A 3-substituted indole glycoside compound, preparation method and application thereof

Abstract

The present invention discloses a 3-substituted indolene sugar compound, a preparation method, and its application. The preparation method has strong regioselectivity, resulting in the reaction of only 3-substituted indolene sugars. The method does not require inert gas protection and is simple to operate. The indolene sugar is synthesized using metallic iron as the first catalyst. When the indole 4-position has a substituent, only the 3-substituted indolene sugar product with a stereospecific α-configuration is obtained. The 3-substituted indolene sugar compound disclosed by the present invention has a strong anti-inflammatory effect.

Description

Technical Field

[0001] The present invention relates to the field of chemical synthesis, and in particular to a 3-substituted indole ene sugar compound, a preparation method and application thereof. Background Art

[0002] Indole is a crucial raw material in organic synthesis and is widely present in various active natural products and drug molecules. Indole glycosides possess diverse biological activities, including anti-inflammatory activity, and are being developed as promising drug precursors. Conventional indole carbonyl glycoside synthesis methods utilize terminally activated sugars or glycales, such as halogenated sugars, as raw materials, and react with metal or thiourea catalysts to form different indole glycosides. However, these methods are characterized by harsh conditions, low yields, poor selectivity, low functional group tolerance, and the inability to rapidly construct diversity-oriented compound libraries, which limits their development.

[0003] Chinese patent CN116947833A, "A 3-indole-deoxycarboglycoside and its preparation method," discloses a 3-indole-deoxycarboglycoside and its preparation method. Using readily synthesizable glycosyl donors and indole derivatives as raw materials, the indole C-3 glycosylation reaction is catalyzed by an inexpensive metal catalyst to construct the 3-indole-deoxycarboglycoside. However, the reaction must be performed under nitrogen protection, resulting in harsh reaction conditions.

[0004] Therefore, it is particularly important to design a 3-substituted indole ene sugar compound and a preparation method with strong regioselectivity. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing a 3-substituted indole sugar compound, which has strong regioselectivity, simple operation and single chirality of the product. The present invention also provides a 3-substituted indole sugar compound, which has a good anti-inflammatory effect.

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

[0007] A 3-substituted indole glycoside compound, the structural formula of the compound is shown in 1:

[0008]

[0009] where R 1 including hydrogen, pyrimidinyl or an acyl group of formula 2;

[0010]

[0011] where R 3 Including amino, alkyl substituted amino, C1-5 alkyl; R 2 Including hydrogen, C1-C3 alkoxy or C1-C3 aldehyde.

[0012] Further R 1 Including pyrimidinyl, amide, and pivaloyl.

[0013] The compound represented by Formula 1 includes the following structure:

[0014]

[0015] A method for synthesizing a 3-substituted indolene sugar compound comprises the following steps: mixing tri-O-acetyl-D-glucal, an indole derivative, and an iron-containing catalyst in a solvent to obtain the 3-substituted indolene sugar compound.

[0016] Furthermore, the iron-containing catalyst includes one or more of ferrous chloride tetrahydrate, ferric chloride hexahydrate, ferric perchlorate monohydrate, ferric chloride, and ferric bromide.

[0017] Furthermore, the solvent includes one or both of dichloroethane and toluene.

[0018] Furthermore, during the reaction, the pH is controlled to be 6-9 by a pH regulator.

[0019] Furthermore, the pH adjuster includes one or more of potassium acetate, potassium phosphate, sodium carbonate, and sodium acetate.

[0020] Furthermore, the fourth position of the indole derivative is connected with a C1-C3 alkoxy group or a C1-C3 aldehyde group.

[0021] The invention also discloses application of a 3-substituted indole ene sugar compound in the preparation of anti-inflammatory drugs.

[0022] The reaction mechanism route of the present invention is:

[0023]

[0024] R in the above route 1 Including hydrogen, pyrimidinyl, amide, acylalkyl; R 2 Including hydrogen, C1-C3 alkoxy or C1-C3 aldehyde.

