Alkaloid compound from davidia involucrata baill with anti-ev71 virus activity and preparation and application thereof

Abstract

The application belongs to the technical field of pharmaceutical chemistry, and particularly relates to alkaloid compounds with anti-Enterovirus 71 (EV71) activity and preparation and application thereof. Four novel alkaloid compounds are isolated from branches and leaves of Daphniphyllum calycinum, and the compounds have novel structures. The skeletons of three compounds (compounds 1-3) are rare polycyclic skeletons substituted by cyano groups, and one compound (compound 4) is a rare Daphmanidin type alkaloid. The four alkaloid compounds have significant anti-EV71 virus activity, and have good application prospects in the development of new drugs for preventing and treating infantile hand-foot-mouth disease induced by EV71 virus.

Description

Technical Field

[0001] The present invention belongs to the technical field of medicinal chemistry, and in particular relates to a nephrite alkaloid compound having anti-EV71 virus activity and a preparation and application thereof. Background Art

[0002] Enterovirus 71 (EV71) is one of the main pathogens causing hand, foot, and mouth disease (HFMD) in infants and young children. It can spread rapidly through feces, water, and air, and is highly infectious and morbid, particularly with neurological complications. Children of all ages can be infected, with the highest incidence in those under three years of age. A small number of severely ill children may develop complications such as aseptic meningitis, brainstem encephalitis, and neurogenic pulmonary edema. In rare cases, the condition can be critical and fatal. Survivors can suffer from sequelae, seriously endangering children's health and life. It has been called the "polio" of the 21st century. HFMD caused by EV71 has been reported in several areas, such as Sarawak, Malaysia, with recurring epidemics every two to three years. EV71 infection has become a significant public health issue globally, particularly in the Asia-Pacific region. EV71 is a single-stranded, positive-sense RNA virus belonging to the Picornaviridae family, Enterovirus genus. Its genome is approximately 7,500 bases long and contains only one open reading frame, encoding a polyprotein. This polyprotein, upon further hydrolysis and cleavage, produces the virus's four structural proteins (VP1-VP4) and seven nonstructural proteins (2A-2C and 3A-3D), flanked by 5' and 3' untranslated regions (UTRs). When the virus begins to infect, the four structural proteins undergo structural changes, making them easier to bind to host cells. Once bound, viral replication begins, and the structural proteins undergo further structural changes, allowing the single-stranded RNA within them to easily enter the infected cell. After a series of gene replication and amino acid coding, the precursor proteins are initially assembled. These precursor proteins are then modified and cleaved by the virus's own functional proteins, rapidly converting them into EV71 viral proteins, which then infect other cells.

[0003] Currently, the main anti-EV71 drugs used clinically are ribavirin and acyclovir, but their therapeutic efficacy is limited, and long-term use can easily cause liver damage. Therefore, the development of specific, highly effective, and low-toxic anti-EV71 drugs is of vital importance for infant health and social development. Natural products, as a key source for drug development, offer advantages such as rich and diverse structures and a wide range of biological activities. Therefore, the discovery of natural products from plants with anti-EV71 activity holds significant scientific significance and development potential. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the present invention isolated four new alkaloid compounds from the branches and leaves of Daphniphyllum calycinum. These compounds all have good anti-EV71 virus activity and can be used to prepare anti-EV71 lead compounds and antiviral drugs, providing candidate compounds for the research and development of new anti-EV71 drugs.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The first aspect of the present invention provides a Caulis Acerola alkaloid compound, wherein the Caulis Acerola alkaloid compound comprises at least one of compounds 1-4, and the structural formulas of compounds 1-4 are shown below:

[0007]

[0008] Preferably, the Niu Er Feng alkaloid compound includes at least one of Compounds 3 and 4, and the structural formulas of Compounds 3 and 4 are as follows:

[0009]

[0010] After EV71 (MOI=0.1) infection for 48h, the alkaloid compounds 3 and 4 provided by the present invention showed that the EC 50 Under the same infection conditions, the EC values ​​of compounds 3 and 4 were 2.826 μg / mL and 3.783 μg / mL, respectively. 50 are smaller than ribavirin (Ribavirin's EC 50 The results showed that the concentration of 1 μg / mL of the 1 μg / mL 2-aminobutyric acid was 65.770 μg / mL), indicating that it has good anti-EV71 virus activity and can be used to prepare anti-EV71 lead compounds and antiviral drugs, providing candidate compounds for the research and development of new anti-EV71 drugs.

