HU201569B - Agricultural compositions regulating the growth of plants containing cyclodextrin inclusion-complexes and process for production of the active substance - Google Patents

Abstract

Plant growth controlling active cpds. of general formula (1) are inclusion complexes contg. cyclo-dextrins of general formula (11), either in pure inclusion complex form and/or as adduct coprecipitate and/or physical mix, the wt. ratio of (1) to (11) being 1: (0.0001-10). In formula (1) n=1, 2, or 3. and X contains cyclodextrins of general formula (11). In (11) m= 6, 7 or 8 and 'R'-s independently represent hydrogen atoms or methyl gps. Provided that the active agent and cyclo-dextrin are present solely as inclusion complexes, the prepn. also contains 5wt.% max of carriers, diluents and/or adjuvants. For the prepn. of active cpds. cyclodextrins (11) are brought into contact in aq. media with plant growth controlling active cpds.

Description

The agricultural plant growth regulating compositions of the present invention contain from 0.04 to 90% by weight of the cyclodextrin inclusion complex of the general formula (I) -

X A-indoleacetic acid, indole-3-butyric acid, indole-3-isobutyric acid, naphthyloxy acid, naphthyloxy acid, naphthylacetic acid, N ^6-10 benzyl adenine or gibberellin A3 and gibberellin A4. Represents a mixture of 7, n is 1 or 2, and

CD represents a cyclodextrin of formula II wherein R is hydrogen or one of R is hydrogen and two are methyl and m is 7 with up to 30% of free X - X is as defined above and together with 20 carriers and, if appropriate, other excipients.

The invention further relates to a process for the preparation of compounds of formula (I).

X. [CD] _n (1)

Description: 10 pages, 1 drawing, 1 figure

HU 201569 Β

FIELD OF THE INVENTION The present invention relates to agricultural compositions containing cyclodextrin inclusion complexes having plant growth regulating activity. The invention further relates to a process for the preparation of the active ingredients of the compositions. 5

Plant growth regulators, also known as plant hormones, are natural compounds or synthetic analogues that, at very low concentrations (e.g., g / ha), are capable of incorporating various biological properties of plants, such as seed germination, growth rate. , the rate of ripening of the crop, the size of the plant, the separation of leaves or fruits, the formation of branches, etc. to modify. In terms of their effects, plant hormones fall into the following main groups:

1 / growth promoters or stimulants,

2 / growth inhibitors or inhibitors, and 20

3 / growth retardants or retardants.

Typical representatives of the first group of plant hormones are auxins (such as indole acetic acid), gibberellins and cytokinins (benzyladenine, N- (2-furanylmethyl) -25H-purin-6-amine), and some vitamins.

Examples of the second group of compounds include abscisic acid, ethylene release compounds (e.g., 2-chloroethylphosphonic acid), triiodobenzoic acid and N-30 (phosphonomethyl) glycine.

A typical representative of the third group of plant hormones is chlorocholine chloride; this group also includes compounds of various quaternary salt types. 35

The grouping is not always clear because the same compound may produce adverse effects depending on the route of administration, time of administration and concentration. For example, growth inhibitors may be maturation accelerators. Ethylene gas, one of the most effective plant hormones, can cause the leaves of the plant to fall off, but it can also accelerate the ripening and dusting of tomatoes or peppers. 45

Because it would be difficult to work with ethylene gas in agriculture, many products have been produced that release ethylene under appropriate conditions. No. 75,058,226. According to the Japanese patent, crystallization of oC-cyclodextrin from an aqueous solution under an atmosphere of ethylene gives an inclusion complex of ethylene-o-C-cyclodextrin, from which the ethylene gas is re-liberated by water.

Alternatively, compounds are used which release ethylene at the pH of the plant cell. An example of such a compound is 2-chloroethane phosphonic acid.

However, the rapid release of ethylene is undesirable because the plant hormone does not stimulate ripening but causes premature fall of leaves and fruits. Therefore, a cyclodextrin complex of 2-chloroethane-phosphonea has been prepared to prolong the effect.

