Morroniside derivative with antioxidant activity and synthesis method thereof

Abstract

The invention belongs to the technical field of organic chemistry and organic compound synthesis, and particularly relates to a morroniside derivative with antioxidant activity and a synthesis method thereof. The morroniside derivative has a structure as shown in the specification, and is synthesized by taking morroniside and 3-bromobenzene sulfonyl chloride as raw materials, carrying out esterification reaction under the catalysis of a catalyst DMAP (Dimethylaminopyridine), and regulating and controlling reaction conditions. The synthesis method has the advantages of easily available raw materials, simple steps and high product purity, and is suitable for industrial production. Moreover, according to a DPPH free radical scavenging experiment, an ABTS free radical scavenging experiment, an iron ion reduction antioxidant capacity determination and a superoxide anion free radical scavenging experiment, the free radical scavenging capacity and the antioxidant capacity of the morroniside derivative are superior to those of morroniside, and the morroniside derivative can be deeply developed and applied in the fields of medicines, health care products and foods as a novel antioxidant. Good application prospects are realized. And # imgabs0 #.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemistry and organic compound synthesis, and particularly relates to a morroniside derivative with antioxidant activity and a synthesis method thereof. Background Art

[0002] The element oxygen is essential for human life, but in certain circumstances, it can also have harmful effects. Free radicals, known as reactive oxygen species (ROS), are generated by oxygen metabolism in the human body and have many biochemical activities at their physiological concentrations, such as cell growth, proliferation, and survival. However, excessive production of ROS and reactive nitrogen species (RNS) can lead to damage to DNA, cellular proteins, carbohydrates, and membrane lipids, ultimately leading to cell damage and death. The body's protection against this damage is achieved through endogenous antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) or non-enzymatic antioxidants (uric acid, bilirubin, lipoic acid, metallothioneins). Antioxidant components can interact with ROS / RNS and prevent free radical chain reactions, thereby delaying or blocking cell damage. When the balance between free radical generation and antioxidant defense is disturbed, this condition is known as oxidative stress (OS). Oxidative stress can lead to various pathological conditions, such as cancer, hypertension, neurological diseases, and diabetes. When the endogenous antioxidant system cannot protect the organism from ROS / RNS damage, it needs to be supplemented by exogenous antioxidants in diet, nutritional supplements or drugs.

[0003] Morroniside, also known as Morroniside, is one of the main active ingredients of the dried root bark of Sambucus williamsii Hance, a plant of the genus Sambucus linn in the family Caprifoliaceae. Modern pharmacological studies have confirmed that Morroniside has a wealth of pharmacological effects. Morroniside has antioxidant and anti-apoptotic protective effects on SH-SY5Y neurons; it can reduce the volume of cerebral infarction in rats with focal cerebral ischemia-reperfusion model; it enhances the antioxidant, anti-inflammatory and anti-apoptotic abilities of the cortex; it has anti-rabbit platelet aggregation effects and promotes osteoblast growth; it has effects on induced diabetes, etc. Antioxidant activity is a very important property of Morroniside, which makes Morroniside valuable in many fields, especially in traditional Chinese medicine preparations. Many diseases such as inflammation and tumors are closely related to oxidative stress. However, Morroniside has the disadvantages of rapid metabolism, short half-life and low bioavailability in its application, which limits its application. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a novel morroniside derivative with high purity and simple synthesis steps. Antioxidant experiments show that the derivative has higher antioxidant activity than morroniside, which is of great significance to the development of antioxidants in the fields of medicine, health products and food.

[0005] Specifically, the present invention is realized through the following technical solutions.

[0006] In a first aspect, the present invention provides a morroniside derivative having a chemical structural formula as shown below: .

