A sea cucumber flower polypeptide with lipid-lowering efficacy, and a preparation method and application thereof

Abstract

The application belongs to the technical field of biological processing, and specifically discloses a sea cucumber flower polypeptide with lipid-lowering efficacy as well as a preparation method and application thereof. The sea cucumber flower polypeptide with lipid-lowering efficacy is composed of short peptides with a molecular weight less than 1000 Da; the short peptides are one or more of GTGATGTF, FTGIVGSL, LAIGETEF, VGITDIESF, VDDEF and YDDVP. The application discloses a sea cucumber flower polypeptide with lipid-lowering efficacy as well as a preparation method and application thereof. The sea cucumber flower polypeptide has a significantly improved inhibition rate on cholesteryl esterase and pancreatic lipase, and has a stronger adsorption capacity on bile acid. The sea cucumber flower polypeptide does not contain the enzyme cutting sites of pepsin and trypsin, can resist secondary digestion and degradation after being taken into the human body, stably maintains structural integrity and biological activity, and solves the problem that traditional lipid-lowering peptides are easily destroyed in activity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological processing, and particularly relates to a sea cucumber flower polypeptide with lipid-lowering efficacy as well as a preparation method and application thereof. BACKGROUND

[0002] As a precious natural product for both medicine and food, sea cucumber is rich in polysaccharides, saponins, proteins and other bioactive substances, and has shown significant value in the fields of anti-tumor, antioxidant, immune regulation and the like. Sea cucumber flower, as a main by-product generated in the process of sea cucumber processing, contains sea cucumber internal organs and eggs, has a high protein content of up to 80%, and contains all the nutritional ingredients of sea cucumber body wall, and is a high-quality raw material for preparing bioactive peptides. However, the comprehensive development and utilization of sea cucumber flower is still at a low level, and there is a problem of resource waste.

[0003] Lipid-lowering peptides, as a kind of bioactive substances that can regulate lipid metabolism, have important potential in preventing and improving hyperlipidemia, and can be obtained from plant, animal and microbial proteins through enzymatic hydrolysis. However, most natural active peptides exist in the form of protein fragments in the natural state, and need to be released after enzymatic hydrolysis to have activity, and the functional stability thereof is highly dependent on the complete structure sequence. Once the peptide bond is broken or the spatial structure is changed in the process of human digestion by gastric acid or digestive enzymes, the lipid-lowering activity will be significantly lost.

[0004] In the prior art, the preparation of lipid-lowering peptides mostly adopts traditional enzymatic hydrolysis method, which can obtain peptide fragments with certain activity, but it is difficult to ensure that the peptide fragments resist secondary digestion in the gastrointestinal tract after being taken into the human body. In addition, the research on sea cucumber flower mostly focuses on the active substances of the body wall, and there is a lack of systematic preparation and functional stability research on lipid-lowering peptides in sea cucumber flower byproducts. There is a lack of sea cucumber flower lipid-lowering peptide preparation technology that can efficiently obtain and maintain the structure integrity and activity during the digestion process, which limits the high-value utilization of sea cucumber flower resources and the development of functional lipid-lowering products. Therefore, it is of important theoretical and application value to develop a method for preparing sea cucumber flower polypeptides with anti-digestion ability and stable lipid-lowering activity. SUMMARY

[0005] The present application aims to provide a sea cucumber flower polypeptide with lipid-lowering efficacy as well as a preparation method and application thereof. The sea cucumber flower polypeptide has significantly improved inhibition rates of cholesterol esterase and pancreatic lipase, and stronger adsorption capacity of bile acids. The sea cucumber flower polypeptide does not contain the enzyme cutting sites of pepsin and trypsin, can resist secondary digestion and degradation after being taken into the human body, stably maintains the structure integrity and biological activity, and solves the problem that traditional lipid-lowering peptides are easily digested and destroyed in activity.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] A sea cucumber flower polypeptide with lipid-lowering effect, wherein the sea cucumber flower polypeptide with lipid-lowering effect is composed of short peptides with a molecular weight of less than 1000 Da;

[0008] The short peptide is one or more of GTGATGTF, FTGIVGSL, LAIGETEF, VGITDIESF, VDDEF, and YDDVP.