The use of cyclodextrin complexes of other plant hormone has not been described in the literature.

No. 184,066. It is known from the Hungarian patent that cyclodextrins have a significant effect on the germination of plant seeds, and subsequently on the growth of the crop developing from them, and in some cases on the yield. Germination of starch-bearing seeds is slowed by cyclodextrins but accelerates the growth of the plants that emerge from them. The mechanism of this process is not yet known; to our present knowledge we can speak of an auxin-like effect (Hungarian Patent No. 176,764).

Cyclodextrins have also been used to enhance the chemical stability and water solubility of many drugs and pesticides. For example, for cyclodextrin complexes of insecticidal pyrethroids, the role of cyclodextrin is to reduce the rate of decomposition of highly sensitive sunlight pyrethroids (U.S. Pat. No. 3,846,551).

It is also known that the water solubility of poorly water-soluble therapeutic agents can be enhanced by cyclodextrin complexation and thus the absorption of the active compounds is improved (V.F. Smolen, L.A. Ball, Controlled Drug Bioavailability, 365 (Wiley Interscience, New York, 1984)).

Because the plant hormones listed above are partly poorly soluble in water, and in part - especially in aqueous media - are rapidly degraded, it is obvious to complex and test them with cyclodextrins in plants. The unexpected result of the experiments was that cyclodextrins not only increased the solubility and chemical stability of the tested plant hormones, but also synergistically enhanced the auxin effect. This makes it possible to rapidly dissolve poorly soluble drugs in water; the preparation of the solution does not require the use of an organic solvent, which may adversely affect the plants and may lead to environmental pollution; decomposition of the active ingredient in aqueous solutions was slowed; moreover, due to the synergistic enhancement, the application of smaller amounts of plant hormone can be very beneficial.

FIELD OF THE INVENTION The present invention relates to agricultural compositions having plant growth regulating activity which contain from 0.04% to 90% by weight of a cyclodextrin inclusion complex of formula (I):

X represents β-indole acetic acid, indole-3-butyric acid, indole-3-isobutyric acid, naphthyloxyacetic acid, naphthyloxypropionic acid, naphthyl acetic acid, N ⁶ benzyladenine or a mixture of gibberellin A3 and gibberellin A4.7 , n is 1 or 2, and

HU 201569 Β

CD represents a cyclodextrin of formula II wherein R is hydrogen, or one of R is hydrogen and two is methyl, and m is 7 with up to 30% of free X, where X is as defined above, and a carrier, preferably mineral powder, oligosaccharide and / or water, and optionally other excipients, preferably colorants and / or tackifiers.

The agricultural compositions of the present invention may contain, as carriers, talc, zeolite, silica gel, kaolin, sucrose, (uncomplexed) cyclodextrins, flour, corncob, dolomite, limestone, pumice, furfural bran and / or furfurol. An example of a tackifier is aqueous polyvinyl acetate suspensions. The dyes may be those commonly used in the preparation of agricultural preparations.

In addition to the cyclodextrin inclusion complex of formula (I), the agricultural compositions of the present invention may optionally contain Compound X as a plant growth regulator in free (uncomplexed) state. The uncomplexed plant growth regulating compound is preferably adsorbed on the surface of the inclusion complex of the cyclodextrin of formula (I). This solution provides formulations that release the plant growth regulator in two steps at different rates. The amount of free (uncomplexed) compound X is preferably from 10 to 40% by weight of the cyclodextrin inclusion complex I of the composition.

The agricultural compositions of the invention may be mixed with other compounds suitable for agricultural purposes, such as insecticidal or fungicidal agents, or bioavailable additives to the plant, such as fertilizers and trace element sources.

The invention further relates to a process for the preparation of cyclodextrin inclusion complexes of the formula I wherein X, n and CD are as defined above.

