A method for preparing a cranberry anthocyanin acylated derivative
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JINAN UNIVERSITY
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-05
Smart Images
Figure CN122146819A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the multidisciplinary field of natural product isolation and purification and synthetic biology, and relates to a cranberry anthocyanin acylated derivative and its preparation method. Background Technology
[0002] Anthocyanins, as a natural edible pigment, are not only safe and non-toxic, but also possess vibrant colors, abundant resources, and various biological activities, showing great application potential in food, medicine, cosmetics, and other fields. However, their color is unstable and easily affected by factors such as temperature, pH, and light during processing. Furthermore, their low fat solubility makes them difficult to penetrate the phospholipid bilayer biomembrane, resulting in low bioavailability. To overcome the limitations of anthocyanin applications, researchers have developed numerous methods to improve anthocyanin stability, primarily through molecular co-coloring, structural modification, microencapsulation, and genetic engineering. In recent years, acylation has become an effective means of improving the stability and lipophilicity of anthocyanins. Currently, the main acylation methods for anthocyanins are chemical acylation and enzymatic acylation. While chemical acylation can improve the stability and lipophilicity of anthocyanins, it typically exhibits low regioselectivity and easily binds to or blocks the main active phenolic hydroxyl groups on the flavonoid parent, leading to a weakening or even loss of the original antioxidant activity of the flavonoid. Due to the poor stability of anthocyanin molecules, they are likely to be destroyed during chemical reactions. Furthermore, chemical acylation reactions are complex and cumbersome, usually requiring the preparation of an activated acyl donor before the acylation reaction. Enzymatic acylation, on the other hand, is carried out under mild reaction conditions, involves fewer steps, has a high conversion rate, allows for material recovery, and exhibits high regioselectivity. It can acylate hydroxyl groups at specific sites on flavonoids, offering greater advantages in acylation reactions. In recent years, significant progress has been made in the enzymatic acylation of anthocyanins. Li et al. (LiJ, GuoX, WangR, et al. Ultrasonic assisted extraction of anthocyanins from rose flower petal in des system and enzymatic acylation[J]. LWT, 2023, 180:114693.) isolated paeoniflorin-3,5-diglucoside from rose and acylated it with methyl benzoate using Candida antarctica lipase B catalysis. The resulting acylated product exhibited good light and heat stability and antioxidant activity. Cruz et al. (Cruz L, Guimarães M, Araujo P, et al. Malvidin 3-glucoside–fatty acid conjugates: From hydrophilic toward novel lipophilic derivatives[J]. Journal of Agricultural and Food Chemistry, 2017, 65(31): 6513-6518.) enzymatically acylated malvidin-3-glucoside with saturated fatty acids of different chain lengths. By measuring the octanol-water partition coefficient and hydrophobicity index of different derivatives, they confirmed that the lipophilicity increases with the increase of fatty acid chain length. For the enzymatic acylation modification of anthocyanins, most current studies focus on the acylation of single anthocyanin monomers, and studies on the acylation of mixed anthocyanins are very few. Summary of the Invention
[0003] The primary objective of this invention is to provide a method for preparing cranberry anthocyanin acylated derivatives. This method can efficiently synthesize high-purity cranberry anthocyanin acylated derivatives, and the prepared anthocyanins have better lipophilicity, stability, and antioxidant function.
[0004] The present invention discloses a method for preparing an anthocyanin acylated derivative of cranberry, comprising the following steps: A. Preparation of crude anthocyanin extract from cranberries; B. Dissolve the crude extract of cranberry anthocyanins in an organic alcohol, add fatty acid acyl donors and mix well, add lipase, and promote the catalytic reaction by constant temperature shaking. After the reaction, the acylation reaction solution of cranberry anthocyanins is obtained. C. The cranberry anthocyanin acylation reaction solution was separated and purified by liquid-liquid extraction and medium-pressure liquid chromatography, and then freeze-dried to obtain high-purity cranberry anthocyanin acylated derivatives.
[0005] According to a further feature of the preparation method of the present invention, step A includes: a. Fresh cranberries were homogenized with citric acid-acidified ethanol at a mass ratio of 1:10, and then extracted at 4 °C for 12 h to obtain cranberry anthocyanin extract; b. Filter the extract and remove the ethanol using a rotary evaporator at 37 °C; c. Extract the extract three times with an equal volume of ethyl acetate, collect the lower layer extract, and remove the ethyl acetate from the lower layer extract using a rotary evaporator at 37 °C. d. Cranberry extract was purified using macroporous adsorption resin D101, eluted with 80% ethanol, and the anthocyanin eluent was collected. e. Concentrate the cranberry anthocyanin eluent to remove ethanol, and freeze-dry for 48 h to obtain crude cranberry anthocyanin extract.
