Loganin derivatives and preparation methods thereof and use thereof in preparing drugs for preventing or treating diabetes and diabetic complications

Abstract

The present invention belongs to the technical field of organic synthesis, and specifically relates to loganin derivatives and preparation methods thereof and applications in the preparation of drugs for preventing or treating diabetes and diabetic complications. The loganin derivatives provided by the present invention are derived from the natural product loganin, and have a structure shown in formula I, formula II-1 or formula II-2. Compared with loganin with great polarity, it has low polarity and good fat solubility, which is conducive to its absorption in the body. The loganin derivatives provided by the present invention have a significant inhibitory effect on the abnormal proliferation of HBZY-1 cells induced by high sugar at different concentrations; the SOD activity in HBZY-1 cells can be significantly increased and the content of MDA can be reduced. The loganin derivatives provided by the present invention have the characteristics of high efficiency and low toxicity. Therefore, the loganin derivatives with a structure shown in formula I or formula II provided by the present invention can be used in the preparation of drugs for preventing or treating diabetes and diabetic complications.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and specifically relates to loganin derivatives and preparation methods thereof, and applications thereof in preparing drugs for preventing or treating diabetes and diabetic complications. Background Art

[0002] Diabetes mellitus (DM) is a syndrome caused by insufficient secretion or utilization of insulin, which leads to disorders in sugar, fat and protein metabolism.

[0003] Diabetic nephropathy (DN) is one of the common complications of DM patients and the main cause of end-stage renal disease and death in DM patients. About 30-40% of DM patients will develop DN, and the incidence increases with the duration of the disease. The early clinical manifestations of DN are increased glomerular filtration rate, increased microalbumin in urine, increased plasma urea nitrogen and creatinine, and finally progress to chronic renal failure. The main pathological features of early DN are glomerular hypertrophy, thickening of glomerular and tubular basement membranes, and progressive accumulation of extracellular matrix in the mesangial region; the late stage is fibrosis of the glomeruli and tubular interstitium, and ultimately leads to proteinuria and renal failure.

[0004] At present, the treatment of DM is mainly based on hypoglycemia. One treatment method to prevent postprandial hyperglycemia is to delay the digestion and absorption of carbohydrates in the gastrointestinal tract by inhibiting enzymes (such as α-amylase and glucosidase). Since 1990, three α-glucosidase inhibitors have been known clinically, acarbose, voglibose and miglitol. The treatment of DN is mainly based on combined medication, which combines drugs that reduce blood sugar, blood pressure and blood lipids. It mainly delays the development of DN and cannot achieve a radical effect. At present, although hormones and cytotoxic drugs are used clinically to treat DN, although certain effects have been achieved, there are adverse reactions such as easy recurrence and easy hormone dependence. Angiotensin converting enzyme inhibitors (such as captopril, enalapril, etc.) have a therapeutic effect on DN; however, angiotensin converting enzyme inhibitors have large side effects and can cause symptoms such as hypotension, hyperkalemia, renal insufficiency, and cough. So far, there is no ideal treatment for DM and DN. Summary of the invention

[0005] The purpose of the present invention is to provide a loganin derivative and a preparation method thereof and use of the loganin derivative in the preparation of a medicament for preventing or treating diabetes and diabetic complications. The loganin derivative provided by the present invention is derived from the natural product loganin. Compared with loganin with high polarity, the loganin derivative has low polarity and good fat solubility, which is conducive to its absorption in the body and can prevent or treat diabetes and diabetic complications.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a loganin derivative having a structure shown in Formula I, Formula II-1 or Formula II-2:

[0008]

[0009] In formula I, R is hydrogen or C 1～3 Hydrocarbon; R 1 ~R 5 are independently hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl, 2',3'-dihydroxybenzoyl or β-pyranoglucopyranosyl; 1 ~R 5 are not hydrogen at the same time; when R is methyl, R 1 ~R 5 Not at the same time hydrogen;

[0010] R 2 When it is β-pyranose, R is methyl, and R 1 , R 3 , R 4 , R 5 is hydrogen;

[0011] R 2 When it is not β-pyranose, R 1 , R 2 , R 3 , R 4 , R 5 are independently hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl or 2',3'-dihydroxybenzoyl;

[0012] In Formula II-1 and Formula II-2, R 1' are independently hydrogen or C 1～3 Hydrocarbon; R 2' Independently for C 1～10 Saturated and unsaturated hydrocarbons, hydrogen, hydroxymethyl, hydroxyethyl, benzyl, R 3' are independently hydrogen, methyl, hydroxymethyl, R 4' are independently hydrogen, halogen, methoxy, hydroxy, benzyloxy or methyl.

[0013] Preferably, in Formula I, R is methyl; R 1 ~R 5 are independently hydrogen, β-glucopyranosyl, benzoyl, acetyl or 2',3'-dihydroxybenzoyl, and R 1 ~R 5 Not hydrogen at the same time.

[0014] Preferably, in Formula II-1 and Formula II-2, R 1' are independently methyl; R 2' are independently methyl, ethyl, propyl, benzyl, R 3' are independently hydrogen, methyl, hydroxymethyl,

[0015] Preferably, the loganin derivative has any one of formulas I-1 to I-7, formulas II-1-1 to II-1-4, and formula II-2-1:

[0016]

[0017] The present invention provides a method for preparing the loganin derivatives described in the above technical solution.

[0018] R 2 is β-pyranose, R is methyl, and R 1 , R 3 , R 4 , R 5 When is hydrogen, the loganin derivative has a structure shown in Formula I-1; the preparation method of the loganin derivative with the structure shown in Formula I-1 comprises the following steps: extracting the underground part of the plant of the genus Dipsacus of the family Dipsacus with a mixed solvent of alcohol and water, concentrating the obtained extract and dissolving it in water to obtain an extract solution; subjecting the extract solution to column chromatography separation to obtain the loganin derivative with the structure shown in Formula I-1; the column chromatography separation is eluted by an eluent, the eluent is a mixed solvent of methanol and water, and the volume ratio of methanol to water is (1-3):(7-9);

[0019] R 2 Not β-pyranose, R is hydrogen or C 1～3 Hydrocarbon; R 1 , R 2 , R 3 , R 4 , R 5 When independently being hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl or 2',3'-dihydroxybenzoyl, the preparation method of the loganin derivative of the structure shown in formula I comprises the following steps:

[0020] The compound of formula III, an acylation reaction reagent, an organic base and an organic solvent are mixed to undergo an acylation reaction to obtain the loganin derivative;

[0021]

[0022] The preparation method of the loganin derivative having the structure shown in formula II-1 or formula II-2 comprises the following steps:

[0023] The compound represented by the structure of formula IV, R 2′ -NH2, a reducing agent and an organic solvent are mixed to undergo a reductive amination reaction to obtain a loganin derivative having a structure shown in formula II-1 or formula II-2;

[0024]

[0025] Preferably, the method for preparing the compound of the structure shown in Formula IV comprises the following steps:

[0026] In a protective gas atmosphere, a compound of the structure shown in formula III, β-glucosidase and a citric acid-sodium citrate buffer solution are mixed to undergo an enzymatic hydrolysis reaction to obtain a compound of the structure shown in formula IV; the temperature of the enzymatic hydrolysis reaction is 10 to 45° C.; and the pH value of the enzymatic hydrolysis reaction is 4 to 6.

[0027] Preferably, the column chromatography separation obtains an eluate, and after the column chromatography separation, the eluate is purified to obtain a loganin derivative having a structure shown in Formula I-1; the purification is:

[0028] The eluate is purified by reverse phase column chromatography, silica gel column chromatography and gel column chromatography in sequence;

[0029] The eluent for the reverse phase column chromatography purification is a mixed solvent of water and methanol, and the volume ratio of water to methanol is 3:1; the eluent for the silica gel column chromatography purification is a mixed solvent of chloroform and methanol, and the volume ratio of chloroform to methanol is 5:1; the eluent for the gel column chromatography purification is methanol;

[0030] The acylation reagent includes an acyl halide compound or an acid anhydride;

[0031] When the acylation reaction reagent is an acyl halide compound, the organic base is triethylamine; when the acylation reaction reagent is an acid anhydride, the organic base is pyridine; the temperature of the acylation reaction is room temperature.

[0032] Preferably, the reducing agent is sodium cyanoborohydride; the temperature of the reductive amination reaction is 10 to 60° C., and the insulation time of the reductive amination reaction is 1 to 24 hours.

[0033] The present invention provides the use of the loganin derivatives described in the above technical solution or the loganin derivatives prepared by the preparation method described in the above technical solution in the preparation of drugs for preventing or treating diabetes and diabetic complications.

[0034] The present invention provides the use of loganin or loganinic acid in preparing a medicine for preventing or treating diabetes or diabetic complications.

[0035] The present invention provides a loganin derivative having a structure shown in Formula I, Formula II-1 or Formula II-2. The loganin derivative provided by the present invention is subjected to an anti-diabetic and diabetic nephropathy activity test, and the experimental results show that the inhibition rate of the loganin and its derivatives provided by the present invention on α-glucosidase is greater than 50%, and the IC 50 The value is less than the IC of the positive control acarbose 50 . It is explained that the loganin derivatives provided by the present invention have the effect of significantly inhibiting α-glucosidase. At the same time, the loganin and its derivatives provided by the present invention have a significant inhibitory effect on the abnormal proliferation of HBZY-1 cells induced by high sugar at different concentrations; and the loganin and its derivatives provided by the present invention can significantly increase the SOD activity in HBZY-1 cells and reduce the content of MDA. Specifically: the compound loganin acid, loganin, and loganin derivatives of the structure shown in formula II-1-1 are in the concentration range of 1 to 100 μmol / L, and the loganin derivatives of the structure shown in formula I-1 and the loganin derivatives of the structure shown in formula I-2 are in the concentration range of 10 to 100 μmol / L. The loganin and its derivatives provided by the present invention have the characteristics of high efficiency and low toxicity. Therefore, the loganin derivatives having the structure shown in formula I or formula II provided by the present invention can be used in the preparation of drugs for preventing or treating diabetes and diabetic complications.