The Bull. Chem. Soc. Japan 52, 1807-1812 (1979) deals with the reactions of β-cyclodextrin and 2-substituted naphthalene derivatives. The authors have shown that 2-naphthoxy-oxyacetic acid in the presence of 50 to 100 times the molar excess of β-cyclodextrin in 10 ⁴ M (i.e. very dilute) aqueous solution It forms a 1: 1 molar inclusion complex. However, this inclusion complex has not yet been produced in solid state. Die Pharmacie in general dealing with the formation of cyclodextrin inclusion complexes

36, 694 (1981), in a very dilute solution in the presence of a very high excess of cyclodextrin, equilibrium conditions favor formation of inclusion complexes. However, as the concentration of the solution increases and the amount of cyclodextrin decreases, the equilibrium conditions change and in most cases the inclusion complex is no longer detectable in aqueous solution containing cyclodextrin and the molecule to be closed in the molar ratio of the inclusion complex. Thus, the fact that in very dilute aqueous solution the presence of the inclusion complex can be detected by physico-chemical means (e.g. also adjustable.

The cyclodextrin inclusion complexes of formula I wherein X, n and CD are as defined above are prepared according to the present invention by one or two molar equivalents of cyclodextrin of formula II wherein R is and m is in the above water or in a mixture of water and a C 1 -C 4 alcohol, and a molar equivalent of the plant growth regulator X, or X, as defined above, or acetone or cyclodextrin stable, is added to the mixture at 20-60 ° C with stirring. non-complexed C 1--C alkoh alcohol and the solvent (s) removed after equilibration.

The invention is further illustrated by the following non-limiting examples.

Example 1

Beta-cyclodextrin (11.35 g, 0.01 mol) was dissolved in ethanol / water (100 mL, 1: 2) with vigorous stirring at 55 ° C. A solution of 0.875 g (0.005 mole) of β-indole acetic acid in 8.0 ml of 96% ethanol was added slowly. After the addition of the plant hormone, the reaction mixture was cooled slowly to 22 ° C over a period of 4 hours and then left to stand at 0 ° C to 5 ° C for 18 hours. The crystalline inclusion complex was filtered and air-dried at room temperature. 11.8 g of inclusion complex are obtained, containing 6.4% by weight of β-indole acetic acid.

From this inclusion complex, the total amount of β-indole acetic acid is liberated and completely dissolved within 1 minute in an aqueous buffer solution at 22 ° C, pH 6.5. The complete dissolution of the unbound β-indole-acetic acid takes 5 minutes under the same conditions.

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Example 2

To a suspension of 11.35 g (0.01 mol) of β-cyclodextrin in 100 ml of water was added dropwise at 22 ° C a solution of 0.875 g of 5-indole acetic acid in 8 ml of 96X ethanol with stirring. The slurry was stirred vigorously at room temperature for 24 hours, then the solid was filtered and air-dried to a constant lake. 12.1 g of product are obtained, containing 6.8-6.9% by weight of β-indole acetic acid.

Example 3 Dimethyl-8-cyclodextrin (15 g, 9.76 mmol) was dissolved in water (100 mL) at room temperature with vigorous stirring and then slowly treated with 0.875 g (5 mmol) of β-indole acetic acid in 8 mL of 96X ethanol. solution is added dropwise. The resulting homogeneous slightly opalescent solution was stirred at room temperature for 12 hours and then the solvent was evaporated in vacuo. A solid foamy powderable product is obtained which dissolves completely in water within 1 minute. Yield: 13.5 g; β-indole acetic acid content: 6.0% by weight.

Example 4

U-cyclodextrin (11.35 g, 0.01 mol) was wetted vigorously with 2 ml of water while a solution of β-indole-35-acetic acid (0.875 g, 0.005 mol) in ethanol (8 ml) was added in 1 ml portions. The kneading is continued for 1 hour and the resulting powdery product is dried to constant weight. 12.1 g of product are obtained which contains 6.85% by weight of ε -indole-40-acetic acid.