[0025] Beneficial effects:

[0026] The preparation method of the present invention has strong regioselectivity, and only 3-substituted indole glycans are obtained in the reaction; no inert gas protection is required, and the operation is simple; the indole glycans are synthesized for the first time using metallic iron as a catalyst; and when there is a substituent at the 4-position of the indole, only a stereospecific α-configuration 3-substituted glycan product is obtained.

[0027] The 3-substituted indole sugar compound disclosed by the invention has good anti-inflammatory effect.

[0028] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is the H NMR spectrum of compound 4aa obtained in Example 1 in the specific embodiment;

[0031] Figure 2 This is the H NMR spectrum of compound 4ag obtained in Example 2 in the specific embodiment;

[0032] Figure 3 This is the H NMR spectrum of compound 4ak obtained in Example 3 in the specific embodiment;

[0033] Figure 4 This is the H NMR spectrum of compound 4a1 obtained in Example 4 in the specific embodiment;

[0034] Figure 5 The crystal structure diagram of compound 4aa obtained in Example 1 in the specific embodiment;

[0035] Figure 6 is the survival rate of inflammatory cells by samples 4a1 (sample 1) and 4aa (sample 2) in a specific embodiment;

[0036] Figure 7 4a1 (Sample 1) and 4aa (Sample 2) in a specific embodiment are compared before and after 24 hours of administration to determine the effects of inflammatory cell proliferation;

[0037] Figure 8 In the specific embodiment, the absorbance of samples 4a1 (sample 1) and 4aa (sample 2) was detected by CCK8 and the statistical difference diagram was shown. Figure 8 (a) is the absorbance graph, Figure 8 (b) is a statistical difference diagram. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0039] Example 1

[0040] The present invention adopts a model reaction: the substrate N-pyrimidine indole derivative 3a (195.23, 0.1mmol, 19.5mg), the substrate tri-O-acetyl-D-glucal 2a (272.25, 0.2mmol, 54.5mg), the catalyst ferric bromide (295.56, 0.01mmol, 3.0mg) and the base sodium acetate (82.03, 0.2mmol, 16.4mg) are placed in a Schlenk tube, 1.0mL of solvent toluene is added, and the reaction is magnetically stirred at 120°C for 24h to obtain the target compound 4aa. The reaction scheme is shown below. The final product was tested, and the nuclear magnetic hydrogen spectrum of 4aa is shown in FIG. Figure 1 The crystal structure of 4aa is shown in Figure 5 .

[0041]

[0042] Example 2

[0043] The substrate NN dimethylaminoformyl indole derivative 3b (188.23, 0.1 mmol, 19 mg), substrate tri-O-acetyl-D-glucal 2a (272.25, 0.2 mmol, 54.5 mg), catalyst ferric bromide (295.56, 0.01 mmol, 3.0 mg) and base sodium acetate (82.03, 0.2 mmol, 16.4 mg) were placed in a Schlenk tube, 1.0 mL of solvent toluene was added, and the reaction was stirred magnetically at 120 ° C for 24 h to obtain the target compound 4ag. The final product was tested, and the nuclear magnetic hydrogen spectrum of 4ag was shown in FIG. Figure 2 .

[0044]

[0045] Example 3

[0046] The substrate N-pivaloyl-4-methoxyindole derivative 3c (231.30, 0.1 mmol, 23.2 mg), the substrate tri-O-acetyl-D-glucal 2a (272.25, 0.2 mmol, 54.5 mg), the catalyst ferric bromide (295.56, 0.01 mmol, 3.0 mg) and the base sodium acetate (82.03, 0.2 mmol, 16.4 mg) were placed in a Schlenk tube, 1.0 mL of toluene was added, and the reaction was stirred magnetically at 120°C for 24 h to obtain the target compound 4ak. The final product was tested, and the H NMR spectrum of 4ak is shown in FIG. Figure 3 ,Depend on Figure 3 It can be seen that 4ak only has α configuration.