[0011] The second aspect of the present invention provides the use of the Achyranthes bidentata alkaloid compounds described in the first aspect in the preparation of anti-EV71 virus drugs or drugs for preventing and treating hand, foot and mouth disease in infants and young children induced by EV71 virus.

[0012] The third aspect of the present invention provides an anti-EV71 drug, wherein the anti-EV71 drug comprises at least one of compounds 1-4 as an active ingredient, and the structural formulas of compounds 1-4 are shown below:

[0013]

[0014] Preferably, the anti-EV71 drug uses at least one of compounds 3 and 4 as an active ingredient, and the structural formulas of compounds 3 and 4 are as follows:

[0015]

[0016] Preferably, the anti-EV71 drug further comprises a pharmaceutically acceptable excipient.

[0017] More preferably, the excipients are diluents, adhesives, lubricants, disintegrants, solubilizers, stabilizers, etc. that can be used in the pharmaceutical field, as well as some pharmaceutical matrices; they can also be functional pharmaceutical excipients available in the pharmaceutical field, including surfactants, suspending agents, emulsifiers, and some new pharmaceutical polymer materials, such as cyclodextrin, chitosan, polylactic acid (PLA), polyglycolic acid-polylactic acid copolymer (PLGA), hyaluronic acid, etc.

[0018] Preferably, the dosage forms of the anti-EV71 drug include tablets, granules, capsules, pills, sustained-release preparations, oral liquid preparations, powder for injection, and injection.

[0019] Preferably, the anti-EV71 drug is administered orally or by injection.

[0020] The pharmaceutical preparations of the present invention can be administered orally or parenterally (e.g., intravenously, subcutaneously, intraperitoneally, or topically), i.e., can be flexibly administered orally, subcutaneously, intramuscularly, and intravenously. If certain drugs are unstable under gastric conditions, they can be prepared as enteric-coated tablets.

[0021] The fourth aspect of the present invention also provides a method for preparing four alkaloid compounds from Rhizoma Cynanchum, comprising the following steps:

[0022] (1) soaking and extracting dried Acer truncatum branches and leaves with an ethanol solution, and recovering the solvent by rotary decompression to obtain an extract;

[0023] (2) dissolving the extract with water and adjusting the pH of the aqueous solution;

[0024] (3) extracting the aqueous solution of step (2) with ethyl acetate, adjusting the pH of the extracted aqueous layer, extracting it again with dichloromethane, and concentrating it;

[0025] (4) extracting the aqueous layer from step (3) with dichloromethane and concentrating;

[0026] (5) The dichloromethane layer extract is separated and purified to obtain the alkaloid compounds of the Herba Cynanchifoliae.

[0027] Preferably, in step (1), the ethanol is an ethanol aqueous solution with a volume fraction of 90% to 95%.

[0028] Preferably, in step (2), the pH of the aqueous solution is adjusted to 2-3 using 3% tartaric acid and hydrochloric acid.

[0029] Preferably, in step (3), the pH of the water layer is adjusted to pH = 9-10 using a saturated sodium carbonate solution.

[0030] Preferably, in step (5), the separation is first performed by elution through silica gel column chromatography and then by separation through Sephadex LH-20 column.

[0031] More preferably, the elution system for the silica gel column chromatography is dichloromethane and methanol in a volume ratio of (80:1)-(1:1).

[0032] Preferably, in step (5), the purification is performed by semi-preparative high performance liquid chromatography using a reverse phase C18 column, with the mobile phase being methanol and water.