[0036] The present invention provides a method for preparing the loganin derivatives described in the above technical solution. The preparation method provided by the present invention has a simple process and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The synthetic route of the loganin derivatives of the structure described in some formula I;

[0038] Figure 2 A synthetic route of a loganin derivative having a structure shown in formula II-1 or II-2;

[0039] Figure 3 The synthetic route of the loganin derivative of the structure described in formula II-1-1;

[0040] Figure 4 The synthetic route of the loganin derivatives of the structure described in formula II-1-2;

[0041] Figure 5 The synthetic route of the loganin derivative of the structure described in formula II-1-3;

[0042] Figure 6 The synthetic route of the loganin derivative of the structure described in formula II-1-4;

[0043] Figure 7 The synthetic route of the α-amino acid methyl ester of the structure described in Formula VI is as follows;

[0044] Figure 8 A synthetic route for loganin derivatives having the structure described in some formula II-1 or formula II-2;

[0045] Fig. 9 The synthetic route of the loganin derivatives with the structure shown in formula II-2-1;

[0046] Fig.10 The effects of different glucose concentrations and different culture times on HBZY-1 cells;

[0047] Fig.11 This is a bar graph showing the effects of loganin derivatives with different structures on the high glucose-induced HBZY-1 cell viability. DETAILED DESCRIPTION

[0048] The present invention provides a loganin derivative having a structure shown in Formula I, Formula II-1 or Formula II-2:

[0049]

[0050] In formula I, R is hydrogen or C 1～3 Hydrocarbon; R 1 ~R 5 are independently hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl, 2',3'-dihydroxybenzoyl or β-pyranoglucopyranosyl; 1 ~R 5 are not hydrogen at the same time; when R is methyl, R 1 ~R 5 Not at the same time hydrogen;

[0051] R 2 When it is β-pyranose, R is methyl, and R 1 , R 3 , R 4 , R 5 is hydrogen;

[0052] R 2 When it is not β-pyranose, R 1 , R 2 , R 3 , R 4 , R 5 are independently hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl or 2',3'-dihydroxybenzoyl;

[0053] In Formula II-1 and Formula II-2, R 1 ' are independently hydrogen or C 1～3 Hydrocarbon; R 2 'Independently for C 1～10 Saturated and unsaturated hydrocarbons, hydrogen, hydroxymethyl, hydroxyethyl, benzyl, R 3 ' are independently hydrogen, methyl, hydroxymethyl, R 4 ' is independently hydrogen, halogen, methoxy, hydroxy, benzyloxy or methyl.

[0054] In the present invention, in Formula I, R is methyl; R 1 ~R 5 are independently hydrogen, β-glucopyranosyl, benzoyl, acetyl or 2',3'-dihydroxybenzoyl, and R 1 ~R 5 Not hydrogen at the same time.

[0055] In the present invention, in Formula II-1 and Formula II-2, R 1' are independently methyl; R 2' are independently methyl, ethyl, propyl, benzyl, R 3' are independently hydrogen, methyl, hydroxymethyl,

[0056] In the present invention, the loganin derivative has any one of formulas I-1 to I-7, formulas II-1-1 to II-1-4, and formula II-2-1:

[0057]

[0058] The present invention provides a method for preparing the loganin derivatives described in the above technical solution.

[0059] R 2 is β-pyranose, R is methyl, and R 1 , R 3 , R 4 , R 5When is hydrogen, the loganin derivative has a structure shown in Formula I-1; the preparation method of the loganin derivative with the structure shown in Formula I-1 comprises the following steps: extracting the underground part of the plant of the genus Dipsacus of the family Dipsacus with a mixed solvent of alcohol and water, concentrating the obtained extract and dissolving it in water to obtain an extract solution; subjecting the extract solution to column chromatography separation to obtain the loganin derivative with the structure shown in Formula I-1; the column chromatography separation is eluted by an eluent, the eluent is a mixed solvent of methanol and water, and the volume ratio of methanol to water is (1-3):(7-9);

[0060] R 2 Not β-pyranose, R is hydrogen or C 1～3 Hydrocarbon; R 1 , R 2 , R 3 , R 4 , R 5 When independently being hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl or 2',3'-dihydroxybenzoyl, the preparation method of the loganic acid derivative comprises the following steps:

[0061] The compound of formula III, an acylation reaction reagent, an organic base and an organic solvent are mixed to undergo an acylation reaction to obtain the loganin derivative;

[0062]

[0063] When the loganin derivative has a structure shown in Formula II, the preparation method of the loganin derivative comprises the following steps:

[0064] The compound represented by the structure of formula IV, R 2′ -NH2, a reducing agent and an organic solvent are mixed to undergo a reductive amination reaction to obtain a loganin derivative having a structure shown in Formula II;

[0065]

[0066] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0067] In the present invention, the preparation method of the loganin derivative with the structure shown in formula I-1 comprises the following steps: extracting the underground part of the plant of the genus Dipsacus of the family Dipsacus with a mixed solvent of alcohol and water, concentrating the obtained extract and dissolving it in water to obtain an extract solution; subjecting the extract solution to column chromatography separation to obtain the loganin derivative with the structure shown in formula I-1; eluting the column chromatography separation is performed by using an eluent, the eluent is a mixed solvent of methanol and water, and the volume ratio of methanol to water is (1-3):(7-9).

[0068] In the present invention, the plant of the genus Dipsacus in the family Dipsacus asper is preferably Dipsacus asper or Dipsacus macrophylla.

[0069] In the present invention, the underground part of the plant of the genus Dipsacus in the family Dipsacus is preferably the underground root of the plant of the genus Dipsacus in the family Dipsacus.

[0070] In the present invention, the underground part of the plant of the genus Dipsacus in the family Dipsacus is preferably dried.

[0071] In the present invention, the alcohol-water mixed solvent is preferably a mixed solvent of ethanol and water, and the mass percentage of alcohol in the alcohol-water mixed solvent is preferably 95%.

[0072] The present invention has no special requirements on the mass ratio between the underground part of the Dipsacus plant of the Dipsacus family and the alcohol-water mixed solvent, and it only needs to be able to submerge the underground part of the Dipsacus plant of the Dipsacus family.

[0073] In the present invention, the number of extractions is preferably 3 times; the time for each extraction is preferably 24 hours. In the present invention, the concentration is preferably performed after combining the extracts obtained from each extraction.

[0074] In the present invention, the concentration obtains an extract, and the present invention has no special requirements on the mass ratio relationship between the extract and water.

[0075] In the present invention, the column chromatography separation is preferably carried out using a macroporous adsorption resin packed column. In the present invention, the elution is preferably gradient elution, and the gradient elution preferably includes sequentially performing a first gradient elution and a second gradient elution; the volume ratio of methanol to water during the first gradient elution is preferably 0:1; the second gradient elution obtains the loganin derivative of the structure shown in formula I-1; during the second gradient elution, the volume ratio of methanol to water is (1-3):(7-9), preferably (1.5-2.5):(7.5-8.5).

[0076] In the present invention, the column chromatography separation obtains an eluent, and after the column chromatography separation, the present invention preferably further comprises purifying the eluent to obtain a loganin derivative having a structure shown in formula I-1; the purification is preferably: the eluent is purified by reverse phase column chromatography, silica gel column chromatography and gel column chromatography in sequence; the reverse phase column chromatography purification preferably uses an ODS reverse phase column; the gel column chromatography purification preferably uses a Sephadex LH-20 gel column; the eluent for the reverse phase column chromatography purification is preferably a mixed solvent of water and methanol, and the volume ratio of water and methanol is preferably 3:1; the eluent for the silica gel column chromatography purification is preferably a mixed solvent of chloroform and methanol, and the volume ratio of chloroform and methanol is preferably 5:1; the eluent for the gel column chromatography purification is preferably methanol.

[0077] In the present invention, R 2 Not β-pyranose, R is hydrogen or C 1～3 Hydrocarbon; R 1 , R 3 , R 4 , R 5 When independently being hydrogen, acetyl, benzoyl, 2'-hydroxybenzoyl or 2',3'-dihydroxybenzoyl, the preparation method of the loganin derivative comprises the following steps:

[0078] The compound of the structure shown in formula III, an acylation reaction reagent, an organic base and an organic solvent (hereinafter referred to as the first organic solvent) are mixed (hereinafter referred to as the first mixture) to undergo an acylation reaction to obtain the loganin derivative.

[0079] In the present invention, the compound with the structure represented by formula III is preferably loganinic acid or loganin.

[0080] In the present invention, the acylation reaction reagent preferably includes an acyl halide compound or an acid anhydride; when the acylation reaction reagent is preferably an acyl halide compound, the organic base is preferably triethylamine; when the acylation reaction reagent is preferably an acid anhydride, the organic base is preferably pyridine; the temperature of the acylation reaction is preferably room temperature.

[0081] In the present invention, the first organic solvent is preferably tetrahydrofuran (THF). The present invention has no special requirements on the amount of THF used, as long as it can ensure that the acylation reaction proceeds smoothly.

[0082] In the present invention, the molar ratio of the compound of formula III to the acylation reagent is preferably 1:2. The molar ratio of the compound of formula III to the organic base is preferably 1:10.

[0083] In the present invention, the first mixing preferably comprises: dissolving the compound of structure represented by formula III in a first organic solvent to obtain an organic solution of the compound of structure represented by formula III; adding the organic base dropwise to the organic solution of the compound of structure represented by formula III to obtain a first mixed solution; and adding the acylation reaction reagent dropwise to the first mixed solution under ice-water bath conditions.