[0006] According to a further feature of the preparation method of the present invention, in step B, the crude extract of cranberry anthocyanins includes cyanidin-3-O-galactoside (C3Ga) and paeoniflorin-3-O-galactoside (Pn3Ga).
[0007] In a further feature of the preparation method according to the present invention, in step B, the organic alcohol is tert-amyl alcohol.
[0008] In a further feature of the preparation method according to the present invention, in step B, the fatty acid acyl donor is octanoic acid (OA).
[0009] According to a further feature of the preparation method of the present invention, in step B, the concentration of the lipase is 5-30 mg / mL (preferably 10 mg / mL), the molar ratio of crude anthocyanin extract to fatty acids is 1:100-500 (preferably 1:500), the reaction time is 12-48 h (preferably 24 h), and the reaction temperature is 40-60 °C (preferably 50 °C). The lipase may be Novozyme 435 or other lipases.
[0010] According to a further feature of the preparation method of the present invention, in step C, the liquid-liquid extraction includes: sequentially extracting the reaction solution with equal volumes of saturated sodium chloride solution and ethyl acetate, shaking thoroughly and allowing it to stand until complete separation, collecting the upper organic phase rich in anthocyanin acylated derivatives; combining the upper organic phases, concentrating under reduced pressure at 37 °C to remove the organic solvent, and collecting the concentrate.
[0011] According to a further feature of the preparation method of the present invention, in step C, the separation conditions of the medium-pressure liquid chromatography are as follows: a C18 spherical column (20-35 μm, 100 A, 120 g) is used, with 0.1% hydrochloric acid water as mobile phase A and acetonitrile as mobile phase B, the flow rate is 60 mL / min, the detection wavelength is set to 280 nm, and the monitoring wavelength is set to 520 nm; the elution gradient of the mobile phase is: 0-5 min, 6% B; 5-15 min, 6-20% B; 15-75 min, 20-30% B; 75-91 min, 100% B; 91-96 min, 100-6% B; 96-106 min, 6% B.
[0012] A second objective of this invention is to provide an anthocyanin acylated derivative of cranberry obtained using the preparation method described herein.
[0013] A further feature of the cranberry anthocyanin acylated derivatives according to the present invention is that the cranberry anthocyanin acylated derivatives include cyanidin-3-O-(6"-octanoyl)galactoside (C3Ga-OA) and paeoniflorin-3-O-(6"-octanoyl)galactoside (Pn3Ga-OA).
[0014] The cyanidin-3-O-(6"-octanoyl)galactoside and paeoniflorin-3-O-(6"-octanoyl)galactoside obtained by the preparation method described in this invention have a purity greater than 97%, significantly improved lipophilicity, thermal stability and photostability, and excellent antioxidant capacity in both aqueous and lipid systems. Attached Figure Description
[0015] Figure 1 This is the mass spectrum of the anthocyanin acylated derivative described in this application.
[0016] Figure 2 The NMR spectrum of cyanidin-3-O-(6"-octanoyl)galactoside (Pn3Ga-OA) described in this application.
[0017] Figure 3 The NMR spectrum of paeoniflorin-3-O-(6"-octanoyl)galactoside (C3Ga-OA) described in this application.
[0018] Figure 4 This is a thermal degradation curve of anthocyanins and anthocyanin acylated derivatives described in this application.
[0019] Figure 5 This is a photodegradation curve of anthocyanins and anthocyanin acylated derivatives described in this application.
[0020] Figure 6 Figures A and B show the DPPH radical scavenging rate and peroxide value of the anthocyanins and anthocyanin acylated derivatives described in this application, respectively. Detailed Implementation
[0021] The technical solutions in the embodiments of this application will be described more clearly below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0022] Example 1: Preparation of anthocyanin acylated derivatives from cranberries (1) Fresh cranberries were homogenized with citric acid-acidified ethanol at a mass ratio of 1:10, and then extracted at 4 °C for 12 h to obtain cranberry anthocyanin extract.
[0023] (2) Filter the extract and remove the ethanol by rotary evaporator at 37 °C.
[0024] (3) Extract the extract three times with an equal volume of ethyl acetate, collect the lower layer extract, and remove the ethyl acetate from the lower layer extract using a rotary evaporator at 37 °C.
