Solvates Of Abscisic Acid And Liquid Compositions Containing Abscisic Acid

Abstract

The invention relates to new modifications of abscisic acid, to liquid compositions of abscisic acid and to their use in agrochemical applications. The modifications and compositions of the invention contain abscisic acid in the form of a solvate with at least one N-alkyl pyrrolidone, wherein the N-alkyl group has 3 to 6 carbon atoms. These solvates enable formulations with high concentrations of abscisic acid.

Claims

1. A solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00005## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms.

2. The solvate according to claim 1, which is in an amorphous state.

3. The solvate according to claim 1 or 2, wherein the abscisic acid is the naturally occurring form (S)-(+)-abscisic acid.

4. An agrochemical composition comprising a) 10 to 50% by weight, based on the total weight of the composition, of abscisic acid; and b) 0.1 to 90% by weight, based on the total weight of the composition, of one or more N-substituted pyrrolidones of the formula (I), ##STR00006## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms; c) 0 to 50% by weight, based on the total weight of the composition, of one or more co-solvents; and d) 0 to 50% by weight, based on the total weight of the composition, of one or more formulation auxiliaries and e) 0 to 50% by weight, based on the total weight of the composition, of one or more additional active ingredients, including derivatives of abscisic acid.

5. The agrochemical composition according to claim 4, comprising a solvate according to claim 1.

6. The agrochemical composition according to claim 4, wherein abscisic acid is (S)-(+)-abscisic acid.

7. The agrochemical composition according to claim 4, wherein the N-substituted pyrrolidone of formula (I) is N-n-butylpyrrolidone.

8. The agrochemical composition according to claim 4, comprising a) 10 to 50% by weight, based on the total weight of the composition, of abscisic acid; and b) 0.1 to 90% by weight, based on the total weight of the composition, of one or more N-substituted pyrrolidones of the formula (I), ##STR00007## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms, c) 0 to 50% by weight, based on the total weight of the composition, of one or more co-solvents; and d) 0.1 to 50% by weight, based on the total weight of the composition of one or more formulation auxiliaries; and e) 0 to 50% by weight, based on the total weight of the composition, one or more additional active ingredients, including other derivatives of abscisic acid.

9. The agrochemical composition according to claim 4, wherein one or more formulation auxiliaries of component d) are selected from the group consisting of acidifiers, adjuvants, dispersing agents, emulsifiers, photodegradation stabilizer, spontaneity agents and wetting agents.

10. The agrochemical composition according to claim 4 wherein a) abscisic acid is present in an amount of 10 to 40% by weight, based on the total weight of the composition; b) the one or more N-substituted pyrrolidones are present in an amount of 10 to 90% by weight, based on the total weight of the composition; c) the one or more co-solvents are present in an amount of 0 or 0.1 to 30% by weight, based on the total weight of the composition; and d) the formulation auxiliaries are present in an amount of 0.1 to 35% by weight, based on the total weight of the composition; and e) the additional active compounds, incl. other derivatives of abscisic acid are present in an amount of 0 or 0.1 to 30% by weight, based on the total weight of the composition.

11. A spray liquid formulation comprising a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00008## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms.

12. The spray liquid formulation according to claim 11, wherein the solvent is water, glycerin or any vegetable oil-based liquid carrier.

13. (canceled)

14. A method of regulating a plant growth and/or a plant development comprising the step of applying a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00009## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms to the plant.

15. A method of improving stress tolerance or initiating or affecting physiological processes managing stress of a plant, comprising the step of applying a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00010## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms to the plant.

16. A method of adjusting the flowering phase of a plant comprising the step of applying a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00011## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms to the plant.

17. A method of improving the yield and quality of a crop comprising the step of applying a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00012## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms to the crop.

18. A method of enhancing red grape coloration comprising the step of applying a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00013## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms to the plant.

