Glucoside acid derivative as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of medicines, and discloses a glucoside acid derivative as well as a preparation method and application thereof. According to the method disclosed by the invention, a plurality of glycoside acid derivatives with novel structures are obtained by comprehensively applying a plurality of separation technologies and means by taking chrysosplenium nigrum seeds as a separation target. In-vitro experiments prove that the glycoside acid derivative provided by the invention has remarkable alpha-glucosidase or PTP1B inhibitory activity, can be used as an active ingredient of an anti-diabetic drug, and has wide application.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medicine, and relates to a glycoside acid derivative and a preparation method and application thereof. BACKGROUND

[0002] Cuscuta japonica Choisy, also known as Japanese dodder and large dodder, is a plant of the Cuscuta genus in the Convolvulaceae family. The seeds of Cuscuta japonica Choisy have the effects of nourishing liver and kidney, consolidating essence, preventing miscarriage, improving eyesight, and stopping diarrhea, and are commonly used for treating flaccid limbs, impotence and spermatorrhea, lumbago and soreness, tinnitus, and dizziness caused by deficiency of kidney qi. Modern pharmacological studies have shown that the seeds of Cuscuta japonica Choisy have biological activities such as anti-inflammatory and antioxidant, anti-aging, immune regulation, protection of the reproductive system, and anti-tumor.

[0003] Diabetes is an endocrine and metabolic disease mainly characterized by high blood sugar. Due to long-term high blood sugar, patients with diabetes will have chronic damage and even dysfunction of various tissues including eyes, heart, kidney, blood vessels, and nerves. Alpha-glucosidase inhibitors can reduce the hydrolysis of carbohydrates, delay the generation and absorption of glucose, and thus lower the postprandial blood glucose level, and are symptomatic treatment drugs for controlling postprandial blood glucose. Protein tyrosine phosphatase 1B (PTP1B) is a non-transmembrane protein tyrosine phosphatase, which plays a key negative regulatory role in the insulin signaling pathway. Therefore, PTP1B inhibitors can reduce or even reverse insulin resistance, which is of great significance for the treatment of patients with diabetes.

[0004] Resin glycosides are a class of novel compounds with complex structures, mainly distributed in plants of the Convolvulaceae family. Resin glycosides are mainly composed of three parts, including an oligosaccharide chain, an aglycone, and a modified fatty acid. The hydroxyl groups on the oligosaccharide chain are usually connected to the carboxyl terminal of the aglycone through an ester bond to form a 15-27-membered macrocycle. In recent years, it has been found that the carboxyl group of the aglycone of many resin glycosides does not form an ester bond with the oligosaccharide chain, but exists in a free or methyl ester state, and such resin glycosides are also called glycoside acid compounds. Studies have shown that glycoside acid compounds have various biological activities such as anti-tumor, anti-virus, anti-tumor migration, and reversal of tumor multidrug resistance.

[0005] Therefore, strengthening the research on the chemical components and biological activities of glycoside acid derivatives of the Convolvulaceae family has important scientific significance and application value for discovering lead structures of drugs. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a glycoside acid derivative and a preparation method and application thereof.

[0007] To solve the above problems, the technical solutions of the present application are as follows:

[0008] In a first aspect of the present application, a glycoside acid derivative is provided, which is a glycoside acid derivative having any one of the following structural formulae:

[0009]

[0010] In a second aspect of the present application, a preparation method of the above glycoside acid derivative is provided, which comprises the following steps of:

[0011] In some embodiments of the present application, the preparation method comprises the following steps:

[0012] S1. Extracting seeds of Ipomoea pes-caprae with a polar solvent to obtain an extract, vacuum-concentrating the extract, and then sequentially extracting the vacuum-concentrated extract with dichloromethane and n-butanol to obtain an n-butanol extract;

[0013] S2. Separating the n-butanol extract by silica gel column chromatography and gradient eluting with a dichloromethane-methanol two-phase system to obtain an enriched glycoside acid derivative;

[0014] S3. Purifying the enriched glycoside acid derivative by reverse-phase ODS column chromatography, gel chromatography, amino-silica gel column chromatography, and reverse-phase ODS column chromatography in sequence, collecting each component, and obtaining a target component;

[0015] S4. Purifying the target component by reverse-phase high-performance liquid chromatography to obtain the glycoside acid derivative.