[0084] In the present invention, the acylation reaction is preferably carried out in a protective gas, and the protective gas is preferably nitrogen. The time of the acylation reaction is preferably 24±4h. The acylation reaction is preferably carried out under stirring. The present invention preferably uses TLC to monitor the acylation reaction.

[0085] In the present invention, the acylation reaction obtains an acylation reaction liquid, and the present invention preferably performs post-treatment on the acylation reaction liquid to obtain the loganin derivative. In the present invention, the post-treatment preferably includes: extracting the acylation reaction liquid after diluting it with water to obtain an extracted organic phase; drying the extracted organic phase and removing the solvent to obtain a solid product; purifying the solid product by column chromatography to obtain the loganin derivative. In the present invention, the extraction agent is preferably ethyl acetate, and the number of extractions is preferably 3 times. The drying agent is preferably dried with anhydrous Na2SO4. The specific implementation of the solvent removal is preferably reduced pressure distillation. The column chromatography purification is preferably carried out using a silica gel column.

[0086] In the present invention, when the loganin derivative is a structure shown in Formula II-1 or Formula II-2, the preparation method of the loganin derivative comprises the following steps:

[0087] The compound represented by the structure of formula IV, R 2′ -NH2, a reducing agent and an organic solvent (hereinafter referred to as the second organic solvent) are mixed (hereinafter referred to as the second mixture), and a reductive amination reaction occurs to obtain a loganin derivative with a structure shown in Formula II-1 or Formula II-2.

[0088] In the present invention, the method for preparing the compound of the structure shown in Formula IV preferably comprises the following steps:

[0089] In a protective gas atmosphere, a compound of the structure shown in formula III, β-glucosidase and a citric acid-sodium citrate buffer solution are mixed to undergo an enzymatic hydrolysis reaction to obtain a compound of the structure shown in formula IV; the temperature of the enzymatic hydrolysis reaction is 10 to 45° C.; and the pH value of the enzymatic hydrolysis reaction is 4 to 6.

[0090] The present invention has no special requirements for the amount of the β-glucosidase, and the compound of the structure shown in formula III can be completely enzymatically hydrolyzed. In the present invention, the temperature of the enzymatic hydrolysis reaction is preferably 45°C, the pH value of the enzymatic hydrolysis reaction is preferably 6; the insulation time of the enzymatic hydrolysis reaction is preferably 24 to 48 hours. In the present invention, the protective gas is preferably nitrogen.

[0091] In the present invention, the R 2′ When -NH2 is preferably an α-amino acid methyl ester of the structure shown in Formula VI, the preparation method of the α-amino acid methyl ester of the structure shown in Formula VI preferably includes the following steps: mixing the α-amino acid of the structure shown in Formula V and SOCl2-CH3OH solution to undergo a methylation reaction to obtain the α-amino acid methyl ester of the structure shown in Formula VI.

[0092]

[0093] In the present invention, the methylation reaction preferably includes: performing a first methylation reaction and a second methylation reaction in sequence; the first methylation reaction is preferably: the α-amino acid of the structure shown in formula V and the first SOCl2-CH3OH solution are mixed to undergo a first methylation reaction, and the obtained first methylation reaction liquid is dried for the first time to obtain a solid product. The second methylation reaction is preferably: the solid product is mixed with a second SOCl2-CH3OH solution to undergo a second methylation reaction, and the obtained second methylation reaction liquid is dried for the second time to obtain an α-amino acid methyl ester of the structure shown in formula VI. The molar concentration of the first SOCl2-CH3OH solution is preferably 1 mol / L; the mass ratio of the α-amino acid of the structure shown in formula V to the first SOCl2-CH3OH solution is preferably 1:1; the first methylation reaction is preferably carried out under heating reflux conditions, and the insulation time of the first methylation reaction is preferably 1h; the first drying is preferably rotary evaporation, and the present invention has no special requirements for the specific implementation process of the rotary evaporation. The molar concentration of the second SOCl2-CH3OH solution is preferably 2 mol / L; the mass ratio of the solid product to the second SOCl2-CH3OH solution is preferably 1:2; the second methylation reaction is preferably carried out under heating reflux conditions, and the insulation time of the second methylation reaction is preferably 1 h; the second drying is preferably rotary evaporation, and the present invention has no special requirements for the specific implementation process of the rotary evaporation.

[0094] In the present invention, the compound of formula IV and R 2′ The molar ratio of -NH2 is preferably 1:1 to 1.5.

[0095] In the present invention, the second organic solvent is preferably an alcohol solvent or dichloromethane. The present invention has no special requirements on the amount of the second organic solvent, as long as it can ensure that the reductive amination reaction proceeds smoothly.

[0096] In the present invention, the reducing agent is sodium cyanoborohydride; the molar ratio of the compound of the structure shown in formula IV to the reducing agent is preferably 1:1-3.

[0097] In the present invention, the second mixing is preferably: mixing the compound represented by formula IV and a reducing agent to obtain a mixture; mixing the mixture, a second organic solvent and R 2′ -NH2 mixed.

[0098] In the present invention, the temperature of the reductive amination reaction is 10 to 60° C., more preferably 45° C.; the holding time of the reductive amination reaction is 1 to 24 hours. The reductive amination reaction is preferably monitored by TLC. The reductive amination reaction is preferably carried out under stirring, and the present invention has no special requirements for the specific implementation process of the stirring.

[0099] In the present invention, after the reductive amination reaction is completed, a reductive amination reaction liquid is obtained. In the present invention, the reductive amination reaction liquid is preferably post-treated to obtain the loganin derivative. In the present invention, the post-treatment preferably includes: extracting the reductive amination reaction liquid after diluting it with water to obtain an extracted organic phase; drying the extracted organic phase and removing the solvent to obtain a solid product; purifying the solid product by column chromatography to obtain the loganin derivative. In the present invention, the extraction agent is preferably ethyl acetate, and the number of extractions is preferably 3 times. The drying reagent is preferably dried with anhydrous Na2SO4. The specific implementation of the solvent removal is preferably reduced pressure distillation. The column chromatography purification is preferably carried out using a silica gel column, and the eluent used in the column chromatography purification is preferably a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio of the petroleum ether to ethyl acetate is preferably (1 to 5): 1.

[0100] The present invention provides the use of the loganin derivatives described in the above technical solution or the loganin derivatives prepared by the preparation method described in the above technical solution in the preparation of drugs for preventing or treating diabetes and diabetic complications.

[0101] The present invention provides the use of loganin or loganinic acid in preparing a medicine for preventing or treating diabetes or diabetic complications.

[0102] In the present invention, the diabetic complication is preferably diabetic nephropathy.

[0103] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0104] Example 1

[0105] 3 kg of underground dried roots of the plant Dipsacus spp. of the Dipsacus spp. family were taken and crushed, extracted three times with a mixed solvent of ethanol and water with an ethanol mass percentage of 95% at room temperature, each time for 24 hours, and the extracts were combined and concentrated into an extract. The extract is dissolved in water, and separated by macroporous adsorption resin column chromatography under gradient elution conditions using methanol and water as eluents, wherein the gradient elution is: a first gradient elution and a second gradient elution are performed in sequence, wherein the volume ratio of methanol to water in the first gradient elution is 0:1, and the volume ratio of methanol to water in the second gradient elution is (1-3):(9-7); the eluate obtained by the second elution is purified by ODS reverse phase column chromatography in sequence, wherein the eluent during purification is a mixed solvent of water and methanol, and the volume ratio of water to methanol is 3:1; the eluent is purified by silica gel column chromatography, wherein the eluent during purification is a mixed solvent of chloroform and methanol, and the volume ratio of chloroform to methanol is 5:1; the eluent is purified by Sephadex LH-20 gel column chromatography, wherein the eluent during purification is methanol, and a loganin derivative (20 mg) having a structure shown in formula I-1 is purified.

[0106] Loganin derivatives with the structure shown in formula I-1: 3′-O-β-pyranose loganin, white needle-shaped crystals; C 23 H 36 O 15 ; HRESI-MS m / z 551.1983[MH] － (Calculated value is 551.1991). IR(KBr)cm -1 :3363,2925,2860,1629,1452,1378,1074,1032; UVλ max (MeOH): 232 nm; 1 H NMR (400MHz, MeOD) δ: 5.22 (d, J = 8.0 Hz, 1H, H-1), 7.34 (d, J = 1.2 Hz, 1H, H-3), 3.05 (m, 1H, H-5), 2.18(ddd,J=14.0,7.9,1.6Hz,1H,H-6a),1.56(ddd,J=14.0,7.6,5.0Hz,1H,H-6b),3.99(td,J =4.8,1.4Hz,1H,H-7),1.81(ddd,J=9.4,6.9,4.6Hz,1H,H-8),1.98(td,J=9.2,4.4Hz,1H,H-9) ,1.04(d,J=6.9Hz,3H,-CH3),3.64(s,3H,-OCH3),4.66(d,J=8.0Hz,1H,H-1′),3.39(m,1H,H-2′ ),3.53(t,J=8.7Hz,1H,H-3′),3.23(m,1H,H-4′),3.28(d,J=3.3Hz,1H,H-5′),3.59(dt,J=11. 9,6.0Hz,1H,H-6a′),3.84(ddd,J=11.9,8.5,2.1Hz,1H,H-6b′),4.53(d,J=7.7Hz,1H,H-1″),3 .26(dd,J=2.8,1.3Hz,1H,H-2″),3.37(d,J=3.1Hz,1H,H-3″),3.40(d,J=1.7Hz,1H,H-4″),3.3 1(m,1H,H-5″),3.59(dt,J=11.9,6.0Hz,1H,H-6a″),3.84(ddd,J=11.9,8.5,2.1Hz,1H,H-6b″); 13C NMR (100MHz, CD3OD) δ: 97.69 (C-1), 152.07 (C-3), 113.96 (C-4), 32.08 (C-5), 42.62 (C -6),75.00(C-7),42.09(C-8),46.35(C-9),169.46(C=O),13.44(-CH3),51.71(-OCH3) ,99.62(C-1′),74.02(C-2′),87.40(C-3′),71.43(C-4′),77.89(C-5′),62.57(C-6′), 105.07(C-1″), 75.38(C-2″), 77.64(C-3″), 69.91(C-4″), 78.02(C-5″), 62.54(C-6″).

