CN110935191B

CN110935191B - Method for extracting and purifying industrial hemp wax

Info

Publication number: CN110935191B
Application number: CN201911258708.6A
Authority: CN
Inventors: 赵立宁; 张江江; 严江涛; 潘根; 常丽; 李德芳; 黄思齐; 陈安国; 李建军; 唐慧娟; 张翠平; 邓勇
Original assignee: Institute of Bast Fiber Crops of CAAS
Current assignee: Institute of Bast Fiber Crops of CAAS
Priority date: 2019-12-10
Filing date: 2019-12-10
Publication date: 2021-12-17
Anticipated expiration: 2039-12-10
Also published as: CN110935191A

Abstract

The invention relates to the technical field of plant extraction, and discloses a method for extracting hemp wax. The extraction method comprises the steps of ultrasonically extracting hemp flowers and leaves with ethyl acetate, removing residues to obtain an extracting solution, and performing reduced pressure concentration and evaporation to dryness to obtain an extract concentrated paste; dissolving the concentrated paste with methanol under ultrasound, and filtering to separate solid from liquid, wherein the obtained solid is industrial hemp wax crude extract; washing the crude extract with 10%, 30% and 50% methanol solution respectively to obtain refined waxy substance. According to the invention, the proper extraction solvents of ethyl acetate and methanol are selected, and the two solvents are combined for use, so that the wax with high yield and high purity can be extracted from industrial hemp, and the active component hemp phenolic substance of the industrial hemp can be separated to the maximum extent.

Description

Method for extracting and purifying industrial hemp wax

Technical Field

The invention relates to the technical field of plant extraction, in particular to a method for extracting and purifying industrial hemp wax.

Background

The composition of plant waxes is varied. The waxy components and amounts contained in different species also vary, and the amount of waxy material varies from part to part of the same plant. The main compounds of the plant wax are sterol compounds, cyclic compounds, aliphatic compounds and the like. The wax of leaf epidermis such as rice, corn, etc. contains primary alcohol, aldehyde and fatty acid as main components.

The industrial hemp flowers and leaves not only have special hemp phenols, but also have a large amount of waxiness, and the main component of the industrial hemp flowers and leaves is alkane substances. Hemp wax is easily decomposed by heat, so it cannot be extracted at high temperature. In addition, cannabinoids and waxes are soluble in most organic solvents, so that the selection of a suitable extraction solvent for extracting the desired substances is particularly important for the separation and purification thereof.

Disclosure of Invention

In view of the above, the present invention aims to provide an extraction method capable of significantly improving the extraction amount and purity of industrial hemp wax.

In order to achieve the above purpose, the invention provides the following technical scheme:

a method for extracting industrial hemp wax comprises ultrasonic extracting hemp flower and leaf with ethyl acetate, removing residue to obtain extractive solution, concentrating under reduced pressure, and evaporating to obtain concentrated extract;

extracting the concentrated paste with methanol under ultrasound, filtering to separate solid from liquid, wherein the obtained solid is industrial hemp wax crude extract;

washing the crude extract with 10%, 30% and 50% methanol solution respectively from high to low to obtain refined waxy substance.

Preferably, the material-liquid ratio of the ultrasonic extraction is 1: 20.

Preferably, the time of ultrasonic extraction is 15-20 min.

Preferably, the concentrated paste is extracted by methanol under ultrasound, and the concentrated paste and the methanol are subjected to ultrasound for 15min at a material-liquid ratio of 1:20 and at a temperature of 25-35 ℃.

Compared with the scheme of the invention, the result shows that the scheme of the invention can obtain higher wax yield and purity, and the comparison scheme does not generate a target peak of the industrial hemp wax.

According to the technical scheme, the proper extraction solvents of ethyl acetate and methanol are selected, and the combination of the ethyl acetate and the methanol can extract wax with high yield and high purity from industrial hemp, so that the active component hemp phenolic substances of the industrial hemp can be separated to the maximum extent.

Drawings

FIG. 1 shows HPLC detection spectra of samples at various stages in the extraction method of the present invention; wherein A represents a hemp extract; b represents a waxy crude extract, C represents a phenolic extract, and D represents purified waxy;

FIG. 2 shows HPLC detection profiles for different solvent extraction schemes; wherein A represents ethyl acetate and methanol extraction, and B represents petroleum ether and ethanol extraction.

Detailed Description

The invention discloses a method for extracting industrial hemp wax, which can be realized by a person skilled in the art by properly improving process parameters by referring to the content in the text. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the extraction methods of the present invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications of the extraction methods described herein, as well as appropriate variations and combinations of the methods described herein, may be made to implement and use the techniques of the present invention without departing from the spirit and scope of the invention.

In the specific embodiment, except for the due technical differences in the comparative test, the test environments of the other used raw materials, reagents and the like are kept consistent;

the method for extracting the industrial hemp wax provided by the invention is further explained below.

Example 1: the extraction method of the invention

Taking crushed industrial hemp flower leaves, carrying out ultrasonic extraction for 20min by using ethyl acetate with a material-liquid ratio of 1:20, wherein the extraction times are two times, discarding residues, and combining extracting solutions.

Concentrating the mixed extractive solution under reduced pressure, and evaporating to obtain concentrated extract.

Performing ultrasonic treatment on the concentrated paste with methanol of the same material-to-liquid ratio at 25-35 deg.C for 15min, filtering to separate solid and liquid, wherein the solid is industrial hemp waxy crude extract, and the liquid is industrial hemp phenolic substance extract;

the crude extract was washed 3-5 times with 10%, 30%, 50% methanol solutions, respectively, in a concentration gradient from high to low. Obtaining the refined waxy substance.

HPLC detection is carried out on the extracting solution, the industrial hemp wax crude extract, the industrial hemp phenol substance extracting solution and the purified wax in the scheme, and the result is shown in figure 1; FIG. 1 shows that the main components of the extract are waxy and cannabis-specific phenolic substances, such as cannabidiol, cannabinol and tetrahydrocannabinol, after extraction with ethyl acetate. The cannabis phenol substances and the waxes can be separated by concentrating and enriching and then using methanol, and finally the cannabis waxes can be separated from the phenols substances thereof by dissolving and centrifuging and washing the methanol for many times, thereby purifying the cannabis waxes.

Example 2: comparison of different extraction solvents

Referring to the petroleum ether and ethanol solvents used in the prior patent CN107365622A, the petroleum ether is used to replace ethyl acetate, and the ethanol is used to replace methanol, and the others are consistent with the invention;

the hemp wax yield and purity of each protocol were counted by comparing the protocol of example 1 of the present invention with the above control protocol, and fig. 2 shows that the extraction with petroleum ether instead of ethyl acetate and ethanol instead of methanol under the same conditions did not show the appearance of hemp wax peaks.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A method for extracting industrial hemp wax is characterized in that hemp flowers and leaves are subjected to ultrasonic extraction for 15-20min by ethyl acetate according to a material-liquid ratio of 1:20, residues are discarded to obtain an extracting solution, and the extracting solution is subjected to reduced pressure concentration and evaporation to dryness to obtain an extract concentrated paste;

performing ultrasonic treatment on the concentrated paste for 15min at 25-35 ℃ by using methanol according to the material-liquid ratio of 1:20, and filtering to separate solid from liquid, wherein the obtained solid is industrial hemp wax crude extract;