阅读说明：本技术 抗rna病毒药物及其应用 (anti-RNA virus medicine and application thereof ) 是由 李洪林 徐可 李诗良 朱丽丽 赵振江 于 2021-03-02 设计创作，主要内容包括：本发明涉及新型噻唑类衍生物在治疗RNA病毒感染以及制备治疗RNA病毒感染的药物中的应用。具体而言,本发明涉及下式I所示的化合物、含有下式I化合物的药物组合物在治疗RNA病毒感染以及制备治疗冠状病毒感染的药物中的用途：(The invention relates to application of novel thiazole derivatives in treatment of RNA virus infection and preparation of medicaments for treating RNA virus infection. In particular, the invention relates to the use of compounds of formula I, pharmaceutical compositions containing compounds of formula I, in the treatment of RNA viral infections and in the preparation of medicaments for the treatment of coronavirus infections:)

1. Use of a compound of formula I or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for treating RNA viral infection:

in the formula (I), the compound is shown in the specification,

R₁selected from: H. substituted or unsubstituted C1-C6 alkyl, C3-C6 cycloalkyl;

R₂independently selected from: H. halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, CN, NO₂Hydroxyl group, NR^aR^b；

R^a、R^bCan be independently selected from H or C1-C6 alkyl

R₃Selected from: H. substituted or unsubstituted C1-C6 alkyl;

R₄independently selected from: H. halogen;

m is an integer of 0 to 4;

n is an integer of 0 to 5.

2. The use of claim 1, wherein the RNA virus includes, but is not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV) and 2019 New coronavirus (COVID-19(Corona virus Disease)), Ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2 and the like.

3. The use of claim 2, wherein the RNA virus includes, but is not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

4. Use according to any one of claims 1 to 3, wherein the compound is of formula II:

in the formula (I), the compound is shown in the specification,

R₅and R₆Independently selected from: H. halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, hydroxy, NH₂；

R₇、R₈And R₉Independently selected from: H. halogen;

R₁and R₃As claimed in claim 1.

5. The use according to claim 4, wherein in formula (I)

R₁Selected from: H. C1-C6 alkyl;

R₃selected from: H. substituted or unsubstituted C1-C6 alkyl;

R₅and R₆Independently selected from: H. halogen, unsubstituted or halogen-substituted C1-C3 alkyl;

R₇and R₈Independently selected from: H. halogen;

R₉is H.

6. The use according to any one of claims 1 to 3, wherein the compound of formula I or a pharmaceutically acceptable salt thereof is a compound selected from the group consisting of:

7. the use of claim 6, wherein the compound is a compound selected from the group consisting of:

8. the use according to claim 4, wherein, in the compound of formula II,

R₁selected from: H. C1-C3 alkyl;

R₃selected from: H. substituted or unsubstituted C1-C3 alkyl;

R₅and R₆Independently selected from: H. unsubstituted or halogen-substituted C1-C3 alkyl;

R₇and R₈Independently selected from: H. cl (preferably, R)₇Is Cl, R₈Is H);

R₉is H.

9. The use according to claim 8, wherein the compound is selected from the group consisting of:

10. a pharmaceutical composition comprising a compound of any one of claims 1-9, or a pharmaceutically acceptable salt thereof, in combination with other antiviral drugs, and a pharmaceutically acceptable carrier or excipient.

11. The pharmaceutical composition of claim 10, wherein the other antiviral drug is selected from one or more of lopinavir, ritonavir, ribavirin, ridciclovir, oseltamivir, dabrafil, ranimi, veperamivir, arbidol, chloroquine (chloroquine phosphate), and the like; one or more of oseltamivir, lopinavir, ritonavir, ribavirin, ridciclovir, and chloroquine (chloroquine phosphate) are preferred.

12. Use of a pharmaceutical composition comprising a compound of any one of claims 1-9, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient in the manufacture of a medicament for the treatment of an RNA viral infection.

13. The use of claim 12, wherein the RNA virus includes, but is not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV) and 2019 New coronavirus (COVID-19(Corona virus Disease)), Ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2 and the like.

14. The use of claim 13, wherein the RNA virus includes, but is not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

15. A pharmaceutical composition for treating RNA viral infection comprising a compound of any one of claims 1-8, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

16. The use of claim 15, wherein the RNA virus includes, but is not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV) and 2019 New coronavirus (COVID-19(Corona virus Disease)), Ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2 and the like.

