JPH0288580A - Brassinolide analogous compound and use thereof - Google Patents

Abstract

NEW MATERIAL:A brassinolide analogous compound expressed by formula I [R<1> and R<2> are lower alkyl: A is formula II or III]. EXAMPLE:(22S,23S,24S)-22,23-Epoxy-2alpha,3alpha-isopropylidenedioxy-B- homo-7-oxa-5alpha- stigmastan-6-one. USE:An active ingredient of plant growth regulators, having excellent plant growth promoting action with long persistence and useful for promoting growth of vegetables, such as tomato, flowering plants, such as chrysanthemum, gramineous plants, such as paddy rice, barley or wheat, fruit trees, such as apple or pear, promoting thickening of the above-mentioned flowers and fruits and increasing yield of grains, such as the gramineous plants, beans, such as soybean, and potato. PREPARATION:A compound expressed by formula IV is oxidized with an oxidizing agent, such as m-chloroperbenzoic acid, to afford the compound expressed by formula I when A is formula II. Alternatively, a compound expressed by formula V is reacted with a ketone compound expressed by formula Vl in the presence of an acid, such as p-toluenesulfonic acid, to provide the compound expressed by formula I when A is formula III.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application gf] This invention relates to novel brannolide analogs useful as plant growth regulators.

[Prior Art and Problems] Conventionally, plant growth regulators have been extremely shortened, but in recent years brassinolide has been used as a new plant hormone. Synthetic research has been carried out on various related compounds of IF.

However, although these brassinolides and their analogues exhibit remarkable plant growth-promoting effects, the duration of their effects is short, making it difficult to obtain stable expression of efficacy in practical use.

[Object of the Invention] The present invention provides a novel plannolide analog compound that has a strong plant growth promoting effect and is long-lasting, a method for producing the same, and a plant growth regulator containing the same as an active ingredient.

[Structure of the Invention] The compound of the present invention that can achieve the above object has the following chemical structural formula (1).

[In the formula, R and R2 each mean a group represented by a lower alkyl group -CH-CH- (in the formula, R and R2 have the same meanings as above)] In the above formula, the lower alkyl in R and R2 As a preferable example,
Examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl and the like.

Compound (I) of the present invention is a new compound and can be produced by the following formula and the method described below.

(1) Method 1: (In the formula, R1 and R2 have the same meanings as above) <1) Method 1 Among the compounds (I[) used in this method, (22E
, 24S)-2α,3α-impropylidenedioxy-5α-stigmast-22-en-6-one, for example, Tetrahedron, Vol. 38, No. 14, No. 2099
-2109 (1982).

The oxidizing agents used in this oxidation reaction include perbenzoic acid, m-chloroperbenzoic acid, m-bromoperbenzoic acid, performic acid, peracetic acid, chloroperacetic acid, trifluoroperacetic acid, monoperphthalic acid, and Examples include organic peroxides such as sodium or potassium salts thereof, hydrogen peroxide, and mixtures of hydrogen peroxide and the various peroxides described above.

This reaction is usually carried out in a solvent, and the solvents used include methylene chloride, ethylene chloride, ethyl acetate, chloroform, dioxane, tetrahydrofuran, benzene,
Examples include toluene and hexane. Among these, hydrophilic solvents can be used in combination with water.

Further, the temperature of the reaction is not particularly limited, and is appropriately selected depending on the types of raw materials, oxidizing agent, solvent, and the like.

Among these, more preferable results are often obtained when the reaction is carried out in the dark at room temperature using m-chloroperbenzoic acid as the oxidizing agent and methylene chloride or chloroform as the solvent.

(2) Method 2 (22R, 2
3R)-28-homopranolide (I[[) is a known compound described, for example, in Chemical and Pharmaceutical Research, Renan, Vol. 30, p. 4181 (1982).

The target compound (Ib) is obtained by adding an acidic ion exchanger to this compound (III) in addition to an organic acid such as sulfonic acid. ! Resins can also be used. These acids may also serve as solvents.

Among the target compounds (1) of this invention, representative compounds are as follows.

Compound (1) (target compound of Example 1): Can be produced by reacting reactive equivalents. A typical example of such a ketone compound is acetone, and a reactive equivalent thereof is, for example, 2,2-dimethoxypropane.

This reaction is carried out in a commonly used solvent at room temperature to heating.

This reaction is usually carried out in the presence of an acid, such as inorganic acids such as hydrochloric acid, hydrobromic acid, and sulfuric acid;
Acetic acid, acetic acid, trifluoroacetic acid, propionic acid, benzenesulfonic acid, P-toluene [(223,23S, 24S
)-22,23-evoquin-2α.

3α-inpropylidenedioquine-B-homo-7oxer 5α-stigmastane-61 year old Nco compound (2) (
Target compound of Example 2): [C22R,23R,24S
)-2α, 3α, 22.23-diisopropylidenenooxy-B-homo-7-oxa-5α-stigmastane-6-onco The object compound (1) of the present invention has a strong plant growth promoting effect, It is useful as a plant growth regulator. For example, promoting the growth of cane vegetables such as tomatoes, eggplants, and peppers; promoting the growth of grasses such as grasses, carnations, and cosmos; promoting the growth of grasses such as paddy rice and wheat; promoting the growth of fruit trees such as apples and pears; It can be used as a plant growth regulator for the purpose of increasing the yield of grains such as the grasses mentioned above, increasing the yield of legumes such as soybeans, horn beans, peanuts, and peas, increasing the yield of potatoes, etc. can.

