CN1453289A - Process of extracting and separating ursolic acid from plant - Google Patents

Abstract

The present invention is process of extracting and separating ursolic acid from plant. The extracting and separating process of ursolic acid includes methanol reflux extraction of coarse paulownia leaf powder, recovering methanol to small volume, settling, filtering to eliminate filtrate, washing the precipitate with acetone for many times to eliminate impurity, and re-crystallization for three times in anhydrous alcohol and methanol to obtain ursolic acid. Compared with other processes of extracting ursolic acid, the present invention has the advantages of cheap material, simple technological process, low cost and being suitable for industrial production.

Description

A method for extracting and isolating ursolic acid from plants

1. Field

The invention belongs to the research of natural products, relates to the extraction of a natural product with important application value, in particular to a method for extracting and separating ursolic acid from plants.

2. Background technology

Ursolic acid has obvious stabilizing and cooling effects. It is active against Gram-positive bacteria, negative bacteria and yeasts in vitro, and has a very significant inhibition rate on liver cancer cell culture in vitro. Animal experiments have proved that ursolic acid has the effect of reducing transaminase . The pharmaceutical industry has used ursolic acid as a raw material for pharmaceutical production. There are many research reports on ursolic acid. Many plants contain ursolic acid, but the content is different. The content of ursolic acid in Paulownia leaves is high, and this study was only reported in Japan in 1963. Regarding the extraction method of ursolic acid, most of the methods reported in the literature are extracted with different solvents after extraction, and then different parts are subjected to silica gel column chromatography or alumina column chromatography, and gradient elution is obtained. This method is not only time-consuming, but also unfavorable for industrial mass production. There are also reports in the literature that three solvents are used for stripping, and most of the solvents used are chloroform, sherwood oil, diethyl ether and ethyl acetate. According to experiments, these solvents are incomplete in removing impurities, and repeated extractions lead to large loss of components and increase production costs.

3. Contents of the invention

Aiming at the difficulty and content difference of the extraction methods of ursolic acid, the purpose of this method is to provide a method for extracting and separating ursolic acid from plants that is simple, low-cost, high-yield, and suitable for industrial production.

The solution that realizes the above-mentioned purpose is, extracts the method for separating ursolic acid from plant, carries out according to the following steps: 1. extract

Take the coarse powder of paulownia leaves, add 6-8 times the amount of methanol to reflux extraction, the first two times are two hours each, and the last two times are one hour each. Combine the extracts and let stand overnight. After filtration, the filtrate was concentrated, methanol was recovered to a small volume, and the precipitate was placed. Filter, discard the filtrate, and wash the precipitate with a small amount of acetone several times to remove impurities. Dissolve it in absolute ethanol, filter it hot, and place it for crystallization; recrystallize once in the same way. Finally, it was recrystallized with methanol-ethanol (1:5) mixed solvent. Stand to get white needle crystals. 2. Identification

Take a small amount of this crystal and dissolve it with absolute ethanol, and apply it simultaneously with the ursolic acid standard. Developed on a silica gel G plate with benzene-95% ethanol (9:1) as the developer, and acetic anhydride-concentrated sulfuric acid as the developer, the spots were purple-red under sunlight and orange-yellow fluorescent spots at 365 nm. Both have the same Rf value and the same color. Developed with cyclohexane-chloroform-ethyl acetate (20:5:8) as the developing solvent, there were spots of the same color at the same position after color development.

The melting point was measured with a small amount of crystals, mp: 277°C-278°C, so it was proved that the obtained crystals were ursolic acid.

The extraction process of the method is simple, the cost is low, the raw material is easy to obtain, the extraction efficiency is high, and it is beneficial to industrial production.

4. Specific implementation

The present invention will be further described in detail below in conjunction with the preferred embodiments given by the inventor.