[0016] In some embodiments of the present application, in step S1, the polar solvent is 95% ethanol aqueous solution.

[0017] In some embodiments of the present application, step S2 specifically comprises the following steps: separating the n-butanol extract by silica gel column chromatography and gradient eluting with a dichloromethane-methanol mixed solvent with a volume ratio of 10:1, 5:1, 2:1, and 1:1 to obtain four components Frs. 1-4, wherein component Fr. 3 is the enriched glycoside acid derivative.

[0018] In some embodiments of the present application, step S3 comprises the following steps:

[0019] S31. Purifying the enriched glycoside acid derivative by reverse-phase ODS column chromatography and sequentially eluting with a methanol-water mixed solvent with a volume ratio of 30:70, 50:50, 70:30, 80:20, and 100:0 to obtain five components Frs. 3.1-3.5;

[0020] S32. The component Fr.3.2 is subjected to gel column chromatography separation with pure methanol as elution solvent to obtain two components Fr.3.2.1-3.2.2;

[0021] S33. The component Fr.3.2.1 is subjected to amino-silica gel column chromatography separation with dichloromethane / methanol mixed solvents with volume ratio of 5:1, 2:1, 1:1 and 0:1 in sequence for gradient elution to obtain three components Fr.3.2.1.1-3.2.1.3;

[0022] S34. The component Fr.3.2.1.1 is subjected to reverse phase ODS column chromatography with methanol / water mixed solvents with volume ratio of 70:30, 80:20, 90:10 and 100:0 in sequence for elution to obtain seven components Fr.3.2.1.1.1-3.2.1.1.7, wherein the components Fr.3.2.1.1.1, Fr.3.2.1.1.2 and Fr.3.2.1.1.4 are target components.

[0023] In some embodiments of the present application, the conditions of the reverse phase high performance liquid chromatography purification include: using a YMC RP-C18 chromatographic column with a specification of 10x200mm, using methanol-water solution with a volume ratio of 70:30 as the mobile phase, and controlling the flow rate to be 3.0mL / min.

[0024] In a third aspect of the present application, the above-mentioned glycoside acid derivative is provided as an active ingredient in the preparation of an anti-diabetic drug.

[0025] In a fourth aspect of the present application, a pharmaceutical composition is provided, which comprises the above-mentioned glycoside acid derivative or a pharmaceutically acceptable salt thereof.

[0026] Compared with the prior art, the present application selects the seeds of Ipomoea nil, reflux extracts with ethanol, extracts with dichloromethane and n-butanol, and then subjects the n-butanol extract to various separation technologies and means such as silica gel, gel, amino-silica gel, reverse phase ODS and reverse phase high performance liquid chromatography to obtain glycoside acid derivatives which are all new compounds that have not been reported. Moreover, such glycoside acid derivatives with novel structures have significant α-glucosidase or PTP1B inhibitory activity, can be used as active ingredients of anti-diabetic drugs, and have wide application. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A hydrogen spectrum data graph of the compound I obtained in Example 1 of the present application;

[0028] Figure 2 A hydrogen spectrum data graph of the compound II obtained in Example 1 of the present application;

[0029] Figure 3 The hydrogen spectrum data chart of compound III obtained from Example 1 of the present application;

[0030] Figure 4 The hydrogen spectrum data chart of compound IV obtained from Example 1 of the present application;

[0031] Figure 5 The hydrogen spectrum data chart of compound V obtained from Example 1 of the present application;

[0032] Figure 6 The hydrogen spectrum data chart of compound VI obtained from Example 1 of the present application. DETAILED DESCRIPTION

[0033] In order to further illustrate the present application, the preparation method of the glycoside acid derivative in the Rauvolfia tetraphylla and the application thereof in preparing anti-diabetic drugs are described in detail below in combination with examples.