[0107] Example 2

[0108] Weigh 500 mg (4.097 mmol) of benzoic acid into a round-bottom flask, add 5 drops of dry DMF as a catalyst, slowly and uniformly add 893 μL (12.2914 mmol) of SOCl2 under constant pressure and ice bath conditions, stir to make it fully miscible, then warm to room temperature and stir for 1.5 hours, and reflux for 4 hours. After the reflux is completed, the excess SOCl2 is drained under reduced pressure and dried to obtain a yellow oily substance, which is benzoyl chloride, 558 mg, and the yield is: 97.3%.

[0109] according to Figure 1 The synthetic route shown is as follows: weigh 150 mg (0.3845 mmol) of loganin into a round-bottom flask, add 2 mL of THF to dissolve, and add 534 μL (3.845 mmol) of triethylamine. After the addition is complete, slowly and uniformly add 107.06 mg (0.7689 mmol) of benzoyl chloride under ice-water bath conditions, and stir at room temperature for 24 ± 4 hours under N2 protection. After the TLC monitoring of the generated spots stabilizes, the reaction solution is transferred to a separatory funnel with water, extracted with ethyl acetate three times, the organic phases are combined, dried over anhydrous Na2SO4, and the solvent is evaporated under reduced pressure. The residue is chromatographed on a silica gel column, and the eluent is V 石油醚 :V 乙酸乙酯 =1:1 purification to obtain the loganin derivative (99.2 mg, yield: 52%) of the structure shown in formula I-2, eluent: V 石油醚 :V 乙酸乙酯 =2:1 purification to obtain the loganin derivative of the structure shown in formula I-3 (40 mg, yield: 17.2%), eluent: V 石油醚 :V 乙酸乙酯 =3:1 purification to obtain a loganin derivative with the structure shown in formula I-4 (45.9 mg, yield 14.8%).

[0110] Loganin derivatives with the structure shown in formula I-2: 6′-benzoyl loganin, white powder; molecular formula C 24 H 30 O 11 ; HRESI-MS m / z 517.1684[M+Na] + (Calculated value is 517.1680); UVλ max (MeOH) 230nm; IR (KBr) cm -1 : 3432, 2976, 2933, 2749, 2674, 2496, 2370, 1497, and 1024; 1 H-NMR(400MHz,CD3OD)δ:8.05–8.01(m,2H),7.67–7.61(m,1H),7.53–7.47(m,2H),7.39(d,J=1.3Hz,1H ),4.99(d,J=5.6Hz,1H),4.71(d,J=7.9Hz,1H),4.67(d,J=2.4Hz,1H),4.54(dd,J=11.8,6.8Hz,1H),3.9 3–3.88(m,1H),3.69(s,4H),3.45(dd,J=8.2,6.5Hz,2H),3.28(s,1H),3.10–3.02(m,1H),2.21–2.12(m, 1H),1.92–1.85(m,1H),1.76(ddd,J=8.9,7.0,4.9Hz,1H),1.29(d,J=5.0Hz,1H),0.96(d,J=6.9Hz,3H); 13 C-NMR(100MHz,CD3OD)δ:169.32,167.65,152.36,134.43,131.21,130.48,130.48,129.68,129.68,111. 56,100.44,98.63,77.86,75.45,74.69,74.66,71.97,64.90,51.73,46.15,42.90,42.40,32.66,13.70.

[0111] Loganin derivatives with the structure shown in formula I-3: 3′,6′-dibenzoyl loganin, white powder; molecular formula C 31 H 34 O 12 ; HRESI-MS m / z 621.1936[M+Na] +(Calculated value is 621.1942); UVλ max (MeOH) 229nm; IR (KBr) cm -1 : 3438, 2951, 2357, 1719, 1276, 1093 and 714; 1 H-NMR(400MHz,CD3OD)δ:8.07–8.04(m,2H),8.03–7.99(m,2H),7.60–7.54(m,2H),7.45(td,J=7.8,7.4,1.7Hz,4H),7.35(d,J=1.3Hz,1H),5. 24(t,J=9.3Hz,1H),5.01(d,J=5.4Hz,1H),4.82(d,J=7.9Hz,1H),4.66(dd,J=11.9,2.4Hz,1H),4.54(dd,J=11.8,6.3Hz,1H),3.87(dt,J=5.2 ,2.6Hz,1H),3.80(ddd,J=9.9,6.3,2.4Hz,1H),3.72(d,J=9.3Hz,1H),3.63(s,3H),3.51(dd,J=9.6,7.9Hz,1H),3.02(d,J=8.4Hz,1H),2.16– 2.09(m,1H),1.88(td,J=8.8,5.3Hz,1H),1.74(dtd,J=11.6,8.0,7.5,5.7Hz,1H),1.30(ddd,J=13.6,8.6,4.7Hz,1H),0.93(d,J=6.9Hz,3H); 13 C-NMR(100MHz,CD3OD)δ:169.38,167.77,167.68,152.36,134.40,134.19,131.61,131.30,130.77,130.77,130.60,130.60,129.68, 129.68,129.47,129.47,113.72,100.50,98.60,79.22,75.47,74.87,73.06,70.30,64.65,51.65,46.25,42.91,42.46,32.61,13.60.

[0112] Loganin derivatives with the structure shown in formula I-4: 2′,3′4′,6′-tetrabenzoyl loganin, white powder; molecular formula C 45 H 42 O 14 ; HRESI-MS m / z 829.2466[M+Na] +(Calculated value is 829.2467); UVλ max (MeOH) 228nm; IR (KBr) cm -1 : 3432, 2926, 1732, 1649, 1270, 1099 and 714; 1 H-NMR(400MHz,CD3OD)δ:7.98(dd,J=4.0,1.3Hz,4H),7.84(ddt,J=11.5,7.0,1.4Hz,3H),7.75–7.71(m,1H),7.57–7.51(m,4H),7.41(dd,J=8 .7,6.9Hz,4H),7.33(td,J=7.9,4.0Hz,3H),7.24(t,J=7.8Hz,1H),5.99(t,J=9.3Hz,1H),5.64(t,J=9.7Hz,1H),5.43(d,J=8.2Hz,1H),5.39(d ,J=3.3Hz,1H),5.27(d,J=3.0Hz,1H),4.55(t,J=3.5Hz,2H),4.39(dt,J=9.9,4.1Hz,1H),3.88(t,J=4.7Hz,1H),3.24(s,3H),2.84(q,J=8.2Hz ,1H),2.07–2.03(m,1H),2.01(dd,J=8.4,1.8Hz,1H),1.64(ddd,J=11.3,6.9,4.6Hz,1H),1.48(dt,J=14.6,5.6Hz,1H),0.95(d,J=6.9Hz,3H); 13 C-NMR(100MHz,CD3OD)δ:168.53,167.45,166.98,166.70,166.33,150.47,134.75,134.58,134.4 9,134.43,130.93,130.77,130.70,130.70,130.70,130.70,130.67,130.67,130.57,130.32,130 .15,130.08,129.59,129.59,129.59,129.57,129.49,129.45,129.45,129.45,150.47,114.83,97.88,97.12,75.04,74.35,73.34,72.93,71.07,63.95,51.55,43.30,42.22,41.56,31.12,15.47.

[0113] Example 3

[0114] according to Figure 2The synthetic route shown is as follows: Loganin and β-glucosidase are dissolved in a citric acid-sodium citrate buffer solution (pH=6.0) at a molar equivalent ratio of 10:1, and enzymatic hydrolysis is carried out at 45°C for 24-48 hours under N2 protection conditions, and monitored by TLC. After the loganin reaction is complete, ethyl acetate is added and extracted five times with a separatory funnel, and the ethyl acetate is recovered to obtain the aglycone of loganin;

[0115] according to Figure 2 and Figure 3 The synthetic route shown is as follows: 35 mg (0.1533 mmol) of the aglycone of loganin and 19.6 mg (0.3066 mmol) of sodium cyanoborohydride are weighed and placed in a sealed tube, and then 1 mL of 27% to 32% methylamine ethanol solution is added, and the reaction is stirred for 5±2 h in an oil bath at 45°C. After TLC monitoring of the disappearance of the substrate, the reaction solution is transferred to a separating funnel with water, extracted with ethyl acetate three times, and the organic phases are combined, dried over anhydrous Na2SO4, and the solvent is evaporated under reduced pressure. The residue is purified by silica gel column chromatography (eluent: V petroleum ether: V ethyl acetate = 1:1) to obtain a loganin derivative (17.5 mg, yield: 50.7%) of the structure shown in formula II-1-1.

[0116] Loganin derivatives with the structure shown in formula II-1-1 are yellow oily substances; the molecular formula is HRESI-MS m / z 226.1442[M+H] + (Calculated value is 226.1438); UVλ max (MeOH) 293nm; IR (KBr) cm -1 : 3444, 2945, 1675, 1611, 1435, 1251, 999 and 771; 1 H-NMR (400MHz, CD3OD) δ: 7.31 (d, J = 0.7Hz, 1H), 4.01 (td, J = 5.3, 1.8Hz, 1H), 3.56 (s, 3 H),3.03(dd,J=12.5,4.9Hz,1H),2.93(d,J=7.9Hz,1H),2.89(s,3H),2.68(dd,J=12.4 ,6.7Hz,1H),2.12(ddd,J=13.9,7.5,1.9Hz,1H),1.88(ddd,J=12.9,9.8,6.3Hz,1H),1 .68(pd,J=7.1,4.9Hz,1H), 1.45(ddd,J=13.7,8.2,5.3Hz,1H), 1.00(d,J=7.1Hz,3H); 13C-NMR (100MHz, CD3OD) δ: 171.42, 148.69, 100.72, 74.99, 50.98, 49.77, 43.83, 43.32, 43.11, 43.00, 33.12, 13.64.

