A method for preparing high purity all-trans lutein ester

Abstract

The application relates to the technical field of biological medicine, and discloses a method for preparing high-purity all-trans lutein ester, which comprises the following steps: S1, marigold is added into a first solvent for extraction to obtain an extraction liquid; S2, the extraction liquid is subjected to impurity adsorption by an adsorbent, and then is evaporated and concentrated to obtain a crude product; and S3, the crude product is added into a second solvent for separation, filtration, and drying of a filter cake to obtain the lutein ester. Through the technical scheme, the problems of low extraction rate and poor purity of the lutein ester in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to a method for preparing high-purity all-trans lutein esters. Background Technology

[0002] Lutein esters are found in non-photosynthetic tissues of plants, such as petals and fruits, and are important carotenoid fatty acid esters. Lutein esters possess long C=C chromophores, making them highly stable food coloring agents. As a powerful antioxidant, lutein esters inhibit the activity of reactive oxygen species (ROS) and prevent their damage to normal skin cells. Therefore, lutein esters can be formulated into various skincare and cosmetic products to protect skin health and prevent skin damage.

[0003] The main configuration of lutein esters is all-trans, which can be further divided into lutein monoesters and lutein diesters. It is widely found in plants such as marigolds, pumpkins, cabbages, and wild vegetables, with the highest content (30% to 40%) in marigold flowers. Currently, the main methods for extracting lutein esters from marigolds include solvent extraction, supercritical CO2 extraction, and ultrasound-assisted extraction. However, solvent extraction leaves a large amount of residual organic solvent, which does not meet food safety requirements. Supercritical CO2 extraction and ultrasound-assisted extraction suffer from low extraction rates and poor purity of lutein esters. Therefore, to address the problems of low extraction rates and poor purity in existing technologies, it is extremely important to develop a method for preparing high-purity all-trans lutein esters. Summary of the Invention

[0004] This invention proposes a method for preparing high-purity all-trans lutein esters, which solves the problems of low extraction rate and poor purity of lutein esters in related technologies.

[0005] The technical solution of the present invention is as follows:

[0006] This invention proposes a method for preparing high-purity all-trans lutein esters, comprising the following steps:

[0007] S1. Marigold is added to the first solvent for extraction to obtain the extract;

[0008] S2. After the extract is subjected to an adsorbent to adsorb impurities, it is evaporated and concentrated to obtain the crude product;

[0009] S3. The crude product is added to the second solvent for separation, filtered, and the filter cake is dried to obtain lutein ester.

[0010] As a further technical solution, the first solvent is acetone or ethyl acetate.

[0011] As a further technical solution, the mass-to-volume ratio of the marigold to the first solvent is 1:5 to 1:10, calculated in g / mL.

[0012] As a further technical solution, the extraction temperature is 30℃~40℃, and the extraction time is 1~3h.

[0013] As a further technical solution, the adsorbent is a macroporous resin adsorbent.

[0014] As a further technical solution, the macroporous resin adsorbent is one of XAD-7 or XAD-16 with a 2-methacrylate skeleton structure or NKA-9 with a divinylbenzene skeleton structure.

[0015] As a further technical solution, the macroporous resin adsorbent is a macroporous resin adsorbent modified by a mixture of dimethylethanolamine and acetanilide in a mass ratio of 3:7 to 7:3.

[0016] As a further technical solution, the mass ratio of dimethylaminoethanol to acetanilide is 4:6.

[0017] As a further technical solution, the sum of the mass of the dimethylaminoethanol and acetanilide is 3% to 5% of the mass of the macroporous resin adsorbent.

[0018] As a further technical solution, the second solvent is a mixed solvent of diethyl ether and petroleum ether in a volume ratio of 1:1 to 3:1.

[0019] The working principle and beneficial effects of this invention are as follows:

[0020] 1. In this invention, since marigolds contain a large number of flavonoids, the extract obtained after extraction with the first solvent is adsorbed by an adsorbent, which effectively separates the flavonoids from the extracted lutein esters, thereby improving the extraction rate and purity of the lutein esters. Adding the crude product to the second solvent allows other impurities in the marigolds to dissolve better, further separating the lutein esters and improving the extraction efficiency and purity.