[0009] Preferably, the amino acid sequence of the short peptide GTGATGTF is as shown in SEQ ID NO:1;

[0010] The amino acid sequence of the short peptide FTGIVGSL is shown in SEQ ID NO:2;

[0011] The amino acid sequence of the short peptide LAIGETEF is shown in SEQ ID NO:3;

[0012] The amino acid sequence of the short peptide VGITDIESF is shown in SEQ ID NO:4;

[0013] The amino acid sequence of the short peptide VDDEF is shown in SEQ ID NO:5;

[0014] The amino acid sequence of the short peptide YDDVP is shown in SEQ ID NO:6.

[0015] The present invention also provides a method for preparing the sea cucumber flower polypeptide as described, comprising the following steps:

[0016] S1. Dissolve the freeze-dried sea cucumber flower powder in ice water and stir evenly to obtain a sea cucumber flower homogenate.

[0017] S2. Add n-hexane-anhydrous ethanol mixture to the sea cucumber flower homogenate obtained in step S1, extract, remove the upper layer of oil, and obtain defatted sea cucumber flower homogenate.

[0018] S3. Add simulated gastric and intestinal fluids to the defatted sea cucumber flower homogenate obtained in S2, perform enzymatic hydrolysis, repeat the enzymatic hydrolysis twice, after the enzymatic hydrolysis is completed, heat to inactivate the enzyme, centrifuge, discard the precipitate, and ultrafilter to obtain sea cucumber flower lipid-lowering polypeptide concentrate.

[0019] S4. The concentrated sea cucumber flower lipid-lowering polypeptide obtained in S3 is freeze-dried to obtain sea cucumber flower lipid-lowering polypeptide.

[0020] Preferably, in S1, the ratio of the freeze-dried sea cucumber flower powder to the ice-water solution is 1:35~45.

[0021] Preferably, in S2, the volume ratio of n-hexane to anhydrous ethanol in the n-hexane-anhydrous ethanol mixture is 2~4:1.

[0022] Preferably, in S2, the extraction conditions are as follows: extraction at 50°C for 4-6 hours, and repeated 1-2 times.

[0023] Preferably, in S3, the simulated gastric fluid is prepared by mixing gastric electrolyte solution (SGF) and pepsin (2000 U / mL) at a volume ratio of 1:0.5~1.5;

[0024] The simulated intestinal fluid was prepared by mixing intestinal electrolyte solution (SIF) and pancreatic enzyme (100 U / mL) at a volume ratio of 1:0.5~1.5, and adding 10 mmol / L bile. The pH value was kept stable with 1M HCl during digestion.

[0025] Preferably, the SGF comprises the following components: 6.9 mmol / L KCl, 0.9 mmol / L KH2PO4, 25 mmol / L NaHCO3, 47.2 mmol / L NaCl, 0.1 mmol / L MgCl2(H2O)6, 0.5 mmol / L (NH4)2CO3, and 15.6 mmol / L HCl;

[0026] The SIF comprises the following components: 6.8 mmol / L KCl, 0.8 mmol / L KH2PO4, 85 mmol / L NaHCO3, 38.4 mmol / L NaCl, 0.33 mmol / L MgCl2(H2O)6, and 8.4 mmol / L HCl.

[0027] Preferably, in S3, the volume ratio of the simulated gastric juice, simulated intestinal juice, and defatted sea cucumber flower homogenate is 1~2:10.

[0028] Preferably, in step S3, after adding simulated gastric fluid, the pH is adjusted to 2.0~5.0, and the reaction is carried out for 60~150 min at a temperature of 30~40℃; after adding simulated intestinal fluid, the pH is adjusted to 7.0~9.0, and the reaction is carried out for 60~120 min at a temperature of 35~38℃.