Example 5

A solution of 1.9 g (0.01 mol) of naphthylacetic acid in 10 ml of acetone was added dropwise to a mixture of 22.7 g (0.02 mol) of 3-cyclodextrin and 100 ml of water. After stirring for 72 hours under protection from light, the precipitated crystalline material is filtered off and air-dried to constant weight. 22.5 g of inclusion complex are obtained in the form of a microcrystalline powder containing 7.30% by weight of naphthylacetic acid. 55

This inclusion complex is released in distilled water at 25 ° C in 3-4 minutes in aqueous buffer at pH 6.5 and all naphthyl acetic acid is dissolved. It takes 90 minutes and 75-80 minutes, respectively, to completely dissolve the unbound naphthyl 60 acetic acid under the same conditions.

Example 6

The procedure of Example 5 was followed except that 0.01 mol of β-cyclodextrin and 0.01 mol of naphthyloxypropionic acid were used. The resulting inclusion complex contains 15.8% by weight of naphthyloxypropionic acid.

This inclusion complex liberates all of the naphthyloxypropionic acid in aqueous buffer at pH 6.5 for 3 minutes. The complete dissolution of the unbound naphthyloxypropionic acid under the same conditions takes 50 minutes.

Example 7

By the procedure described in the previous examples

- indole-3-butyric acid,

- indole-3-isobutyric acid,

- naphthyloxyacetic acid,

- N-benzyl adenine, and

- A mixture of gibberellin A3 and A7 (crude extract)

Inclusion complexes with 3-cyclodextrin.

The dynamic water solubility of the inclusion complexes thus obtained was investigated by the following method:

The free drug or the inclusion compound corresponding to the same drug was added to distilled water and the suspension was stirred for 1 hour at room temperature. The amount of solids, screened to the same particle size, was chosen so that the system would remain in suspension throughout the measurement. Samples were taken at 2, 5, 10, 15, 30 and 60 minutes. Samples were filtered on a G3 glass filter and the diluted drug concentration was determined photometrically after appropriate dilution. The results are shown in I-V. in Table.

-4EN 201569 Β í. spreadsheet

Dynamic Solubility of Indole-3-Butyric Acid and O-Cyclodextrin Complex in Distilled Water at 22 ± 0.5 ° C

Time, minutes Dissolved indole-3-butyric acid mg / ml

Free state in β-Cyclodextrin complex

2 0.24 1.05 5 0.26 0.76 10 0.29 0.78 15 0.30 0.80 30 0.32 0.80 45 0.36 0.80 60 0.39 0.78

II. spreadsheet

Dynamic solubility of a 1: 2 molar complex of indole-3-isobutyric acid and? 3-cyclodextrin in distilled water at 22 ± 0.5 ° C

Time, minutes

Dissolved in-3-iso-butyric acid mg / ml

Free state in β-Cyclodextrin complex

2 0,200 1.15 5 0.280 0.920 10 0.290 1.20 15 0.316 0,985 30 0.290 0,950 45 0.320 0,950 60 .340 .905

III. spreadsheet

Dynamic solubility of the complex of naphthyloxyacetic acid and Β-cyclodextrin in distilled water at 22 + 0.5 ° C

Time, minutes

Dissolved naphthyloxyacetic acid mg / ml

Free in 6-Cyclodextrin Complex

2 0,150 .590 5 0,170 0,500 10 0.172 0.465 15 0.171 0.470 30 0,190 0.530 45 0.195 0.530 60 0.210 0.560

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ARC. spreadsheet

Dynamic solubility of γ-cyclodextrin complexes of γ-benzyladenine and 1: 1 and 1: 2 molar in distilled water at 22 ° C-0.5 ° C

Time, minutes Dissolved N ⁶ benzyladenine mg / liter In free state In a 1: 1 molar CD complex In a 1: 2 molar CD complex 2 35 48 75 5 40 55 78 10 50 73 120 15 55 86 136 30 70 116 150 45 70 135 198 60 68 145 224 Table V. GA3 + GA4.7 containing crude gibberellin extract and β-cyclodextrin complex dynamic solubility in distilled water 22 + 0.5 ° C Time, minutes Dissolved gibberellin mg / ml In free state β-Cyclodextrin complex 2 0.10 1.00 5 0.13 1.05 10 0.14 0.96 15 0.25 0.98 30 0.30 1.00 45 0.45 1.00 60 0.62 1.00

