JPH0725718A - Antiplant viral agent - Google Patents

Abstract

PURPOSE:To obtain an antiplant viral agent, consisting essentially of saponin extracted from a leaf, a seed, etc., of green tea widely cultivated for drinking or medical uses from ancient times and effectively used for plants such as tobacco, rice plant, barleys or wheats, beans, lawn or corn. CONSTITUTION:This antiplant viral agent is obtained by extracting, e.g. a leaf or a seed of green tea with an alcohol such as methanol or ethanol, adding an ether such as ethyl ether to the resultant extracted solution, precipitating an ingredient containing the saponin, using the formed precipitate as a crude saponin and dissolving the resultant saponin in water, etc. The agent is capable of controlling the infection or onset of a crop with a plant virus by applying the obtained solution to soil, applying or coating thereof on a leaf, a stem, etc., of the crop. Furthermore, the plant virus can be prevented from spreading from a sap of the attacked plant by dipping a hand, a tool, etc., in the solution before or during the operation. Tobacco mosaic virus, tobacco rattle virus, cucumber green mottle mosaic virus, etc., are cited as the plant virus to be an object of this antiplant viral agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an anti-plant virus agent, and more particularly to an anti-plant virus agent containing tea saponin as a main component.

[0002]

2. Description of the Related Art Plants cultivated in farmland or ordinary households are often infected with plant viruses, and as a result, the commercial value of agricultural products,
The production volume, appearance, etc. will decrease significantly. Therefore, control measures against plant viruses have been emphasized, and several anti-plant virus agents have been proposed, but most of them are not only due to their productivity, but also due to problems such as actual effects and safety against plants and animals. Has not been put to practical use. Therefore, an object of the present invention is to develop and provide an effective anti-plant virus agent from a natural material that is available in large quantities and is safe.

[0003]

[Means for Solving the Problems] The present inventors focused on tea that has been widely cultivated for beverages or medicinal purposes since ancient times, and extracted saponin from tea leaves, seeds, etc., and examined its anti-plant virus action. As a result, they have found that they meet the above-mentioned object, and have reached the present invention.

That is, the present invention relates to an anti-plant virus agent containing tea saponin as a main component.

The tea saponin used in the present invention is obtained by extracting it from tea leaves, seeds, etc. One example of the extraction method is shown below. Tea leaves and tea seeds are extracted with an alcohol such as methanol and ethanol, and ether such as ethyl ether is added to the extract to precipitate a component containing saponin. This precipitate can be used in the present invention as crude saponin. If desired, this crude saponin can also be used after being purified by the method shown in Examples below. The method for extracting and purifying tea saponin used in the present invention is not limited to these, and known methods can be applied. The raw tea leaves are not limited to fresh green leaves, and non-fermented tea, semi-fermented tea, green tea, instant green tea, etc. may also be used.

[0006] The tea saponin thus obtained is dissolved in water or the like and sprayed on the soil, or sprayed or applied to the leaves or stems of the crop to prevent the plant virus from being infected or infected by the plant virus. be able to. Further, by dipping hands, instruments, etc. in the above solution before or during the work, it is possible to prevent the spread of plant viruses from the sap of the diseased plant.

The plant virus which is a target of the anti-plant virus agent of the present invention is not particularly limited and includes, for example, tobacco mosaic virus, tobacco stem gangrene virus, cucumber green spot mosaic virus, cucumber mosaic virus, tomato yellow gangrene virus, potato. S, X, Y viruses, pumpkin mosaic virus, cauliflower mosaic virus, carnation latent virus, cymbidium mosaic virus, soybean mosaic virus, soybean dwarf virus and the like can be mentioned. Further, as the target plant, tobacco, rice, wheat, beans, turf, corn, citrus, melon, cucumber, pumpkin, lettuce, radish,
Komatsuna, cauliflower, eggplant, potato, tomato,
There are various items such as orchids, carnations and chrysanthemums.