19. A method for pre-harvest treatment of a cereal to avoid pre-harvest sprouting, as well as sprouting during storage of a cereal grain comprising the step of applying a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00014## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms to the cereal or cereal grain.

20. (canceled)

21. (canceled)

22. A method for preparing a solvate of abscisic acid with a N-substituted pyrrolidone of the formula (I) ##STR00015## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms, comprising the steps of (i) dissolving a precursor molecule of abscisic acid, in an N-substituted pyrrolidone of formula (I); and (ii) generating abscisic acid in situ from the precursor molecule.

23. A spray liquid formulation comprising agrochemical composition comprising a) 10 to 50% by weight, based on the total weight of the composition, of abscisic acid; and b) 0.1 to 90% by weight, based on the total weight of the composition, of one or more N-substituted pyrrolidones of the formula (I), ##STR00016## wherein R is a linear or branched, saturated alkyl group with 3 to 6 carbon atoms; c) 0 to 50% by weight, based on the total weight of the composition, of one or more co-solvents; and d) 0 to 50% by weight, based on the total weight of the composition, of one or more formulation auxiliaries and e) 0 to 50% by weight, based on the total weight of the composition, of one or more additional active ingredients, including derivatives of abscisic acid.

Description

EXAMPLES

[0170] The percentages stated hereinafter are percent by weight (% by weight), unless explicitly stated otherwise.

[0171] The raw materials used are:

TABLE-US-00001 Abscisic acid (S)-(+)-abscisic acid (purity 90% by weight), JiangXi New Reyphon Biochemical Co., LTD Genagen NBP N-butyl pyrrolidone solvent, Clariant Genagen PA Nonanoyl dimethyl amide solvent, Clariant Emulsogen EL 360 Castor oil ethoxylate dispersing agent/emulsifier, Clariant Tivogen DR3401 Polyglycerinester with 20% NBP dispersing agent/emulsifier, Clariant Synergen 848 n-butyl EO/PO co-polymer emulsifier/wetting agent, Clariant mPEG ester Fatty acid mPEG ester/wetting agent, Clariant Propionic acid Propionic acid acidifier, Sigma Aldrich Emulsogen MTP030 Vegetable fatty alcohol alkoxylate, emulsifier/ dispersing agent/adjuvant, Clariant Synergen KN Adjuvant blend, adjuvant, Clariant LMF 1002   S-ABA 0.1% SL commercial Formulation Sichuan Lomon Bio Technology CO. LTD LMF 1009   S-ABA 10% commercial Formulation Sichuan Lomon Bio Technology CO. LTD

Example 1: Physical State of the Abscisic Acid in Correlation with the Solvent

[0172] In this test, the modification of physical state of the abscisic acid in correlation with the solvent was observed in the microscope with and without polarized light (POLAM).

[0173] The following solutions 1) to 6) are prepared:

[0174] Solution 1: 5% Abscisic acid in N-butylpyrrolidone

[0175] Solution 2: 5% Abscisic acid in N-methylpyrrolidone

[0176] Solution 3: 5% Abscisic acid in N-butylpyrrolidone/deionised water (9:1)

[0177] Solution 4: 5% Abscisic acid in N-methylpyrrolidone/deionised water (9:1)

[0178] Solution 5: 5% Abscisic acid in N-butylpyrrolidone/tap water (9:1)

[0179] Solution 6: 5% Abscisic acid in N-methylpyrrolidone/tap water (9:1)

[0180] In each case 1 μl of the solutions described above 1) to 6) where applied on silanized glass. The solutions were allowed to stand on the slides at a room temperature of approx. 25° C. and 20-50% relative humidity for 24 hours were a drying took place. The slides were examined and pictures were taken of the original edge A) and center of the droplet B) at magnification 400×, with and without a polarized light filter. The results are shown in FIG. 1 (NMP) and FIG. 2 (NBP).