[0029] Preferably, in step S3, after the enzymatic hydrolysis is completed, the temperature is raised to 85-95℃ to inactivate the enzyme, centrifuged at 8000-10000 r / min for 5-15 min, and ultrafiltered to obtain a concentrated solution of sea cucumber flower lipid-lowering polypeptide.

[0030] Preferably, in step S4, the freeze-drying temperature is -75 to -55°C, and the freeze-drying time is 48 to 72 hours.

[0031] This invention also provides the application of the sea cucumber flower polypeptide as described above in the preparation of functional health products.

[0032] The present invention also provides the application of the sea cucumber flower polypeptide as described above in the preparation of health products with lipid-lowering effects.

[0033] Compared with the prior art, the present invention has the following advantages and technical effects:

[0034] This invention discloses a sea cucumber flower polypeptide with lipid-lowering effects, its preparation method, and its applications. This sea cucumber flower polypeptide exhibits significantly higher inhibition rates against cholesterol esterase and pancreatic lipase than components with larger molecular weights, and demonstrates stronger adsorption capacity for bile acids, effectively reducing the absorption of cholesterol and fat by the human body, resulting in outstanding lipid-lowering effects. Furthermore, this invention employs an in vitro simulated gastrointestinal digestion model for enzymatic hydrolysis, ensuring that the peptide fragments do not contain pepsin or trypsin cleavage sites, thus resisting secondary digestion and degradation after human ingestion, and stably maintaining structural integrity and biological activity. This solves the problem of traditional lipid-lowering peptides being easily digested and losing their activity.

[0035] This invention makes full use of sea cucumber processing byproducts, transforming resources with a protein content of up to 80% into high-value lipid-lowering peptides, realizing the comprehensive utilization of biological resources and providing high-quality raw materials for the field of functional foods and health products.

[0036] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0037] Figure 1 A statistical graph showing the inhibition rate of cholesterol esterase by the lipid-lowering polypeptide of sea cucumber flower provided in Example 1;

[0038] Figure 2 A statistical chart showing the adsorption rate of bile acids by the lipid-lowering polypeptide from sea cucumber flower provided in Example 1;

[0039] Figure 3 A statistical graph showing the inhibition rate of pancreatic lipase by the lipid-lowering polypeptide from sea cucumber flower provided in Example 1;

[0040] Figure 4 The structural formula of the sea cucumber flower lipid-lowering short peptide GTGATGTF provided in Example 1;

[0041] Figure 5 The structural formula of the sea cucumber flower lipid-lowering short peptide VDDEF provided in Example 1;

[0042] Figure 6 The structural formula of the sea cucumber flower lipid-lowering short peptide FTGIVGSL provided in Example 1;

[0043] Figure 7 The structural formula of the sea cucumber flower lipid-lowering short peptide VGITDIESF provided in Example 1;

[0044] Figure 8The structural formula of the sea cucumber flower lipid-lowering short peptide YDDVP provided in Example 1;

[0045] Figure 9 The structural formula of the sea cucumber flower lipid-lowering short peptide LAIGETEF provided in Example 1. Detailed Implementation

[0046] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0048] In this invention, unless otherwise specified, all other test materials and instruments are conventional test materials in the field and can be purchased through commercial channels.

[0049] In this invention, the gastric electrolyte solution (SGF) is prepared as follows: 6.9 mL of 6.9 mmol / L KCl, 0.9 mL of 0.9 mmol / L KH2PO4, 12.5 mL of 25 mmol / L NaHCO3, 11.8 mL of 47.2 mmol / L NaCl, 0.4 mL of 0.1 mmol / L MgCl2(H2O)6, 0.5 mL of 0.5 mmol / L (NH4)2CO3, and 1.3 mL of 15.6 mmol / L HCl are dissolved in 400 mL of distilled water to prepare SGF.

[0050] The semi-intestinal electrolyte solution (SIF) was prepared as follows: 6.8 mL of 6.8 mmol / L KCl, 0.8 mL of 0.8 mmol / L KH2PO4, 42.5 mL of 85 mmol / L NaHCO3, 9.6 mL of 38.4 mmol / L NaCl, 1.1 mL of 0.33 mmol / L MgCl2(H2O)6, and 0.7 mL of 8.4 mmol / L HCl were dissolved in 400 mL of distilled water to prepare SIF.