17. The use of claim 16, wherein the RNA virus includes, but is not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

18. A method of treating an RNA viral infection, comprising administering to a subject in need of treatment for an RNA viral infection a therapeutically effective amount of a compound of any one of claims 1-9 or a pharmaceutical composition of any one of claims 10, 11, 15-17.

Technical Field

The present invention relates to the field of pharmaceutical chemistry; in particular, the invention relates to the application of novel thiazole derivatives in the preparation of medicaments for treating RNA virus infection and in the treatment of RNA virus infection.

Background

The virus completes self propagation in the host cell, and infects the host cell through 5 processes of adsorption, invasion, replication, maturation and release, thereby seriously affecting the human health.

Coronaviruses are a class of enveloped single-stranded positive-stranded RNA viruses. The international committee for classification of viruses classified coronaviruses into 4 major groups of α, β, γ, and δ in 2012. At present, 7 kinds of human-infectable coronaviruses, namely human coronavirus 229E (HCoV-229E), human coronavirus NL63(HCoV-NL63), human coronavirus OC43(HCoV-OC43), human coronavirus HKU1(HCoV-HKU1), severe acute respiratory syndrome coronavirus (SARS-CoV) and middle east respiratory syndrome coronavirus (MERCoV), and novel coronavirus (CoVID-19(Corona virus Disease)) have been found. Among them, SARS-CoV, MERS-CoV and 2019-nCoV are highly pathogenic coronaviruses found at present, and bring serious harm to human health.

Currently, the prevention and treatment of viral diseases mainly depends on vaccines and drugs. The vaccine itself has certain limitations: the immunization rate is low, and effective group immunity is difficult to generate; the immunity hardly generates effective immunity for high risk people, such as the elderly and people with immunodeficiency; due to the lack of post-translational correction mechanisms of viral RNA polymerase, development of new vaccines is continually ongoing in the face of continuous viral mutations, and it is difficult to generate sufficient amounts of new vaccines in a short time at the early stage of rapid epidemic.

Antiviral drug research remains a hot topic in the field of antiviral research. The commonly used antiviral drugs mainly include two main classes of chemical drugs and Chinese herbal medicines. Different antiviral drugs have different mechanisms of action. In the early infection stage of the virus, the antiviral drug can block the combination of the virus shell and the cell surface receptor of the organism to resist the virus by inhibiting the adsorption and invasion of the virus; after the virus enters the cell, the antiviral drug can achieve the antiviral effect by inhibiting the replication, transcription and protein synthesis of virus nucleic acid; yet another mode of action of antiviral drugs after viral particle assembly is complete is to inhibit viral release. In addition, viruses easily invade the host under the condition that the body resistance is reduced, and in this case, the antiviral drugs can also resist viruses by enhancing the body resistance.

Antiviral drugs include two ion channel inhibitors: amantadine, two neuraminidase inhibitors, oseltamivir and zanamivir, inhaled. However, most influenza viruses develop resistance to both amantadine and oseltamivir, for example. Seasonal H1N1 virus, which occurred in the united states in 2009, developed resistance to oseltamivir, while nearly all H3N2 virus was resistant to amantadine.

Against the outbreak of 2019-nCoV which also has no specific medicine, several broad-spectrum antiviral medicines are recommended at present, including lopinavir/ritonavir and some traditional Chinese medicine preparations. In the face of the current emergency, the research and development of novel antiviral drugs are very necessary.

Disclosure of Invention

The object of the present invention is to provide a novel, broad-spectrum compound having an activity against coronavirus infection for use as a therapeutic agent for coronavirus infection.

In a first aspect, the present invention provides the use of a compound of formula I, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for the treatment of an RNA viral infection:

in the formula (I), the compound is shown in the specification,

R₁selected from: H. substituted or unsubstituted C1-C6 alkyl, C3-C6 cycloalkyl;

R₂independently selected from: H. halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, CN, NO₂Hydroxyl group, NR^aR^b；

R^a、R^bCan be independently selected from H or C1-C6 alkyl;

R₃selected from: H. substituted or unsubstituted C1-C6 alkyl;

R₄independently selected from: H. halogen;

m is an integer of 0 to 4;

n is an integer of 0 to 5.

In particular embodiments, the RNA viruses include, but are not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV), and 2019 neocoronavirus (2019-nCoV); ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2, etc.