[0034] Example 1: Preparation of compounds

[0035] The Rauvolfia tetraphylla seeds are used in the present application to be extracted by refluxing with 95% ethanol, and the compounds of the present application are prepared through extraction, enrichment, separation and other steps. The Rauvolfia tetraphylla seeds are collected from Nanning, Guangxi.

[0036] 1) Extraction, extraction, enrichment and primary separation

[0037] The dried Rauvolfia tetraphylla seeds (10.0 kg) are crushed, 95% ethanol aqueous solution is added, and the extraction is performed by heating refluxing three times. The extraction liquid is combined and concentrated to obtain the total extract. The total extract is resuspended with water, and dichloromethane and n-butanol are used to extract three times in sequence to obtain the n-butanol extract.

[0038] 2) Silica gel column chromatography separation

[0039] The n-butanol extract (60 g) is subjected to silica gel column chromatography separation, and gradient elution is performed using dichloromethane / methanol mixed solvents. The elution solvents are dichloromethane / methanol with a volume ratio of 10:1, dichloromethane / methanol with a volume ratio of 5:1, dichloromethane / methanol with a volume ratio of 2:1, and dichloromethane / methanol with a volume ratio of 1:1 in sequence, and four components Frs. 1-4 are obtained in sequence.

[0040] 3) Reverse phase ODS column chromatography separation

[0041] The component Fr. 3 (24.3 g) is subjected to reverse phase ODS column chromatography separation, and elution is performed using methanol / water with a volume ratio of 30:70, methanol / water with a volume ratio of 50:50, methanol / water with a volume ratio of 70:30, methanol / water with a volume ratio of 80:20, methanol / water with a volume ratio of 90:10, and methanol / water with a volume ratio of 100:0 in sequence, and five components Frs. 3.1-3.5 are obtained.

[0042] 4) Gel column chromatography separation

[0043] Fr.3.2.1 was subjected to amino-silica gel column chromatography separation, and gradient elution was performed using dichloromethane / methanol mixed solvents, and the elution solvents were dichloromethane / methanol with a volume ratio of 5:1, dichloromethane / methanol with a volume ratio of 2:1, dichloromethane / methanol with a volume ratio of 1:1, and dichloromethane / methanol with a volume ratio of 0:1, respectively, to obtain three components Fr.3.2.1.1-3.2.1.3.

[0044] 5) Amino-silica gel column chromatography separation

[0045] Fr.3.2.1 was subjected to amino-silica gel column chromatography separation, and gradient elution was performed using dichloromethane / methanol mixed solvents, and the elution solvents were dichloromethane / methanol with a volume ratio of 5:1, dichloromethane / methanol with a volume ratio of 2:1, dichloromethane / methanol with a volume ratio of 1:1, and dichloromethane / methanol with a volume ratio of 0:1, respectively, to obtain three components Fr.3.2.1.1-3.2.1.3.

[0046] 6) Reverse phase ODS column chromatography separation

[0047] Fr.3.2.1.1 was subjected to reverse phase ODS column chromatography separation, and elution was performed using methanol / water with a volume ratio of 70:30, methanol / water with a volume ratio of 80:20, methanol / water with a volume ratio of 90:10, and methanol / water with a volume ratio of 100:0, respectively, to obtain seven components Frs.3.2.1.1.1-3.2.1.1.7.

[0048] 7) Reverse phase high performance liquid chromatography purification

[0049] Fr.3.2.1.1.1 was subjected to reverse phase high performance liquid chromatography purification. The preparation conditions were as follows: a YMC RP-C18 column (10×200 mm), methanol-water (70:30, V / V), a flow rate of 3.0 mL / min, and a detector of Shimadzu RID 10A. Compounds I and III were obtained by preparation, and the structures of compounds I and III were identified, and the results are shown in Figure 1 and 3 , respectively. Figure 1 is the hydrogen spectrum data graph of compound I, Figure 3 is the hydrogen spectrum data graph of compound III.