[0007] In a second aspect, the present invention provides a method for synthesizing the above-mentioned morroniside derivatives, the method comprising the following steps: (1) Add a mixture of triethylamine and chloroform to a mixture of morroniside and a catalyst, mix well, add 3-bromobenzenesulfonyl chloride at low temperature, return to room temperature, and react for 8-12 hours to obtain a reaction solution containing morroniside derivatives. The synthetic route is as follows: ; (2) concentrating the reaction solution obtained in step (1) under reduced pressure to obtain a residue; (3) The residue obtained in step (2) was extracted with ethyl acetate and saturated sodium bicarbonate aqueous solution, and the extraction was repeated three times. The ethyl acetate layer was concentrated under reduced pressure and then purified by column chromatography using dichloromethane and methanol as eluents to obtain a white powder, i.e., a morroniside derivative.

[0008] In a preferred embodiment, in step (1).

[0009] The catalyst is DMAP, and the amount of the catalyst used is 1%-4% of the mass of the morroniside, preferably 2%-3%, and more preferably 2.5%.

[0010] The molar ratio of morroniside to 3-bromobenzenesulfonyl chloride is 1:1-2, preferably 1:1.5-2, and more preferably 1:1.8.

[0011] The volume ratio of triethylamine to chloroform is 1-3:5, preferably 1.5-2.5:5, and more preferably 2:5.

[0012] The low temperature is 0-5°C.

[0013] In a preferred embodiment, in step (3).

[0014] The volume ratio of dichloromethane to methanol is 15:1.

[0015] In a third aspect, the present invention provides a use of the morroniside derivative described in the first aspect in the preparation of an antioxidant.

[0016] In a preferred embodiment, the antioxidant is used in the fields of medicine, health care products and food.

[0017] Compared with the prior art, the present invention has the following beneficial effects.

[0018] The present invention utilizes morroniside and 3-bromobenzenesulfonyl chloride to react and synthesize a new compound, namely a morroniside derivative. Morroniside and 3-bromobenzenesulfonyl chloride are used as raw materials, and an esterification reaction is carried out under the catalysis of a catalyst DMAP, and a novel morroniside derivative is synthesized by regulating reaction conditions. The synthetic method has easy-to-obtain raw materials, simple steps, high product purity, and is suitable for industrial production. Moreover, it is found through DPPH free radical scavenging experiments, ABTS free radical scavenging experiments, iron ion reduction antioxidant capacity determination, and superoxide anion free radical scavenging experiments that the free radical scavenging capacity and antioxidant capacity of the morroniside derivative are both better than morroniside, and the morroniside derivative can be used as a new antioxidant for in-depth development and application in the fields of medicine, health products, and food, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0020] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of the morroniside derivative of the present invention.

[0021] Figure 2 The carbon nuclear magnetic resonance spectrum of the morroniside derivative of the present invention is shown in FIG.

[0022] Figure 3 Schematic diagram of the DPPH free radical scavenging ability of morroniside and its morroniside derivatives of the present invention.

[0023] Figure 4 Schematic diagram of the ABTS free radical scavenging ability of morroniside and its morroniside derivatives of the present invention.

[0024] Figure 5 Schematic diagram of the superoxide anion free radical scavenging ability of morroniside and its morroniside derivatives of the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below. The embodiments are given to better illustrate the contents of the present invention and are only used to explain the present invention, but should not be understood as limiting the present invention.

[0026] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0027] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are commercially available products unless otherwise specified. Example 1

[0028] The synthetic method of the morroniside derivative of the present invention: (1) Add a mixture of 2 mL of triethylamine and 5 mL of chloroform to a mixture of 1 g of morroniside and 25 mg of DMAP. After mixing evenly, add 1.133 mg of 3-bromobenzenesulfonyl chloride at a low temperature of 0 to 5°C, return to room temperature, and react for 10 hours to obtain a reaction solution containing morroniside derivatives. The synthetic route is as follows: ; (2) Concentrating the reaction solution obtained in step (1) under reduced pressure at a temperature of 40° C. and a vacuum degree of −0.07 MPa to obtain a residue; (3) The residue obtained in step (2) was extracted with ethyl acetate and saturated sodium bicarbonate aqueous solution, and the extraction was repeated 3 times. The ethyl acetate layer was concentrated under reduced pressure and then purified by column chromatography. V / V ) was used as the eluent for elution to obtain a white powder, i.e., a morroniside derivative, with a yield of 43.8%.

