.

The invention also provides application of the ionic liquid in preventing and treating plant fungal diseases, wherein the fungal diseases are plant diseases caused by penicillium citrinum, colletotrichum, rice blast, sclerotinia sclerotiorum, phytophthora, fusarium or ustilaginoidea virens, particularly pepper anthracnose, and more preferably pepper colletotrichum.

Further, the present invention provides a method for preparing the above ionic liquid, which comprises the following steps:

weighing raw imazalil, adding organic alcohol, preferably methanol, and fully dissolving imazalil;

adding the ligand, and stirring for reaction at 50-80 ℃, preferably 60-70 ℃;

and removing organic alcohol from the reaction compound to obtain the ionic liquid.

Wherein in a particularly preferred embodiment, the ligand added and imazalil are added equimolar.

In one embodiment, the reaction is followed by thin layer chromatography to completion to determine when to perform the methanol removal operation.

In a more specific embodiment, the removing methanol is removing methanol from the reaction mixture using a rotary evaporator.

The imazalil ionic liquid is successfully prepared, and specifically comprises imazalil-acetic acid ionic liquid, imazalil-nonanoic acid ionic liquid, imazalil-oleic acid ionic liquid, imazalil-benzoic acid ionic liquid and imazalil-salicylic acid ionic liquid, the recovery yield is more than 89%, and the nuclear magnetic resonance hydrogen spectrum characteristics show that the chemical shifts of H near reaction sites participating in the reaction on imidazole rings in 6 ionic liquids are changed to different degrees, and the chemical shifts are 0.1ppm-0.4 ppm. The 6 ionic liquids have melting points lower than the self melting point (52.7 ℃) of imazalil, are liquid or wax at normal temperature and meet the preparation requirement of the ionic liquids. The inventor creatively takes imazalil as a parent (regarded as alkali) and obtains the imazalil ionic liquid by carrying out acid-base neutralization reaction with organic acid anion ligands with different carbon chain lengths and containing benzene rings and heterocycles. Experimental results show that the imazalil ionic liquid used as a test reagent and the pepper anthracnose, rice blast, fusarium and phytophthora capsici used as test strains show different synergistic bacteriostatic activities to the test strains. Wherein the imazalil-salicylic acid ionic liquid shows synergistic activity on colletotrichum capsici, rice blast and fusarium, and the maximum synergistic effect reaches 47.19 percent. In addition, imazalil is mainly used for preventing and controlling penicillium citrinum, is easy to generate resistance, is rarely used for pepper anthracnose pathogen, fusarium and the like, and shows that the imazalil can be used for preventing and controlling other bacteria in ionic liquid and has better effect according to the invention.

Drawings

FIG. 1 shows the NMR spectrum of imazalil.

FIG. 2 shows the NMR spectrum of imazalil-acetic acid ion liquid.

FIG. 3 shows the NMR spectrum of imazalil-nonanoic acid ionic liquid.

FIG. 4 shows the NMR spectrum of imazalil-oleic acid ionic liquid.

FIG. 5 shows the NMR spectrum of imazalil-benzoic acid ion liquid.

FIG. 6 shows the NMR spectrum of imazalil-salicylic acid ion liquid.

FIG. 7 determination of sensitivity of different Colletotrichum capsici to imazalil.

FIG. 8 sensitivity of colletotrichum gloeosporioides to imazalil and derivatives thereof.

FIG. 9 sensitivity of Pyricularia oryzae to imazalil and derivatives thereof.

FIG. 10 sensitivity of Fusarium to imazalil and its derivatives.

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but not to limit the present invention.

EXAMPLE Synthesis of Imidazolyl Ionic liquids

Weighing 0.297g of imazalil as a raw material into a 50mL three-necked bottle, and adding 20mL of methanol to fully dissolve the imazalil; adding related anion ligands (acetic acid, pelargonic acid, oleic acid, salicylic acid and benzoic acid) in equimolar amount respectively, stirring for reaction at 60-70 ℃, and tracking the reaction by a thin-layer chromatography separation method until the reaction is complete. And removing the methanol from the reaction compound by using a rotary evaporator to obtain the related imazalil ionic liquid.

6 types of the anion ligands are selected and synthesized into 6 types of imazalil ion ligands through acid-base neutralization reaction. Wherein, the number 1 is imazalil; number 2 is imazalil-acetic acid ionic liquid; the number 3 is imazalil-nonanoic acid ionic liquid; number 4 is imazalil-oleic acid ionic liquid; number 5 is imazalil-benzoic acid ionic liquid; no. 6 is imazalil-salicylic acid ionic liquid.