[0025] (4) The cranberry extract was purified by macroporous adsorption resin D101, eluted with 80% ethanol, and the cranberry anthocyanin eluent was collected.
[0026] (5) The cranberry anthocyanin eluent was concentrated to remove ethanol and freeze-dried for 48 h to obtain crude cranberry anthocyanin extract.
[0027] (6) Dissolve the crude anthocyanin extract of cranberry obtained in step 5 in tert-amyl alcohol to obtain an anthocyanin solution. (7) Add octanoic acid to the anthocyanin solution obtained in step 6 at an anthocyanin / fatty acid molar ratio of 1:500 to obtain a reaction solution.
[0028] (8) Add Novozymes 435 (10 mg / mL) to the reaction solution obtained in step 7 to carry out the enzymatic acylation reaction. React at 50 °C for 24 h. After the reaction, filter to remove the enzyme to terminate the enzymatic reaction.
[0029] (9) In step 8, the reaction mixture was transferred to a separatory funnel and extracted sequentially with equal volumes of saturated sodium chloride solution and ethyl acetate. After thorough shaking, the mixture was allowed to stand until complete separation, and the upper organic phase rich in acylated anthocyanins was collected. The upper organic phases were combined and concentrated under reduced pressure at 37 °C to remove the organic solvent. A mixture of anthocyanin acylated derivatives was obtained.
[0030] (10) The anthocyanin acylated derivative mixture obtained in step 8 was separated and purified using a medium-pressure liquid chromatograph (AS-204PII, Agela). A C18 spherical column (20-35 μm, 100 A, 120 g) was used, with 0.1% hydrochloric acid water as mobile phase A and acetonitrile as mobile phase B. The flow rate was 60 mL / min, the detection wavelength was set to 280 nm, and the monitoring wavelength was set to 520 nm. The elution gradient was as follows: 0-5 min, 6% B; 5-15 min, 6-20% B; 15-75 min, 20-30% B; 75-91 min, 100% B; 91-96 min, 100-6% B; 96-106 min, 6% B. The eluents of the anthocyanin acylated derivatives were collected separately, concentrated under reduced pressure at 37°C to remove organic solvents, and freeze-dried to obtain the anthocyanin acylated derivatives, which were named cyanidin-3-O-(6"-octanoyl)galactoside (C3Ga-OA) and paeoniflorin-3-O-(6"-octanoyl)galactoside (Pn3Ga-OA).
[0031] Example 2: Purity analysis of the prepared anthocyanin acylated derivatives of cranberry The purity of the cranberry anthocyanin acylated derivatives prepared in Example 1 was analyzed using a high-performance liquid chromatography system equipped with a Venusil ASB C18 column (4.6 × 250 mm, 5 μm).
[0032] The analytical conditions were as follows: mobile phase A was 5% formic acid in water, and mobile phase B was 5% formic acid in acetonitrile. Column temperature: 40 ℃; detector: PDA UV detector; injection volume: 10 μL; the PDA detector monitored peaks at dual wavelengths (280 nm and 520 nm). Gradient elution was performed at a flow rate of 1.0 mL / min, with the following elution program: 0–5 min, 11% B; 5–25 min, 11–25% B; 25–40 min, 25–40% B; 40–45 min, 40–90% B; 45–50 min, 90% B; 50–55 min, 90–11% B; 55–60 min, 11% B.
[0033] Analysis results: Based on the comparison of the peak area of each compound at 280 nm wavelength with other impurity peaks in high performance liquid chromatography, the purity of both C3Ga-OA and Pn3Ga-OA is greater than 97%.
[0034] Example 3: Structural characterization of the prepared anthocyanin acylated derivatives of cranberry The structure of the cranberry anthocyanin acylated derivatives prepared in Example 1 was characterized using a high-resolution Q-TOF liquid chromatography-mass spectrometry (Agilgent, 1290Infinity II-6546, USA) and nuclear magnetic resonance spectroscopy (Bruker AVANCE-III, Switzerland).
[0035] The LC-MS / MS analysis conditions were as follows: Mobile phase A was 0.1% formic acid; mobile phase B was acetonitrile; gradient elution was performed at a flow rate of 0.2 mL / min, with the following elution program: 0–10 min, 5–20% B; 10–15 min, 20–30% B; 15–17 min, 30–50% B; 17–18 min, 50% B; 18–19 min, 50–10% B; 19–20 min, 10% B. The injection volume was 10 μL, the column temperature was 30 ℃, and the measurement wavelength was set at 520 nm. Mass spectrometry conditions: ESI ion emission source; positive ion mode; scan range: 50–1100 m / z; capillary voltage 4.0 kV; drying gas was nitrogen; drying gas temperature 320 ℃, flow rate 8.0 L / min; sheath gas temperature 350 ℃, flow rate 12 L / min.