Example 8 To a suspension of g-β-cyclodextrin in 100 ml of water was added in portions a solution of 0.99 g of N ^e -benzyladenine in 10 ml of 96% ethanol at 20 ° C with stirring. The suspension was stirred vigorously for 1 hour at 20 ° C. Then the suspension - the total amount included in the N ⁶ -benzyl-adenine salts of beta-cyclodextrin inclusion complex - based on the analysis of the sample taken; the inclusion complex has a N ^e benzyl adenine content of 9.1% by weight.

To the slurry was added 5 g of solid N ⁶ benzyl adenine and stirring was continued for another 30 hours. The resulting reaction mixture was concentrated in vacuo.

15.8 g of product are obtained containing 37.5 weight percent ^N? -Benzyl-adenine; of which 9.1% by weight x in the inclusion complex, and 28.6 by weight in the form of an uncomplexed active substance adsorbed homogeneously on the surface of the inclusion complex. The resulting product initially releases the drug quickly, and then the rate of drug release is reduced.

Example 9

Agricultural compositions of the following compositions are prepared by methods known per se (e.g. homogenization, suspension, pre-mixing, etc.):

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HU 201569 Β

(a) Wettable powder formulation. γ-Indole-acetic acid complex with γ-cyclodextrin (active substance content: 6% by weight) 83.3 g

Sucrose 16 | 5 g

Methylene blue 0 »2 g

(b) Dipping powder.

Complex of indole-3-butyric acid with γ-cyclodextrin (active ingredient content: 8.9% by weight) 11.2 g

Benomyl [1- (butylcarbamoyl) benzimidazole-2-methylcarbamate] _v 2.0 g

Kaolin 86ιθ &

Purpur colored dye θ> 2 g

c) Tablet:

The product obtained in Example 8 (N-benzyl-adenine ^B content 37.5 wt%) 22.0 g

Sucrose 77.8 g

Methylene blue 0> 2 g

(d) Paste:

β-Indole-acetic acid complex with β-cyclodextrin (drug content: 6% by weight) 16.6 g

Benomil 2.0 g

Bentonites 21.2 g

Polyvinyl acetate suspension 60.0 g

Methylene blue 0.2 g

As in Fig. 9 / b. and 9 / d. As shown in Example 1, the compositions may optionally contain other agriculturally valuable chemicals in addition to the plant growth regulator. Since these chemicals exert their own effect in the composition and do not modify the effect on plant growth, they are considered as additives for the purposes of the present invention. 35

Example 10

The effect of naphthyloxypropionic acid and 15.8% by weight on 40-active ingredient γ-cyclodextrin complexes on peppers (Capsicum annuum. Soroksári ') was investigated under greenhouse conditions. The experiments were carried out in two series of 160 cm ² plastic culture vials filled with Sopron propellers. Plants were sown on May 20 and June 18 and treated with aqueous dispersions of test compounds on June 6 and July 7, respectively. The naphthyloxypropionic acid dispersion contained 150 ppm of the active ingredient, while the zero complex dispersion contained 950 ppm of the inclusion complex (corresponding to 150 ppm of naphthyloxypropionic acid). The results were evaluated on July 6 and August 9, respectively. The observed results are shown in Table VI as the average of two series of experiments.

VI. spreadsheet

Treatment Green weight, g Height, cm None (control) 77.8 21.0 % 100 100 Naphthyloxy propionate 9.6 18.8 % 123.0 89.5 Naphthyloxy pro pionic acid γ-cyclo- dextrin complex 10.7 19.6 % 137.1 93.3

VI. It can be seen from the data in Table 3, that the complex of naphthyloxypropionic acid with γ-cyclodextrin increases the green mass of the peppers to a much greater extent than the parent compound, but it can compensate for the height reduction effect of the known parent compound.

