Anti-ice nucleation active composition, frost protection composition, and method for reducing frost damage

Abstract

The objective is to provide an anti-ice nucleation active composition containing carboxymethylcellulose salt and catechins. [Solution] Contains carboxymethylcellulose salt and catechins, wherein the molecular weight of the carboxymethylcellulose salt is 2 × 10 4 The above 8 x 10 5 The following is an anti-ice nucleation active composition.

Description

[Technical Field]

[0001] The present invention relates to an anti-ice nucleation active composition, a frost protection composition, and a method for reducing frost damage. [Background technology]

[0002] Frost damage refers to crops being harmed by low temperatures. Crops in the early stages of growth and flowering are particularly susceptible, leading to reduced yields and deterioration of quality. Measures to prevent frost damage include combustion methods such as burning kerosene in the field, sprinkler-based watering and freezing methods, frost protection methods using frost protection fans, and the use of covering materials.

[0003] Patent Document 1 discloses a freeze inhibitor comprising a water-insoluble fiber selected from the group consisting of cellulose, chitin, and chitosan. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-35302 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of this invention is to provide an anti-ice nucleation active composition containing carboxymethylcellulose salt and catechins. [Means for solving the problem]

[0006] The present invention may have, but is not limited to, the following configurations. [1] Carboxymethylcellulose salt, It contains catechins, The molecular weight of the carboxymethylcellulose salt is 2 × 10 4 The above 8 x 10 5 The following is: Anti-ice nucleation active composition. [2] A carboxymethyl cellulose salt, and a catechin, are contained, The molecular weight of the carboxymethyl cellulose salt is 2×10 4 or more and 8×10 5 or less, Anti-frost composition. [3] The composition according to [1] or [2], wherein the catechin is one or more selected from the group consisting of catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. [4] A method for reducing frost damage to plants, comprising the step of applying the composition to a plant or its cultivation site, The composition contains a carboxymethyl cellulose salt and catechins, and the molecular weight of the carboxymethyl cellulose salt is 2×10 4 or more and 8×10 5 or less, the method for reducing frost damage to plants. [Effects of the Invention]

[0007] According to the present invention, an anti-ice nucleation active composition containing a carboxymethyl cellulose salt and catechins can be provided. [Modes for Carrying Out the Invention]

[0008] Hereinafter, the anti-ice nucleation active composition and the anti-frost composition (hereinafter also referred to as "the present composition") according to the embodiments of the present invention will be described.

[0009] The present composition contains a carboxymethyl cellulose salt.

[0010] The molecular weight of the carboxymethyl cellulose salt is 2×10 4 or more and 8×10 5 or less, may be 3×10 4 or more and 8×10 5 or less, may be 2×10 4 or more and 3×10 5 or less, and may be 9×104 8×10 or more 5 or less, and may be 9×10 4 or more and 3×10 5 or less. When the molecular weight of the carboxymethyl cellulose salt is within the above range, the anti-ice nucleation activity of the present composition becomes favorable. As used herein, the molecular weight refers to a viscosity-average molecular weight. The viscosity-average molecular weight of the carboxymethyl cellulose salt can be calculated from the intrinsic viscosity of the carboxymethyl cellulose salt using the Mark-Houwink-Sakurada equation.

[0011] The content of the carboxymethyl cellulose salt in the present composition may be 1 ppm to 5000 ppm, may be 5 ppm to 5000 ppm, may be 1 ppm to 1000 ppm, may be 5 ppm to 1000 ppm, may be 50 ppm to 1000 ppm, may be 5 ppm to 500 ppm, and may be 50 ppm to 500 ppm.

[0012] The content of the carboxymethyl cellulose salt can be measured by the following carboxymethyl cellulose salt quantification method. 66 mL of sulfuric acid is added to 34 mL of water, and after cooling, 50 mg of anthrone is added and dissolved. Next, 1 g of thiourea is added and dissolved. This is designated as an anthrone-sulfuric acid solution. 2 mL of carboxymethyl cellulose salt aqueous solutions of various concentrations are each mixed with 10 mL of the anthrone-sulfuric acid solution. After heating for 10 minutes in a 100°C water bath, the mixture is rapidly cooled in cold water, and the absorbance at 620 nm is measured. Using the present composition instead of the carboxymethyl cellulose salt aqueous solution, the absorbance at 620 nm is measured in the same manner. A calibration curve is created from the absorbance at 620 nm of the carboxymethyl cellulose salt aqueous solutions of various concentrations. The content of the carboxymethyl cellulose salt contained in the present composition is measured from the absorbance of the present composition at 620 nm and the calibration curve.