[0050] Fr.3.2.1.1.2 was subjected to reverse phase high performance liquid chromatography purification. The preparation conditions were as follows: a YMC RP-C18 column (10×200 mm), methanol-water (70:30, V / V), a flow rate of 3.0 mL / min, and a detector of Shimadzu RID 10A. Compounds II and IV were obtained by preparation, and the structures of compounds II and IV were identified, and the results are shown in Figure 2 and 4 , respectively. Figure 2 is the hydrogen spectrum data graph of compound II, Figure 4Figure 1 is a1H NMR spectrum of compound IV.

[0051] Component Fr. 3.2.1.1.4 was purified by reverse phase high performance liquid chromatography. The preparative conditions were: column YMC RP-C18 (10 x 200 mm), methanol-water (89:11, V / V), flow rate 3.0 mL / min, detector Shimadzu RID 10A, and compounds V and VI were obtained. Compounds V and VI were identified by structure, and the results are shown in Figure 5 and 6 Figure 5 Figure 1 is a1H NMR spectrum of compound IV. Figure 6 Figure 2 is a1H NMR spectrum of compound VI.

[0052] The spectroscopic data of compounds I-VI are shown below.

[0053] Compound I: optical rotation [a] 20 D -22.5 (c 0.03, MeOH); infrared spectrum main absorption peaks (KBr) v max 3429.16, 2930.18, 1632.86, 1067.34 cm -1 ; high resolution mass spectrum m / z 1033.5062 [M-H] - (calcd for C 46 H 81 O 25 1033.5067);1H and13C NMR data are shown in Table 1.

[0054] Compound II: optical rotation [a] 20 D -65.0 (c 0.04, MeOH); infrared spectrum main absorption peaks (KBr) v max 3441.07, 2931.92, 1630.15, 1083.79 cm -1 ; high resolution mass spectrum m / z 1071.5189 [M+Na] + (calcd for C 47 H 84 O 25 Na 1071.5199);1H and13C NMR data are shown in Table 1.

[0055] Compound III: optical rotation [a] 20 D -42.5 (c 0.04, MeOH); infrared spectrum main absorption peaks (KBr) v max 3431.26, 2933.22, 1628.07, 1062.75 cm -1 ​High resolution mass spectrum m / z 1057.5035 [M + Na] + (calcd for C 46 H 82 O 25 Na 1057.5043); NMR hydrogen and carbon spectral data are shown in Table 1.

[0056] Compound IV: [α] 20 D -26.8 (c 0.04, MeOH); infrared spectrum main absorption peaks (KBr) v max 3430.83, 2932.71, 1725.98, 1654.62, 1044.67 cm -1 High resolution mass spectrum m / z 1041.5096 [M + Na] + (calcd for C 46 H 82 O 24 Na 1041.5094); NMR hydrogen and carbon spectral data are shown in Table 1.

[0057] Compound V: [α] 20 D -25.0 (c 0.04, MeOH); infrared spectrum main absorption peaks (KBr) v max 3427.64, 2926.33, 1737.15, 1074.76 cm -1 High resolution mass spectrum m / z 1111.5515 [M + Na]+(calcd for C 50 H 88 O 25 Na 1111.5512); NMR hydrogen and carbon spectral data are shown in Table 2.

[0058] Compound VI: [α] 20 D -14.6 (c 0.06, MeOH); infrared spectrum main absorption peaks (KBr) v max 3430.23, 2926.22, 1742.94, 1074.16 cm -1 High resolution mass spectrum m / z 1011.4988 [M + Na]+(calcd for C 45 H 80 O 23 Na 1011.4988); NMR hydrogen and carbon spectral data are shown in Table 2.

[0059] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table 1. NMR hydrogen and carbon spectral data of compounds I-IVa

[0060] Table

[0061]

[0062] a Overlapped signals are reported without designating multiplicity; b Abbreviations: Glc=glucopyranosyl, Rha=rhamnopyranosyl, Fuc=fucopyranosyl, Ag=11-hydroxypentadecanoyl for I, III, and IV, and 11-hydroxyhexadecanoyl for II.

