JPS6253985A - Method of separating alkaloid by host-guest complex method - Google Patents

Abstract

PURPOSE:To extremely simply separate alkaloids such as nicotine, etc., in high purity, by host.guest complex method using 1,1',6,6'-tetraphenyl-2,4-hexadiyne-1,6- diol as a host compound. CONSTITUTION:Leaves of tobacco are added to 5% aqueous solution of NaOH, stirred, filtered, the filtrate is removed, the residue is extracted with an ether three times, the extracted solution is concentrated and the concentrate is dissolved in methanol. Then, 1,1',6,6'-tetraphenyl-2,4-hexadiyne-1,6-diol shown by the formula is added to the solution, which is allowed to stand at 5 deg.C for 24hr to settle a complex of nicotine and the host compound of 1:1, which is separated. Further acetone in an amount required to dissolve the complex is added to the complex, the solution is cooled, a complex of the host compound and acetone of 1:2 of settled and high-purity nicotine remaining in the mother liquor is separated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for separating alkaloids, and particularly to a method for separating nicotine or caffeine by a host φ-guest complex method.

[Prior Art] Alkaloids such as nicotine and caffeine are separated from plants containing them by alkali treatment or solvent extraction, and then isolated and purified by steam distillation, solvent treatment, etc. For example, nicotine is Since it is present in tobacco leaves as malate or citrate, milk of lime is added to liberate the base, which is then distilled and extracted with ether from the distillate. Caffeine can also be obtained by leaching tea leaves with boiling water, adding basic lead acetate to precipitate proteins, tannins, etc., removing them with excess lead i sulfuric acid, extracting the filtrate with chloroform, and evaporating and crystallizing it. can get. Caffeine is similarly separated from alcoholic extracts used in the production of decaffeinated coffee.

On the other hand, the present inventor has developed a host compound in which a specific compound (host compound) takes in a specific molecule (guest molecule) to form a complex.
We have been conducting research on guest complexes or inclusion complexes, and found that tetraphenylhexadiindiol incorporates various guest compounds to form crystalline host-guest complexes.

[Problems to be solved by the invention] Most alkaloids, which are vegetable bases, are obtained by extraction from natural products, but since various substances are extracted at the same time, it is necessary to isolate and purify the target substance. The method differs depending on the target alkaloid, is not necessarily simple, and requires many steps to obtain a highly pure alkaloid, resulting in a low yield.

Therefore, the present inventor attempted to utilize the host-guest complex method for the separation and purification of natural products since it is effective in separating specific substances.

[Means for solving the problems] That is, the present invention provides host compounds having the following formulas 1,1',
8.8°-tetraphenyl-2,4=hexadiyne-1
The present invention provides a method for separating alkaloids by a host-guest complex method characterized by using , 8-diol, and in particular, caffeine and nicotine can be separated extremely easily.

In order to separate alkaloids by the method of the present invention, first, a natural product containing the target alkaloid is treated by a method known for each alkaloid to liberate the alkaloid and make it into a solution state, and then add 1, 1°
, 8.8'-tetraphenyl-2,4-hexadiyne-
1,8-diol (hereinafter simply referred to as host) is added as is and dissolved, or a solution prepared in advance is added. Preferably 1. If the alkaloid is extracted as an alcohol solution such as methanol, it can be dissolved simply by adding the host.

When the alkaloid solution in which the host is added and dissolved is left preferably at a low temperature, the alkaloid solution is
A complex of 1 to 3 molecules is formed. Since this complex precipitates in an alcohol solvent, it can be separated by filtration.After heating and dissolving the washed complex in a minimum amount of acetone, when it is cooled, the host acetone complex precipitates, and the alkaloid is removed from the mother liquor as an acetone solution. Because it remains in.

The desired alkaloid can be recovered by evaporating the acetone.

[Operations and Effects] The alkaloid separation method of the present invention adds the host of the present invention to an alkaloid solution extracted from a natural product and separates the target alkaloid as an inclusion complex, making it extremely easy to isolate the alkaloid. , and a highly pure alkaloid is recovered from the separated complex. In addition, the host after recovering the alkaloid is reused, and the extraction solvent used is easily recovered, and the process is simplified, resulting in resource and energy savings.

[Example] Example 1 17g of Tobacco R Piece manufactured by Japan Tobacco Inc.
was added to 100 ml of 5% NaOH aqueous solution, stirred for 15 minutes, and then filtered. The filtrate was removed, and the remaining liquid was extracted three times with 251 ether. Concentrate this extract.

Add 15+sl of methanol and add 1.1', 1
3,8°-tetraphenyl-2,4-hexadiyne-1
, 8-diol (phos)) was dissolved. 5℃
The host 1:1 nicotine complex precipitated after being left for a day and night, and the melting point of this complex was 112-115°C. Also,
The yield of the complex was 135 mg, and its nicotine content was 38 g, 1114% of the expected amount of nicotine in the raw material.

A sufficient amount of acetone was added to dissolve the obtained complex by heating, and when the mixture was cooled after dissolution, the host l:27 heptone complex precipitated, and nicotine remained in the mother liquor as an acetone solution.

Acetone was evaporated from this mother liquor to obtain 35 layers of nicotine. The nicotine recovery rate is 862.

Example 2 5 g of green tea was heated under reflux in 80 ml of methanol for 8 hours, and then filtered, and host 5 was added to the resulting mother liquor.
00 layer was dissolved and left overnight at 5°C, host 1:
150 mg of a biphasic phein complex was obtained. The melting point of this complex was 168-170°C.

A minimum amount of acetone is added to the resulting complex, and the host a7tone complex is precipitated by heating and dissolving it and cooling it. This is washed with water, and the resulting filtrate and washings are evaporated to yield 59+*g of caffeine. The zero recovery rate was 81%.

Claims (3)

[Claims] (1) A method for separating alkaloids by a host-guest complex method, characterized in that 1,1',6,6'-tetraphenyl-2,4-hexadiyn-1,6-diol is used as a host compound. (2) The method according to claim 1, wherein the alkaloid is nicotine. (3) The method according to claim 1, wherein the alkaloid is caffeine.