[0033] Preferably, the volume ratio of methanol to water is (100-10):(0-90), and the flow rate of the mobile phase is 1-3 mL / min.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] To screen compounds with anti-EV71 activity from natural products, the present invention isolated four new Daphniphyllum calycinum alkaloid compounds from the branches and leaves of Daphniphyllum calycinum. These compounds have novel structures. The skeletons of compounds 1–3 are rare polycyclic skeletons substituted with cyano groups, and compound 4 is a rare daphmanidin-type alkaloid. These compounds have enterovirus 71 inhibitory activity, especially compounds 3 and 4. Compounds 3 and 4 showed EC inhibition after 48 hours of EV71 infection (MOI = 0.1). 50 Under the same infection conditions, the EC values ​​of compounds 3 and 4 were 2.826 μg / mL and 3.783 μg / mL, respectively. 50 are smaller than ribavirin (Ribavirin's EC 50 The four new alkaloid compounds from Atractylodes macrocephala provided by the present invention have good application prospects in the development of new drugs for the prevention and treatment of hand, foot and mouth disease in infants and young children induced by EV71 virus. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The H NMR spectrum of the alkaloid compound 1 from Niuerfeng ( 1 HNMR spectrum);

[0037] Figure 2 The C NMR spectrum of the alkaloid compound 1 from Niuerfeng ( 13 C NMR spectroscopy) and distortionless polarization transfer technique spectroscopy (DEPT spectroscopy);

[0038] Figure 3 This is the high-resolution electrospray ionization mass spectrum (HRESIMS spectrum) of Niuerfeng alkaloid compound 1;

[0039] Figure 4 This is the infrared spectrum (IR spectrum) of the alkaloid compound 1 from the herbaceous pine;

[0040] Figure 5 This is the ultraviolet spectrum (UV spectrum) of the Niuerfeng alkaloid compound 1;

[0041] Figure 6 It is a compound of the alkaloids of Niuerfeng 1 HNMR spectrum;

[0042] Figure 7 It is a compound of the alkaloids of Niuerfeng 13 C NMR and DEPT spectra;

[0043] Figure 8 This is the HRESIMS spectrum of Niuerfeng alkaloid compound 2;

[0044] Figure 9 This is the IR spectrum of the alkaloid compound 2 from Niuerfeng;

[0045] Figure 10 This is the UV spectrum of Niuerfeng alkaloid compound 2;

[0046] Figure 11 For the alkaloid compound 3 of Niuerfeng 1 HNMR spectrum;

[0047] Figure 12 For the alkaloid compound 3 of Niuerfeng 13 C NMR and DEPT spectra;

[0048] Figure 13 This is the HRESIMS spectrum of Niuerfeng alkaloid compound 3;

[0049] Figure 14 This is the IR spectrum of the alkaloid compound 3 from Niuerfeng;

[0050] Figure 15 This is the UV spectrum of the alkaloid compound 3 from Niuerfeng;

[0051] Figure 16 For the alkaloid compound 4 of Niuerfeng 1 HNMR spectrum;

[0052] Figure 17 For the alkaloid compound 4 of Niuerfeng 13 C NMR and DEPT spectra;

[0053] Figure 18 This is the HRESIMS spectrum of Niuerfeng alkaloid compound 4;

[0054] Figure 19 This is the IR spectrum of the alkaloid compound 4 from Niuerfeng;

[0055] Figure 20 This is the UV spectrum of the alkaloid compound 4 from Niuerfeng;

[0056] Figure 21 This is the preliminary screening result of the antiviral activity of alkaloid compounds 1–4 from Niuerfeng using the CCK8 method;

[0057] Figure 22 Determination of EC of alkaloid compound 3 from Niuerfeng by CCK8 method 50 Result graph;

[0058] Figure 23 Determination of EC of alkaloid compound 4 from Niuerfeng by CCK8 method 50 Result graph;

[0059] Figure 24 The EC of the positive control drug ribavirin was determined by CCK8 method. 50 Result graph. DETAILED DESCRIPTION

[0060] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0061] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0062] Example: Isolation and identification of alkaloid compounds from Atractylodes macrocephala

[0063] 1.1 Reagents and instruments used in the experiment

[0064] (1) Analytical ethanol, ethyl acetate, dichloromethane, and methanol were purchased from Guangzhou Bell Biotechnology Co., Ltd.; chromatographic grade methanol was purchased from TEDIA, Inc.; and water used for HPLC was Wahaha purified water (Hangzhou Wahaha Company).

[0065] (2) Silica gel for column chromatography (80–120 mesh, 200–300 mesh, 300–400 mesh) and thin-layer chromatography silica gel plates (GF254) were purchased from Shanxi Nuotai Biotechnology Co., Ltd.