[0117] Example 4

[0118] according to Figure 2 The synthetic route shown is as follows: Loganin and β-glucosidase are dissolved in a citric acid-sodium citrate buffer solution (pH=6.0), and enzymatic hydrolysis is carried out at 45°C for 24-48h under N2 protection conditions to obtain the aglycone of loganin;

[0119] according to Figure 2 and Figure 4 The synthetic route shown is as follows: 21 mg (0.0920 mmol) of the aglycone of loganin and 10 mg (0.1656 mmol) of sodium cyanoborohydride are weighed and placed in a sealed tube, and then 1 mL of ethylamine alcohol solution is added, and the reaction is stirred in an oil bath at 45°C for about 1 hour. After TLC monitoring of the disappearance of the substrate, the reaction solution is transferred to a separating funnel with water, extracted with ethyl acetate three times, and the organic phases are combined, dried over anhydrous Na2SO4, and the solvent is evaporated under reduced pressure. The residue is purified by silica gel column chromatography (eluent: V petroleum ether: V ethyl acetate = 2:1) to obtain a loganin derivative (9.8 mg, yield: 44.5%) of the structure shown in formula II-1-2.

[0120] Loganin derivatives with the structure shown in formula II-1-2 are yellow oily substances; the molecular formula is C 13 H 21 NO3; HRESI-MS m / z 240.1599[M+H] + (Calculated value is 240.1594); UVλ max (MeOH) 294nm; IR (KBr) cm -1 : 3444, 2933, 1675, 1611, 1428, 1163, 999 and 765; 1H-NMR (400MHz, CDCl3) δ: 7.37 (d, J = 0.7Hz, 1H), 4.13 (td, J = 5.1, 1.5Hz, 1H), 3.65 (s, 3H) ,3.47(s,1H),13.16(q,J=7.2Hz,2H),3.09–3.04(m,1H),2.72(dd,J=12.2,6.5Hz,1H),2. 21(ddd,J=14.3,7.5,1.6Hz,1H),1.97(tdd,J=8.2,6.4,4.7Hz,1H),1.73(pd,J=7.1,4.8 Hz,1H),1.59(ddd,J=14.3,7.9,5.2Hz,1H),1.15(t,J=7.2Hz,3H),1.06(d,J=7.0Hz,3H); 13 C-NMR (100MHz, CDCl3) δ: 169.45, 145.79, 100.00, 74.65, 50.62, 50.33, 46.35, 43.23, 42.04, 41.66, 32.54, 14.11, 13.12.

[0121] Example 5

[0122] according to Figure 2 The synthetic route shown is as follows: Loganin and β-glucosidase are dissolved in a citric acid-sodium citrate buffer solution (pH=6.0), and enzymatic hydrolysis is carried out at 45°C for 24-48h under N2 protection conditions to obtain the aglycone of loganin;

[0123] according to Figure 2 and Figure 5 The synthetic route shown is as follows: 27 mg (0.1182 mmol) of the aglycone of loganin and 14 mg (0.2364 mmol) of sodium cyanoborohydride were weighed and placed in a sealed tube, and then 1 mL of propanol solution was added, and the reaction was stirred in an oil bath at 45°C for about 1 hour. After TLC monitoring, the reaction solution was transferred to a separating funnel with water after the aglycone substrate of loganin disappeared, and the organic phases were combined after extraction with ethyl acetate for 3 times, dried over anhydrous Na2SO4, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: V petroleum ether: V ethyl acetate = 3:1) to obtain the loganin derivative (8.6 mg, yield: 28.8%) of the structure shown in formula II-1-3.

[0124] Loganin derivatives with the structure shown in formula II-1-3 are yellow oily substances; the molecular formula is C 14 H 23 NO3; HRESI-MS m / z 254.1750[M+H] + (The calculated value is 254.1751); UVλmax (MeOH) 294nm; IR (KBr) cm -1 : 3432, 2951, 2926, 1662, 1611, 1428, 1163, 999 and 765; 1 H-NMR (400MHz, CDCl3) δ: 7.36 (s, 1H), 4.14 (d, J = 5.2Hz, 1H), 3.65 (d, J = 7.4H z,3H),3.06(t,J=6.6Hz,3H),2.76(ddd,J=39.5,13.3,7.0Hz,2H),2.21(dd, J=14.2,7.4Hz,1H),1.94(p,J=6.8Hz,1H),1.70(dp,J=23.2,7.5,7.1Hz,2H) ,1.56(hept,J=7.5,6.0Hz,2H),1.06(d,J=7.2Hz,3H),0.88(t,J=7.3Hz,3H); 13 C-NMR (100MHz, CDCl3) δ: 169.55, 146.49, 99.22, 74.59, 57.62, 50.64, 46.82, 43.17, 41.94, 41.79, 32.56, 21.97, 13.20, 11.23.

[0125] Example 6

[0126] according to Figure 2 The synthetic route shown is as follows: Loganin and β-glucosidase are dissolved in a citric acid-sodium citrate buffer solution (pH=6.0), and enzymatic hydrolysis is carried out at 45°C for 24-48h under N2 protection conditions to obtain the aglycone of loganin;

[0127] according to Figure 2 and Figure 6 The synthetic route shown is as follows: 14.8 mg (0.0648 mmol) of the aglycone of loganin and 7 mg (0.1166 mmol) of sodium cyanoborohydride were weighed and placed in a sealed tube, 2 mL of dichloromethane was added to dissolve, 13 μL (0.0778 mmol) of benzylamine was added after stirring evenly, and the reaction was stirred overnight in an oil bath at 45°C. After TLC monitoring of the disappearance of the substrate, the reaction solution was transferred to a separating funnel with water, and the organic phases were combined after extraction with ethyl acetate for 3 times, dried over anhydrous Na2SO4, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: V petroleum ether: V ethyl acetate = 4:1) to obtain a loganin derivative (9.1 mg, yield: 46.7%) of the structure shown in formula II-1-4.

[0128] Loganin derivatives with the structure shown in formula II-1-4: yellow oily substance; molecular formula C 18 H23 NO3; HRESI-MS m / z 302.1755[M+H] + (Calculated value is 302.1756); UVλ max (MeOH) 203, 294nm; IR (KBr) cm -1 : 3444, 2920, 1649, 1510 and 739; 1 H-NMR(400MHz, CDCl3)δ:7.54(s,1H),7.35(dd,J=8.0,6.2Hz,2H),7.33–7.27(m,1H),7.25–7 .20(m,2H),4.27(q,J=15.0Hz,2H),4.14–4.08(m,1H),3.68(s,3H),3.08(q,J=7.9Hz,1H),3.0 0(dd,J=12.3,4.7Hz,1H),2.64(dd,J=12.3,6.2Hz,1H),2.22(ddd,J=14.3,7.7,1.4Hz,1H),1 .96(tdd,J=8.4,6.1,4.7Hz,1H),1.72–1.63(m,1H),1.63–1.58(m,1H),0.88(d,J=7.0Hz,3H); 13 C-NMR(100MHz, CDCl3)δ:169.39,146.24,137.03,128.87,128.87,127.99,127.80 ,127.80,100.98,74.72,59.83,50.74,46.27,43.13,41.87,41.56,32.53,12.77.

[0129] Example 7

[0130] according to Figure 2 The synthetic route shown is as follows: Loganin and β-glucosidase are dissolved in a citric acid-sodium citrate buffer solution (pH=6.0), and enzymatic hydrolysis is carried out at 45°C for 24-48h under N2 protection conditions to obtain the aglycone of loganin;

[0131] according to Figure 7The synthetic route is as follows: add a 1 mol / L SOCl2-CH3OH solution in an amount equivalent to the molar equivalent of the α-amino acid of the structure of Formula V to a round-bottom flask containing the α-amino acid of the structure of Formula V, and heat to reflux for 1 hour. Remove the SOCl2-CH3OH solution by rotary evaporation to obtain a solid product, add 2 times the equivalent of 2 mol / L SOCl2-CH3OH solution to the solid product, heat to reflux for 1 hour, and spin dry to obtain a white solid, which is the hydrochloride product of the α-amino acid methyl ester of the structure of Formula VI;

[0132]

[0133] according to Figure 2 , Figure 8 and Fig. 9 The synthetic route shown in the figure is as follows: 30 mg (0.1314 mmol) of the aglycone of loganin and 16 mg (0.2628 mmol) of sodium cyanoborohydride are weighed and placed in a sealed tube, 2 mL of dichloromethane is added to dissolve, and after stirring for 5 min, a hydrochloride solution of the α-amino acid methyl ester of the structure shown in Formula VI is added, and then ammonia water is added until the pH is greater than 9, and ethyl acetate is added to extract five times to obtain the α-amino acid methyl ester of the structure shown in Formula VI. The α-amino acid methyl ester of the structure shown in Formula VI (R 3 ' is methyl) 27 mg (0.2628 mmol), stirred and reacted under oil bath at 20-60°C for about 1 hour. After TLC monitoring the disappearance of the substrate, the reaction solution was transferred to a separatory funnel with water, extracted with ethyl acetate three times, and then the organic phases were combined, dried over anhydrous Na2SO4, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: V 石油醚 :V 乙酸乙酯 =4:1) to obtain a loganin derivative (12.4 mg, yield: 31.8%) with the structure shown in formula II-2-1.