[0181] It was found that the active compound abscisic acid from the solutions containing N-methylpyrrolidone (solution 2) 4) 6)) was crystallized (see FIG. 1) and no longer present in an available form for uptake out of the spray deposit in contrast to the solutions containing N-butylpyrrolidone (solution 1) 3) 5)) were the active compound abscisic acid is still present in a solvated form (see FIG. 2). This solvate of the active compound abscisic acid helps to improve the solubilization as well as the availability of those active ingredients in the spray deposit for uptake into the plant.

Example 2: Preparation of High Loaded Abscisic Acid Formulations

[0182] The abscisic acid formulations A1 to A7 displayed in Table 1 were produced by mixing the various components. The preparations are then stored for eight weeks at −10° C., 40° C., 25° C. (room temperature) and for two weeks at 54° C. in order to determine the storage stability and the phase behavior.

TABLE-US-00002 TABLE 1 Abscisic acid formulations (numbers are % by weight based on formulation) Formulation A2 A4 A6 Non Non Non inventive inventive inventive A1 example A3 example A5 example A7 (S)-Abscisic acid 40.00 40.00 30.00 30.00 30.00 30.00 30.00 (ABA) 90% by weight Genagen NBP 60.00 39.00 30.00 27.50 NMP 60.00 39.00 30.00 Genagen PA 10.00 Tivogen DR3401 5.00 5.00 5.00 5.00 5.00 Emulsogen EL 15.00 15.00 2.50 2.50 2.50 360 Synergen 848 5.00 5.00 5.00 5.00 5.00 Emulsogen MTP 6.00 6.00 030 Propionic acid 4.00 4.00 3.00 mPEG ester 17.50 17.50 17.00 Synergen KN 6.00 6.00 Total 100.00 100.00 100.00 100.00 100.00 Appearance Clear Clear Clear Unstable Clear Unstable Clear liquid liquid liquid suspension liquid suspension, liquid ai not soluble Storage stability OK 40° C. and OK — OK — OK 8 weeks −10/ 25° C. 40/25° C. OK; at −10° C. crystallization 2 weeks 54° C. OK OK OK — OK — OK

[0183] Comparison of the formulations A3 versus A4 and A5 versus A6 shows that the formulations with NBP are significantly more stable than otherwise identical formulations with NMP.

Example 3: Penetration Enhancement

[0184] In this test, the penetration of abscisic acid through enzymatically isolated cuticles of pear tree leaves was measured. The principle of the method has been published and described in detail e.g. in WO-A-2005/194844 or WO2017211572 A1.

[0185] To determine the penetration, 10 μl a spray liquor of the composition mentioned in the examples were applied to the outer side of a cuticle. In the spray liquors tap water was used in each case.

[0186] After application of the spray liquors was allowed to evaporate in each case the water, then in each case the chambers were inverted and placed in thermostated troughs, with air being blown at a defined temperature and humidity to the outside of the cuticle. The incipient penetration therefore took place at a relative humidity of 56% and a set temperature at 10° C. and 25° C. The penetration of active ingredients was determined by High Performance Liquid Chromatography (HPLC).

[0187] The table shows that the uptake of the active ingredient from the abscisic acid formulations of the invention is strongly increased compared to the ai on its own and increased compared to the tested commercial benchmark formulations. As uptake through cuticular penetration is important for biological activity, we expect excellent performance of the inventive compositions in the field.

TABLE-US-00003 TABLE 2 Penetration of abscisic acid (active ingredient concentration 0.1 g/L in spray liquid) in the presence of test substances Mean penetration for abscisic acid (amount of active ingredient 0.1 g/L) after time (n = 8-10) in % 25° C./56% rH 10° C./56% rH Test substance 1 day 2 day 1day 2 day Control (pure active 1.4 2.2 5.3 8.2 ingredient) Composition A3 5.3 11.4 9.9 10.6 Composition A4 2.4 4.4 11.0 13.6 Composition A5 7.0 14.5 11.3 11.6 Composition A6 Not Not Not Not measur- measur- measur- measur- able able able able Commercial LMF 1002 5.3 8.7 12.1 13.3 (ABA SL 0.1%) Commercial LMF 1009 1.6 2.8 — — (ABA SP 10%) rH = air humidity

Example 4: Phytotoxicity

[0188] The plant compatibility of the abscisic acid was checked using indicator plants such as poinsettia plants, e.g. the Merlot variety. If no necrosis or other phytotoxicity symptoms such as leaf curl-up or deformation in any case were observed the substance is considered plant compatible and not phytotoxic.