[0029] The physicochemical properties and structural identification of the morroniside derivatives of the present invention.

[0030] Morroniside derivatives are white powders, soluble in dichloromethane, dimethyl sulfoxide and methanol, but insoluble in water. The thin layer chromatography ratio is 0.5 (developing solvent is dichloromethane: methanol = 7:1); the nuclear magnetic resonance hydrogen spectrum of morroniside derivatives is as follows Figure 1 As shown, the carbon NMR spectrum is Figure 2 Compared with the NMR data of morroniside, it was confirmed that the reaction site was the primary hydroxyl group of the glycosidic bond.

[0031] The spectrum data are as follows: 1H NMR (600 MHz, MeOD) δ 8.11 (s, 1H), 7.94 (t, J = 7.8Hz, 2H), 7.69 – 7.61 (m, 1H), 7.53 (s, 1H), 5.84 – 5.70 (m, 1H), 4.81 (d, J= 7.9 Hz, 1H), 4.77 (d, J = 3.8 Hz, 1H), 4.45 (dd, J = 10.6, 2.0 Hz, 1H), 4.31 – 4.19 (m, 2H), 3.72 (s, 3H), 3.43 – 3.21 (m, 4H), 3.10 – 3.04 (m, 1H),2.01 – 1.89 (m, 1H), 1.84 – 1.78 (m, 1H), 1.48 (td, J = 13.5 Hz, 3.9Hz, 1H), 1.33 – 1.27 (m, 3H). 13 C NMR (151 MHz, MeOD) δ 168.64, 154.44, 139.15, 138.19,132.65, 131.59, 127.76, 123.98, 112.05, 100.19, 99.13, 96.00, 77.71, 75.23,74.67, 71.15, 71.02, 65.86, 51.74, 40.51, 33.64, 27.77, 19.62.HR-MS m / z calcdfor C 23 H 29 O 13 BrS [M+H] + 626.4360, found 626.4358. Purity: 98%.

[0032] Antioxidant experimental part of the morroniside derivatives of the present invention.

[0033] (1) DPPH free radical scavenging rate experiment Weigh 7.88 mg DPPH (1,1-diphenyl-2-trinitrophenylhydrazine) and dissolve it in 10 mL of anhydrous ethanol, and dilute it to an absorbance of 0.8. Weigh 3.2 mg of morroniside and morroniside derivative samples, respectively, and prepare them into 3.2 mg / mL with methanol, and dilute them into sample solutions of 1.6 mg / mL, 0.8 mg / mL, 0.4 mg / mL, and 0.2 mg / mL in sequence. Take 350 μL of samples of different concentrations, add 350 μL of DPPH solution, react in the dark for 30 minutes, and measure the absorbance at 517 nm with an enzyme reader. Repeat the measurement 3 times for each set of data, take the average value, and calculate the formula as follows: DPPH free radical scavenging rate (%) = [1-(A1-A2) / A0] × 100 A1: absorbance of samples with different concentrations and DPPH solution; A2: absorbance of samples with different concentrations and anhydrous ethanol; A0: absorbance of methanol and DPPH solution.

[0034] GraphPad Prism Version 8.0 (La Jolla, CA, USA) was used for statistical analysis and plotting. One-way analysis of variance (One-way ANOVA) was used for inter-group comparisons, and the IC was calculated using the Nonlinear Regression analysis method. 50 .

[0035] The DPPH free radical scavenging rate of the morroniside derivatives of the present invention is as follows: Figure 3 As shown, the calculated IC 50 As shown in Table 1.