[0036] Using deuterated methanol as solvent, 1D and 2D NMR experiments were performed at 600 MH. 1 H, 13 C, HSQC), to analyze the acylation sites of the cranberry anthocyanin acylated derivative prepared in Example 1.
[0037] Characterization results as follows Figure 1 As shown. Figure 1 In diagram A, the compound [M+H] + The ion peak is located at m / z 575, and the mother ion at m / z 575 produces an MS / MS spectrum of the daughter ion at m / z 287, verifying that the compound is C3Ga-OA; Figure 1 In diagram B, the compound [M+H] + The ion peak is located at m / z 589, and the parent ion at m / z 589 produces the MS / MS spectrum of the daughter ion at m / z 301, verifying that the compound is Pn3Ga-OA. The structure and acylation site of the acylated anthocyanin were determined based on NMR data, such as... Figure 2 and Figure 3 As shown, acylation leads to a lower field shift of the chemical shifts of the 6''aH and 6''bH of the galactoside, indicating that acylation occurs at the 6″-OH of the galactoside. Therefore, the acylated products were identified as cyanidin-3-O-(6"-octanoyl)galactoside and paeoniflorin-3-O-(6"-octanoyl)galactoside, respectively.
[0038] Example 4: Lipophilicity of the prepared cranberry anthocyanin acylated derivative By determining the n-octanol / water partition coefficient (log P The lipophilicity of C3Ga and Pn3Ga and their corresponding acylated derivatives was assessed, following a slight modification of the method described by Yang et al. (Process Biochem, 130). A 2% aqueous hydrochloric acid solution and n-octanol (1:3, v / v) were pre-saturated for at least 24 h. 1 mg of each of C3Ga, Pn3Ga, C3Ga-OA, and Pn3Ga-OA were dissolved in 1 ml of saturated n-octanol, and the absorbance at 520 nm was measured. A 0). Then add 1 ml of saturated acidified water, and place the mixture in a constant temperature shaker for 1 h. Finally, incubate the mixture at 4 °C for 2000 h. g Centrifuge for 10 min and measure the absorbance of the upper n-octanol solution at a wavelength of 520 nm. A x log P The value is calculated using the following formula: log P =log[ A x / ( A 0- A x (1).
[0039] Measurement results: logarithmic values of C3Ga and Pn3Ga PThe values were -0.55 and -0.42, respectively, indicating strong hydrophilicity. After acylation with octanoic acid, the log values of the two acylated anthocyanins were... P The values of all three were significantly increased, and the logarithm of C3Ga-OA was significantly increased. P When the value was increased to -0.24, the logP value of Pn3Ga-OA changed from negative to positive (0.09), indicating a significant increase in lipophilicity.
[0040] Example 5: Stability of the prepared anthocyanin acylated derivatives of cranberry A 10% DMSO aqueous solution was prepared using 0.01M hydrochloric acid (pH=2.1). Anthocyanin solutions of C3Ga, Pn3Ga, and their corresponding acylated derivatives were then prepared to a concentration of 300 μM using this solution. The thermal stability of these anthocyanin solutions was investigated in constant-temperature water baths at 65 ℃, 80 ℃, and 95 ℃. The absorbance at 520 nm was measured every 1 h using a UV-Vis spectrophotometer. At room temperature, the absorbance was measured using a spectrophotometer with an intensity of 28 μW / cm². 2 The anthocyanin solution was irradiated with ultraviolet light (253.7 nm) and incandescent light with an illuminance of 2000 lx, and the absorbance change at 520 nm was measured every 12 h. The degradation kinetics of the anthocyanins were analyzed using first-order reaction kinetics. The first-order reaction rate constant (… k ) and half-life ( t 1 / 2 It is calculated using the following formula: ln( C / C 0) = - k × t (2); t 1 / 2 = - ln(1 / 2) × k -1 (3); ln k = ln k 0- E a / RT (4).
