HU190622B - Process for producing concentrate containing 1-triacontanol or 1-triacontanone from leaves of medicago sativa l. - Google Patents

Abstract

1-triacontanol or concentrates contg. 1-triacontanol are prepd. from the leaves of lucerne (medicago sativa) by extn. of the wet or dry ground vegetable matter with solvents which are not good solvents for 1-triacontanol, like alkanols with 1-3 carbons, pref. methanol at 0-10 deg.C.. The soaked vegetable matter is now repeatedly extd. with boiling chloroform, benzene, chlorobenzene, xylene, THF or pyridine, the resulting organic phase is concentrated, the concentrate dissolved in boiling acetone and left to stand at a temp. around zero deg.C. for pptn. to occur. The ppte. is sepd. by centrifugation. - (a) The fraction contg. 10-20 wr.% 1-triacontanol is added to boiling acetonitrile. At a temp. in excess of 50 deg.C. 1-triacontanol goes into soln., while the waxy impurities form a separate molten phase. In this way a concentrate contg. at least 70 wt.% 1-triacontanol is obtd.. (b) A 98 wt.% pure end prod. cna be prepd. by recrystallisation from chloroform, hexane, cyclo-hexane or benzene.

Description

The present invention relates to a process for the preparation of 1-triacontanol or 1-triacontanol (CH 2 -CH 1) n (OH) machine concentrate by extraction from alfalfa leaves.

1-Thyracontanol is a known plant growth regulator that was first isolated from alfalfa as a component of leaf wax (Biochem. J. 27, 1833. 1885).

1-Triacontanol, when used as a plant growth regulator, significantly increases the growth, content, and yield of various arable and horticultural plants (J.Amer. Soc. Hort. Sci. 103, 361, 1978; Sylvatrop, 4, 261, 1980; 4,230,485). U.S. Pat.

Another advantage of its agricultural application is that it is non-toxic and has biological effects in the low concentration range (0.1-100 ppm).

Several synthetic methods have been described for the preparation of 1-triacontanol. They have the common disadvantage that they are obtained from expensive starting compounds in complex, multi-step synthesis flasks (J. Org. Chem. 45, 737, 1980; Tetrahedron Letters, 23, 1982, 157; U.S. Patent 4,667,641). .

Isolation of aliphatic long-chain primary alcohols from plant materials is also known. The methods are mostly non-preparative, rather they are only used to determine minor components of vegetable waxes.

Known methods for preparing 1-triacontanol from plant material include:

The plant material is pulverized with water, the resulting colloidal system is fractionated through two complex extraction phases, and the waxes (paraffins and other unidentified substances) are recovered. The wax components are obtained from the vase components after saponification and separation with alcoholic potassium hydroxide and re-esterified with phthalic anhydride in the presence of pyridine. The resulting phthalic acid ester mixture is then dissolved in ether and the ethereal solution is treated with warm aqueous sodium carbonate solution. Sodium salts of the phthalate salt of the primary alcohols, including 1-triacontanol, are precipitated, while the sodium salts of the other semi-esters remain in solution. After isolation, the precipitated salts are re-saponified with sodium ethoxide in a benzene medium and the resulting crude primary alcohol mixture is recovered in four recrystallization phases from 1-triacontanol.

The extraction solvent used is water, ether, ethanol, acetone, benzene, carbon disulphide, alternately and repeatedly (Biochem. J. 1931, 25, 2111).

By another known method, the dried alfalfa broth is mixed with 0.1 M phosphate buffer (pH 9.00), the solid fraction is centrifuged, the aqueous phase is extracted with chloroform, the chloroform extract is evaporated and the Sephadex LH-20 gel column is separated. The

The fractions containing 1-triaconlanol are combined and evaporated to give the pure final product by recrystallization from n-hexane and chloroform (Science 1977, 195, 1339).

A common disadvantage of the two processes detailed above is the use of aqueous dispersion digestion, which results in a difficult to handle and separable colloidal system. Its decomposition and extraction requires a lot of organic solvents, but it also produces a large volume of waste aqueous phase.

One of the foundations of the present invention is the discovery that 1-triacontanol is not esterified in lucerne leaves but is in free form and can thus be directly recovered by various organic solvents. This avoids both the chemical and chromatographic isolation methods detailed above and the aqueous buffer buffering. In our experiments we found that

The solubility of 1-triacontanol in organic solvents is temperature dependent, which can be used to prepare pure 1-triacontanol or a machine concentrate containing 1-triacontanol in an amount.

The present invention relates to a process for the preparation of a 1-triacontanol or 1-triacontanol-containing concentrate by extraction from alfalfa leaves by soaking the alfalfa leaf meal at 0-15 ° C, preferably with 1 to 3 carbon atoms at room temperature in methanol, and after drying in an aprotic solvent. extraction with benzene, xylene, chlorobenzene, tetrahydrofuran or pyridine, the resulting extract, preferably after evaporation, is heated to 4-8 times acetone at 40-50 times the content of 1-triacontanol and then 0-5. By cooling at <RTI ID = 0.0> C, </RTI> the acetone phase was used to remove impurities and finally the resulting 1-triacontanol-containing material. optionally added to acetonitrile at its atmospheric boiling point, after boiling, the coat phase is separated off and crystallized from 1-triacontanol from the acetonitrile phase.