[0051] The simulated gastric juice was prepared by mixing SGF and pepsin (2000 U / mL) in a volume ratio of 1:1.

[0052] The simulated intestinal fluid was prepared by mixing SIF and pancreatic enzyme (100 U / mL) at a volume ratio of 1:1 and adding 10 mmol / L bile. The pH value was kept stable with 1M HCl during digestion.

[0053] Example 1

[0054] A method for preparing sea cucumber flower polypeptide with lipid-lowering effects includes the following steps:

[0055] S1. Dissolve the freeze-dried sea cucumber flower powder in ice water at a ratio of 1:40 and stir evenly to obtain a sea cucumber flower homogenate.

[0056] S2. Add a hexane-anhydrous ethanol mixture with a volume ratio of 2:1 to the sea cucumber flower homogenate obtained in step S1, extract at 50°C for 6 hours, remove the upper layer of oil, and obtain defatted sea cucumber flower homogenate.

[0057] S3. Simulated gastric juice was added to the defatted sea cucumber flower homogenate obtained in S2 to adjust the pH to 2.0. Enzymatic hydrolysis was carried out at 37℃ for 120 min. Simulated intestinal juice was then added to adjust the pH to 7.0, and enzymatic hydrolysis was carried out at 37℃ for 120 min. During digestion, 1M HCl was used to maintain a stable pH. After enzymatic hydrolysis, the temperature was raised to 90℃ to inactivate the enzyme, and the mixture was centrifuged at 8000 r / min for 15 min. The precipitate was discarded, and ultrafiltration was performed using 3000 Da and 1000 Da ultrafiltration membranes to obtain three different components of concentrated sea cucumber flower lipid-lowering polypeptides (component 1: polypeptides with a molecular weight below 1000 Da; component 2: polypeptides with a molecular weight between 1000 and 3000 Da; component 3: polypeptides with a molecular weight greater than 3000 Da).

[0058] S4. The concentrated sea cucumber flower lipid-lowering polypeptide obtained in S3 was freeze-dried at -55℃ for 72 hours to obtain sea cucumber flower lipid-lowering polypeptide.

[0059] Example 2

[0060] A method for preparing sea cucumber flower polypeptide with lipid-lowering effects includes the following steps:

[0061] S1. Dissolve the freeze-dried sea cucumber flower powder in ice water at a ratio of 1:35 and stir evenly to obtain a sea cucumber flower homogenate.

[0062] S2. Add a mixture of n-hexane and anhydrous ethanol at a volume ratio of 3:1 to the sea cucumber flower homogenate obtained in step S1, extract at 50°C for 4 hours, remove the upper layer of oil, and obtain defatted sea cucumber flower homogenate.

[0063] S3. Simulated gastric juice was added to the defatted sea cucumber flower homogenate obtained in S2 to adjust the pH to 3.0. Enzymatic hydrolysis was carried out at 30℃ for 60 min. Simulated intestinal juice was then added to adjust the pH to 8.0, and enzymatic hydrolysis was carried out at 35℃ for 60 min. During digestion, 1M HCl was used to maintain a stable pH. After enzymatic hydrolysis, the temperature was raised to 85℃ to inactivate the enzyme, and the mixture was centrifuged at 9000 r / min for 10 min. The precipitate was discarded, and ultrafiltration was performed using 3000 Da and 1000 Da ultrafiltration membranes to obtain three different components of concentrated sea cucumber flower lipid-lowering polypeptides (component 1: polypeptides with a molecular weight below 1000 Da; component 2: polypeptides with a molecular weight between 1000 and 3000 Da; component 3: polypeptides with a molecular weight greater than 3000 Da).

[0064] S4. The concentrated sea cucumber flower lipid-lowering polypeptide obtained in S3 was freeze-dried at -65℃ for 60h to obtain sea cucumber flower lipid-lowering polypeptide.