[0013] Examples of the carboxymethylcellulose salt include sodium carboxymethylcellulose salt, potassium carboxymethylcellulose salt, lithium carboxymethylcellulose salt, and ammonium carboxymethylcellulose salt. The carboxymethylcellulose salt may be at least one selected from the group consisting of sodium carboxymethylcellulose salt and potassium carboxymethylcellulose salt.

[0014] The carboxymethylcellulose salt has at least a portion of the hydroxyl groups derived from cellulose substituted with carboxymethyl groups. The degree of substitution may be 0.1 to 2.5, 0.3 to 2.0, or 0.5 to 1.5.

[0015] The carboxymethylcellulose salt may be insoluble in water or may be water-soluble. It is preferable that the carboxymethylcellulose salt be water-soluble.

[0016] The shape of the carboxymethylcellulose salt is not particularly limited and may be particulate or fibrous. The carboxymethylcellulose salt may be a mixture of particulate carboxymethylcellulose salt and fibrous carboxymethylcellulose salt. The carboxymethylcellulose salt is preferably particulate. When the carboxymethylcellulose salt is particulate, the average aspect ratio may be 1.3 or less, 1.2 or less, or 1.1 or less. The average aspect ratio of carboxymethylcellulose salt can be measured by the following method: In an image of carboxymethylcellulose salt or the composition taken using a scanning electron microscope, 100 particles are identified, and the aspect ratio of each particle is measured by dividing the length of the major axis by the length of the minor axis. The average aspect ratio is obtained by simply averaging the aspect ratios of the 100 particles.

[0017] This composition contains catechins.

[0018] The catechin content in this composition may be 1 ppm to 1000 ppm, 1 ppm to 500 ppm, 1 ppm to 100 ppm, 5 ppm to 100 ppm, 1 ppm to 50 ppm, or 5 ppm to 50 ppm. The catechin content can be measured by high-performance liquid chromatography as follows: The catechins are extracted from the composition or its dilution with 2% phosphoric acid:ethanol (1:1). The catechins contained in the extract are separated by reverse-phase chromatography using a 0.2% aqueous phosphoric acid solution (mobile phase A) and a methanol / acetonitrile mixture (mobile phase B) as mobile phases, and quantified by detection with a UV detector (detection wavelengths: 242nm, 272nm).

[0019] The catechins include catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. In this specification, catechins include stereoisomers of the catechins. The catechins may be used individually or in combination of two or more. The catechins are preferably one or more selected from the group consisting of catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. From the viewpoint of improving the anti-ice nucleation activity of this composition, epigallocatechin gallate or (+)-catechin is preferred, and epigallocatechin gallate is more preferred.

[0020] This composition exhibits the effect of lowering the freezing point of water. This indicates that freezing point depression is occurring, and therefore, this composition can be considered a freezing point depression promoting composition.

[0021] The freezing of water is thought to involve the process of ice nucleation and the growth of these ice nuclei. The mechanism by which this composition exhibits the effect of lowering the freezing temperature of water is not fully understood, and various factors are thought to be involved. However, one possible reason is that this composition inhibits the process of ice nucleation, i.e., it possesses anti-ice nucleation activity. Therefore, this composition may be an anti-ice nucleation active composition.

[0022] This composition can reduce frost damage to plants by adhering to the surface of plants, lowering the freezing point of water, and inhibiting the process of ice nucleation. Therefore, this composition can be used as an antifrost composition.

[0023] This composition may exhibit good anti-ice nucleation activity due to the inclusion of both the carboxymethylcellulose salt and the catechins. The anti-ice nucleation activity of this composition can be measured by the method described in the examples below.

[0024] In this composition, the ratio of the carboxymethylcellulose salt to the catechins (carboxymethylcellulose salt / catechins) may be 0.25 or more and 100 or less, 0.25 or more and 50 or less, 0.25 or more and 25 or less, or 2.5 or more and 25 or less.

[0025] The viscosity of this composition may be 15,000 mPa·s or less, 10,000 mPa·s or less, 5,000 mPa·s or less, 0.1 mPa·s to 15,000 mPa·s, 1 mPa·s to 10,000 mPa·s, or 5 mPa·s to 5,000 mPa·s. The viscosity of this composition can be measured using a Type B viscometer (TVB-15M model, manufactured by Toki Sangyo, rotor No. 2, rotation speed: 50 rpm, measurement temperature: 25°C). However, if the viscosity of this composition is 5,000 mPa·s or more, rotor No. 3 should be used instead of rotor No. 2.