[0041] In the formula, C 0 represents the initial anthocyanin concentration; C The anthocyanin concentration after t hours of heating or light treatment; k The degradation rate constant (h) -1 ); t 1 / 2 The degradation half-life of anthocyanins (h); k 0 is the frequency factor (h) -1 ); Ea Activation energy (kJ / mol); R The universal gas constant is 8.314 J / mol·K. T Kelvin represents absolute temperature.
[0042] Test results: The thermal degradation curves and parameters of C3Ga, Pn3Ga, and their corresponding acylated derivatives at 65, 80, and 95 °C are as follows: Figure 4 As shown in Table 1, the four anthocyanins degraded most slowly at 65℃ and fastest at 95℃. C3Ga-OA and Pn3Ga-OA exhibited lower rate constants and longer half-lives at the three different temperatures compared to their corresponding proanthocyanidins, indicating that the thermal stability of both C3Ga and Pn3Ga was improved after acylation.
[0043] Table 1. Thermal degradation parameters of C3Ga and Pn3Ga and their corresponding acylated derivatives
[0044] Degradation curves and parameters of C3Ga, Pn3Ga and their acylated derivatives under ultraviolet and incandescent light are as follows: Figure 5 As shown in Table 2, both acylated derivatives, C3Ga-OA and Pn3Ga-OA, exhibited lower rate constants and longer half-lives than the original anthocyanin under both UV and incandescent light, demonstrating superior stability. This indicates that acylation effectively enhances the photostability of anthocyanins. The improvement in photostability of anthocyanins by acylation was particularly significant under incandescent light, with the half-lives of the two acylated derivatives, C3Ga-OA and Pn3Ga-OA, being 3.62 times and 2.30 times that of their original anthocyanins, respectively. Under UV light, the half-lives of the two acylated derivatives, C3Ga-OA and Pn3Ga-OA, were 1.61 times and 1.02 times that of their original anthocyanins, respectively.
[0045] Table 2. Photodegradation parameters of C3Ga and Pn3Ga and their corresponding acylated derivatives
[0046] Example 6: Antioxidant capacity of the prepared cranberry anthocyanin acylated derivative The antioxidant capacity of C3Ga and Pn3Ga and their corresponding acylated derivatives in aqueous solution was determined using the 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical scavenging method, with slight modifications based on the method of Teng et al. (Foodchem, 372). A 0.2 mmol / L DPPH ethanol solution was prepared and stored at 4 °C in the dark. Sample solutions of C3Ga and Pn3Ga and their corresponding acylated derivatives at concentrations of 20, 40, 60, 80, and 100 μM were prepared for use. Equal volumes of DPPH ethanol solution and anthocyanin solutions of different concentrations were added to 96-well plates, mixed thoroughly, and incubated at room temperature in the dark for 30 min. The absorbance was measured at 517 nm using a multi-mode microplate reader. A 1. Replace the DPPH ethanol solution with an equal volume of anhydrous ethanol, and perform all other operations as before to eliminate the influence of the sample's own color, and then measure the absorbance. A 2. Replace the sample solution with an equal volume of anhydrous ethanol, and perform the same other operations to measure the absorbance. A 0. Vitamin E was used as a positive control, and each experiment was conducted in triplicate. The DPPH free radical scavenging rate was calculated using the following formula: [1 - ( A 1– A 2) / A 0]×100%(5).
[0047] The antioxidant capacity of C3Ga, Pn3Ga, and their corresponding acylated derivatives in lipid systems was determined using the Schaal oven method for oxidation induction experiments. 50 g of docosahexaenoic acid (DHA) was weighed into a 250 mL Erlenmeyer flask, and 10 mg of C3Ga, Pn3Ga, their corresponding acylated derivatives, and vitamin E (VE) were added. The mixture was dissolved by sonication and placed in a 180 ℃ drying oven for accelerated oxidation induction for 30 min. Then, it was placed in a 65 ± 2 ℃ forced-air drying oven, with shaking and repositioning every 12 h. The peroxide value of the lipids was measured periodically.