Wherein, the serial numbers 2-6 are all liquid, and the yield of 5 ionic liquids is more than 89%, and the highest yield reaches 98%. Due to the relationship of the selected ligand ions, the molecular symmetry of the ionic liquid of the synthesized product is weak, so that the lattice energy and the molecular acting force are reduced, the melting point of each synthesized product is also low and is less than the melting point (52.7 ℃) of the original imazalil, and the structural formulas, states, melting points and recovery rates of different imazalil ionic liquids are shown in table 1.

TABLE 1 structural formulas and states of imazalil ionic liquid derivatives

Numbering

Molecular formula

Structural formula (I)

Melting Point (. degree.C.)

Status of state

Recovery rate

1

C14H14Cl2N2O

Formula

1

52.7

Powder

—

2

[C14H15Cl2N2O]+[C2H3O2]-

Formula 2

—

Liquid

94.51％

3

[C14H15Cl2N2O]+[C9H17O2]-

Formula 3

—

Liquid

98.03％

4

[C14H15Cl2N2O]+[C18H33O2]-

Formula 4

—

Liquid

95.51％

5

[C14H15Cl2N2O]+[C7H5O2]-

Formula 5

—

Liquid

97.43％

6

[C14H15Cl2N2O]+[C7H5O3]-

Formula 6

—

Liquid

89.72％

Note: 1: imazalil; 2: imazalil-acetic acid ionic liquid; 3: imazalil-nonanoic acid ionic liquid; 4: imazalil-oleic acid ionic liquid; 5: imazalil-benzoic acid ionic liquid; 6: imazalil-salicylic acid ionic liquid.

EXAMPLE characterization of Imidazoles Ionic liquids

And (3) adding a proper amount of the imazalil ionic liquid prepared in the first embodiment into a nuclear magnetic tube, adding 600 mu L of deuterated trichloromethane, and performing nuclear magnetic resonance hydrogen spectrum characterization by using a nuclear magnetic resonance instrument Bruker Avance DPX 300MHz to analyze the structural characteristics of the imazalil ionic liquid.

Performing nuclear magnetic resonance hydrogen spectrum characterization on the obtained imazalil ionic liquid by using a nuclear magnetic resonance spectrometer, wherein the active hydrogen of carboxyl positioned in a high field in all paired ions disappears from the hydrogen spectrum data in table 2, and the N-CH-N hydrogen spectrum displacement on imidazole rings of the imazalil-acetic acid ionic liquid, the imazalil-nonanoic acid ionic liquid and the imazalil-oleic acid ionic liquid in a synthetic product moves to the high field by about 0.1 ppm; the N-CH-N hydrogen spectral shift on the imidazole ring of the imazalil-benzoic acid ionic liquid is shifted by about 0.25ppm to a high field; the N-CH-N hydrogen shift on the imidazole ring of imazalil-salicylic acid ionic liquid is shifted by about 0.4ppm to the high field. According to the melting point and the corresponding hydrogen spectrum result, the imazalil ionic liquid is successfully synthesized (see the figure 1-7).

TABLE 2 NMR spectra data for imazalil ionic liquids

Example three: sensitivity determination of pepper anthracnose pathogenic bacteria to imazalil

1. Preparation of the culture Medium

PDA medium-potato dextrose agar medium without antibiotics purchased from Solebao corporation, 46g was dissolved in 1L ddH2O and autoclaved at 121 ℃ for 20min for use.

2. Preparation of drug-containing Medium

And dissolving imazalil completely with a mixed solution of methanol and water to prepare an imazalil mother liquor with the concentration of 5.0 mg/mL. And (3) cooling to about 55 ℃ in 200mL of PDA culture medium, adding 5mg/L imazalil with the corresponding volume, and fully and uniformly mixing to prepare PDA flat plates containing 0.5mg/L, 1.0mg/L, 2.0mg/L, 4.0mg/L, 8.0mg/L and 16.0mg/L imazalil.

3. Sensitivity determination of pepper anthracnose pathogenic bacteria to imazalil

Sensitivity determination experiments were performed using the growth rate method. The test strains HHBY48 (C.acettum), YYGXZ07(C.brevisporum), HBLF01(C.capsici), CZHP03 (C.truncataum), CSLL11(C.gloeosporioides) were cultured on PDA medium without drugs for 5 days, hypha blocks were taken from the edge of the colony using a punch with a diameter of 5mm, inoculated on PDA culture dishes containing imazalil at different concentrations (0.5mg/L, 1.0mg/L, 2.0mg/L, 4.0mg/L, 8.0mg/L, and 16.0mg/L), cultured in a constant temperature incubator at 26 ℃ and 50% RH for 7d in the dark, and from the start of growth (3d), the colony diameter was measured by a cross method, and the hyphal growth rate was calculated and recorded on an Excel worksheet.