[0066] (3) Analytical column XB-C185μM (250mm×4.6mm), semi-preparative column XB-C 18 5μM (250mm×10mm), Sephadex TM LH-20 was purchased from Merck, Germany.

[0067] (4) The color developer used for thin layer chromatography (TLC) was 10% sulfuric acid-ethanol solution.

[0068] (5) Others: UV spectrophotometer (WHF-203B); rotary evaporator (EYEKAN-1300); rotary evaporator (XD-5210A); Agilent 1120 high performance liquid chromatograph (HPLC); Waters e2695 (HPLC); Bruker AM-500 and Bruker AM-600 nuclear magnetic resonance spectrometers (Bruker, Karlsruhe, Germany).

[0069] 1.2. Acquisition of alkaloid compounds from Acer truncatum

[0070] The sample of Acer truncatum used in the experiment was collected in Liannan Yao Autonomous County, Guangdong Province in August 2022. It was authenticated by Professor Zheng Xilong of Guangdong Pharmaceutical University and is stored in the Department of Natural Medicine, School of Pharmacy, Sun Yat-sen University (Shenzhen). The specimen is designated SYSUSZ-2022-Galk.

[0071] The specific preparation method comprises the following steps:

[0072] (1) 15 kg of dried branches and leaves of Acer truncatum were soaked and extracted three times in 20 L of 95% ethanol aqueous solution at room temperature, each time for 3 h. The obtained extracts were filtered, combined and concentrated to form an extract.

[0073] (2) Add water and stir the extract into a suspension (the mass ratio of extract to water is 1:2), and adjust the aqueous solution to pH = 2-3 with 3% tartaric acid and hydrochloric acid, and then use ethyl acetate for extraction. The volume ratio of the water layer to the ethyl acetate layer is 1:1. Extract 3-5 times, and separate the water layer and the ethyl acetate layer for later use.

[0074] (3) The aqueous layer in step (2) was adjusted to a pH of 9-10 with saturated sodium carbonate, extracted three times with dichloromethane and water in a volume ratio of 1:1, and the dichloromethane layer was evaporated and concentrated to prepare an extract for later use.

[0075] (4) The dichloromethane extract was taken and subjected to silica gel column chromatography using a dichloromethane / methanol (80:1–3:1, V / V, with 1‰ diethylamine) elution system to obtain five fractions (Fr.1 to Fr.5).

[0076] (5) Fr.2 was purified by silica gel column chromatography (mobile phase: petroleum ether / ethyl acetate 20:1–0:1, with 1‰ diethylamine) to obtain six components (Fr.2.A–Fr.2.F). Component Fr.2.D was further separated by Sephadex LH-20 (MeOH) column to obtain six subcomponents Fr.2.4.1–Fr.2.4.6. Component Fr.2.4.2 was purified by semi-preparative RP-HPLC (chromatographic column RP-C 18 , 5 μmol / L, 250×10 mm, Welch Materials, Inc.) (mobile phase: methanol / water (volume ratio 65:35, flow rate 3 mL / min)) to prepare compound 2 (1.4 mg, retention time t R 32.0min); component Fr.2.4.3 was subjected to semi-preparative RP-HPLC (chromatographic column RP-C 18 , 5 μmol / L, 250×10 mm, Welch Materials, Inc.) (mobile phase: methanol / water with a volume ratio of 80:20, flow rate 3 mL / min) to prepare compound 3 (1.7 mg, retention time t R 30.3 min) and compound 4 (1.5 mg, retention time t R 26.0min);

[0077] (6) Fr.4 was purified by silica gel column chromatography (mobile phase: petroleum ether / ethyl acetate 15:1–0:1, with 1‰ diethylamine) to obtain four components (Fr.4.1–Fr.4.4). Component Fr.4.3 was further separated by Sephadex LH-20 (MeOH) column to obtain six subcomponents Fr.4.3.1–Fr.4.3.6. Component Fr.4.3.3 was purified by semi-preparative RP-HPLC (chromatographic column RP-C 18 , 5 μmol / L, 250×10 mm, Welch Materials, Inc.) (mobile phase: methanol / water (volume ratio 40:60, flow rate 3 mL / min)) to prepare compound 1 (3.4 mg, retention time t R is 28.0min).