[0036] (2) ABTS free radical scavenging experiment Weigh 38.4 mg ABTS (2,2-azino-di(3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt) and 13.4 mg K2S2O8 and dissolve them in 10 ml of anhydrous ethanol, mix well and react at 4 °C for 16 hours. After the reaction is completed, dilute to an absorbance of 0.8. Weigh 3.2 mg of morroniside and morroniside derivative samples, respectively, and prepare them into 3.2 mg / mL with methanol, and dilute them into sample solutions of 0.8 mg / mL, 0.2 mg / mL, 0.05 mg / mL, and 0.0125 mg / mL in sequence. Take 350 μL of samples of different concentrations, add 350 μL of ABTS solution, react in the dark for 6 minutes, and measure the absorbance at 734 nm with an enzyme reader. Repeat the measurement 3 times for each group of data, take the average value, and calculate the formula as follows: ABTS free radical scavenging rate (%) = [1-(A1-A2) / A0] × 100 A1: absorbance of samples with different concentrations and ABTS solution; A2: absorbance of samples with different concentrations and anhydrous ethanol; A0: absorbance of methanol and ABTS solution.

[0037] GraphPad Prism Version 8.0 (La Jolla, CA, USA) was used for statistical analysis and plotting. One-way analysis of variance (One-way ANOVA) was used for inter-group comparisons, and the IC was calculated using the Nonlinear Regression analysis method. 50 .

[0038] The ABTS free radical scavenging rate of the morroniside derivatives of the present invention is as follows: Figure 4 As shown, the calculated IC 50 As shown in Table 1.

[0039] (3) Determination of iron ion reducing antioxidant capacity Weigh 7.165 g Na2HPO4·12H2O and 12.48 g NaH2PO4·2H2O and dissolve them in 500 mL of water to prepare a buffer solution. Weigh 1 g potassium ferrocyanide and use 100 mL of buffer solution to prepare a 1% potassium ferrocyanide solution. Weigh 10 g trichloroacetic acid and add it to 100 mL of buffer solution to prepare a 10% trichloroacetic acid solution. Weigh 0.1 g ferric chloride and add it to 100 mL of buffer solution to prepare a 0.1% ferric chloride solution. Weigh 3.2 mg / mL methanol solutions of morroniside and morroniside derivatives. Take 1 mL of sample methanol solution and add 1 mL of 1% potassium ferricyanide solution, react at 50°C for 20 min, quench the reaction in ice water, add 1 mL of 10% trichloroacetic acid solution to the system after the reaction, shake and centrifuge (5000 r / min) for 5 min, and after centrifugation, draw 1.5 mL of supernatant into a new centrifuge tube, add 1.2 mL of water and 0.3 mL of 0.1% ferric chloride solution in turn, react at room temperature in the dark for 10 min, and measure the absorbance at 700 nm after the reaction. The greater the absorbance, the stronger the reducing ability. Each set of data was measured 3 times, and the average value was taken. The results are shown in Table 1.

[0040] (4) Superoxide anion free radical scavenging experiment Weigh 0.9692 g of tris(hydroxymethyl)aminomethane, add 0.4 mL of concentrated hydrochloric acid and appropriate amount of water to 500 mL to prepare Tris-HCL buffer solution. Weigh 36.57 mg of NADH (beta-nicotinamide adenine dinucleotide disodium salt hydrate), add Tris-HCL buffer solution to 100 mL to prepare NADH solution. Weigh 24.53 mg of NBT (nitro blue tetrazolium chloride), add Tris-HCL buffer solution to 100 mL to prepare NBT solution. Weigh 1.838 mg of PMS, add Tris-HCL buffer solution to 100 mL to prepare PMS (5-methylphenazine methyl sulfate) solution. Weigh 3.2 mg of morroniside and morroniside derivative samples respectively, prepare them into 3.2 mg / mL with methanol, and dilute them into 0.8 mg / mL, 0.2 mg / mL, 0.05 mg / mL, and 0.0125 mg / mL sample solutions in sequence.