[0065] Example 3

[0066] A method for preparing sea cucumber flower polypeptide with lipid-lowering effects includes the following steps:

[0067] S1. Dissolve the freeze-dried sea cucumber flower powder in ice water at a ratio of 1:45 and stir evenly to obtain a sea cucumber flower homogenate.

[0068] S2. Add a mixture of n-hexane and anhydrous ethanol at a volume ratio of 4:1 to the sea cucumber flower homogenate obtained in step S1, extract at 50°C for 5 hours, remove the upper layer of oil, and obtain defatted sea cucumber flower homogenate.

[0069] S3. Simulated gastric juice was added to the defatted sea cucumber flower homogenate obtained in S2 to adjust the pH to 4.0. Enzymatic hydrolysis was carried out at 40℃ for 90 min. Simulated intestinal juice was then added to adjust the pH to 9.0, and enzymatic hydrolysis was carried out at 38℃ for 90 min. During digestion, 1M HCl was used to maintain a stable pH. After enzymatic hydrolysis, the temperature was raised to 95℃ to inactivate the enzyme. The mixture was centrifuged at 10000 r / min for 10 min, the precipitate was discarded, and ultrafiltration was performed using 3000 Da and 1000 Da ultrafiltration membranes to obtain three different components of concentrated sea cucumber flower lipid-lowering polypeptides (component 1: polypeptides with a molecular weight below 1000 Da; component 2: polypeptides with a molecular weight between 1000 and 3000 Da; component 3: polypeptides with a molecular weight greater than 3000 Da).

[0070] S4. The concentrated sea cucumber flower lipid-lowering polypeptide obtained in S3 was freeze-dried at -75℃ for 48 hours to obtain sea cucumber flower lipid-lowering polypeptide.

[0071] The efficacy of the sea cucumber flower lipid-lowering polypeptide prepared in Example 1 was verified through the following experiments.

[0072] 1. Based on the results of in vitro lipid-lowering experiments, the peptide component with a value less than 1000 Da was determined to have the best lipid-lowering effect.

[0073] The specific experimental protocol for in vitro lipid-lowering activity assay is as follows:

[0074] PNPB (4 mmol / L) was dissolved in acetonitrile beforehand and stored at -20°C. The polypeptide solution and cholesterol esterase were dissolved in ultrapure water. The reactions were carried out in phosphate buffer (0.1 mol / L, pH=7) containing sodium taurocholate (5.16 mmol / L) and NaCl (0.1 mol / L). PNPB was added to start the reaction, and the reaction was carried out at 25.0°C for 30 min. After standing for 3 min, the absorbance was measured at 405 nm.

[0075] ;

[0076] In the formula: A1 is the blank group; A2 is the blank control group; A3 is the sample group; A4 is the sample control group.

[0077] The three components obtained in Example 1 were subjected to control experiments, and the cholesterol esterase activity inhibition system is shown in Table 1.

[0078] Table 1 Cholesterol esterase activity inhibition system

[0079] ;

[0080] The results are as follows Figure 1 As shown.

[0081] Depend on Figure 1 It is known that polypeptides with a molecular weight below 1000 Da exhibit the highest inhibition rate against cholesterol lipase, indicating a good inhibitory effect on cholesterol lipase. This component is the sea cucumber flower lipid-lowering polypeptide. Cholesterol lipase is a crucial enzyme in the cholesterol esterification process. Cholesterol esters must be hydrolyzed into free cholesterol and then combine with other substances to form cholesterol micelles before they can be absorbed by the human body. Sea cucumber flower lipid-lowering polypeptide reduces the absorption of cholesterol by inhibiting the activity of cholesterol lipase, thereby lowering blood lipids and preventing the occurrence of hyperlipidemia.