[0134] Loganin derivatives with the structure shown in formula II-2-1 are yellow oily substances; the molecular formula is C 15 H 20 NO5; HRESI-MS m / z 300.1805[M+H] + (Calculated value is 300.1805); UVλ max (MeOH) 197nm; IR (KBr) cm -1 : 3426, 3274, 2958, 1725, 1441, 1156 and 967; 1H-NMR(400MHz,CD3OD)δ:4.12(td,J=6.5,3.1Hz,1H),3.66(s,3H),3.63(s,3H),3.34(q,J=6.9Hz,1H),3. 28(p,J=1.7Hz,1H),2.92(ddd,J=11.0,3.7,1.9Hz,1H),2.77(dt,J=11.9,2.2Hz,1H),2.57(dd,J=11.9,4. 2Hz,1H),2.32(dd,J=11.0,3.6Hz,1H),2.08–1.97(m,1H),1.90(ddd,J=14.7,6.8,2.3Hz,1H),1.78(ddd, J=11.9,5.7,3.6Hz,1H),1.70(ddd,J=14.7,7.8,3.1Hz,1H),1.22(d,J=7.1Hz,3H),0.93(d,J=6.9Hz,3H); 13 C-NMR (100MHz, CD3OD) δ: 176.10, 174.88, 74.94, 63.52, 52.20, 51.84, 51.56, 50.92, 47.89, 44.64, 40.92, 39.74, 39.15.

[0135] Example 8

[0136] Weigh 200 mg (0.5126 mmol) of loganin into a round-bottom flask, add 3 mL of pyridine to dissolve, and then add 121 μL of acetic anhydride. Stir the reaction at room temperature under N2 protection for about 5 hours. After the TLC monitoring of the generated spots is stable, add saturated NaHCO3 solution to neutralize the excess acetic anhydride, add water to separate, and extract with ethyl acetate 3 times, combine the organic phases, dry over anhydrous Na2SO4, evaporate the solvent under reduced pressure, and purify the residue by silica gel column chromatography to obtain loganin derivatives of the structure shown in formula I-5 (42.6 mg, yield: 17.5%), loganin derivatives of the structure shown in formula I-6 (75.5 mg, yield: 26.4%), and loganin derivatives of the structure shown in formula I-7 (114.5 mg, yield: 37.2%).

[0137] Loganin derivatives with the structure shown in formula I-5: white powder; molecular formula is C 21 H 30 O 12 ; 1H-NMR(400MHz, CDCl3)δ:7.33(s,1H),5.13(d,J=4.0Hz,1H),4.99–4.92(m,1H),4.71(d,J=7.9Hz,1H) ,4.46–4.39(m,1H),4.34(d,J=12.2Hz,1H),4.15–4.08(m,1H),3.69(s,3H),3.54(d,J=5.4Hz,2H),3. 47(s,1H),3.13(d,J=8.2Hz,1H),2.27(dd,J=14.4,8.3Hz,1H),2.04–1.97(m,1H),2.16(s,3H),2.11( s,3H),1.83(ddd,J=10.6,7.2,4.5Hz,1H),1.63(ddd,J=14.8,7.2,5.1Hz,1H),1.10(d,J=7.0Hz,3H); 13 C-NMR(100MHz, CDCl3)δ:172.36,171.69,167.64,149.97,113.51,98.74,96.51,77.36,74 .59,74.46,71.67,68.83,62.98,51.50,44.85,41.77,40.79,30.67,21.17,21.04,12.78.

[0138] Loganin derivatives with the structure shown in formula I-6: white powder; molecular formula C 25 H 34 O 14 ; HRESI-MS m / z 581.1788[M+Na] + (The calculated value is 581.1840).UVλ max (MeOH) 259nm; IR (KBr) cm -1 : 2964, 2297, 1764, 1262, 1068; 1H-NMR(400MHz, CDCl3)δ:7.44–7.15(m,1H),5.18(q,J=10.7,10.1Hz,2H),5.08(d,J=7.6Hz,1 H),5.00–4.90(m,1H),4.83(p,J=8.7,7.9Hz,1H),4.27(d,J=13.2Hz,1H),4.12(d,J=10.7Hz, 1H),4.07(s,1H),3.66(q,J=9.3,7.2Hz,4H),2.99(q,J=7.8Hz,1H),2.27–2.12(m,2H),2.11– 2.02(m,3H),2.03–1.92(m,6H),1.92–1.79(m,3H),1.79–1.58(m,2H),1.06(t,J=7.5Hz,3H); 13 C-NMR(100MHz, CDCl3)δ:170.79,170.35,169.52,169.22,167.45,149.15,114.04,95.92,95.37,74.43,7 2.58,72.13,70.68,68.27,61.76,51.34,44.66,41.52,40.30,29.96,20.83,20.69,20.69,20.27,12.40.

[0139] Loganin derivatives with the structure shown in formula I-7: white powder; molecular formula C 27 H 36 O 15 ; HRESI-MS m / z 623.1849[M+Na] + (The calculated value is 623.1946).UVλ max (MeOH) 250nm; IR (KBr) cm -1 : 2962, 2963, 2851, 1753, 1742, 1262, 1040 and 803; 1H-NMR(400MHz, CDCl3)δ:7.28(d,J=1.2Hz,1H),5.25–5.22(m,1H),5.21(d,J=9.6Hz,1H),5.15–5.11(m,1H),5.09(d, J=9.6Hz,1H),4.98(dd,J=9.7,8.1Hz,1H),4.84(d,J=8.2Hz,1H),4.33–4.27(m,1H),4.13(dd,J=12.4,2.4Hz,1H),3. 73(ddd,J=10.0,4.5,2.3Hz,1H),3.68(s,3H),2.99(td,J=8.6,5.1Hz,1H),2.23(ddtd,J=9.7,8.0,6.2,5.4,1.5Hz,2 H),2.09(s,3H),2.03(d,J=1.7Hz,6H),2.00(s,3H),1.90(s,3H),1.81(dt,J=15.3,5.4Hz,1H),1.01(d,J=6.8Hz,3H); 13 C-NMR(100MHz, CDCl3)δ:170.84,170.77,170.35,169.55,169.27,149.14,113.73,95.91,94.64,77.48,77.22,7 2.52,72.24,70.65,68.26,61.80,51.45,45.48,38.91,38.88,29.80,21.24,20.90,20.75,20.75,20.31,12.50.

[0140] Test Case

[0141] In order to ensure the scientificity and effectiveness of the experimental scheme of the present invention, the anti-diabetic and diabetic nephropathy activity experiments were carried out on the loganin derivatives prepared in the examples of the present invention.

[0142] This test example uses the α-glucosidase activity inhibition model to detect the sample's inhibitory effect on α-glucosidase; uses the high-glucose cultured rat HBZY-1 cell model to detect the sample's inhibitory effect on the abnormal proliferation of high-glucose cultured HBZY-1 cells; and measures the effect of the active ingredient on the superoxide dismutase (SOD) and malondialdehyde (MDA) content in high-glucose-induced HBZY-1 cells. The sample's anti-diabetic and diabetic nephropathy activity is evaluated.

[0143] The activity screening method is as follows:

[0144] 1. Inhibitory activity test of samples on α-glucosidase

[0145] α-Glucosidase (AGI) hydrolyzes p-nitrophenyl-α-D-glucoside (PNPG) into glucose and p-nitrophenol (PNP), and PNP has a maximum absorption at 405nm. Based on this principle, after adding the sample to be tested, the change in its absorbance is measured, and the inhibition rate of the sample on AGI is calculated. The IC value of the positive control acarbose is also used to determine the inhibition rate of the sample on AGI. 50 The values ​​were compared to evaluate the inhibitory effect of the samples on AGI.

[0146] 1.1 Experimental reagents, as shown in Table 1

[0147] Table 1 Experimental reagents

[0148]

[0149]

[0150] 1.2 Experimental Grouping

[0151] Sample group: The concentrations of the test compounds were prepared at 12.5, 25, 50, 100, and 200 nmoL / L.

[0152] Positive control group: acarbose, the concentration was the same as that of the sample group; sample control group, negative control group, and blank group.

[0153] 1.3 Solvent preparation and experimental operation

[0154] Solvent preparation: The samples: loganic acid, loganin, loganin derivatives of the structure shown in formula I-1, loganin derivatives of the structure shown in formula I-2, loganin derivatives of the structure shown in formula I-3, loganin derivatives of the structure shown in formula I-4, loganin derivatives of the structure shown in formula II-1-1, loganin derivatives of the structure shown in formula II-1-2, loganin derivatives of the structure shown in formula II-1-3, loganin derivatives of the structure shown in formula II-1-4, loganin derivatives of the structure shown in formula II-2-1 are respectively prepared to 12.5, 25, 50, 100, 200 nmmoL / L, the concentration of α-glucosidase is 0.5U / mL, the concentration of PNPG is 5mmoL / L, the concentration of sodium carbonate is 0.2moL / L, and the above reagents are all dissolved in PBS (pH=6.8). The experimental steps are operated according to Table 2:

[0155] Table 2 Order of adding reagents in α-glucosidase experiment

[0156]

[0157] Calculation formula: Inhibition rate: I = [1-(ab) / (dc)] × 100%; The experimental data of this test case were analyzed using GraphPad Prism 8.0 software.

[0158] 1.4 Experimental results, as shown in Table 3

[0159] Table 3 Inhibitory activity of compounds on α-glucosidase

[0160] Compound Name Inhibition rate (%) <![CDATA[IC 50 (nmoL / L)]]> Acarbose 94.5 65.20 Loganin 98.5 60.67 Loganin 98.1 52.93 Compound of formula I-1 84.6 80.81 Compound of formula I-2 69.2 116.79 Compound of formula II-2-1 88.9 60.12

[0161] As can be seen from the table, the inhibition rates of loganinic acid, loganin, the compound of formula I-1, the compound of formula I-2 and the compound of formula II-2-1 on α-glucosidase are all greater than 50%, and the IC values ​​of the compounds loganinic acid, loganin and the compound of formula II-2-1 are 50 The value is less than the IC of the positive control acarbose 50 . This indicates that they have a significant inhibitory effect on α-glucosidase.