[0078] The four alkaloid compounds 1–4 have the following molecular structures:

[0079]

[0080] The above compounds 1–4 were subjected to structural analysis, and the obtained carbon and hydrogen data assignments are shown in Table 1.

[0081] Table 1 Assignment of carbon and hydrogen data in the NMR spectra of compounds 1–4

[0082]

[0083]

[0084] a Deuterated chloroform was used as solvent. b Deuterated methanol is used as solvent.

[0085]

[0086] a Deuterated chloroform was used as solvent. b Deuterated methanol was used as solvent.

[0087] Combined with the carbon-hydrogen data of compounds 1-4, the structural analysis of the above compounds 1-4 was performed, and the obtained physicochemical property data are as follows:

[0088] Compound 1: colorless crystals; 1 H NMR (CDCl3, 600 MHz) and 13 C NMR (CDCl3, 150 MHz), such as Figure 1 –2; HRESIMS [M+H] + m / z 379.2386 (calcd. for C 24 H 31 N2O,2379.2386);IRν max 3434,2927,1701,1632cm –1 ; UV(MeOH)λ max (logε)204.0nm,298.5nm, such as Figure 3 –5.

[0089] Compound 2: colorless crystals; 1 H NMR (CD3OD, 600 MHz) and 13 C NMR (CD3OD, 150 MHz), such as Figure 6 –7; HRESIMS [M+Na] + m / z 417.2154 (calcd. for C 24 H 30 N2O3Na,417.2156);IRν max 3439,2950,2926,2140,1699,1653,1632,1507,1438,1384,1352,1326,1187,1069,1043cm –1 ; UV(MeOH)λmax (logε)203.0nm,298.0nm, such as Figure 8 –10.

[0090] Compound 3: colorless crystals; 1 H NMR (CDCl3, 600 MHz) and 13 C NMR (CDCl3, 150 MHz), such as Figure 11 –12; HRESIMS [M+Na] + m / z 417.2154 (calcd. for C 24 H 30 N2O3Na,417.2153);IRν max 3433,2958,2924,2854,2140,1703,1637,1463,1383,1263,1189,1081,1026,968,804,559cm –1 ; UV(MeOH)λ max (logε)233.5nm,291.5nm, such as Figure 13 –15.

[0091] Compound 4: white solid; 1 H NMR (CD3OD, 600 MHz) and 13 C NMR (CD3OD, 150 MHz), such as Figure 16 –17; HRESIMS [M+H] + m / z 368.2226 (calcd. for C 23 H 30 NO3,368.2226);IRν max 3427,2928,2872,1702,1648,1630,1438,1384,1351,1254,1115,1066,1030,763,584,567cm –1 ; UV(MeOH)λ max (logε)204.0nm,299.5nm, such as Figure 18 –20.

[0092] Experimental example: Anti-EV71 activity of alkaloid compounds 1–4 from Aquilegia serrata

[0093] 1. Experimental Materials

[0094] (1) Main reagents: Ribavirin (Rb) was purchased from Selleck; DMEM (high glucose) culture medium was purchased from Sangon Biotech Co., Ltd.; penicillin and streptomycin were purchased from Nanjing Shenghang Biotechnology Co., Ltd., and fetal bovine serum (FBS) was purchased from ZETAlife; 0.25% trypsin (containing EDTA) and CCK-8 were purchased from Suzhou Xinsaimei Biotechnology Co., Ltd.

[0095] (2) Test cells and virus strains: RD cells and EV71 strains were obtained from the Shanghai Institute of Major Infectious Diseases and Biosafety.

[0096] 2. Test methods and results

[0097] First, all compounds 1–4 were preliminarily screened for activity, and the compounds with preliminarily screened activity better than the positive control drug were rescreened and their EC 50 curve, and obtain EC 50 value.