[0026] This composition may optionally contain other components besides the carboxymethylcellulose salt and the catechins.

[0027] Examples of the other components include pesticide active ingredients, surfactants, solid carriers, formulation aids, and solvents. Examples of the pesticide active ingredients include insecticidal active ingredients, fungicidal active ingredients, and herbicidal active ingredients. Examples of the solid carriers include clays and inorganic minerals. Examples of the surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Examples of the formulation aids include thickeners, preservatives, freeze inhibitors, and defoamers. Examples of the solvent include water.

[0028] This composition may take the form of a solid. As a solid, this composition can be dissolved or dispersed in water to prepare a stock solution or a treatment solution. In this specification, “dilution” includes dissolving or dispersing a solid in water.

[0029] This composition may take the form of a liquid. As a liquid, this composition may take the form of a stock solution or a treatment solution. As a stock solution, this composition can be used exclusively for preparing a treatment solution by dilution.

[0030] When the embodiment of this composition is the undiluted solution, the content of the carboxymethylcellulose salt in this composition may be 1 ppm or more and 100,000 ppm or less, 1 ppm or more and 50,000 ppm or less, or 1 ppm or more and 10,000 ppm or less.

[0031] When the embodiment of this composition is the undiluted solution, the content of catechins in this composition may be 1 ppm to 50,000 ppm, 1 ppm to 10,000 ppm, 1 ppm to 5,000 ppm, 1 ppm to 1,000 ppm, or 1 ppm to 500 ppm.

[0032] When the embodiment of this composition is a processing liquid, the content of the carboxymethylcellulose salt in this composition may be 1 ppm to 5000 ppm, 5 ppm to 5000 ppm, 1 ppm to 1000 ppm, 5 ppm to 1000 ppm, 50 ppm to 1000 ppm, 5 ppm to 500 ppm, or 50 ppm to 500 ppm. If the content of the carboxymethylcellulose salt in the treatment solution is 1 ppm or more, good anti-ice nucleation activity can be achieved. If the content of the carboxymethylcellulose salt in the treatment solution is 5000 ppm or less, an excessive increase in the viscosity of the treatment solution can be suppressed.

[0033] When the embodiment of this composition is a processing solution, the content of catechins in this composition may be 1 ppm to 100 ppm, 5 ppm to 100 ppm, 1 ppm to 50 ppm, or 5 ppm to 50 ppm. The anti-ice nucleation activity may be good if the catechin content in the treatment solution is 1 ppm or more.

[0034] The content of the carboxymethylcellulose salt and the catechins in the processing solution may be 1 ppm or more for the carboxymethylcellulose salt and 1 ppm or more for the catechins; 5 ppm or more and 1000 ppm or less for the carboxymethylcellulose salt and 1 ppm or more and 50 ppm or less for the catechins; or 5 ppm or more and 500 ppm or less for the carboxymethylcellulose salt and 5 ppm or more and 50 ppm or less for the catechins.

[0035] In the processing solution, the ratio of the carboxymethylcellulose salt to the catechins (carboxymethylcellulose salt / catechins) may be, for example, 0.25 to 100, 0.25 to 50, 0.25 to 25, or 2.5 to 25.

[0036] The method for producing this composition is not particularly limited, and can be obtained, for example, by mixing the carboxymethylcellulose salt, the catechins, and, if necessary, the other components.

[0037] As the catechins, tea extracts extracted from tea leaves may be used. The tea extract may contain multiple catechins. That is, the tea extract may be a mixture of multiple catechins. The tea extract can be obtained, for example, by extracting tea leaves such as green tea, semi-fermented tea generally called oolong tea, or fermented tea generally called black tea with water or hot water. When using a tea extract, the extract from the tea leaves may be used as is, or a solution obtained by dissolving a concentrate of the extract in water may be used. The concentrate of the extract may be in the form of a solid, aqueous solution, slurry, etc.

[0038] The method for producing this composition may include a step of mixing the carboxymethylcellulose salt, the catechins, and other components as needed, such that the content of the carboxymethylcellulose salt in the composition is 1 ppm to 5000 ppm, 5 ppm to 5000 ppm, 1 ppm to 1000 ppm, 5 ppm to 1000 ppm, 50 ppm to 1000 ppm, 5 ppm to 500 ppm, or 50 ppm to 500 ppm.