The sensitivity of the pepper anthracnose pathogenic bacteria to imazalil is greatly different among different species. The results show that: EC of different species of Colletotrichum capsici on imazalil₅₀The values are significantly different, i.e., C.acutatum (C.acutatum) and C.truncataum (C.truncataum) EC₅₀The values were 2.85mg/L and 176.34mg/L, respectively, which are different by a factor of 62 (see Table 3 and FIG. 8).

TABLE 3 regression equation of toxicity of imazalil against 5 species of Colletotrichum capsici

Bacterial strains	Linear regression equation (Y ═)	Coefficient of correlation R²	EC₅₀(㎎/L)
				C.acutatum	1.91x+4.13	0.934	2.85
C.brevisporum	1.27x+3.93	0.977	7.38
				C.capsici	0.80x+3.98	0.580	19.14
C.truncatum	0.57x+3.58	0.621	176.34
				C.gloeosporioides	1.74x+3.62	0.947	6.23

Example four: sensitivity determination of colletotrichum gloeosporioides pathogenic bacteria to imazalil and ionic liquid

1. Preparation of drug-containing Medium

The imazalil and the derivatives of the imazalil are completely dissolved by a mixed solution of methanol and water to prepare a mother solution of the imazalil and the derivatives with the concentration of 5.0 mg/mL. And (3) cooling to about 55 ℃ in 200mL of PDA culture medium, adding the imazalil and the derivatives thereof with corresponding volumes, and fully and uniformly mixing to prepare the imazalil PDA flat plate containing 0.5mg/L, 1.0mg/L, 2.0mg/L, 4.0mg/L, 8.0mg/L and 16.0 mg/L.

2. Sensitivity determination of colletotrichum gloeosporioides pathogenic bacteria to imazalil and ionic liquid

A sensitivity determination experiment was performed by a hyphal growth rate method. A test strain CSLL11(C. gloeosporioides) was cultured on a PDA medium without drugs for 5 days, hypha blocks were taken from the edge of the colony using a punch with a diameter of 5mm, and inoculated on PDA culture dishes containing imazalil and its ion solutions at different concentrations (0.5mg/L, 1.0mg/L, 2.0mg/L, 4.0mg/L, 8.0mg/L, and 16.0mg/L), respectively, and cultured in the dark for 7 days in a constant temperature incubator at 26 ℃ and 50% RH, and from the start of hypha growth (3d), the colony diameter was measured by a cross-hatch method, the hypha growth rate was calculated, and photographed and recorded on an Excel worksheet.

The sensitivity difference of the colletotrichum gloeosporioides pathogenic bacteria to the imazalil and the ionic liquid thereof is obvious, wherein the derivative of the imazalil-acetic acid ionic liquid, imazalil-nonanoic acid ionic liquid, imazalil-oleic acid ionic liquid, imazalil-salicylic acid ionic liquid and imazalil EC as raw material₅₀Compared with the value, the values are all obviously reduced, wherein the imazalil-salicylic acid ionic liquid EC₅₀The value is 3.61mg/L, then the imazalil-oleic acid ionic liquid, EC₅₀EC with value of 4.24mg/L for imazalil-acetic acid ionic liquid and imazalil-nonanoic acid ionic liquid₅₀The values were 4.37mg/L and 4.53mg/L, respectively. EC with imazalil₅₀Compared with the value, the sensitivity of the hyphae of the colletotrichum gloeosporioides to the ionized derivatives of the colletotrichum gloeosporioides is improved to different degrees, the synergistic effect is 29 to 47 percent, wherein the synergistic effect of the imazalil-salicylic acid ionic liquid reaches 47 percent, and the fact that the imazalil is combined with a selective ligand to prepare the ionic liquid is beneficial to improving the biological activity of a parent medicament. Interestingly, we also found that imazalil-benzoic acid ionic liquids reduced their sensitivity, with the highest reduction of 36.28%, indicating that both ligands negatively affected the parent activity (see table 4 and fig. 9 in particular).

TABLE 4 regression equation of toxicity of imazalil and its ionic liquid to colletotrichum gloeosporioides

Example fungicidal Spectrum determination of imazalil and its Ionic liquids

And (4) adopting a hypha growth rate method to carry out a determination experiment on whether the bactericidal spectrum is expanded. Test strains of rice blast and fusarium are cultured on a PDA culture medium without drugs for 5 to 6 days, a puncher with the diameter of 5mm is used for taking hypha blocks on the edge of a colony, the hypha blocks are respectively inoculated on PDA culture dishes containing imazalil with different concentrations (0.5mg/L, 1.0mg/L, 2.0mg/L, 4.0mg/L, 8.0mg/L and 16.0mg/L) and ionic liquid of the imazalil, the PDA culture dishes are cultured in a constant temperature incubator with the temperature of 26 ℃ and 50 percent RH for 7d in the dark, the diameter of the colony is measured by a cross method from the beginning of hypha growth (3d), the growth rate of the hypha is calculated, and the hypha is photographed and recorded by an Excel worksheet.