The method of using the plant growth regulator of the present invention varies depending on the target plant, but it is generally appropriate to spray the plant growth regulator on the leaves. The concentration used varies depending on the target plant, but it is generally used in an extremely low concentration range of about 1 x 110-5 pp to 1 pp111.

When using the plant growth regulator of this invention, it is mixed with various carriers depending on the usage situation, such as powder, granules, tablets, etc.
It can be used as a wettable powder, emulsion, etc. The carrier referred to herein may be either solid or liquid, or a combination thereof. For example, talc, clay, kaolin, diatomaceous earth, carunium subacid, potassium chlorate, saltpeter, nitrocellulose, starch, gum arabic, water, alcohol, benzene, acetone, etc. are used as carriers. Furthermore, auxiliary agents that can be used in the formulation of agricultural chemicals, such as spreading agents and emulsifiers, can be added as necessary.

(Although the above preparations can be used alone as they are, they can also be used in combination with fungicides, insecticides, herbicides, other plant growth regulators, or fertilizers.

[Effects of the Invention] Next, the effects of the plant growth regulator of the present invention will be explained using test examples.

Test example Paddy rice (variety - Japan) was grown in a bot with a diameter of 7 cm and a depth of 7 cm.
) were grown in groups of 5 and subjected to efficacy testing at the 3-leaf stage. The test compound was dissolved in ethanol to give LQOppm, and further diluted with water to a predetermined concentration. A spreading agent (Enthene) was added to this to make it 2000 times more concentrated. 10 m/2 pots of the drug prepared in this way
Q was carefully distributed evenly. After spraying, 20
It was grown in a constant-temperature growth cavity at ~21°C (natural growth, test period was August).

Twenty days after spraying, the above-ground parts of 10 rice plants in two bonds in each district were harvested and the total fresh weight was measured.

The results are shown in the table below, and the values in the table are expressed as a percentage (%) of the live weight of the drug-undefeated configuration.

[Example] Next, examples of this invention will be shown.

Example 1 (22E, 24S)-2α,3α-impropylidenedioxy-5α-stigmast-22-en-6-one (5.0 g) (7) Dichloromethane (8αml)
Add m-chloroperbenzoic acid (5.0 g) to the la solution,
2 weeks in the dark at room temperature! * Add Cal/Rum hydroxide powder (7.0 g) to the stirring reaction mixture and stir for 1 hour at room temperature. After the precipitate is filtered off, it is washed twice with dichloromethane. When the filtrate and washing liquid are combined and concentrated, the crude target product is obtained. This was subjected to cynogel chromatography using hexane-ethyl acetate (4:1-3:1).
When eluted with a mixed solution, (22S, 23S, 24S)-2
2,23-epoxy-2α,3α-isopropylidenedioxy-B-homo-7-year-old xar 5α-stigmastan-6-one (1,03 g) is obtained.

'H-NMR (200MHz, CDC13) S: 0.
68 (3H, s), 089 (3H, s), 1.3
2 (3H, s), 1.52 (3H, s) 2.47
(2H, m), 3.29 (IH, dd, J
=IQ and4.5Hz), 4. Ll (2H,
m>, 4.37 (IH, m>FD-MS mHz
: 517 (M”+1).

Example 2 Raw material (22R, 23R)-28-homobrassinolide (
50mg), P-toluenesulfonic acid (5mg) and 2,2-dimethoxypropane (51nQ) at 100"C.
I stirred it for 2 hours. After cooling to room temperature, extraction with ethyl acetate, washing with saturated sodium bicarbonate solution, dehydration with anhydrous magnesium sulfate, concentration, and dilution with cylindrical gel column chromatography, benzene-ethyl acetate (5
:1) When eluted with a mixture, (22R, 23R, 24S)
-2α,3α,22.23-diisopropylidenedioxy-B-homo-7-oxa-5α-stigmastan-6-one (46 mg) is obtained.

'HNMR (200MHz, CDC1a) S: 0.
70 (3H1s), 0.90 (3H,s), 1
．． 32 (3H, s), 1.34 (6H, s).

1.52 (3H, s), 3.29 (LH, dd,
J=10 and4.6Hz>, 3.76 (2H,
m), 4.10 (2H, m).

4.36 (1) 1. m).

Claims (2)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1 and R^2 each represent lower alkyl, A is a formula: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Mathematical formula, There are chemical formulas, tables, etc. ▼ (In the formula, R^1 and R^2 mean the same meanings as above) Brassinolide analogue compound. (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1 and R^2 each represent lower alkyl, A is a formula: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Mathematical formula, A plant growth regulator containing a brassinolide analog compound as an active ingredient, which has chemical formulas, tables, etc. ▼ (in the formula, R^1 and R^2 mean the same meanings as above) .