[0189] The compositions of the invention did not show phytotoxicity symptoms at relevant use concentrations of 0.1 g/Lai. The tested reference substance (ethoxylated lauryl alcohol at 1 g/L) caused strong distinct necrosis within one day.

Example 5: Differential Scanning Calorimetry (DSC)

[0190] In order to determine differences in the crystallographic form of the abscisic acid a DSC was conducted out of the deposit of A) 40% abscisic acid in N-butylpyrrolidone solution; B) 40% abscisic acid in N-methylpyrrolidone solution C) active ingredient of abscisic acid (90% purity).

[0191] For the deposit the 40% abscisic acid solution was dried until weight constancy. Afterwards the samples were used in the test sorptions isotherme. As there were no changes in weight from 3-30% rh, these samples were used for the DSC Measurement compared to abscisic acid active (New Reyphon 90%/also taken from the sorption isotherme experiment).

TABLE-US-00004 TABLE 3 Differential Scanning Calorimetry (DSC) Desolvation onset and peak of heating phase one and two 1. heating phase 2. heating phase desolvation desolvation desolvation desolvation glas point onset [° C.] peak [° C.] onset [° C.] peak [° C.] [°C.] A average 52.67 107.74 103.46 125.62 7.74 St. dev. 42.58 19.71 9.47 9.04 0.79 B average 142.99 149.64 141.06 150.86 28.74 St. dev. 5.39 4.69 1.79 1.44 0.61 C average 157.86 161.11 149.98 157.34 35.77 St. dev. 0.48 0.23 0.62 0.20 0.51

[0192] In addition a TGA was conducted with the same samples.

Example 6: Thermogravimetric Analysis (TGA)

[0193] After long term drying and evaporation of deposits of abscisic acid in NMP and NBP striking analytical differences have been observed in the TGA.

[0194] Deposits of abscisic acid in NBP show two distinct peaks in the DTG-curve whereas deposits of abscisic acid show only one peak at approx. 268° C. Deposits of abscisic acid in NMP show occasionally a small second peak in front of the peak at approx. 262° C.-268° C., which is visible in all three measurements.

TABLE-US-00005 TABLE 4 TGA data characterizing by the TG curve Peak1 Peak 2 phase turning average phase turning average [%] point [° C.] [° C.] [%] point [° C.] [° C.] A average 32.62 180.45 166.82 66.89 262.61 256.37 St. dev. 14.28 18.14 6.16 14.07 2.09 4.82 B average 4.28 149.84 136.67 98.20 263.17 255.42 St. dev. 2.05 0.23 2.02 2.68 6.95 3.22 C average 99.67 268.50 261.66 St. dev. 0.45 5.37 2.29 NBP ′4-1 1.02 172 152.04

Example 7: Precipitation in an Aqueous Solution

[0195] To precipitate the solvate in an aqueous solution samples were prepared by mixing A) solutions of 40% abscisic acid in N-butylpyrrolidone and B) 40% abscisic acid in N-methylpyrrolidone in deionized water at a ratio of 1:1 and 1:2. To separate the precipitation samples were centrifugated for a short time (min).

[0196] Striking differences were observed between the samples. Whereas the samples prepared in the 40% abscisic acid in N-methylpyrrolidone solution were strongly crystalizing, the samples with the 40% abscisic acid in N-butylpyrrolidone solution formed two liquid phases which even stay stable when cooling the aqueous solution down to 5° C. as well as trying to inoculate in order to provoke a crystallization.