JP2903778B2 - Abscisic acid analogs and plant growth regulators - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to abscisic acid analogs which are effective as a growth inhibitor, a maturation promoter and the like in agriculture, and a plant growth regulator containing the same as an active ingredient.

[0002]

2. Description of the Related Art Abscisic acid has the following formula (IV)

[0003]

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A kind of plant hormone represented by
Its physiological actions are very different from other plant hormones and exert an inhibitory or aging effect on plant growth. In addition, since the concentration increases in plants due to various stresses, it is considered that the plant also has an anti-stress effect. A typical example is a stoma closing effect at the time of water depletion.

Conventionally, it has been difficult to obtain a natural optically active substance. Therefore, in a study on the use of abscisic acid, a synthetic racemic form has been used. However, it has been found that the natural optically active substance is produced by mold. Next (Sho 61-358
No. 38), and industrial production is becoming possible by the method described in JP-A-2-60590.

[0006] In addition, many studies on the structure-activity relationship of abscisic acid analogs have been carried out, and the structure essential for the expression of the activity has been elucidated (Japanese Patent Laid-Open No. 1-254638).
Gazette, "Abscisic acid" by Frederick Adicott, p113-146).

[0007]

However, no compound having an activity superior to that of natural abscisic acid has been found among the conventional abscisic acid analogs.

At present, natural abscisic acid is expected to be available at a low cost. If natural abscisic acid can be used as a raw material to obtain a more active abscisic acid analog, it can be widely used in the agricultural field. Becomes

Accordingly, an object of the present invention is to provide a novel compound having higher activity than natural abscisic acid and a plant growth regulator containing the compound as an active ingredient.

[0010]

That is, the present invention provides the following general formula (I):

[0011]

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Wherein R is the following formula (II)

[0013]

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Or the following formula (III)

[0015]

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Represents a group represented by ), And a plant growth regulator containing these abscisic acid analogs as active ingredients.

Hereinafter, the present invention will be described in detail.

The compound of the present invention is an abscisic acid analog represented by the above formula (I),

[0019]

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(Hereinafter referred to as abscisic acid analog I) or the following formula (VI)

[0021]

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(Hereinafter referred to as abscisic acid analog II).

First, the method for producing the abscisic acid analogs I and II of the present invention will be described.

The abscisic acid analog I of the present invention can be synthesized, for example, by subjecting a natural abscisic acid and 7-hydroxycoumarin to an esterification reaction as shown in the following reaction formula (A).

[0025]

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The abscisic acid analog II of the present invention can be synthesized by, for example, esterifying natural abscisic acid and methyl parahydroxycinnamate as shown in the following reaction formula (B).

[0027]

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As the natural abscisic acid used as a raw material, any one obtained by any method can be used. For example, known natural abscisic acid described in JP-B-61-35838 and JP-A-2-60590 can be used. It can be manufactured by a method.

The natural abscisic acid is generally used in an amount of 1 mol per 1 mol of the other raw material, 7-hydroxycoumarin or parahydroxycinnamic acid methyl ester.

The reaction of natural abscisic acid with 7-hydroxycoumarin or parahydroxycinnamic acid methyl ester is usually carried out in the presence of a reactant. As a reactant,
For example, 4- (N, N-dimethylamino) pyridine,
N, N-dicyclohexylcarbodiimide and the like can be used. As the reaction solvent, for example, dichloromethane can be used, and the use amount is 10 parts by weight or more based on 1 part by weight of natural abscisic acid.

The reaction temperature is usually from 0 to 50 ° C., and room temperature is sufficient. Although the reaction time depends on the reaction temperature, it is generally 5 to 20 hours, and the reaction is completed in about 12 hours.

Thus, after completion of the reaction, isolation and purification of the abscisic acid analog I or II of the present invention from the reaction mixture can be performed, for example, by thin layer chromatography. That is, for example, the reaction mixture is concentrated, dissolved in ethyl acetate, washed with a saturated sodium bicarbonate solution, the ethyl acetate layer is washed with water and saturated saline, dehydrated with anhydrous sodium sulfate, and then subjected to thin layer chromatography. Isolate and purify.