[0162] 2.1 Establishment of the high glucose model of HBZY-1 cells

[0163] 2.1.1 Experimental groups

[0164] A (control group): cells, low-glucose (11mmol / L) DMEM complete medium; B (high-glucose group): cells, high-glucose (22.5, 25, 27.5, 30, 32.5mmol / L) DMEM complete medium; C (blank group): low-glucose DMEM complete medium (11mmol / L). Five parallel wells were set up in a 96-well plate for each group.

[0165] 2.1.2 Solution preparation

[0166] Complete medium (50mL) with a glucose content of 22.5mmol / L: 50mL low glucose medium + 102.5mg glucose; complete medium (50mL) with a glucose content of 25mmol / L: 50mL low glucose medium + 125mg glucose; complete medium (50mL) with a glucose content of 27.5mmol / L: 50mL low glucose medium + 147.5mg glucose; complete medium (50mL) with a glucose content of 30mmol / L: 50mL low glucose medium + 170mg glucose; complete medium (50mL) with a glucose content of 32.5mmol / L: 50mL low glucose medium + 192.5mg glucose; complete medium (50mL) with a glucose content of 35mmol / L: 50mL low glucose medium + 215mg glucose.

[0167] 2.1.3 Experimental methods

[0168] After cell digestion according to the method in 2.2.1, take 10 μL onto a cell counting plate and count under a microscope. Follow the cell counting principle of counting the top and not the bottom, and counting the left and not the right. Use (number of cells in the four grids / 4)×10 4 × The cell dilution multiple is calculated by the formula to calculate the cell density and dilute it to make the seed plate density reach 5×10 4 / mL. The experiment was divided into groups. The glucose concentration of the high-sugar group was (25, 27.5, 30, 32.5, 35mmol / L). The cells were cultured for different time periods (24, 48, 72, 96h). The culture medium in each well was 200μL. After reaching the corresponding culture time, 20μL of CCK-8 reagent was added for detection. After 15min of culture in a CO2 incubator, the absorbance at 450nm was measured to compare the cell viability of abnormally proliferating HBZY-1 cells under different glucose concentrations and time conditions. According to this formula, cell viability % = ((A B -A C ) / (A A -A C ))×100% for calculation.

[0169] 2.1.4 Data Processing

[0170] The experimental data of this test case were analyzed using GraphPad Prism 8.0. The experimental results were expressed as mean±SEM. Single-factor analysis was used to compare the mean values ​​of multiple groups of samples. A p value less than 0.05 indicated statistical significance.

[0171] 2.1.5 Experimental Results

[0172] In vitro pharmacological activity experiments showed that when the glucose concentration was 30mmoL / L and the culture time was 48h, the cell proliferation was significant and the modeling was successful. The results are as follows Fig.10 Drug intervention was performed under this condition.

[0173] Fig.10 The effects of different glucose concentrations and different culture times on HBZY-1 cells; Fig.10 Middle: Data represent mean±SEM, n=5; “*” indicates p less than 0.05, and “**” indicates p less than 0.01 compared with HG.

[0174] 2.2 Effects of compounds on abnormal proliferation of HBZY-1 cells induced by high glucose

[0175] 2.2.1 Experimental Grouping

[0176] A (control group): cells, low-glucose DMEM complete medium (glucose content 11mmol / L); B (high-glucose group): cells, high-glucose (30mmol / L) DMEM complete medium; C (drug group): compounds, cells, high-glucose (30mmol / L) DMEM complete medium, different concentrations of each drug (0.01, 0.1, 1, 10, 100μmol / L); D (blank group): high-glucose (30mmol / L) DMEM complete medium. Five parallel wells were set in each group in a 96-well plate.

[0177] 2.2.2 Experimental methods

[0178] The CCK-8 method was used to detect whether the compounds at different concentrations had an inhibitory effect on high glucose-induced HBZY-1 cell proliferation.

[0179] Take the cells cultured in normal sugar, digest them, add culture medium, blow evenly and count them. Refer to the counting method in 2.2.4.3 and adjust the cell seeding density to 1×10 4 / mL, according to the experimental grouping, take 100μL in a 96-well plate, add complete medium to 200μL, culture for 24h, aspirate the old medium, add 200μL of serum-free medium to each well, culture for 24h, administer the drug, aspirate the old medium, and the administration volume is 200μL. After 48h of culture, add 20μL of CCK-8 reagent to each well, place in the incubator for reaction for 2h, and then measure the absorbance at 450nm with an enzyme reader to calculate the cell viability and detect whether the drug inhibits the abnormal proliferation of HBZY-1 cells induced by high glucose.

[0180] 2.2.3 Data processing

[0181] Cell viability % = ((A C -A D ) / (A B -A D ))×100%.

[0182] Data processing is the same as 2.2.4.3.

[0183] 2.2.4 Experimental results

[0184] A bar graph was drawn to show the effect of drugs on the viability of HBZY-1 cells induced by high glucose, with the drug concentration as the horizontal axis and the cell viability as the vertical axis. The results showed that loganin acid, loganin, the compound of formula I-1, the compound of formula I-2, the compound of formula II-1-1, and the compound of formula II-1-4 had significant inhibitory effects on the abnormal proliferation of HBZY-1 cells induced by high glucose at different concentrations. Fig.11 shown.

[0185] 3. Effects of compounds on SOD and MDA levels in high glucose-induced HBZY-1 cells

[0186] The experimental methods were in accordance with the instructions of the SOD and MDA kits.

[0187] 3.1 Experimental Grouping

[0188] Control group: cells, low-glucose (11mmol / L) DMEM complete medium; high-glucose group: cells, high-glucose (30mmol / L) DMEM complete medium; drug administration group: (1) test compound: cells, high-glucose (30mmol / L) DMEM complete medium, different concentrations of each drug (50, 100, 200, 400, 800μg / mL), (2) compound: cells, high-glucose (30mmol / L) DMEM complete medium, different concentrations of each drug (0.01, 0.1, 1, 10, 100μmol / L); positive control group: cells, high-glucose complete medium (30mmol / L), positive control group (Tempol, 100μmol / L). Three parallel wells were set up in each group in a 24-well plate.

[0189] 3.2 Experimental methods

[0190] According to the operating instructions of different kits, the contents of SOD and MDA in each component cell were calculated using the BCA method.

[0191] Use the counting method in 2.2.4.3 above and dilute the cells accordingly to make the cell density 6×10 5 / mL, take 100 μL in a 24-well plate, set up experimental groups, that is, each drug contains 8 experimental groups (NG, HG, Tempol, and five dosing groups with different concentrations), and each group needs to set up three parallel replicates. After culturing for 24 hours, change to complete medium without serum and culture for another 24 hours, then change to complete medium containing different drug concentrations. After culturing for 48 hours, operate according to the instructions of the kit.

[0192] 3.3 BCA kit operation

[0193] (1) Cell pretreatment

[0194] Aspirate the old culture medium in the 24 blanks, add 200 μL of trypsin to each well and digest in the incubator for 2 minutes, then add 200 μL of culture medium to terminate the digestion, transfer the cells to a 5 mL centrifuge tube and centrifuge at 1000 rpm for 5 minutes. After the end, aspirate the supernatant, rinse twice with PBS, add 1 mL of PBS, blow evenly and count the cells. After counting, centrifuge again, discard the supernatant PBS, and add the corresponding lysis solution.

[0195] (2) BCA assay

[0196] Add 70-130 μL of protein lysis buffer to each well of a 12-well plate to release the protein in the cells, add 50 μL of lysis buffer to each centrifuge tube, place in the refrigerator for 1-2 hours, centrifuge at 10,000 g for 5 minutes, take 20 μL of supernatant to a 96-well plate, add 200 μL of BCA working solution, react at 37°C for 15 minutes, measure the absorbance at 562 nm with an enzyme reader, and then calculate the protein concentration based on the standard curve.

[0197] Preparation of protein standard curve: Preparation of working solution: Calculate the number of standards and samples, BCA: Cu reagent = 50:1 (V: V), prepare BCA working solution, shake thoroughly, and mix evenly. Dilute standard: dilute 10μL of BSA standard with PBS to 100μL, that is, the final concentration is 0.5mg / mL. Take 0, 2, 4, 6, 8, 12, 16, and 20μL of standard in a 96-well plate, add PBS to 20μL, and then add 200μL of BCA working solution to each well in turn, and place at 37℃ for 15min. Use an enzyme marker to measure its absorbance at 562nm, use protein concentration as the horizontal axis and absorbance as the vertical axis to make a protein standard curve.

[0198] 3.4 SOD Kit Operation

[0199] After counting according to the method in 2.2.4.3, add 1 mL of SOD extract for every 5 million cells, add the corresponding extract, and break the cells by ultrasonication. Ultrasonication should be performed for 3 seconds each time, and 30 times with an interval of 10 seconds each time. Then centrifuge at 8000g and 4℃ for 10 minutes. The supernatant is the sample to be tested and placed on ice for testing.

[0200] Determination steps:

[0201] The microplate reader needs to be preheated for more than 30 minutes before the measurement, and the wavelength should be set to 560nm;

[0202] Before use, reagent 2 needs to be centrifuged and then blown; reagent 4 needs to be added to reagent 5, ultrasonically dissolved, and prepared before use; before testing, reagents 1, 3, and 5 need to be water bathed at 25°C for more than 5 minutes, and then perform the operations in Table 4:

[0203] Table 4 SOD reagent operation steps

[0204] Reagent Name (μL) Determination tube Control tube Blank 1 Blank 2 sample 18 18 - - Reagent 1 45 45 45 45 Reagent 2 2 - 2 - Reagent 3 35 35 35 35 Double distilled water 90 92 108 110 Reagent 5 10 10 10 10

[0205] The reagents in Table 4 were added to the grouped 96-well plate in order, mixed thoroughly, and reacted at 37°C for 30 minutes. The absorbance at 560 nm was measured using an enzyme-labeled instrument.