[0063] Table 2. 1H and 1C NMR data for compounds V and VI

[0064]

[0065]

[0066] a Overlapped signals are reported without designating multiplicity; b Abbreviations: Glc=glucopyranosyl, Rha=rhamnopyranosyl, Fuc=fucopyranosyl, Qui=quinovopyranosyl, Ag=12-hydroxyhexadecanoyl aglycone, Nla=3-hydroxy-2-methylbutanoyl.

[0067] The above results indicate that the structural formulas of the obtained compounds I-VI are chemical formulas I-VI, respectively.

[0068] Example 2: Assay of α-glucosidase inhibitory activity of compounds I-VI

[0069] 1) Experimental materials

[0070] Instruments and reagents: MD 384plus microplate reader, incubator, micropipette, 96-well cell culture plate, pH meter. α-D-glucosidase, 4-nitrobenzene-α-D-glucopyranoside (p-NPG), and genistein were purchased from Sigma-Aldrich; KH₂PO₄, K₂HPO₄, etc., were products of Guangzhou Chemical Reagent Factory; ultrapure water was used; other analytical grade reagents were products of Jiangsu Hanbang Technology Co., Ltd.

[0071] 2) Experimental methods

[0072] Add 140 μL of pH 6.8 phosphate buffer (0.2 M), 10 μL of α-glucosidase solution (0.5 U / mL), and 2 μL of sample solutions of different concentrations sequentially to a 96-well microplate, and incubate at 37°C for 10 minutes. Then add 48 μL of p-NPG solution (2 mM), react again for half an hour, and finally stop the reaction by adding 50 μL of Na2CO3 solution (0.1 M). Measure the absorbance of the reaction mixture over time at 405 nm. Each experiment was repeated three times. IC50 was used as the IC50 value. 50 The values ​​were taken as their average. Gentian isoflavone was used as a positive control.

[0073] Inhibition rate (%) = 100 × (A) control -A sample ) / A control

[0074] 3) Experimental Results

[0075] Based on the test results, the α-glycosidase inhibitory activity of the test samples was calculated, and the results are shown in Table 3.

[0076] Table 3. Screening results of α-glucosidase inhibitory activity of test samples

[0077]

[0078] a Percentage of inhibition measured at 100 μM concentration

[0079] b Concentration of inhibitor when 50% α-glucosidase is inactivated (mean ± SD of three independent experiments)

[0080] The results show that compounds I-IV and VI of the present invention possess significant α-glucosidase inhibitory activity. These results indicate that compounds I-IV and VI of the present invention can serve as active ingredients in antidiabetic drugs.

[0081] Example 3: PTP1B inhibitory activity test of compound I-VI

[0082] 1) Experimental materials

[0083] Instruments and reagents: MD 384plus microplate reader, incubator, micropipette, 96-well cell culture plate, pH meter. PTP1B recombinant protein was purchased from MCE; disodium p-nitrophenyl phosphate (p-NPP) and sodium chloride were purchased from JESK Biotechnology Co., Ltd.; ursolic acid was purchased from Maclean Biotechnology Co., Ltd.; citric acid and EDTA were purchased from Savill Biotechnology Co., Ltd.; DTT was a Biofroxx product; ultrapure water was used; other analytical grade reagents were products of Jiangsu Hanbang Technology Co., Ltd.

[0084] 2) Experimental methods

[0085] Add 140 μL of pH 6.0 citrate buffer (50 mM; containing 0.1 M NaCl, 2 mM EDTA, and 1 mM DTT), 10 μL of PTP1B (5 μg / mL), and 2 μL of sample solutions of different concentrations sequentially to a 96-well microplate, and incubate at 37°C for 10 minutes. Then add 48 μL of p-NPP solution (10 mM), react again for half an hour, and finally stop the reaction by adding 50 μL of NaOH solution (1 M). Measure the absorbance of the reaction mixture over time at 405 nm. Each experiment was repeated three times. IC50 was used. 50 The values ​​were taken as their average. Ursolic acid was used as a positive control.

[0086] Inhibition rate (%) = 100 × (A) control -A sample ) / A control

[0087] 3) Experimental Results

[0088] Based on the test results, the PTP1B inhibitory activity of the test samples was calculated, and the results are shown in Table 4.