The abscisic acid analog I or II of the present invention thus obtained is a white crystal. The compound of the present invention is obtained by introducing an aromatic ring into the structure of abscisic acid by an esterification reaction, and can be easily synthesized,
The activity as a plant growth regulator is significantly improved, and the activity is stabilized.

The abscisic acid analog I or II of the present invention
Is used as an active ingredient of a plant growth regulator.

In the present invention, the term "plant growth regulator" refers to a herbicide having a herbicidal effect by inhibiting the germination or growth of a plant, or by inhibiting the growth of a plant to prevent the plant from falling down. Refers to drugs having various plant growth regulating effects, such as dwarfants having the effect of

The plant growth regulator of the present invention can be used by spraying the abscisic acid analog I or II of the present invention in the form of an aqueous solution or the like on the ground having plants or plant seeds.
It can also be used in combination with known plant growth regulators, herbicides, fungicides, insecticides and the like.

When the plant growth regulator of the present invention is used,
Usually, 0.1 mg to 1000 mg per liter of the abscisic acid analog I or II of the present invention as an active ingredient
The contained solution may be sprayed on the ground about 10 liters per arc.

The plant growth regulator of the present invention can be used in the form of powders, emulsifiers, wettable powders and the like according to a conventional method.

[0039]

The present invention will be specifically described below with reference to examples.

Example 1 (Synthesis of abscisic acid analog I) (+)-2-cis, 4
0.076 mmol of trans-abscisic acid, 0.15 mmol of 7-hydroxycoumarin are combined with 0.03 mmol of 4- (N, N-dimethylamino) pyridine and 0.1% of 7-hydroxycoumarin.
Reaction was carried out with 11 mmol of N, N-dicyclohexylcarbodiimide in 10 ml of anhydrous dichloromethane at room temperature for 12 hours. The obtained reaction mixture was concentrated, dissolved in ethyl acetate, washed with a saturated sodium hydrogen carbonate solution, and then the ethyl acetate layer was washed with water and a saturated saline solution, and dried over anhydrous sodium sulfate. Thereafter, ethyl acetate / n-hexane = 1/1 (volume ratio) was used as a developing solvent.
Purified by preparative silica gel thin layer chromatography.
Compound A was obtained at a yield of 78% by the above operation. Melting point was 155-158 ° C.

The structure of Compound A was confirmed by infrared absorption spectrum (IR) and proton nuclear magnetic resonance spectrum (IR).
¹ H NMR). FIG. 1 shows the result of IR measurement of Compound A, and the result of ¹ HNMR measurement (solvent: CDC
l ₃ , internal standard: TMS) is shown below.

Δ1.02 (s, 3H, CH ₃ ), δ1.
09 (s, 3H, C H ₃ ), δ 1.90 (s, 3H, C
H ₃ ), δ 2.12 (s, 3H, C H ₃ ), δ 2.28
(D, 1H, C H ₂ ), δ 2.47 (d, 1 H, C
H ₂ ), δ 5.90 (s, 1H, CO-C H = C), δ
5.96 (s, 1H, C = C H -CO), δ6.28
(D, 1H, C H = CH-CO), δ6.38 (d, 1
H, CH = C H -CO) , δ7.03~7.12 (m,
2H, Ar H ), δ 7.47 (d, 1H, Ar H ), δ
7.69 (d, 1 H, C-C H = CH), δ 7.88
(D, 1H, COH-C H = CH).

From these results, it was confirmed that Compound A exhibited the structure of abscisic acid analog I.

It was also confirmed from the result of ultraviolet absorption that Compound A obtained had the structure of abscisic acid analog I.

