LU502380B1

LU502380B1 - Method for preparing high-purity conjugated linoleate by using simulated moving bed

Info

Publication number: LU502380B1
Application number: LU502380A
Authority: LU
Inventors: Xiaofei Yin; Zhou Zheng; Aijun Zhang
Original assignee: First Inst Oceanography Mnr
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2022-12-29

Abstract

Disclosed is a method for preparing high-purity conjugated linoleate by using a simulated moving bed. Conjugated ethyl linoleate is selected as a raw material; C8 silica gel and C18 silica gel are selected as stationary phases; and ethanol/water, methanol/water and acetonitrile/water are selected as mobile phases. Preparation of a sample injection solution of a feed comprises: dissolving low-purity conjugated ethyl linoleate in methanol to prepare the feed, with a desorbent of methanol/water; making the feed and the desorbent continuously flow into a simulated moving bed chromatography system which is a four-zone simulated moving bed with each zone composed of more than two chromatographic columns connected in series, wherein the C18 silica gel is filled in all the chromatographic columns; a product is taken out from an extract; and impurities flow out from raffinate. The present invention has the beneficial effects that the raw material with the content of conjugated ethyl linoleate of 80% is purified to a high-purity product with the content of more than 97%.

Description

METHOD FOR PREPARING HIGH-PURITY CONJUGATED LINOLEATE BY USING SIMULATED MOVING BED LU502380 Technical Field The present invention belongs to the technical field of chemical industry, and relates to a method for preparing high-purity conjugated linoleate by using a simulated moving bed. Background Conjugated linoleic acid (CLA for short) is an isomer of linoleic acid, which generally refers to the conjugated linoleic acid with unsaturated double bonds at positions c9 and c11 or c10 and c12. There are four isomers in theory, but contents of isomers c9, t11-CLA and t10, c12- CLA are the highest. CLA is a natural regulator of lipid and sugar metabolism, which participates in a metabolic process of lipid and sugar, improves imbalance of the lipid and sugar, and plays an important role in balancing fat cells and blood sugar. Studies have shown that CLA has a good preventive and therapeutic effect on obesity, hyperlipidemia and other diseases with its unique weight-reducing and lipid-lowering effects. At present, CLA has been listed in the GRAS (GRN No.000153) candidate list by National Nutritional Foods Association, and is widely used in the fields of health care products, functional foods and food additives. China has also approved CLA as a new resource food.

Conjugated linoleic acid is widely used, can be used as a health food, a food additive and a cosmetic raw material, and can be further developed into medicines. In July, 2012, FDA approved high-purity ethyl eicosapentaenoic acid (EEPA) as a prescription drug for treatment of hypertriglyceridemia, which indicates that high-purity functional oils and fats can be developed into medicines. The purity of medicinal functional oils and fats is required to be above 95%, while the purity of conjugated ethyl linoleate (CLA-EE) in the market is mainly 70% and 80% at present, and rarely reaches 90%. There is no product with the purity of conjugated linoleic acid exceeding 95%. Traditional separation and preparation methods, such as urea inclusion method and lipase catalysis method, cannot prepare products with the purity of more than 95%. Therefore, it is necessary to conduct in-depth research on a preparation technology of CLA with high purity, and lay a solid foundation for drug development thereof.

Summary The purpose of the present invention is to provide a method for preparing high-purity conjugated linoleate by using a simulated moving bed. The beneficial effect of the present invention is that a raw material of low-purity conjugated ethyl linoleate (CLA-EE) is purified to a high-purity product with the content of more than 97%.

A technical solution adopted by the present invention is that low-purity conjugated ethyl linoleate (CLA-EE) is selected as a raw material; C8 silica gel and C18 silica gel are selected as stationary phases; and ethanol/water, methanol/water, and acetonitrile/water are selected as LU502380 mobile phases.

Preparation method: (1) Preparation of a sample injection solution of a feed comprises: dissolving low-purity conjugated ethyl linoleate in methanol (or ethanol) to prepare the feed; (2) a desorbent is ethanol/water, methanol/water, and acetonitrile/water; (3) the feed and the desorbent continuously flow into a simulated moving bed chromatography system which is a four-zone simulated moving bed with each zone composed of two chromatographic columns; the C18 silica gel (or one C8 silica gel chromatographic column and one C18 silica gel chromatographic column connected in series) is filled in the two chromatographic columns; a product is taken out from an extract, and impurities flow out from a raffinate.

Further, the raw material of low-purity conjugated ethyl linoleate is dissolved in the methanol (or ethanol).

Further, the desorbent is ethanol/water, methanol/water, and acetonitrile/water.

Description of Drawings Fig. 1 shows a gas phase analysis result of a raw material of conjugated ethyl linoleate with purity of 80.15%; Fig. 2 is a structural schematic diagram of a four-zone simulated moving bed; Fig. 3 shows a gas phase analysis result of high-purity conjugated ethyl linoleate (97.55%) prepared by C18 silica gel as a stationary phase in embodiment 1; and Fig. 4 shows a gas phase analysis result of high-purity conjugated ethyl linoleate (98.33%) prepared by C8 silica gel and C18 silica gel connected in series in embodiment 2.

Detailed Description The present invention will be described in detail below in combination with specific embodiments.

A raw material is low-purity conjugated ethyl linoleate purchased from Qingdao Auhai Biotech Co., Ltd. A gas phase analysis result shows that the content of conjugated ethyl linoleate is 80.15% (Fig. 1).