[0008]

[Examples] The present invention is described in detail below by using tobacco mosaic virus as a plant virus and red alga as an assay plant, but the present invention is not limited thereto. Production Example 1 Extraction and Purification of Tea Leaf Saponin Tea leaves were plucked, immediately steamed, dried and ground, and 4 kg thereof was repeatedly heated and extracted with 97% ethanol, and 20 L of the obtained extract was immediately added with 30 L of ethyl ether. A flocculent precipitate forms. This precipitate is collected and dried, then water 900m
Dissolve in 1 l, acetic acid 150 ml and chloroform 480 ml
When added and shaken, a flocculent precipitate is formed again, so centrifugation (12,000 g) is performed to collect. In this precipitation,
A mixed solution of water, acetic acid and chloroform having the above composition is added, stirred to form a mud, cooled and then centrifuged again to obtain a solid content. After repeating this operation several times, the precipitate was dried with cold air and further sufficiently dried in a vacuum desiccator containing silica gel and potassium hydroxide to obtain about 30 g of a blackish brown powder.
Got

This powder was washed with ethyl ether using a Soxhlet extractor, dried and dissolved in 150 ml of water. When 300 ml of methanol was added, a blackish brown precipitate was formed, which was removed by centrifugation. A small amount of activated carbon is added to the obtained supernatant and filtered to obtain a light brown transparent liquid, which is concentrated to a liquid volume of 100 ml at a temperature of 40 ° C or lower. To this solution, 65 ml of acetic acid was added, and the mixture was filtered. Ethyl ether was added until the filtrate began to become turbid, and the mixture was left standing for 1 to 2 days to form a precipitate. The precipitate was collected by filtration and dried to obtain 3.5 g of a light brown powder. Next, 3.5 g of this powder 9
It was dissolved in 7% ethanol, activated carbon was added, and the mixture was filtered to obtain a filtrate. Methyl ethyl ketone was added until the filtrate began to become cloudy, and the mixture was allowed to stand to obtain a pale brown saponin precipitate. This operation was further repeated to obtain colorless fine crystals, which were used as tea leaf saponin.

Production Example 2 Extraction and Purification of Tea Seed Saponin The tea seed shell was removed, defatted with hexane, extracted with methanol, ethyl ether was added to the resulting extract, and the resulting precipitate was used as crude tea seed saponin. And To 50 g of this crude tea seed saponin, 250 ml of water was added and dissolved, and further 38%
When 25 ml of hydrochloric acid and 50 ml of chloroform were added and shaken, a cotton-like precipitate was immediately formed. The precipitates were collected by centrifugation, saturated chloroform water was added, and the mixture was stirred to make a mud, and then centrifuged again to obtain a precipitate. After repeating this operation several times, it was sufficiently dried in a vacuum desiccator to obtain a light brown powder.

This powder was washed with ethyl ether using a Soxhlet extractor and recrystallized twice from 80% methanol to give colorless crystals. In order to further purify this product, this recrystallization operation was repeated several times to obtain tea seed saponin.

Example 1 Using red azalea (real leaves 8 to 10 leaves) grown in a greenhouse,
A tobacco mosaic virus solution was applied to one half of the developed leaves of this red alga, and a mixed solution of the tobacco mosaic virus solution and a predetermined amount of the tea leaf saponin obtained in Production Example 1 was applied to the remaining half leaves together with carborundum. About one week later, the number of necrotic lesions appearing due to the infection of tobacco mosaic virus was measured for each half leaf, and the anti-plant virus effect was determined from the infection inhibition rate (%) according to the following formula. The results are shown in Table 1. The number of necrotic lesions is an average value of 4 series. As is clear from the table, a remarkable anti-plant virus action by tea leaf saponin was observed.

[0013]

[Equation 1]

[0014]

[Table 1]

Example 2 The anti-plant virus effect was evaluated in the same manner as in Example 1 except that crude tea seed saponin was used instead of tea leaf saponin. The results are shown in Table 2. The number of necrotic lesions is 4
It is the average value of the run. As is clear from the table, an excellent anti-plant virus action by tea seed saponin was observed.

[0016]

[Table 2]

[0017]

The tea saponin used in the anti-plant virus agent of the present invention can be obtained in large quantities and is obtained from tea leaves and tea seeds, which are safe natural materials. Moreover, it has an excellent anti-plant virus action and is highly practical.

Claims (3)

[Claims] 1. An anti-plant virus agent containing tea saponin as a main component. 2. The plant virus is a tobacco mosaic virus, a tobacco stem gangrene virus, a cucumber green spot mosaic virus, a cucumber mosaic virus, a tomato yellow gangrene virus, a potato S, X, Y virus, a pumpkin mosaic virus, a cauliflower mosaic virus, Carnation latent virus, cymbidium mosaic virus,
The anti-plant virus agent according to claim 1, which is either soybean mosaic virus or soybean dwarf virus. 3. The plant is any of tobacco, rice, wheat, beans, turf, corn, citrus, melon, cucumber, pumpkin, lettuce, radish, komatsuna, cauliflower, eggplant, potato, tomato, carnation, orchid and chrysanthemum. The anti-plant virus agent according to claim 1.