[0206] 3.5 MDA kit operation

[0207] After counting according to the method in 2.2.4.3, add the corresponding extract according to the requirement of adding 1 mL of MDA extract for every 5 million cells, and perform ultrasonication to break the cells. Perform ultrasonication for 3 seconds each time, 30 times, with an interval of 10 seconds each time, and then centrifuge at 8000g, 4℃ for 10 minutes. The supernatant is the sample to be tested, which is placed on ice for testing.

[0208] Determination steps:

[0209] The ELISA reader needs to be preheated for more than 30 minutes before the measurement;

[0210] Prepare MDA working solution: When using, add 15mL of reagent 1 to reagent 2 and fully dissolve. Dissolution can be carried out in a water bath at 70°C, shake repeatedly, and use ultrasound to dissolve if it is not well dissolved. Place in a 4°C refrigerator for standby use, and then perform the operations in Table 5:

[0211] Table 5 MDA reagent operation steps

[0212] Reagent Name (μL) Determination tube Blank tube MDA detection working solution 150 150 Distilled water - 50 sample 50 - Reagent 3 50 50

[0213] Add the reagents in Table 5 to a 1.5 mL EP tube. After the addition is completed, react in a 100°C metal bath for 60 min, then cool in an ice bath, centrifuge at room temperature, centrifuge at 10000 g for 10 min, draw 100 μL of the supernatant into a 96-well plate with groups set, and measure the absorbance values ​​at 450 nm, 532 nm, and 600 nm using an enzyme reader.

[0214] 3.6 Calculation method

[0215] The BCA content of each group of samples was calculated based on the protein standard curve.

[0216] SOD activity (U / mL) = 11.11 × inhibition percentage ÷ (1-inhibition percentage) ÷ Cpr × F

[0217] ΔAassay=Aassay-Acontrol, ΔAblank=Ablank1-Ablank2.

[0218] MDA content (nmol / mgpot) = 5 × (12.9 × (ΔA532-ΔA600)-2.58 × ΔA450) ÷ Cpr

[0219] ΔA450=A450 测定 -A450 空白 , ΔA532=A532 测定 -A532 空白 , ΔA600=A600 测定-A600 空白 .

[0220] Cpr: sample protein concentration; F: dilution factor.

[0221] 3.7 Experimental Results

[0222] In vitro pharmacological activity experiments show that loganinic acid, loganin, the compound of structure shown in formula I-1, the compound of structure shown in formula I-2, and the compound of structure shown in formula II-1-1 can significantly increase the SOD activity in HBZY-1 cells and reduce the content of MDA. Loganinic acid, loganin, loganin derivatives of structure shown in formula II-1-1 have the effect of alleviating the oxidative stress of HBZY-1 cells in the concentration range of 1 to 100 μmol / L, loganin derivatives of structure shown in formula I-1, and loganin derivatives of structure shown in formula I-2 have the effect of alleviating the oxidative stress of HBZY-1 cells in the concentration range of 10 to 100 μmol / L, and there is a concentration-dependent relationship. Its SOD activity and MDA content are shown in Tables 6 to 10:

[0223] Table 6 SOD activity and MDA content in HBZY-1 cells induced by high glucose after administration of loganin

[0224] Group(Loganinic Acid) SOD activity (U / mL) MDA content (nmol / mgpot) NG 51.33±6.68** 1.53±0.48** Tempol 59.16±3.02** 1.61±0.50* HG 26.22±1.41 2.39±0.12 0.01μmol / L 25.88±4.64 1.33±0.18** 0.1μmol / L 40.07±3.61 1.21±0.13** 1μmol / L 51.08±8.34** 1.045±0.40** 10μmol / L 59.57±3.10** 0.85±0.23** 100μmol / L 77.93±13.42** 1.26±0.32**

[0225] Table 7 SOD activity and MDA content in HBZY-1 cells induced by high glucose after loganin administration

[0226] Group(Loganin) SOD activity (U / mL) MDA content (nmol / mgpot) NG 102.26±21.60** 1.68±0.06** Tempol 113.58±7.70** 1.67±0.15** HG 15.06±2.79 2.24±0.28 0.01μmol / L 15.49±1.16 2.79±0.26** 0.1μmol / L 23.71±1.46 1.68±0.08** 1μmol / L 32.20±0.85** 0.91±0.06** 10μmol / L 59.23±1.89** 0.72±0.05** 100μmol / L 61.7±34.82** 1.20±0.30**

[0227] Table 8 SOD activity and MDA content in HBZY-1 cells induced by high glucose after administration of loganin derivatives with the structure shown in formula I-1

[0228] Group (compound of formula I-1) SOD activity (U / mL) MDA content (nmol / mgpot) NG 9.05±0.55** 0.81±0.23** Tempol 8.64±0.50* 2.55±0.40* HG 6.17±0.48 5.24±1.38 0.01μmol / L 8.70±0.33* 1.2±0.27* 0.1μmol / L 9.04±0.83** 1.120±0.64* 1μmol / L 6.52±0.73 2.06±0.50* 10μmol / L 7.90±0.70 2.96±0.25 100μmol / L 9.42±3.01** 2.70±0.21

[0229] Table 9 SOD activity and MDA content in HBZY-1 cells induced by high glucose after administration of loganin derivatives of the structure shown in formula I-2

[0230]

[0231]

[0232] Table 10 SOD activity and MDA content in HBZY-1 cells induced by high glucose after administration of loganin derivatives with the structure shown in formula II-1-1

[0233] Group (compound of formula II-1-1) SOD activity (U / mL) MDA content (nmol / mgpot) NG 20.52±2.40* 1.46±0.34** Tempol 11.69±0.25* 1.2720.21** HG 5.17±1.56 3.15±0.65 0.01μmol / L 8.53±2.35 0.64±0.06** 0.1μmol / L 14.02±4.79 1.96±0.14** 1μmol / L 20.82±1.55* 1.58±0.55** 10μmol / L 26.72±8.32** 1.65±0.30** 100μmol / L 24.91±18.01** 1.14±0.15**

[0234] Note: In Tables 7 to 10: Data represent mean±SEM, n=5; compared with HG, “*” indicates p less than 0.05, and “**” indicates p less than 0.01.

[0235] In summary, the inhibition rates of the compounds loganinic acid, loganin, loganin derivatives of the structure shown in formula I-1, loganin derivatives of the structure shown in formula I-2, and loganin derivatives of the structure shown in formula II-2-1 provided by the present invention on α-glucosidase are all greater than 50%, wherein the IC values ​​of the compounds loganinic acid, loganin, and the compound of formula II-2-1 are 50 The value is less than the IC of the positive control acarbose 50 . This indicates that they have a significant inhibitory effect on α-glucosidase.

[0236] The compounds provided by the present invention, loganin acid, loganin, loganin derivatives with structures shown in formula I-1 and I-2, loganin derivatives with structures shown in formula II-1-1 and loganin derivatives with structures shown in formula II-1-4, have significant inhibitory effects on the abnormal proliferation of HBZY-1 cells induced by high glucose at different concentrations.

[0237] The compounds loganinic acid, loganin, loganin derivatives with a structure shown in formula I-1, loganin derivatives with a structure shown in formula I-2 and loganin derivatives with a structure shown in formula II-1-1 provided by the present invention can significantly increase the activity of SOD and reduce the content of MDA in HBZY-1 cells. The compounds loganinic acid, loganin and loganin derivatives with a structure shown in formula II-1-1 can alleviate the oxidative stress of HBZY-1 cells in a concentration-dependent manner within a concentration range of 1 to 100 μmol / L, and the loganin derivatives with a structure shown in formula I-1 and loganin derivatives with a structure shown in formula I-2 can alleviate the oxidative stress of HBZY-1 cells in a concentration-dependent manner within a concentration range of 10 to 100 μmol / L.

[0238] The present invention provides a loganin derivative and a preparation method thereof, as well as the use of the loganin derivative in the preparation of a drug for preventing or treating diabetes and diabetic nephropathy. The preparation method provided by the present invention has the characteristics of mild conditions, simple operation, and rapid and efficient synthesis of new derivatives. It can be achieved through a one-step reaction of loganin, without the extreme reaction of high temperature, high pressure and strong acid and strong base, and the reaction raw materials are natural abundant compounds, which are suitable for large-scale industrial production. The loganin derivative provided by the present invention can be used in the preparation of a drug for preventing or treating diabetes and diabetic nephropathy. The loganin derivative provided by the present invention has the characteristics of high efficiency and low toxicity.

[0239] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A loganin derivative, characterized in that: It has the structure shown in formula II-1: In Formula II-1, R 1 ' is methyl; R 2 ' is methyl, ethyl, propyl or benzyl.

2. The loganin derivative according to claim 1, characterized in that The loganin derivative has any one of formulas II-1-1 to II-1-4:

3. The method for preparing the loganin derivative according to claim 1 or 2, characterized in that: The compound represented by the structure of formula IV, R 2′ -NH2, a reducing agent and an organic solvent are mixed to undergo a reductive amination reaction to obtain a loganin derivative having a structure shown in formula II-1; 4. The preparation method according to claim 3, characterized in that: The preparation method of the compound of the structure shown in formula IV comprises the following steps: In a protective gas atmosphere, a compound of the structure shown in formula III, β-glucosidase and a citric acid-sodium citrate buffer solution are mixed to undergo an enzymatic hydrolysis reaction to obtain a compound of the structure shown in formula IV; the temperature of the enzymatic hydrolysis reaction is 10 to 45° C.; the pH value of the enzymatic hydrolysis reaction is 4 to 6; 5. The preparation method according to claim 3, characterized in that: The reducing agent is sodium cyanoborohydride; the temperature of the reductive amination reaction is 10 to 60° C., and the insulation time of the reductive amination reaction is 1 to 24 hours.

6. Use of the loganin derivative according to claim 1 or 2 in the preparation of a drug for preventing or treating diabetes or diabetic complications.

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