In preferred embodiments, the RNA viruses include, but are not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

In a specific embodiment, the compound is of formula II:

in the formula (I), the compound is shown in the specification,

R₅and R₆Independently selected from: H. halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, hydroxy, NH₂；

R₇、R₈And R₉Independently selected from: H. halogen;

R₁and R₃As described above.

In a specific embodiment, in the formula

R₁Selected from: H. C1-C6 alkyl;

R₃selected from: H. substituted or unsubstituted C1-C6 alkyl;

R₅and R₆Independently selected from: H. halogen, unsubstituted or halogen-substituted C1-C3 alkyl;

R₇and R₈Independently selected from: H. halogen;

R₉is H.

In a preferred embodiment, R in the formula₁Selected from H or methyl.

In a specific embodiment, the compound of formula I or a pharmaceutically acceptable salt thereof is a compound selected from the group consisting of:

in particular embodiments, the compound is a compound selected from the group consisting of:

in a preferred embodiment, in the compound of formula II,

R₁selected from: H. C1-C3 alkyl;

R₃selected from: H. substituted or unsubstituted C1-C3 alkyl;

R₅and R₆Independently selected from: H. unsubstituted or halogen-substituted C1-C3 alkyl;

R₇and R₈Independently selected from: H. cl (preferably, R)₇Is Cl, R₈Is H);

R₉is H.

In a preferred embodiment, the compound is selected from compound No. 1 or 16.

In a second aspect, the present invention provides a pharmaceutical composition comprising a compound of the first aspect or a pharmaceutically acceptable salt thereof in combination with other antiviral drugs, and a pharmaceutically acceptable carrier or excipient.

In a preferred embodiment, the pharmaceutical composition is for use against RNA viral infection.

In preferred embodiments, the RNA viruses include, but are not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV), and 2019 New coronavirus (COVID-19(Corona virus Disease)); ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2, etc.

In preferred embodiments, the RNA viruses include, but are not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

In a preferred embodiment, the other antiviral drug is selected from one or more of lopinavir, ritonavir, ribavirin, ridciclovir, oseltamivir, tamiflu, raney mi, wiperamivir, abidol, chloroquine (chloroquine phosphate), and the like; one or more of oseltamivir, lopinavir, ritonavir, ribavirin, ridciclovir, and chloroquine (chloroquine phosphate) are preferred.

In a third aspect, the present invention provides a use of a pharmaceutical composition for the manufacture of a medicament for the treatment of RNA viral infection, wherein the pharmaceutical composition comprises a compound of the first aspect or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

In preferred embodiments, the RNA viruses include, but are not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV), and 2019 New coronavirus (COVID-19(Corona virus Disease)); ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2, etc.

In preferred embodiments, the RNA viruses include, but are not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

In a fourth aspect, the present invention provides a pharmaceutical composition for use in the treatment of RNA viral infection and comprising a compound of the first aspect or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

In preferred embodiments, the RNA viruses include, but are not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV), and 2019 New coronavirus (COVID-19(Corona virus Disease)); ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2, etc.

In preferred embodiments, the RNA viruses include, but are not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

In a fifth aspect, the present invention provides a method of treating an RNA viral infection, the method comprising administering a compound of the first aspect or a pharmaceutical composition of the second aspect to a subject in need of treatment for an RNA viral infection.

In preferred embodiments, the RNA viruses include, but are not limited to: coronaviruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV), and 2019 New coronavirus (COVID-19(Corona virus Disease)); ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2, etc.

In preferred embodiments, the RNA viruses include, but are not limited to: severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (COVID-19(Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N2, H1N 1.

It is to be understood that within the scope of the present invention, the above-described features of the present invention and those specifically described below (e.g., in the examples) may be combined with each other to form new or preferred embodiments. Not to be reiterated herein, but to the extent of space.

Drawings

FIG. 1 shows the inhibitory efficiency of Compound No. 16(S312) and Compound No. 1(S416) on COVID-19(Corona virus Disease) on Vero cells. Wherein, the abscissa is the drug concentration, the ordinate is the inhibition efficiency to the new coronavirus, and the virus gene copy number in the cell supernatant is taken as the quantitative standard. The red line is a virus inhibitory concentration curve, and the green line is a cytotoxicity concentration curve;

FIG. 2 shows the inhibitory efficiency of compounds S312, S416 on Ebola replicons on BSR T7/5 cells. Wherein, the abscissa is the drug concentration, the ordinate is the inhibition efficiency on the Ebola virus replication, and the expression quantity of the reported gene on the virus genome is taken as a quantitative index. The red line is a virus inhibitory concentration curve, and the green line is a cytotoxicity concentration curve;

fig. 3 shows the inhibitory efficiency of compounds S312, S416 on H9N2 virus on MDCK cells. Wherein, the abscissa is the drug concentration, the ordinate is the inhibition efficiency against influenza virus replication, and the Cell death CPE degree (using Cell Titer-Glo quantitative determination) caused by virus infection is taken as a quantitative index. The red line is the virus inhibitory concentration curve and the green line is the cytotoxicity concentration curve.