[0039] The method for producing this composition may include a step of mixing the carboxymethylcellulose salt, the catechins, and other components as needed, such that the content of the catechins in the composition is 1 ppm to 100 ppm, 5 ppm to 100 ppm, 1 ppm to 50 ppm, or 5 ppm to 50 ppm.

[0040] A method for producing the composition may include the steps of: mixing the carboxymethylcellulose salt, the catechins, and other components as needed to obtain a mixture; and diluting the mixture. The dilution can be carried out using a diluent containing water. When the composition obtained in the step of obtaining the mixture is a solid preparation, the composition obtained in the step of diluting the mixture can be called the stock solution. When the composition obtained in the step of obtaining the mixture is the stock solution, the composition obtained in the step of diluting the mixture can be called the processed solution.

[0041] A method for producing the composition may include the steps of: mixing the carboxymethylcellulose salt, the catechins, and other components as needed to obtain a mixture such that the content of the carboxymethylcellulose salt in the composition is 1 ppm to 100,000 ppm, 1 ppm to 50,000 ppm, or 1 ppm to 10,000 ppm; and diluting the mixture. The dilution can be carried out using a diluent containing water.

[0042] A method for producing the composition may include the steps of: mixing the carboxymethylcellulose salt, the catechins, and other components as needed to obtain a mixture such that the content of the catechins in the composition is 1 ppm to 50,000 ppm, 1 ppm to 10,000 ppm, 1 ppm to 5,000 ppm, 1 ppm to 1,000 ppm, or 1 ppm to 500 ppm; and diluting the mixture. The dilution can be carried out using a diluent containing water.

[0043] This composition can be used to reduce frost damage to plants. The method for reducing frost damage to plants according to the present invention (hereinafter also referred to as "this frost damage reduction method") includes the step of applying this composition to plants or to the cultivation area.

[0044] Frost damage to plants refers to damage to crops caused by low temperatures. The mechanism by which this frost damage reduction method reduces frost damage to plants is not fully understood, and it is thought that various factors are involved. One possible reason is that this composition adheres to the surface of plants, lowering the freezing point of water or inhibiting the process of ice nucleation, thereby reducing frost damage to plants.

[0045] This frost damage reduction method may include a step of preparing a treatment solution by diluting the composition. The dilution can be carried out using a diluent containing water.

[0046] The diluent may be water. Examples of the water include pure water, distilled water, deionized water, tap water, and groundwater.

[0047] Furthermore, the mixing ratio of each component in this composition can be appropriately set according to the dilution ratio when using this composition, so that the content of the carboxymethylcellulose salt and the catechins in the processing solution falls within the above-mentioned preferred range.

[0048] The plants mentioned above are not particularly limited and include, for example, fruit trees and industrial crops, leafy and stem vegetables, fruit vegetables, root vegetables, legumes, and flowers. Examples of fruit trees include apples, pears, peaches, plums, apricots, persimmons, grapes, blueberries, plums, prunes, figs, and kiwis. Examples of industrial crops include tea. Examples of leafy and stem vegetables include Chinese cabbage, cabbage, lettuce, leeks, chives, spinach, and asparagus. Examples of fruit vegetables include cucumbers, pumpkins, sweet corn, and green beans. Examples of root vegetables include potatoes. Examples of legumes include soybeans and adzuki beans. Examples of flowers include chrysanthemums and trumpet lilies.

[0049] In this frost damage reduction method, it is preferable to spray the treatment solution on plants before frost forms due to a drop in temperature, for example, to improve the frost damage reduction effect. The timing for spraying the composition on plants may be one week before frost forms, three days before, one day before, 12 to 20 hours before, or 18 hours before.

[0050] The effectiveness of this frost damage reduction method can be evaluated by visually observing the degree of browning of the petals and pistils of the plants or by measuring the electrolytes leaking from the plant body after a predetermined time has elapsed under low-temperature conditions in which frost damage occurs, following the application of this composition to the plants.