[0021] 2. In this invention, the extract is adsorbed using a macroporous resin adsorbent. The macroporous resin adsorbent has good stability, can be regenerated and reused, and the process is simple and easy to operate. It can also effectively separate flavonoids and lutein esters in marigolds, thereby improving the purity of lutein esters.

[0022] 3. In this invention, macroporous resins with a highly polar 2-methacrylate skeleton structure or a divinylbenzene skeleton structure are used as adsorbents, which can better separate multiple flavonoid compounds from marigolds, improve the purification effect of lutein esters, and thus improve the purity of lutein esters.

[0023] 4. In this invention, the macroporous resin adsorbent is modified with a mixture of dimethylaminoethanol and acetanilide, which not only improves the separation degree of flavonoids and lutein esters, but also promotes the separation of glycosides and lutein esters, thereby further improving the purity of lutein esters.

[0024] 5. In this invention, the crude product is added to a mixed solvent of diethyl ether and petroleum ether, which can better dissolve the zeaxanthin contained in marigold in the mixed solvent, better separate it from lutein ester, improve the purification effect of lutein ester, and thus improve the purity of lutein ester. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] The lutein ester content in marigolds is 30%.

[0027] Weigh 0.1g of the lutein esters prepared in Examples 1-12 and Comparative Example 1 respectively, dissolve them in acetone and make up to 100mL, and measure the absorbance at 445nm using a UV-Vis spectrophotometer.

[0028] Lutein ester content (wt%) = (Absorbance / Sample mass / 1394) × Dilution factor × 100

[0029] In the formula: 1394 is the absorption coefficient at a wavelength of 445nm.

[0030] The mass of lutein esters = the mass of lutein esters obtained × the content of lutein esters.

[0031] Extraction rate (%) = (mass of lutein esters / total mass of lutein esters) × 100.

[0032] Example 1

[0033] S1. Add 50g of marigold to 250mL of acetone for extraction, heat to 30℃, and extract for 3h to obtain the extract;

[0034] S2. Add XAD-7 type macroporous resin adsorbent with 2-methacrylate framework to the extract, adsorb for 3 hours, filter, and evaporate and concentrate the filtrate to obtain crude product.

[0035] S3. Add the crude product to a mixture of 150 mL of diethyl ether and 150 mL of petroleum ether, stir for 30 min, filter, keep the filter cake, and dry to obtain 13.49 g of lutein ester.

[0036] The content of lutein esters was determined to be 93.1% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.7%.

[0037] Example 2

[0038] S1. Add 50g of marigold to 500mL of ethyl acetate for extraction, heat to 40℃, and extract for 1h to obtain the extract;

[0039] S2. Add XAD-7 type macroporous resin adsorbent with 2-methacrylate framework to the extract, adsorb for 3 hours, filter, and evaporate and concentrate the filtrate to obtain crude product.

[0040] S3. Add the crude product to a mixture of 225 mL of diethyl ether and 75 mL of petroleum ether, stir for 30 min, filter, keep the filter cake, and dry to obtain 13.48 g of lutein ester.

[0041] The content of lutein esters was determined to be 93.6% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 84.1%.

[0042] Example 3

[0043] S1. Add 50g of marigold to 350mL of ethyl acetate for extraction, heat to 35℃, and extract for 2h to obtain the extract;

[0044] S2. Add XAD-7 type macroporous resin adsorbent with 2-methacrylate framework to the extract, adsorb for 3 hours, filter, and evaporate and concentrate the filtrate to obtain crude product.

[0045] S3. Add the crude product to a mixture of 200 mL of diethyl ether and 100 mL of petroleum ether, stir for 30 min, filter, keep the filter cake, and dry to obtain 13.47 g of lutein ester.

[0046] The content of lutein esters was determined to be 93.4% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.9%.

[0047] Example 4

[0048] The difference between this embodiment and Embodiment 1 is only in step S3, where the crude product is added to 300 mL of diethyl ether, stirred for 30 min, filtered, the filter cake is collected, and dried to obtain 13.62 g of lutein ester.

[0049] The content of lutein esters was determined to be 92.3% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.8%.

[0050] Example 5

[0051] The difference between this embodiment and Embodiment 1 is only in step S3, where the crude product is added to 300 mL of petroleum ether, stirred for 30 min, filtered, the filter cake is collected, and dried to obtain 13.65 g of lutein ester.