Example 2 (Synthesis of Abscisic Acid Analog II) 0.076 mmol of (+)-2-cis, 4-trans-abscisic acid
0.11 mmol of parahydroxycinnamic acid methyl ester, 0.03 mmol of 4- (N, N-dimethylamino) pyridine and 0.11 mmol of N, N-dicyclohexylcarbodiimide and 10 ml of anhydrous dichloromethane at room temperature The reaction was performed for 12 hours. The obtained reaction mixture was concentrated, dissolved in ethyl acetate, washed with a saturated sodium hydrogen carbonate solution, and then the ethyl acetate layer was washed with water and a saturated saline solution, and dried over anhydrous sodium sulfate. Then, benzene / ethyl acetate = 1/1 (3
% Acetic acid) (by volume). By the above operation, compound B was obtained with a yield of 83%.

The structure of Compound B was confirmed by infrared absorption spectrum (IR) and proton nuclear magnetic resonance spectrum (IR).
¹ H NMR). FIG. 2 shows the result of IR measurement of Compound B, and the result of ¹ HNMR measurement (solvent: CDC
l ₃ , internal standard: TMS) is shown below.

Δ 1.01 (s, 3H, CH ₃ ), δ 1.
08 (s, 3H, C H ₃ ), δ 1.89 (s, 3H, C
H ₃ ), δ 2.10 (s, 3H, C H ₃ ), δ 2.27
(D, 1H, C H ₂ ), δ 2.46 (d, 1 H, C
H ₂ ), δ 3.79 (s, 3H, CH ₃ ), δ 5.89
(S, 1H, CO-C H = C), δ5.92 (s, 1
H, C = C H -CO), δ 6.26 (d, 1H, CH =
C H -C), δ6.37 (d , 1H, CH = C H -C
O), δ7.12 (m, 2H , Ar H), 7.53
(M, 2H, Ar H) , δ7.77 (d, 1H, Ar-
C H = CH), δ7.89 ( d, 1H, COH-C H =
CH).

From these results, it was confirmed that Compound B had the structure of abscisic acid analog II.

It was also confirmed from the result of ultraviolet absorption that Compound B obtained had the structure of abscisic acid analog II.

Example 3 (Test for inhibition of sprout germination) Filter paper impregnated with 3 ml of a sample solution in which the concentration of abscisic acid analog I was changed as shown in Table 1 was placed on a 9 cm-diameter dish, and the test was carried out. After washing the seeds with water, place them on a sample liquid filter paper,
The seeds were germinated in a dark place at a temperature of ℃, and a germination inhibition test was carried out on the seeds of Japanese mustard. Table 1 shows the results.

[0051]

[Table 1]

As is clear from the results shown in Table 1, the abscisic acid analog I of the present invention showed about 10 times stronger activity than the natural abscisic acid.

Example 4 (Rice Seedling Growth Inhibition Test) Seeds of rice (variety: Nipponbare) were germinated in water and a dark place at 25 ° C. for 4 days, and seeds having buds of about 1 mm were selected. As shown in the figure, a sample solution in which the concentration of abscisic acid analog II was changed was used for 7 days.
The seedlings were grown at 30 ° C. in a dark place and subjected to a growth inhibition test of rice seedlings. Table 2 shows the results.

[0054]

[Table 2]

As is evident from the results in Table 2, the compound of the present invention, abscisic acid analog II, showed about four times the activity of the natural abscisic acid.

[0056]

The abscisic acid analogs I and I of the present invention
By I, new compounds can be provided, and these compounds can be synthesized not only by a simple method but also have high plant growth regulating activity and are extremely effective as plant growth regulators.

[Brief description of the drawings]

FIG. 1 shows a chart of an infrared absorption spectrum (IR) of Compound A produced in Example 1 of the present invention.

FIG. 2 shows a chart of an infrared absorption spectrum (IR) of Compound B produced in Example 2 of the present invention.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C07C 69/738 C07D 311/16 101 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. The following general formula (I): (Wherein R is the following formula (II): Or the following formula (III): Represents a group represented by An abscisic acid analog represented by). 2. A plant growth regulator comprising the abscisic acid analog according to claim 1 as an active ingredient.