[0041] Take 0.5 mL of samples of different concentrations and add 0.5 mL of NADH, NBT, and PMS solution, shake, and react at room temperature in the dark for 5 minutes. After the reaction, measure the absorbance at 560 nm. Repeat the measurement 3 times for each group of data, take the average value, and calculate the formula as follows: Superoxide anion radical scavenging rate (%) = [1-(A1-A2) / A0] × 100 A1: absorbance of samples with different concentrations and NADH, NBT, and PMS solutions; A2: absorbance of samples of different concentrations and Tris-HCL buffer solution, NBT, and PMS solution; A0: absorbance of methanol and NADH, NBT, and PMS solutions.

[0042] GraphPad Prism Version 8.0 (La Jolla, CA, USA) was used for statistical analysis and plotting. One-way analysis of variance (One-way ANOVA) was used for inter-group comparisons, and the IC was calculated using the Nonlinear Regression analysis method. 50 .

[0043] The superoxide anion free radical scavenging rate of the morroniside derivatives of the present invention is as follows: Figure 5 As shown, the calculated IC 50 As shown in Table 1.

[0044] (5) Experimental results .

[0045] From Table 1 and Figure 3 , Figure 4 , Figure 5 It can be seen that in the DPPH free radical scavenging experiment, the ABTS free radical scavenging experiment, the iron ion reduction antioxidant capacity determination and the superoxide anion free radical scavenging experiment, the antioxidant capacity and free radical scavenging capacity of the morroniside derivatives are stronger than that of morroniside, which shows that the morroniside derivatives of the present invention can be used as new antioxidants in the fields of medicine, health care products and food for further research and application, and have good application prospects.

[0046] Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A morroniside derivative, characterized in that The morroniside derivative has the chemical structural formula shown below: 。 2. The method for synthesizing the morroniside derivative according to claim 1, characterized in that: The method comprises the following steps: (1) Add a mixture of triethylamine and chloroform to a mixture of morroniside and a catalyst, mix well, add 3-bromobenzenesulfonyl chloride at low temperature, return to room temperature, and react for 8-12 hours to obtain a reaction solution containing morroniside derivatives. The synthetic route is as follows: ； (2) concentrating the reaction solution obtained in step (1) under reduced pressure to obtain a residue; (3) The residue obtained in step (2) was extracted with ethyl acetate and saturated sodium bicarbonate aqueous solution, and the extraction was repeated three times. The ethyl acetate layer was concentrated under reduced pressure and then purified by column chromatography using dichloromethane and methanol as eluents to obtain a white powder, i.e., a morroniside derivative.

3. The method for synthesizing a morroniside derivative according to claim 2, characterized in that: In step (1), the catalyst is DMAP, and the amount of the catalyst used is 1%-4% of the mass of the morroniside, preferably 2%-3%, and more preferably 2.5%.

4. The method for synthesizing a morroniside derivative according to claim 2, characterized in that: In step (1), the molar ratio of morroniside to 3-bromobenzenesulfonyl chloride is 1:1-2, preferably 1:1.5-2, and more preferably 1:1.

8.

5. The method for synthesizing a morroniside derivative according to claim 2, characterized in that: In step (1), the volume ratio of triethylamine to chloroform is 1-3:5, preferably 1.5-2.5:5, and more preferably 2:

5.

6. The method for synthesizing a morroniside derivative according to claim 2, characterized in that: In step (1), the volume ratio of 3-bromobenzenesulfonyl chloride to chloroform is 3:8-12, preferably 3:9-11, and more preferably 3:

10.

7. The method for synthesizing a morroniside derivative according to claim 2, characterized in that: In step (1), the low temperature is 0 to 5°C.

8. The method for synthesizing a morroniside derivative according to claim 2, characterized in that: In step (3), the volume ratio of dichloromethane to methanol is 15:

1.

9. Use of the morroniside derivative according to claim 1 in the preparation of antioxidants.

10. The use according to claim 9, characterized in that: The antioxidant is used in the fields of medicine, health care products and food.

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