Example 11

The effect of the indol-3-yl isobutyric acid and 3.99 wt% γ-cyclodextrin complex on rye (Secale cereale. Sopronhorpécsi ') was examined under greenhouse conditions as in Example 10. Indol-3-yl isobutyric acid was used as the lysine salt in the positive control experiment. Plants were treated with 250 ppm indol-3-yl isobutyrate and corresponding amounts of 713

HU 201569 (i.e. 6250 ppm) containing dispersions containing the inclusion complex. The observed results are shown in Table VII. in Table.

VII. spreadsheet

Treatment Green mass, g Height, cm None (control) 3.8 30.3 X 100 100 Indol-3-yl-i- acid lysine salt 3.6 38.0 X 94.7 125.4 Indol-3-yl-i- butyric acid β-cyclo- dextrin complex 4.1 31.0 X 107.8 102.3

VII. The data in Table III show that the complex of indol-3-yl-isobutyric acid with γ-cyclodextrin increases the green weight of the rye, while the parent compound has a decreasing effect on the green weight. At the same time, the β-cyclodextrin complex is able to prevent the unwanted (without increasing green mass) elongation of the parent compound.

Example 12

The effect of β-indole-acetic acid and 7.7 wt% β-cyclodextrin complex on tomato (Lycopersicum esculentum. Kecskemét 886 * 1) was tested under greenhouse conditions as described in Example 10. The plants were treated with 250 ppm β-indole acetic acid. and the corresponding aqueous dispersions (i.e., 3250 ppm) containing inclusion complexes, the results of which are reported in Table VIII.

VIII. spreadsheet

VIII. It can be concluded from the data of Table II that the β-indole-acetic acid complex with β-cyclodextrin significantly increases the green mass of tomatoes.

Example 13

The effect of N ⁶ -benzyladenine and the product of Example 8 on rye (Secale cereale. The plants were treated with aqueous dispersions containing ^these N-benzyl-adenine, and a corresponding quantity of the product of Example 8 (669 ppm product comprising 208 ppm and 461 ppm of active ingredient is adsorbed on the inclusion complex) 250 ppm. The results for rye detection are reported in Table IX, and those for cucumber are reported in Table X.

IX. spreadsheet

Treatment Green mass, g Height, cm None (control) 3.8 30.3 % 100 100 N ^e -Benzyl-adenine 3.9 102.6 32.2 106.2 Example 8 product 4.6 39.8 X 121 131.4

IX. Table 8 shows that the product prepared according to Example 8, which is only ca. It contains 2/3 of the inclusion complex - it greatly increases the green weight and height of the rye.

Treatment Green weight, g Height, cm None (control) 4.1 13.0 X 100 100 β-indoleacetic acid 4.8 11.4 X 117 87.7 β-indoleacetic acid .beta.-cyclodextrin complex 5.9 11.4 X 143.9 87.7

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EN 201569 táblázat Table X

Treatment Green weight, g Height, cm Flower, pcs None (control) 34.8 37.6 12.6 X 100 100 100 N ^# -Benzyl-adenine The plants were extinct Example 8 product 32.9 39.2 15.0 X 94.54 104.2 119

From the data in Table X, it can be concluded that the product prepared according to Example 8, which is only ca. It contains 2/3 of the inclusion complex and the remainder is N®-benzyladenine - it has only a slight influence on the green weight and height of the plants, but significantly increases the number of flowers. The parent compound completely kills the plants; the perceived effect of the complex is thus extremely surprising.

Example 14

The effect of γ-indole-acetic acid and β-cyclodextrin complexes containing 7.7% by weight of the active compound on peas (Pisum sativum. The miracle of Keledon) was investigated under greenhouse conditions. A series of experiments was performed; the seeds were sown in plastic culture pots of 160 cm ² 20 filled with Budakalasz soil-sand mixture. The sowing was done on March 13 and the treatment was done on March 27. The results were evaluated on April 24.