[0052] The content of lutein esters was determined to be 92.5% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 84.2%.

[0053] Example 6

[0054] The only difference between this embodiment and Example 1 is that the macroporous resin adsorbent used in step S2 is XAD-16 with a 2-methacrylate skeleton. A total of 13.50 g of lutein ester was finally obtained.

[0055] The content of lutein esters was determined to be 93.3% by UV-Vis spectrophotometer, and the extraction rate of lutein esters was 84.0%.

[0056] Example 7

[0057] The only difference between this embodiment and Example 1 is that the macroporous resin adsorbent used in step S2 is NKA-9 with a divinylbenzene skeleton. A total of 13.50 g of lutein ester was finally obtained.

[0058] The content of lutein esters was determined to be 92.9% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.6%.

[0059] Example 8

[0060] The difference between this embodiment and Embodiment 1 lies only in step S2, where the macroporous resin adsorbent is first modified. The modification method is as follows:

[0061] Add 10g of macroporous resin adsorbent to 150mL of chloroform, stir for 30min, heat to 60℃, add 0.09g of dimethylethanolamine and 0.21g of acetanilide, stir, heat to 100℃, react for 8h, cool and filter to obtain modified macroporous resin adsorbent.

[0062] The extract was then subjected to adsorption of impurities using a modified macroporous resin adsorbent, ultimately yielding 13.12 g of lutein ester.

[0063] The content of lutein esters was determined to be 95.8% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.8%.

[0064] Example 9

[0065] The only difference between this embodiment and Example 8 is the addition of 0.12g of dimethylethanolamine and 0.18g of acetanilide in the modification method. The final yield was 13.25g of lutein ester.

[0066] The content of lutein esters was determined to be 95.3% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 84.2%.

[0067] Example 10

[0068] The only difference between this embodiment and Example 8 is the addition of 0.21g of dimethylethanolamine and 0.09g of acetanilide in the modification method. The final yield was 13.16g of lutein ester.

[0069] The content of lutein esters was determined to be 95.6% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.9%.

[0070] Example 11

[0071] The only difference between this embodiment and Example 8 is that only 0.3g of dimethylethanolamine was added in the modification method. The final yield was 13.45g of lutein ester.

[0072] The content of lutein esters was determined to be 93.7% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 84.0%.

[0073] Example 12

[0074] The only difference between this embodiment and Example 8 is that only 0.3g of acetanilide was added in the modification method. The final yield was 13.34g of lutein ester.

[0075] The content of lutein esters was determined to be 94.1% using a UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.7%.

[0076] Comparative Example 1

[0077] The only difference between this comparative example and Example 1 is that in step S2, the extract was directly evaporated and concentrated to obtain the crude product. A total of 14.01 g of lutein ester was finally obtained.

[0078] The content of lutein esters was determined to be 89.5% by UV-Vis spectrophotometer, and the extraction rate of lutein esters was 83.6%.

[0079] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing all-trans lutein ester, characterized in that, Includes the following steps: S1. Marigold is added to the first solvent for extraction to obtain the extract; S2. After the extract is subjected to an adsorbent to adsorb impurities, it is evaporated and concentrated to obtain the crude product; S3. The crude product is added to the second solvent for separation, filtered, and the filter cake is dried to obtain lutein ester; The adsorbent is a macroporous resin adsorbent; The macroporous resin adsorbent is a macroporous resin adsorbent modified from a mixture of dimethylethanolamine and acetanilide in a mass ratio of 3:7 to 7:

3.

2. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The first solvent is acetone or ethyl acetate.

3. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The mass-to-volume ratio of the marigold to the first solvent is 1:5 to 1:10, expressed in g / mL.

4. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The extraction temperature is 30℃~40℃, and the extraction time is 1~3h.

5. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The macroporous resin adsorbent is one of XAD-7 or XAD-16 with a 2-methacrylate skeleton or NKA-9 with a divinylbenzene skeleton.

6. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The mass ratio of dimethylaminoethanol to acetanilide is 4:

6.

7. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The sum of the masses of dimethylaminoethanol and acetanilide is 3% to 5% of the mass of the macroporous resin adsorbent.

8. The method for preparing all-trans lutein ester according to claim 1, characterized in that, The second solvent is a mixed solvent of diethyl ether and petroleum ether in a volume ratio of 1:1 to 3:1.