FIG. 4 shows the antiviral efficacy of compounds S312, S416 administered early in the A/WSN/33(H1N1) (WSN) influenza virus-infected mouse model. Wherein the left graph weight curve has the time of infection on the abscissa and the mean percent weight change ± SEM on the ordinate. The right survival curve has the time to infection on the abscissa and the percent survival on the ordinate. Black lines indicate Non-treatment groups, blue lines indicate marketed control drug oseltamivir (Osel) -20mg/kg groups, and green, red and orange lines indicate test drugs. Asterisks (, asterisks) indicate significance when drug groups were compared to Non-treatment groups. P < 0.05; p < 0.01; and P < 0.001.

Figure 5 shows the antiviral efficacy of compounds S312, S416 administered late in a WSN influenza virus infected mouse model. Wherein the left graph weight curve has the abscissa representing the time to infection, the green line on the abscissa representing the time to administration, and the ordinate representing the mean percent change in body weight ± SEM. The right survival curve has the time to infection on the abscissa and the percent survival on the ordinate. The black line indicates the Non-treatment group, the blue line indicates the oseltamivir-20 mg/kg group, the red line indicates the test compound alone group, and the green line indicates the test compound in combination with oseltamivir. Asterisks (#) indicate significance when drug groups were compared to Non-treatment groups, while pound (#) indicates significance between treatment alone and combination treatment. P < 0.05; # P < 0.01; and P < 0.001.

Figure 6 (day 4 post-infection) and figure 7 (day 7 post-infection) show the antiviral efficacy of compound S416 in a mouse model of new coronavirus infection. Wherein the upper panel weight curve is the time to infection on the abscissa and the mean percent weight change ± SEM on the ordinate. The lower panel shows the viral genes on the abscissa and the relative quantification of fluorescence of mRNA levels of the new coronavirus genes (E gene and N gene) as a percentage. + -. SEM relative to the Non-treatment group on the ordinate. The black line indicates the Non-treatment group, and the red line indicates the compound group. Asterisks (, asterisks) indicate significance when drug groups were compared to Non-treatment groups. P < 0.05; p < 0.01; and P < 0.001.

Figure 8 shows the antiviral efficacy of compound S416 in a hamster model of new coronavirus infection. Wherein the left graph weight curve has the time of infection on the abscissa and the mean percent weight change ± SEM on the ordinate. The right panel shows the relative fluorescence quantification of the mRNA levels of the two genes of the novel coronavirus (ORF1ab and N) on the abscissa and the viral genes on the ordinate. The black line indicates the Non-treatment group, and the red and blue lines indicate the compound group. Asterisks (, asterisks) indicate significance when drug groups were compared to Non-treatment groups. P < 0.05; p < 0.01; and P < 0.001.

Detailed Description

The inventors have conducted extensive and intensive studies and have unexpectedly found a series of thiazole derivatives having a broad spectrum and excellent anti-coronavirus activity. At the same time, these compounds have low toxicity. The present invention has been completed based on this finding.

The present inventors designed novel compounds for nucleic acid synthesis reaction of host cells and screened toxicity and function of the compounds to obtain optimal candidate compounds. Since viral replication is heavily dependent on the nucleic acid resources of the host cell, and excessive inflammatory response due to viral infection is also dependent on gene expression, blocking nucleic acid synthesis in the host cell can inhibit viral replication on the one hand and excessive inflammatory response on the other hand. In normal cells, because the gene synthesis and expression are in a certain steady state and do not depend on new nucleic acid synthesis excessively, the compound of the invention has less toxicity to normal cells and has more obvious effect on virus-infected cells.