The assays were carried out using an aqueous alcoholic spray containing 500 ppm of β-indole acetic acid and an equivalent amount (i.e. 6500 ppm) of inclusion complex. The results are shown in Table XI. in Table.

XI. spreadsheet

Treatment Fresh weight, g Dry weight, g Letter Root Letter Root None (control) 24.3 5.3 5.0 2.0 X 100 100 100 100 .beta.-indole-acetic acid 26.5 6.7 3.6 1.2 X 109 126.4 73.0 62.5 .beta.-indole-acetic acid .beta.-cyclodextrin complex 36.0 6.7 6.6 2.1 X 148.1 126.4 132 107.5

The XI. Table 1 shows that although α-indole acetic acid increases the fresh weight of the leaves and roots compared to untreated control, this results in a significant decrease in dry weight, ie the test substance only loosens the plant cells, but spoil. In contrast, the β-cyclodextrin complex of the given active ingredient significantly increases the dry weight of the plant.

Example 15

The inhibition of diuretic formation of the complex of naphthyl acetic acid and α-cyclodextrin containing 7.3% by weight of the active ingredient was investigated on 3-year-old Starkrimson apple trees. The apple trees were pruned on March 12th and then the pruned surfaces

- in Experiment (a), a commercially available greaseproof preparation containing no growth regulator,

- in experiment (b) with 1 wt% naphthyl acetic acid

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HU 201569 el with a commercially available fascia treatment composition,

- in Experiment c) was treated with a 4.1 wt% inclusion complex (corresponding to 0.3 wt% naphthylacetic acid) with a commercially available fascia treatment composition. The shoots were counted on September 30. The observed results are shown in Table XII. in Table.

XII. spreadsheet

Treatment Number of diuretics in X of untreated control the) 85 b. 20 c) 15

XII. Table 4 shows that the inclusion complex formulation inhibited diuretic formation slightly more than the composition containing uncomplexed naphthyl acetic acid, despite the fact that the naphthyl acetic acid content was only 30% of that of the uncomplexed naphthyl acetic acid.

Claims (2)

PATENT CLAIMS An agricultural composition having a plant growth regulating effect, characterized in that it contains from 0.04 to 90% by weight of the cyclodextrin inclusion complex of formula (I) - in which X β-indoleacetic acid, indole-3-butyric acid, indole-3-isobutyric acid, naphthyloxy-acetic acid methyl naf10-oxy-propionic acid, naphthylacetic acid, N ^fi benzyl adenine and gibberellin A4 or gibberellin As »7 n is 1 or 2; and CD is the cyclodextrin of formula (II) wherein R is hydrogen or one of R is hydrogen and two are methyl and m is 7, optionally up to 30 wt. 20, wherein X is as defined above, and a carrier, preferably mineral powder, oligosaccharide and / or water, and optionally other excipients, preferably colorants and / or tackifiers. 2. A process for the preparation of the cyclodextrin inclusion complexes of the formula I in the formula X denotes indole-3-butyric acid, β-indole acetic acid, indole 30 -3-isobutyric acid, naphthyloxyacetic acid, naphthyloxypropionic acid, naphthyl acetic acid, N ⁶ benzyladenine or a mixture of gibberellin Aa and gibberellin Au 7 , n is 1 or 2, and 35 CD represents a cyclodextrin of formula (II) in which the R groups are hydrogen or one of the R groups is hydrogen and two are methyl and m is 7, 40 characterized in that one or two molar equivalents of cyclodextrin of formula (II), wherein R is and m are as defined herein, are dissolved or suspended in water or a mixture of water and a C 1 -C 4 alcohol and then stirred while stirring. At -60 ° C, X is represented by a molar equivalent of the plant growth regulator or acetone thereof. 50, or a C 1 -C 4 alcohol which does not form a stable cyclodextrin complex, and after equilibration, the solvent is removed.