[0089] Table 4. Screening results of PTP1B inhibitory activity of the tested samples

[0090]

[0091] a Percentage of inhibition measured at 100 μM concentration

[0092] b Concentration of inhibitor when 50% α-glucosidase is inactivated (mean ± SD of three independent experiments)

[0093] The results show that compounds III and V of the present invention have significant PTP1B inhibitory activity. These results indicate that compounds III and V of the present invention can serve as active ingredients in antidiabetic drugs.

[0094] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A glycosidic acid derivative, characterized in that, The glycosidic acid derivative is a compound having any of the following structural formulas:

2. A method for preparing the glycosidic acid derivative as described in claim 1, characterized in that, The preparation method is as follows: the glycosidic acid derivative is isolated from the seeds of *Gynostemma pentaphyllum*.

3. The preparation method according to claim 2, characterized in that, Includes the following steps: S1. Extract the seeds of *Gynostemma pentaphyllum* using a polar solvent to obtain an extract. The extract is then concentrated under vacuum and subsequently extracted with dichloromethane and n-butanol to obtain a n-butanol extract. S2. The n-butanol extract was separated by silica gel column chromatography and eluted with a gradient of dichloromethane-methanol two-phase system to obtain a concentrate of glycosidic acid derivatives; S3. The enriched glycosidic acid derivatives are purified sequentially by reversed-phase ODS column chromatography, gel chromatography, amino silica gel column chromatography and reversed-phase ODS column chromatography, and the components are collected and combined to obtain the target component; S4. The target component is purified by reversed-phase high-performance liquid chromatography to obtain the glycosidic acid derivative.

4. The preparation method according to claim 3, characterized in that, In step S1, the polar solvent is a 95% aqueous ethanol solution.

5. The preparation method according to claim 3, characterized in that, Step S2 specifically involves: separating the n-butanol extract by silica gel column chromatography, using a gradient elution with dichloromethane / methanol mixed solvents at volume ratios of 10:1, 5:1, 2:1, and 1:1 to obtain four fractions Frs.1-4, wherein fraction Fr.3 is an enrichment of glycosidic acid derivatives.

6. The preparation method according to claim 3, characterized in that, Step S3 includes the following steps: S31. The enriched glycosidic acid derivatives were subjected to reverse-phase ODS column chromatography, and eluted sequentially with methanol / water mixed solvents at volume ratios of 30:70, 50:50, 70:30, 80:20, and 100:0 to obtain five fractions Frs.3.1-3.

5. S32. The fraction Fr.3.2 was separated by gel column chromatography using pure methanol as the elution solvent to obtain two fractions Fr.3.2.1-3.2.2; S33. Fraction Fr.3.2.1 was separated by amino silica gel column chromatography, and gradient elution was performed sequentially with dichloromethane / methanol mixed solvents at volume ratios of 5:1, 2:1, 1:1 and 0:1 to obtain three fractions Fr.3.2.1.1-3.2.1.3; S34. Fraction Fr.3.2.1.1 was subjected to reversed-phase ODS column chromatography, and eluted sequentially with methanol / water mixed solvents at volume ratios of 70:30, 80:20, 90:10, and 100:0 to obtain seven fractions Frs.3.2.1.1.1-3.2.1.1.7, of which fractions Fr.3.2.1.1.1, Fr.3.2.1.1.2, and Fr.3.2.1.1.4 were the target fractions.

7. The preparation method according to claim 3, characterized in that, The conditions for purification by reversed-phase high-performance liquid chromatography are as follows: a YMC RP-C18 column with a specification of 10×200mm is used, a methanol-water solution with a volume ratio of 70:30 is used as the mobile phase, and the flow rate is controlled at 3.0mL / min.

8. The use of the glycosidic acid derivatives as described in claim 1 as an active ingredient in the preparation of antidiabetic drugs.

9. A pharmaceutical composition, characterized in that, The pharmaceutical composition comprises the glycosidic acid derivatives as described in claim 1 or a pharmaceutically acceptable salt thereof.

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