As a result of the alcoholic pre-soaking, a considerable amount of ballast material, especially vegetable dyes, is released without loss of 1-triacontanol.

The soaked flour is dried and then extracted, preferably boiling, with 1-liter lactanol in a highly soluble solvent.

After evaporation of the solvent fraction, acetone, preferably hot, is added to the concentrate, and after thorough mixing, the mixture is cooled. The fraction containing 1-triacontanol also precipitates in the form of a gelatinous precipitate which is separated from the mother liquor, preferably by centrifugation. In this way, depending on the quality of the starting material, a concentrate containing 10-200 1% 1-triacontanol is obtained, which is the lucerne meal.

Compared to its content in 1-triacontanol, it represents a concentration of 10C to 200,000.

According to the present invention, acetone is not used for the recovery of 1-triacontanol but selective purification thereof, as is known in the literature. It has been discovered that the solubility of 1-triacontanol in acetone is highly dependent on the temperature and that this temperature dependence can be used for the partial removal of impurity components without significant loss of 1-triacontane.

The possibility of further purification led us to the discovery that acetonitrile on its boiling point dissolves up to 0.73 g / dra ³ in acetone extract.

1-triacontanol, whereas most of the accompanying waxy components remain in a separate melting phase. 1-Triacontanol crystallizes from the acetonitrile solution practically completely at a temperature below 50 ° C.

At this stage of the process, a white crystalline product is obtained which is well filtered and has

It contains at least 70% by weight of 1-triacontanol. When analyzed by gas chromatography, the number of impurities in the acetonitrile extract is five.

From now on, we wanted to get rid of these contaminants with as little loss of 1-triacontanol as possible.

Our experiments have proven that the simplest way to obtain a pure product is by recrystallization. This recrystallization may conveniently be made from chloroform, n-hexane, cyclohexane, or benzene. The white crystalline product thus obtained had a purity of 98%.

The 1-triacontanol content of the extracts was determined by comparison with authentic test substance by gas chromatography. (Science 195, 1339. 1977).

The advantages of our procedure are summarized below:

the. The process described in the present invention is much simpler, less expensive, and easily industrially feasible. The source of the raw material used is an easily grown crop, alfalfa, grown on a large surface, and the usual solvents used in the extraction line are widely used.

b. The purification process detailed in the present invention can be interrupted at any purity after enrichment with acetone, and 1-triacontanol concentrates of various purities can be used for plant growth control purposes. The impurities present do not weaken the physiological effect of 1-triacontanol.

c. ) Organic solvents used in the extraction process do not chemically react with the plant material of natural origin and thus no new, unknown impurity component is introduced into the system.

d. The recovery of 1-triacontanol involves the use of low boiling indifferent solvents which are easily regenerated and recycled with minimal loss.

e. ) Alfalfa meal used as a source of raw material and remaining after extraction, complete removal of solvent traces and blending of recovered flavorings, can be returned to livestock farms and used for feeding purposes.

Hereinafter, the present invention will be illustrated by what we consider to be the best example without limiting it.

Kivileli example

The alfalfa leaf meal (100 g) was soaked for 2 hours, three times in succession, in 2 liters of methanol at 10 ° C with stirring. The plant residue is filtered off, dried and extracted with 1 liter of chloroform in a Soxleth extractor for one hour and then the chloroform extract is concentrated on a rotary evaporator under vacuum. 1.8 g of a concentrate are thus obtained, to which 100 ml of acetone are added and the mixture is boiled for 20 minutes. After refluxing, the mixture was cooled to 0 ° C, allowed to stand for one hour, and the precipitated gelatinous precipitate was settled by centrifugation. The supernatant was discarded and the pellet was resuspended in 100 ml of acetone, then refluxed, cooled and centrifuged.

After repeating these operations five times, 0.6 g of dry product is obtained with a 1-triacontanol content of 17%.

The pale green, waxy powder obtained above is dissolved in 6 ml of hot chloroform and slowly added to 300 ml of acetonitrile at atmospheric boiling point. After refluxing for 10 minutes, the hot acetonitrile solution is decanted from the remaining yellowish green waxy material and the non-acetonitrile fraction is refluxed in acetonitrile. The pure acetonitrile fractions were combined and allowed to stand.

The solution rapidly precipitates a white, well-filtered crystalline material which is filtered off. The product was 0.115 g of 1-triacontanol (purity 78%).

The product was recrystallized from chloroform followed by n-hexane to give 0.082 g of 1-triacontanol, 98% pure, m.p. 185-186

Claims (1)

A process for the preparation of 1-triacontanol-containing concentrate or 1-triacontanol from alfalfa leaf by extraction, characterized in that the alfalfa leaf meal is extracted at 0-15 ° C. Soaked in C3-C4 alkanol, preferably methanol, and after drying it is extracted with an aprotic solvent, preferably chloroform, and the resulting extract is evaporated to dryness. After boiling with 40 to 60 times the weight of 1-triacontanol, acetone was added, and the mixture was cooled to 0-5 ° C, the precipitated precipitate was collected, refluxing, The 1-triacontanol-containing concentrate is optionally dissolved in an aprotic solvent, preferably chloroform, and added to acetonitrile at atmospheric boiling, the two phases are separated after boiling, and the 1-triacontanol is crystallized from the acetonitrile phase.