Embodiment 1: according to technical scheme of the present invention, extract the ursolic acid in the Paulownia leaf, carry out according to the following steps: 1. extract

Take the coarse powder of paulownia leaves, add 6-8 times the amount of methanol to reflux extraction, the first two times are two hours each, and the last two times are one hour each. Combine the extracts and let stand overnight. After filtration, the filtrate was concentrated, methanol was recovered to a small volume, and the precipitate was placed. Filter, discard the filtrate, and wash the precipitate with a small amount of acetone several times to remove impurities. After dissolving in absolute ethanol, it was heated and filtered, and placed for crystallization. Recrystallize once in the same way. Finally, it was recrystallized with methanol-ethanol (1:5) mixed solvent. Stand to get white needle crystals. 2. Identification

Take a small amount of this crystal and dissolve it with absolute ethanol, and apply it simultaneously with the ursolic acid standard. Developed on a silica gel G plate with benzene-95% ethanol (9:1) as the developer, and acetic anhydride-concentrated sulfuric acid as the developer, the spots were purple-red under sunlight and orange-yellow fluorescent spots at 365 nm. Both have the same Rf value and the same color. Developed with cyclohexane-chloroform-ethyl acetate (20:5:8) as the developing solvent, there were spots of the same color at the same position after color development.

The melting point was measured with a small amount of crystals, mp: 277°C-278°C, which proved that the obtained crystals were ursolic acid.

Embodiment 2: The difference between this embodiment and embodiment 1 is that in step 1, absolute ethanol is used for reflux extraction.

Embodiment 3: The difference between this embodiment and embodiment 1 is that in step 1, Soxhlet extraction is used and petroleum ether and chloroform are used to remove impurities.

Embodiment 4: The difference between this embodiment and embodiment 1 is that in step 1, methanol ultrasonic vibration method is used for extraction.

5. References [1]. Bian Xiangmei, Jiang Zhiyi, Shen Lin Research on the active ingredients of the traditional Chinese medicine Gardenia Chinese Herbal Medicine Communication 1976, 15(9): 15-17 [2]. Hou Yucheng Research on the chemical components of Ligustrum leaves Chinese Herbal Medicine Communication 1976, 14 (1): 14-16[3]. Xu Qiang Introduction to the extraction method of ursolic acid Chinese Journal of Traditional Chinese Medicine 1989, 14(3): 41[4]. Zhang Baochen, Zhen Runde, Hu Bolin, etc. Research on the chemical components of Shisheng Pianlei Chinese Herbal Medicine 1980 , 11(4):149-151

Claims (2)

1. A method for extracting and separating ursolic acid from plants, carried out in the following steps: 1) extracting ①Take the coarse powder of Paulownia leaves, add 6-8 times the amount of methanol to reflux extraction, the first two times are two hours each, and the last two times are one hour each, the extracts are combined and left overnight; ② After filtering, concentrate the filtrate, recover the methanol to a small volume, and place the precipitate; ③Filter again, discard the filtrate, and wash the precipitate with a small amount of acetone several times to remove impurities; ④ Dissolve with absolute ethanol, then heat filter, place for crystallization; ⑤ Recrystallize once with the same method; ⑥Finally recrystallize with methanol-ethanol mixed solvent; place to get white needle crystals; 2) identification ①Take a small amount of this crystal and dissolve it in absolute ethanol, and apply it simultaneously with the ursolic acid standard; ② On the silica gel G plate, develop with benzene:95% ethanol, ratio 9:1 as the developing agent, and use acetic anhydride-concentrated sulfuric acid as the developing agent, the spots are purple-red under sunlight and orange-yellow fluorescent spots under 365nm. Both have the same Rf value and the same color; ③Using cyclohexane: chloroform: ethyl acetate, the ratio of 20:5:8 as the developing agent, there are spots of the same color at the same position after color development; ④ Measure the melting point with a small amount of crystals, mp: 277°C-278°C, which proves that the obtained crystals are ursolic acid. 2. the method for extracting and separating ursolic acid from plants as claimed in claim 1, is characterized in that, described methanol reflux extraction step can adopt dehydrated alcohol reflux extraction, can also adopt Soxhlet extraction and remove with sherwood oil and chloroform Impurities can also be extracted by ultrasonic oscillation of methanol.