Selecting 4 imazalil-acetic acid ionic liquid, imazalil-nonanoic acid ionic liquid, imazalil-oleic acid ionic liquid and imazalil-salicylic acid ionic liquid for carrying outAnd (3) bactericidal spectrum activity measurement, which takes rice blast germs and fusarium as research objects and adopts a hypha growth rate method to carry out measurement experiments. The results show that the EC of the 3 ionic liquids on rice blast germs₅₀Has a value equivalent to or even lower than that of imazalil₅₀The synergistic effect is 3% -5% (see table 5 and fig. 9); while Fusarium only has EC on imazalil-salicylic acid ionic liquid₅₀The value is lower than imazalil, and the synergy is 12.91% (see table 6 and figure 10 in particular). The above results indicate that although there is some variation in the bactericidal spectrum of ionic liquids with different ligands, the bactericidal spectrum of a single ionic liquid is extended.

TABLE 5 regression equation of toxicity of imazalil and derivatives thereof to Pyricularia oryzae

Derivatives of the same	Linear regression square (Y ═)	Correlation system R²	EC50(㎎/L)	Increase efficiency (%)
					Imazalil	3.14x+5.60	0.861	0.65	—
Imazalil-acetic acid ionic liquid	3.12x+5.63	0.863	0.63	2.94
					Imidazolyl-nonanoic acid ionic liquid	3.16x+5.59	0.865	0.65	-0.93
Imazalil-oleic acid ionic liquid	3.11x+5.65	0.872	0.62	4.64
					Imazalil-salicylic acid chaotropic agent	2.34x+4.99	0.816	1.01	-56.04

TABLE 6 regression equation of toxicity of imazalil and derivatives thereof to Fusarium

Derivatives of the same	Linear regression equation (Y ═)	Coefficient of correlation R²	EC50(㎎/L)	Increase efficiency (%)
					Imazalil	1.03x+3.95	0.861	10.46	—
Imazalil-acetic acid ionic liquid	1.38x+3.45	0.864	13.18	-26.00
					Imidazolyl-nonanoic acid ionic liquid	1.42x+3.48	0.880	11.84	-13.19
Imazalil-oleic acid ionic liquid	0.97x+3.94	0.931	12.17	-16.35
					Imazalil-salicylic acid ionic liquid	0.89x+4.15	0.901	9.11	12.91

Claims

1. The ionic liquid of the bactericide imazalil is characterized by being prepared by respectively carrying out acid-base neutralization reaction on imazalil and a ligand, wherein the ligand is fatty acid or acid containing a benzene ring; and the fatty acid is acetic acid or oleic acid; the acid containing benzene ring is salicylic acid; the ionic liquid is selected from one of the following:

the structure formula of the imazalil-acetic acid ionic liquid is as follows:

、

the imazalil-oleic acid ionic liquid has a structural formula as follows:

、

the imazalil-salicylic acid ionic liquid has the structural formula:

。

2. a bactericide characterized by containing the ionic liquid according to claim 1 as an active ingredient.

3. The use of the ionic liquid according to claim 1 for controlling plant fungal diseases, wherein the ionic liquid is imazalil-acetic acid ionic liquid or imazalil-oleic acid ionic liquid and is used for controlling plant diseases caused by rice blast fungi.

4. The use of an ionic liquid according to claim 1 for controlling fungal plant diseases, wherein the ionic liquid is imazalil-salicylic acid ionic liquid and is used for controlling diseases caused by fusarium.

5. A method of preparing the ionic liquid of claim 1, comprising the steps of:

weighing original drug imazalil, and adding organic alcohol to fully dissolve the imazalil;

adding ligand and stirring at 50-80 deg.C for reaction;

6. The method of claim 5, wherein the reaction is stirred at 60-70 ℃ after the ligand is added.

7. The method of claim 6, wherein the ligand and imazalil are added equimolar.

8. The method of claim 5 or 6, wherein the reaction is followed to completion by thin layer chromatography.

9. The method of claim 5 or 6, wherein the removing the organic alcohol is removing the organic alcohol from the reaction mixture using a rotary evaporator.

10. The method of claim 5, wherein the organic alcohol is methanol.