[0082] The adsorption effect of the sea cucumber flower lipid-lowering polypeptide provided in Example 1 on bile acids was determined. The specific experimental scheme is as follows:

[0083] Different masses of polypeptide samples (1, 5, 10, 15, 20, 25 mg) were weighed and digested with 1 mL of 0.01 M HCl simulating normal human gastric temperature for 1 h. Then, 4 mL of 0.1 mM bile salt and 5 mL of porcine pancreatic enzyme (10 mg / mL) were added to each sample. The mixture was incubated at 37 °C with continuous shaking for 1 h, centrifuged at 4000 r / min, and the supernatant was collected after 40 min for the determination of unadsorbed bile acids. The determination method is as follows: 2.5 mL of supernatant was placed in a test tube, 7.5 mL of 60% H2SO4 was added, and the mixture was incubated in a 70 °C water bath for 25 min to allow for complete reaction. After cooling to room temperature, the absorbance was measured at 387 nm, with a buffer solution as a blank control. The adsorption rate of each bile acid was calculated according to the formula:

[0084] ;

[0085] In the formula: A0 is the control group (phosphate buffer instead of bile salt solution); A1 is the sample group; A 盐 This is the blank group (phosphate buffer solution is used instead of sample solution).

[0086] The three components obtained in Example 1 were subjected to control experiments, and the results are as follows: Figure 2 As shown.

[0087] Depend on Figure 2 It is known that polypeptides of different molecular weights all have a certain adsorption effect on bile acids, but polypeptides with a molecular weight below 1000 Da have the most significant adsorption effect on bile acids. Timely removal of bile salts from the body has a positive promoting effect on cholesterol breakdown, effectively preventing cholesterol accumulation in the body and exhibiting good lipid-lowering effects. Sea cucumber flower lipid-lowering polypeptides achieve a certain lipid-lowering effect by adsorbing and removing bile salts from the body.

[0088] The adsorption effect of the sea cucumber flower lipid-lowering polypeptide provided in Example 1 on pancreatic lipase was determined. The specific experimental scheme is as follows:

[0089] First, 4-nitrobenzene laurate was dissolved in 5 mmol / L sodium acetate solution (containing 1% Trition X-100) to prepare a 0.8 mg / mL 4-nitrobenzene laurate solution. Pancreatic lipase, PBS solution, polypeptide solutions of various concentrations, and 4-nitrobenzene laurate were added to 96-well plates, respectively. After reacting at 37°C for 30 min, the absorbance was measured at 405 nm, and the inhibition rate was calculated using the formula.

[0090] ;

[0091] In the formula, A1 is the positive control, A0 is the negative control, B1 is the experimental group, and B0 is the control group.

[0092] The three groups obtained in Example 1 were subjected to control experiments, and the pancreatic lipase activity inhibition system is shown in Table 2.

[0093] Table 2 Pancreatic lipase activity inhibition system

[0094] ;

[0095] The results are as follows Figure 3 As shown.

[0096] Depend on Figure 3 It is known that peptides with a molecular weight below 1000 Da exhibit the highest inhibition rate against pancreatic lipase, indicating that they have the best lipid-lowering effect. Pancreatic lipase (PL), produced by pancreatic acinar cells, is responsible for hydrolyzing dietary triglycerides into diacylglycerols, monoacylglycerols, glycerols, and fatty acid anions. Inhibiting the activity of pancreatic lipase can effectively reduce the absorption efficiency of fat in the small intestine, thereby achieving the purpose of lowering lipids.

[0097] The component with the best lipid-lowering effect was selected, and its polypeptide sequence was identified using UPLC-MS. The specific experimental protocol is as follows:

[0098] 1. Liquid Chromatography Conditions: The instrument was an ultra-high performance liquid chromatograph (UHPLC), with a C18 column. Mobile phase A consisted of double-distilled water containing 0.1% formic acid, and mobile phase B consisted of acetonitrile solution containing 0.1% formic acid. The flow rate was 0.5 mL / min, and the temperature was 40℃. The gradient conditions were as follows: 0-2.5 min: maintain 99% A solution and 1% B solution; 2.5-5 min: increase B solution from 1% to 5% and decrease A solution from 99% to 95%; 5-10 min: increase B solution from 5% to 10% and decrease A solution from 95% to 90%; 10-30 min: increase B solution from 10% to 25% and decrease A solution from 90% to 75%; 31-35 min: increase B solution from 25% to 40% and decrease A solution from 75% to 60%; 36-40 min:

[0099] 2. Mass spectrometry conditions: The mass spectrometer was a Thermo QE Orbitrap. The ion mode was ESI. + The mass range is 50-2000 m / z; the capillary voltage is 3.0 kV; the sampling cone voltage is 35.0 V; the ion source temperature is 105 °C; the desolventizing temperature is 350 °C; the cone gas flow rate is 50.0 L / h; the desolventizing gas flow rate is 600.0 L / Hr; the collision energy is 6.0 eV; the collision gas flow rate is 0.6 mL / min; the scan time is 0.26 sec; and the internal scan time is 0.02 sec.

[0100] The identified polypeptide sequences are: GTGATGTF, FTGIVGSL, LAIGETEF, VGITDIESF, VDDEF, YDDVP, and their structural formulas are as follows:Figures 4-9 As shown.

[0101] The amino acid sequence of the short peptide GTGATGTF is shown in SEQ ID NO:1;

[0102] SEQ ID NO: 1: Gly-Thr-Gly-Ala-Thr-Gly-Thr-Phe.

[0103] The amino acid sequence of the short peptide FTGIVGSL is shown in SEQ ID NO:2;

[0104] SEQ ID NO: 2: Phe-Thr-Gly-Ile-Val-Gly-Ser-Leu.

[0105] The amino acid sequence of the short peptide LAIGETEF is shown in SEQ ID NO:3;

[0106] SEQ ID NO: 3: Leu-Ala-Ile-Gly-Glu-Thr-Glu-Phe.

[0107] The amino acid sequence of the short peptide VGITDIESF is shown in SEQ ID NO:4;

[0108] SEQ ID NO: 4: Val-Gly-Ile-Thr-Asp-Ile-Glu-Ser-Phe.

[0109] The amino acid sequence of the short peptide VDDEF is shown in SEQ ID NO:5;

[0110] SEQ ID NO:5: Val-Asp-Asp-Glu-Phe.

[0111] The amino acid sequence of the short peptide YDDVP is shown in SEQ ID NO:6;

[0112] SEQ ID NO:6: Tyr-Asp-Asp-Val-Pro.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mixture of sea cucumber flower polypeptides with lipid-lowering effects, characterized in that, The mixture is prepared by a method comprising the following steps: S1. Dissolve the freeze-dried sea cucumber flower powder in ice water at a ratio of 1:40 and stir evenly to obtain a sea cucumber flower homogenate. S2. Add a hexane-anhydrous ethanol mixture with a volume ratio of 2:1 to the sea cucumber flower homogenate obtained in step S1, extract at 50°C for 6 hours, remove the upper layer of oil, and obtain defatted sea cucumber flower homogenate. S3. Add simulated gastric juice to the defatted sea cucumber flower homogenate obtained in S2, adjust the pH to 2.0, and enzymatically hydrolyze for 120 min at 37℃. Then add simulated intestinal juice to adjust the pH to 7.0, and enzymatically hydrolyze for 120 min at 37℃. During digestion, maintain the pH value stable with 1M HCl. After enzymatic hydrolysis, heat to 90℃ to inactivate the enzyme, centrifuge at 8000 r / min for 15 min, discard the precipitate, and perform ultrafiltration with 3000 Da and 1000 Da ultrafiltration membranes to separate peptides with a molecular weight of less than 1000 Da, obtaining a concentrated sea cucumber flower lipid-lowering peptide solution. S4. The concentrated sea cucumber flower lipid-lowering polypeptide obtained in S3 was freeze-dried at -55℃ for 72 hours to obtain sea cucumber flower lipid-lowering polypeptide. The mixture contains one or more of the short peptides GTGATGTF, FTGIVGSL, LAIGETEF, VGITDIESF, VDDEF, and YDDVP.

2. The application of the sea cucumber flower polypeptide mixture as described in claim 1 in the preparation of health products with auxiliary lipid-lowering effects.

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