[0098] 2.1. Initial screening

[0099] RD cells were plated in a 96-well cell culture plate overnight. When the cells proliferated to about 90% in DMEM (high glucose) medium, the test compounds 1–4 (25 μg / mL) were thoroughly mixed with EV71 virus dilution (MOI = 0.1), added to the cell wells and cultured for 2 hours. The cell supernatant was then aspirated and the cells were washed. Fresh culture medium containing the corresponding concentration of the compound was replaced and cultured for another 48 hours. CCK-8 was used to detect cell activity, i.e., 10 μL of CCK-8 reagent was added to each well. After incubation at 37°C for 1.5 hours, the OD value at a wavelength of 450 nm was measured using a microplate reader. Three replicate wells were set for each sample, and a cell control well without drug and a virus infection control well were also set. Cell survival rate (%) of the drug-treated group = (OD value of the experimental well) 450nm – OD of virus control wells 450nm / OD of cell control well 450nm – OD of virus control wells 450nm ) × 100%. Graph Pad Prism 9.5.1 software was used for graphing.

[0100] like Figure 21 As shown in the figure, when the concentration of compounds 3 and 4 was 25 μg / mL, the cell survival rate was greater than 50% after EV71 (MOI = 0.1) infection for 48 hours, and the antiviral effect was better than that of the positive control drug Ribavirin, indicating that they have certain anti-EV71 virus activity. The subsequent rescreening and determination of EC 50 Although compounds 1 and 2 also have certain anti-EV71 activity, their activity is less than that of the positive control drug Ribavirin, so they are not further screened.

[0101] 2.2 Rescreening

[0102] RD cells were plated in 96 cell culture plates overnight. When the cells proliferated to about 90%, the test compounds 3 and 4 (25 μg / mL) were fully mixed with the virus dilution solution (MOI=0.1), added to the cell wells and cultured for 2 hours. The cell supernatant was then discarded and the cells were washed. Fresh culture medium containing the corresponding concentration of the compound was replaced and cultured for 48 hours. CCK-8 was used to detect cell activity, i.e. 10 μL CCK-8 reagent was added to each well. After incubation at 37°C for 1.5 hours, the OD value at a wavelength of 450 nm was measured using a microplate reader. Three replicate wells were set for each sample, and a cell control well without drug and a virus infection control well were also set. Cell survival rate (%) of the drug-treated group = (OD value of the experimental well) 450nm – OD of virus control wells 450nm / OD of cell control well 450nm – OD of virus control wells 450nm ) × 100%. Graph PadPrism 9.5.1 software was used for graphing.

[0103] like Figure 22 As shown in –24, compounds 3, 4 and Ribavirin were infected with EV71 (MOI = 0.1) for 48 hours. 50 Under the same infection conditions, the EC values ​​of compounds 3 and 4 were 2.826 μg / mL, 3.783 μg / mL, and 65.770 μg / mL, respectively. 50 Both are smaller than ribavirin, indicating that they have better anti-EV71 virus activity.

[0104] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A nephrite alkaloid compound, characterized in that: The Niu Er Feng alkaloid compound is selected from at least one of compounds 1-4, and the structural formulas of compounds 1-4 are shown below:

2. The Niuerfeng alkaloid compound according to claim 1, characterized in that The Niu Er Feng alkaloid compound is selected from at least one of compounds 3 and 4, and the structural formulas of compounds 3 and 4 are shown below:

3. Use of the alkaloid compounds of Rhizoma Cynanchifoliae according to claim 1 or 2 in the preparation of a medicament for preventing and treating hand, foot and mouth disease in infants and young children induced by EV71 virus.

4. An anti-EV71 drug, characterized in that: The anti-EV71 drug contains at least one of compounds 1-4 as an active ingredient, and the structural formulas of the compounds 1-4 are shown below:

5. An anti-EV71 drug according to claim 4, characterized in that: The anti-EV71 drug uses at least one of compounds 3 and 4 as an active ingredient, and the structural formulas of compounds 3 and 4 are as follows:

6. An anti-EV71 drug according to claim 4 or 5, characterized in that: The anti-EV71 drug also includes pharmaceutically acceptable excipients.

7. An anti-EV71 drug according to claim 4 or 5, characterized in that: The dosage forms of the anti-EV71 drug include tablets, granules, capsules, pills, sustained-release preparations, oral liquid preparations, and injections.

8. An anti-EV71 drug according to claim 4 or 5, characterized in that: The anti-EV71 drug can be administered orally or by injection.

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