[0051] In this frost damage reduction method, the method of applying the treatment solution to plants is not particularly limited and may be foliar spraying, soil spraying, or drenching. [Examples]

[0052] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0053] The following carboxymethylcellulose salts and catechins were used in the examples. [Carboxymethylcellulose salt] Carboxymethylcellulose salt 1 (Catalog No.: 419273, manufactured by Sigma Aldrich, molecular weight 9 × 10) 4 ) Carboxymethylcellulose salt 2 (Catalog No.: Selogen 7A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., molecular weight 3 x 10) 4 ) Carboxymethylcellulose salt 3 (Catalog No.: 419303, manufactured by Sigma Aldrich, 2.5 x 10) 5 ) Carboxymethylcellulose salt 4 (Catalog No.: 419338, manufactured by Sigma Aldrich, 7 x 10) 5 ) [Catechins] Epigallocatechin gallate (Catalog No.: 056-08961, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (+)- Catechin (Product code: C0705, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0054] [Method for measuring anti-ice nucleation activity] Aluminum foil was placed on top of a copper plate water-cooled heat sink (product number: HS-SC140-300, manufactured by Kawasoh Texcel) connected to a high-performance constant-temperature water bath (product number: ECO RE630G, manufactured by Lauda). 500 μL of mineral oil (product number: 150138, manufactured by MP Biomedicals) was then applied to the aluminum foil. Thirty 5 μL droplets of the test solution were then added, and the container was covered with an acrylic plate and polystyrene foam. The temperature was lowered at a rate of 0.5°C per minute until 50% of the 30 droplets froze (T). 50 The result was calculated. The measurement was averaged over three trials. When a mixture of potassium iodide (2.5 mM), silver nitrate (2.5 mM), 50 mM phosphate buffer, and water was used as the test solution, the T 50 to T 50_initial The T values ​​were determined when compositions 1 to 12 were used as test solutions. 50 to T 50_added The anti-ice nucleation activity (ΔT) of compositions 1 to 12 was calculated according to the following formula. 50 ) was calculated. ΔT 50 =|T 50_added |-|T 50_initial |

[0055] (Example 1) Carboxymethylcellulose salt 1 (molecular weight 9 × 10) 4 Composition 1 was prepared by mixing (500 ppm), epigallocatechin gallate (20 ppm), potassium iodide (2.5 mM), silver nitrate (2.5 mM), 50 mM phosphate buffer, and water. Here, the concentration (ppm) refers to the mass-based concentration in the test composition (the same applies to the following examples). The anti-ice nucleation activity value was measured using the above measurement method. The results are shown in Table 1.

[0056] (Examples 2-3) Compositions 2 and 3 were prepared in the same manner as in Example 1, except that the compositions were as shown in Table 1. The anti-ice nucleation activity values ​​were measured using the measurement method described above. The results are shown in Table 1.

[0057] (Examples 4-9) Compositions 4 to 9 were prepared in the same manner as in Example 1, except that (+)-catechin was used instead of epigallocatechin gallate to obtain the compositions shown in Table 1. The anti-ice nucleation activity values ​​were measured using the measurement method described above. The results are shown in Table 1.

[0058] (Example 10) Molecular weight is 3 × 10 4 Composition 10 was prepared in the same manner as in Example 1, except that carboxymethylcellulose salt 2 was used to obtain the composition shown in Table 1. The anti-ice nucleation activity value was measured using the measurement method described above. The results are shown in Table 1.

[0059] (Example 11) Molecular weight is 2.5 × 10 5 Composition 11 was prepared in the same manner as in Example 1, except that carboxymethylcellulose salt 3 was used and the composition was as shown in Table 1. The anti-ice nucleation activity value was measured using the measurement method described above. The results are shown in Table 1.

[0060] (Example 12) Molecular weight is 7 × 10 5 Composition 12 was prepared in the same manner as in Example 1, except that carboxymethylcellulose salt 4 was used to obtain the composition shown in Table 1. The anti-ice nucleation activity value was measured using the measurement method described above. The results are shown in Table 1.

[0061] [Table 1]

[0062] In Table 1, CMC salt refers to carboxymethylcellulose salt. In Table 1, EGCg refers to epigallocatechin gallate.

Claims

1. Carboxymethylcellulose salt, It contains catechins, The molecular weight of the carboxymethylcellulose salt is 2 × 10 ４ The above 8 x 10 ５ The following is: Anti-ice nucleation active composition.

2. Carboxymethylcellulose salt, It contains catechins, The molecular weight of the carboxymethylcellulose salt is 2 × 10 ４ The above 8 x 10 ５ The following is: Anti-frost composition.

3. The composition according to claim 1 or 2, wherein the catechins are one or more selected from the group consisting of catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate.

4. A method for reducing frost damage to plants, comprising the step of applying a composition to plants or their cultivation area, The composition contains a carboxymethylcellulose salt and catechins, and the molecular weight of the carboxymethylcellulose salt is 2 × 10 ４ The above 8 x 10 ５ The following are methods for reducing frost damage to plants.

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