An instrument is a simulated moving bed chromatographic separation system CSEP9116 of KNAUER Advanced Scientific Instruments Co., Ltd., which is a four-zone simulated moving bed with each zone composed of two chromatographic columns. C18 silica gel (or C8 silica gel and (C18 silica gel connected in series) is selected as the chromatographic columns; and ethanol/water, methanol/water, and acetonitrile/water can be used as mobile phases, preferably methanol/water.

Purification experiment:

(1) Preparation of a feed comprises: dissolving a raw material of low-purity conjugated ethyl 502380 linoleate in methanol (or ethanol) to prepare the feed; (2) a desorbent is ethanol/water, methanol/water, and acetonitrile/water, preferably methanol/water (80:20 w/w); (3) the feed and the desorbent continuously flow into a simulated moving bed chromatography system which is a four-zone simulated moving bed with each zone composed of two chromatographic columns; the two chromatographic columns are C18 silica gel chromatographic columns, or one C8 silica gel chromatographic column and one C18 silica gel chromatographic column are connected in series; a product is taken out from an extract; and impurities flow out from a raffinate. Appropriate switching time is set for separation and purification. A specific process flow is shown in Fig. 2.

The content of purified conjugated ethyl linoleate is measured by gas chromatography. Two drops of the product are taken through a pipette at one time and dissolved in 2 ml of n-hexane; and about 0.6 microliter is taken for injection. Gas chromatography with a 30m polar capillary column is selected; injection is performed at 250°C; a column temperature is 200°C; and a detection hydrogen flame is at 260°C. The content of conjugated ethyl linoleate is calculated by an area normalization method.

Embodiment 1 A preparation method of high-purity conjugated ethyl linoleate comprises the following steps: Preparation of a raw material sample injection solution comprises: dissolving conjugated ethyl linoleate with the purity of 80.15% in methanol to prepare a 25mg/ml solution.

A desorbent is methanol/water (80:20 w/w).

The feed and the desorbent continuously flow into a simulated moving bed chromatography system which is a four-zone simulated moving bed with each zone composed of two chromatographic columns; the two chromatographic columns are C18 silica gel chromatographic columns; a product is taken out from an extract; and impurities flow out from a raffinate. Switching time is set as 5 min. Flows rate in I-IV zones are 3.8 ml/min, 3.2 ml/min, 3.5 ml/min and 2.8 ml/min successively. Separation and purification are carried out.

The content of separated and purified conjugated ethyl linoleate is measured by gas chromatography. Results show that a yield of prepared high-purity conjugated ethyl linoleate is

76.3%; and the purity is 97.55%. A gas chromatogram is shown in Fig. 3.

Embodiment 2 A preparation method of high-purity conjugated ethyl linoleate comprises the following steps:

Preparation of a raw material sample injection solution comprises: dissolving conjugated LU502380 ethyl linoleate with the purity of 80.15% in methanol to prepare a 25mg/ml solution.

A desorbent is methanol/water (80:20 w/w).

The feed and the desorbent continuously flow into a simulated moving bed chromatography system which is a four-zone simulated moving bed with each zone composed of two chromatographic columns; the two chromatographic columns include a C8 silica gel chromatographic column and a C18 silica gel chromatographic column which are connected in series; a product is taken out from the extract; and impurities flow out from the raffinate. Switching time is set as 5.2 min. Flows rate in I-IV zones are 3.6ml/min, 3.1 ml/min, 3.3 ml/min and 2.5 ml/min successively. Separation and purification are carried out.

78.2%; and the purity is 98.33%. A gas chromatogram is shown in Fig. 4.

Embodiment 1 and embodiment 2 can obtain high-purity conjugated linoleic acid; and the purity of the prepared conjugated ethyl linoleate exceeds 97%.

The above only describes the preferred embodiments of the present invention, and does not limit the present invention in any form. Any simple changes, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention belong to the scope of the technical solution of the present invention.

Claims

1. A method for preparing high-purity conjugated linoleate by using a simulated moving bed, 5 wherein low-purity conjugated ethyl linoleate (CLA-EE) is selected as a raw material; C8 silica gel (or C8 silica gel and C18 silica gel connected in series) is selected as a stationary phase; and methanol/water (or ethanol/water, or acetonitrile/water) is selected as a desorbent, the method comprising the following steps: (1) preparation of a sample injection solution of a feed comprises: dissolving low-purity conjugated ethyl linoleate in methanol to prepare the feed; (2) providing methanol/water as desprbent; (3) allow the the feed and the desorbent to continuously flow into a simulated moving bed chromatography system which is a four-zone simulated moving bed with each zone composed of two chromatographic columns; filling the C18 silica gel (or C8 silica gel and C18 silica gel connected in series) filled in the two chromatographic columns; removing product from the extract, wherein impurities flow out from the raffinate.

2. The method for preparing high-purity conjugated linoleate by using the simulated moving bed according to claim 1, wherein conjugated ethyl linoleate with purity of 80% is dissolved in the methanol.

3. The method for preparing high-purity conjugated linoleate by using the simulated moving bed according to claim 1, wherein the simulated moving bed is a four-zone simulated moving bed.

4. The method for preparing high-purity conjugated linoleate by using the simulated moving bed according to claim 1, wherein the desorbent is methanol/water with 80 : 20 w/w.