[0047]

[0048] Example 4

[0049] The substrate N-pivaloyl-4-aldehyde indole derivative 3d (229.28, 0.1mmol, 23mg), the substrate tri-O-acetyl-D-glucal 2a (272.25, 0.2mmol, 54.5mg), the catalyst ferric bromide (295.56, 0.01mmol, 3.0mg) and the base sodium acetate (82.03, 0.2mmol, 16.4mg) were placed in a Schlenk tube, 1.0mL of solvent toluene was added, and the reaction was stirred magnetically at 120℃ for 24h to obtain the target compound 4al. The final product was tested, and the H NMR spectrum of 4al was shown in Figure 4 ,Depend on Figure 4 It can be seen that 4al has only α configuration.

[0050]

[0051] The solvent optimization of compound 4aa is shown in Table 1 below

[0052] Table 1 Yield of compound 4aa and optimization of synthesis solvent

[0053] No. 2a 3a Catalysis Base Solvent Yield note 1 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc DCE 10％ 24h,120℃ 2 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc Dioxane nd 24h,120℃ 3 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc <![CDATA[CH3COCH3]]> trace 24h,120℃ 4 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc <![CDATA[PhCH3]]> 32％ 24h,120℃ 5 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc DMF nd 24h,120℃ 6 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc CH3CN trace 24h,120℃ 7 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc tAmOH nd 24h,120℃ 8 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc MTBE Trace 24h,120℃ 9 0.2mmol 0.1mmol <![CDATA[FeCl2 4H2O]]> NaOAc DMSO nd 24h,120℃

[0054] The catalyst optimization of compound 4aa is shown in Table 2 below.

[0055] Table 2 Yield of compound 4aa and optimization of synthesis catalyst

[0056]

[0057]

[0058] The yield and synthesis temperature optimization of compound 4aa are shown in Table 3 below.

[0059] Table 3 Synthesis temperature optimization of compound 4aa

[0060] No. 2a 3a Catalysis Base Solvent Yield Air 1 0.2mmol 0.1mmol <![CDATA[FeBr3]]> NaOAc <![CDATA[PhCH3]]> 78％ 16h,120℃ 2 0.2mmol 0.1mmol <![CDATA[FeBr3]]> NaOAc <![CDATA[PhCH3]]> 55％ 16h,100℃ 3 0.2mmol 0.1mmol <![CDATA[FeBr3]]> NaOAc <![CDATA[PhCH3]]> 30％ 16h,60℃

[0061] The optimized base species of compound 4aa is shown in Table 4 below

[0062] Table 4 Yield of compound 4aa and optimization of synthetic base types

[0063] No. 2a 3a Catalysis Base Solvent Yield Air 1 0.2mmol 0.1mmol <![CDATA[FeBr3]]> KOAc <![CDATA[PhCH3]]> 22％ 12h,120℃ 2 0.2mmol 0.1mmol <![CDATA[FeBr3]]> DMAP <![CDATA[PhCH3]]> nd 12h,120℃ 3 0.2mmol 0.1mmol <![CDATA[FeBr3]]> <![CDATA[K3PO4]]> <![CDATA[PhCH3]]> 42％ 12h,120℃ 4 0.2mmol 0.1mmol <![CDATA[FeBr3]]> <![CDATA[Na2CO3]]> <![CDATA[PhCH3]]> 57％ 12h,120℃ 5 0.2mmol 0.1mmol <![CDATA[FeBr3]]> DBU <![CDATA[PhCH3]]> nd 12h,120℃ 6 0.2mmol 0.1mmol <![CDATA[FeBr3]]> <![CDATA[N(Et)3]]> <![CDATA[PhCH3]]> nd 12h,120℃ 7 0.2mmol 0.1mmol <![CDATA[FeBr3]]> NaOAc <![CDATA[PhCH3]]> 77％ 12h,120℃ 8 0.2mmol 0.1mmol <![CDATA[FeBr3]]> NaOAc <![CDATA[PhCH3]]> 86％ 24h,120℃

[0064] As can be seen from Tables 1 to 4, the solvent in the present invention can be dichloroethane or toluene, preferably toluene; the iron-containing catalyst can be: ferrous chloride tetrahydrate, ferric chloride hexahydrate, ferric perchlorate monohydrate, ferric chloride, ferric bromide, preferably ferric chloride; the pH adjuster includes potassium acetate, potassium phosphate, sodium carbonate, sodium acetate, preferably sodium acetate.