[0048] Results: The DPPH radical scavenging rate and peroxide value of C3Ga, Pn3Ga, and their corresponding acylated derivatives are as follows: Figure 6As shown in the figure, both acylated derivatives, C3Ga-OA and Pn3Ga-OA, exhibited slightly stronger scavenging abilities than their proanthocyanidins. At high concentrations (100 μM), the scavenging rates of DPPH free radicals by the two acylated derivatives reached 96.03% and 96.86%, respectively, demonstrating excellent antioxidant activity. Furthermore, their antioxidant capacity was significantly stronger than that of the control group, vitamin E. In the early stage of accelerated oxidation (0-6 days), the peroxide value of DHA in the two acylated derivative treatment groups increased slowly and significantly lower than that in the proanthocyanidin treatment group and the vitamin E control group, both demonstrating excellent antioxidant capacity. On day 12 of accelerated oxidation, the peroxide values of the blank group and the vitamin E-treated group reached 74.14 mmol / kg and 72.83 mmol / kg, respectively, while the peroxide values of DHA with added C3Ga-OA and Pn3Ga-OA were 39.98 mmol / kg and 45.97 mmol / kg, respectively. Acylated anthocyanins significantly reduced the peroxide content in DHA, played a protective role for DHA, and effectively delayed the oxidative rancidity of oils.
[0049] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. For those skilled in the art, any modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, based on the technical concept of this application, should fall within the protection scope defined by the claims of this application.
Claims
1. A method for preparing an anthocyanin acylated derivative of cranberry, characterized in that, Includes the following steps: A. Preparation of crude anthocyanin extract from cranberries; B. Dissolve the crude extract of cranberry anthocyanins in an organic alcohol, add fatty acid acyl donors and mix well, add lipase, and promote the catalytic reaction by constant temperature shaking. After the reaction, the acylation reaction solution of cranberry anthocyanins is obtained. C. The cranberry anthocyanin acylation reaction solution was separated and purified by liquid-liquid extraction and medium-pressure liquid chromatography, and then freeze-dried to obtain high-purity cranberry anthocyanin acylated derivatives.
2. The preparation method according to claim 1, characterized in that, Step A includes: a. Fresh cranberries were homogenized with citric acid-acidified ethanol at a mass ratio of 1:10, and then extracted at 4 °C for 12 h to obtain cranberry anthocyanin extract; b. Filter the extract and remove the ethanol using a rotary evaporator at 37 °C; c. Extract the extract three times with an equal volume of ethyl acetate, collect the lower layer extract, and remove the ethyl acetate from the lower layer extract using a rotary evaporator at 37 °C. d. Cranberry extract was purified using macroporous adsorption resin, eluted with 80% ethanol, and the anthocyanin eluent was collected. e. Concentrate the cranberry anthocyanin eluent to remove ethanol, and freeze-dry for 48 h to obtain crude cranberry anthocyanin extract.
3. The preparation method according to claim 1, characterized in that: In step B, the crude extract of cranberry anthocyanins includes cyanidin-3-O-galactoside (C3Ga) and paeoniflorin-3-O-galactoside (Pn3Ga).
4. The preparation method according to claim 1, characterized in that: In step B, the organic alcohol is tert-amyl alcohol.
5. The preparation method according to claim 1, characterized in that: In step B, the fatty acid acyl donor is octanoic acid.
6. The preparation method according to claim 1, characterized in that: In step B, the concentration of the lipase is 5-30 mg / mL, the molar ratio of anthocyanin crude extract to fatty acids is 1:100-500, the reaction time is 12-48 h, and the reaction temperature is 40-60 ℃.
7. The preparation method according to claim 1, characterized in that, In step C, the liquid-liquid extraction includes: sequentially extracting the reaction solution with equal volumes of saturated sodium chloride solution and ethyl acetate, shaking thoroughly, and allowing it to stand until complete separation, collecting the upper organic phase rich in anthocyanin acylated derivatives; combining the upper organic phases, concentrating under reduced pressure at 37 °C to remove the organic solvent, and collecting the concentrate.
8. The preparation method according to claim 1, characterized in that, In step C, the separation conditions for the medium-pressure liquid chromatography are as follows: A C18 spherical column (20-35 μm, 100 A, 120 g) was used, with 0.1% hydrochloric acid water as mobile phase A and acetonitrile as mobile phase B. The flow rate was 60 mL / min, the detection wavelength was set to 280 nm, and the monitoring wavelength was set to 520 nm. The elution gradient of the mobile phase was: 0-5 min, 6% B; 5-15 min, 6-20% B; 15-75 min, 20-30% B; 75-91 min, 100% B. 91-96 min, 100-6% B; 96-106 min, 6% B.
9. Cranberry anthocyanin acylated derivatives obtained by the preparation method according to any one of claims 1 to 8.
10. The cranberry anthocyanin acylated derivative according to claim 9, characterized in that: The cranberry anthocyanin acylated derivatives include cyanidin-3-O-(6"-octanoyl)galactoside and paeoniflorin-3-O-(6"-octanoyl)galactoside.