[0065] Detection of anti-inflammatory activity of 4aa and 4al

[0066] To 5 mg of 4al (sample 1) and 4aa (sample 2), 1 mL of DMSO was added in a spinner flask. The mixture was shaken and ultrasonically dissolved to obtain a mother liquor. An appropriate amount of the mother liquor was added to complete culture medium to make the volume to 4 mL and vortexed thoroughly to obtain a 10 μg / mL sample solution. The solution was passed through a membrane and set aside.

[0067] MH7A cells were digested with trypsin at 37°C for 1 minute, and then complete culture medium was added to terminate the digestion. The cells were pipetted into a centrifuge tube and centrifuged at 1000 r×5 min. The precipitate was added with 4 mL of complete culture medium to resuspend the cells. After mixing, 10 μL was spotted on a cell counting plate. The cells were counted using a cell counting plate and the cell stock solution was diluted according to the formula to obtain 1×10 cells per mL of complete culture medium. 6 100 μL of cell culture medium was added to each well of the inner layer of a 96-well cell culture plate. 200 μL of PBS buffer was then added to each well of the outermost layer to minimize evaporation. After completing these steps, the plate was covered with a lid and sterilized by heating the edges with an alcohol burner. After spraying with 75% alcohol for sterilization, the plate was placed in a 5% CO2 incubator for 24 hours. After 24 hours, the remaining culture medium was aspirated and rinsed with 100 μL of PBS buffer. The buffer and floating dead cells were aspirated. The treated group received 100 μL of complete culture medium containing the drug, while the control group received an equal volume of complete culture medium. After 24 hours, the culture medium was aspirated, and 100 μL of complete culture medium containing 10% CCK8 was added to each well according to the cell type. After incubation for 2 hours, the cells were protected from light and incubated with foil. The absorbance was then measured at 450 nm using a microplate reader. Cell viability was calculated according to the formula.

[0068] Cell viability = [(AS-AB) / (AC-AB)] × 100%;

[0069] AS: absorbance of the experimental well (culture medium containing cells, CCK8, and drug to be tested);

[0070] AC: absorbance of control wells (culture medium containing cells, CCK8, and no test drug);

[0071] AB: absorbance of blank wells (culture medium without cells, CCK8).

[0072] Experimental results

[0073] like Figure 6 As shown, Normal is a control group containing CCK8 and an equal amount of cells, and its cell viability is the default value of 100%; due to the color error between the reagent and the complete culture medium, a blank group (containing an equal amount of complete culture medium and an equal amount of CCK8) was used to eliminate this error; Control is a control group containing TNF-α (15ng / mL) to promote the growth of inflammatory cells, and its inflammatory cell survival rate was 112.34%, indicating that the model was successful. After inflammatory cells MH7A were co-cultured with 10μg / mL samples for 24 hours, the cell viability was detected by CCK8 reagent, and was 89.46% and 94.79%, respectively. Figure 7 and Figure 8 The results showed that both 4a1 and 4aa had good anti-inflammatory effects.

[0074] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A 3-substituted indole glycoside compound, characterized in that: The compound includes the following structure: 。 2. A method for synthesizing the 3-substituted indole glycoside compound according to claim 1, comprising the following steps: The invention relates to a 3-substituted indole glucal compound obtained by mixing tri-O-acetyl-D-glucal, an indole derivative and an iron-containing catalyst in a solvent.

3. The synthesis method according to claim 2, characterized in that The iron-containing catalyst includes one or more of ferrous chloride tetrahydrate, ferric chloride hexahydrate, ferric perchlorate monohydrate, ferric chloride, and ferric bromide.

4. The synthesis method according to claim 2, characterized in that The solvent includes one or two of dichloroethane and toluene.

5. The synthesis method according to claim 2, characterized in that During the reaction, the pH is controlled to 6-9 using a pH adjuster.

6. The synthesis method according to claim 5, characterized in that The pH regulator includes one or more of potassium acetate, potassium phosphate, sodium carbonate and sodium acetate.

7. Use of the 3-substituted indole ene sugar compound according to claim 1 in the preparation of anti-inflammatory drugs.

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