Definition of terms

Some of the groups referred to herein are defined as follows:

as used herein, "alkyl" refers to a saturated, branched or straight chain alkyl group having a carbon chain length of 1 to 10 carbon atoms, with preferred alkyl groups including those varying in length from 2 to 8 carbon atoms, 1 to 6, 1 to 4 carbon atoms, 1 to 3 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, heptyl, and the like. The alkyl group may be substituted with 1 or more substituents, for example, with halogen or haloalkyl. For example, the alkyl group may be an alkyl group substituted with 1 to 4 fluorine atoms, such as a trifluoromethyl group, or the alkyl group may be an alkyl group substituted with a fluoroalkyl group.

As used herein, "cycloalkyl" refers to saturated alkyl groups containing an alicyclic structure, e.g., C3-C6 cycloalkyl. In particular embodiments, the cycloalkyl groups include, but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl. Cycloalkyl groups described herein may be substituted or unsubstituted, including but not limited to being substituted with one or more halogen atoms, such as fluorine atoms.

As used herein, "amino" refers to a group of formula "NRxRy", wherein Rx and Ry may be independently selected from H or C1-C3 alkyl or C1-C3 haloalkyl. In a specific embodiment, "amino" as used herein refers to NH 2.

Herein, "halogen" refers to fluorine, chlorine, bromine and iodine. In a preferred embodiment, halogen is chlorine or fluorine; more preferably fluorine.

Compounds of the invention

The inventors have unexpectedly found a series of thiazole derivatives having a broad spectrum and excellent anti-coronavirus activity. These compounds show excellent anti-coronary activity in animal experiments.

In a specific embodiment, the compound of the invention is a compound of formula I or a pharmaceutically acceptable salt thereof:

in the formula (I), the compound is shown in the specification,

R₁selected from: H. substituted or unsubstituted C1-C6 alkyl, C3-C6 cycloalkyl;

R₂independently selected from: H. halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, CN, NO₂Hydroxyl group, NR^aR^b；

R^a、R^bCan be independently selected from H or C1-C6 alkyl

R₃Selected from: H. substituted or unsubstituted C1-C6 alkyl;

R₄selected from: H. halogen;

m is an integer of 0 to 4;

n is an integer of 0 to 5.

In a preferred embodiment, the compounds of the present invention are represented by formula II:

in the formula (I), the compound is shown in the specification,

R₅and R₆Independently selected from: H. halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, hydroxy, NH₂；

R₇、R₈And R₉Independently selected from: H. halogen;

R₁and R₃As described above.

In a further embodiment, R₁Selected from: H. C1-C6 alkyl, preferably C1-C3 alkyl; r₃Selected from: H. substituted or unsubstituted C1-C6 alkyl, preferably C1-C3 alkyl; r₅And R₆Independently selected from: H. halogen, preferably F, unsubstituted or halogen, preferably F-substituted C1-C3 alkyl; r₇And R₈Independently selected from: H. halogen, preferably Cl; r₉Is H.

In a preferred embodiment, the compound of the invention is selected from the following compound No. 1 and compound No. 16:

in addition, one skilled in the art can understand, based on the common general knowledge in the art and the contents of the present invention, that the compound of the present invention can form a salt or an ester due to the carboxyl group contained therein, and further can form a prodrug.

Virus

The RNA viruses described herein (RNA viruses) are a type of biological virus whose genetic material consists of ribonucleic acids (RNA ribonuclear acids), which are usually single-stranded (ssRNA) and also double-stranded (dsRNA).

The term "coronavirus (Coronaviruses)" as used herein is a single-stranded positive-strand RNA virus belonging to the order Nidovirales (Nidovirales) Coronaviridae (Coronaviridae) orthocoronaviridae (orthocoronaviridae). The virus can infect various species such as human, bat, pig, mouse, cow, horse, goat, monkey, etc. There are known 7 kinds of human-infecting coronavirus (HCoV), including middle east respiratory syndrome-associated coronavirus (MERSR-CoV) and severe acute respiratory syndrome-associated coronavirus (SARSr-CoV).

The coronavirus named as COVID-19(Corona virus Disease) by WHO belongs to a novel coronavirus of beta genus, and is the 7 th coronavirus capable of infecting human. At present, no effective vaccine and therapeutic drug aiming at coronavirus exist, and virus diffusion is mainly controlled through precautionary measures, epidemic situation is closely monitored, and suspected cases are isolated and observed. At present, no specific treatment method for coronavirus exists, and symptomatic support treatment is mainly adopted.

The present invention further provides, on the basis of the above compounds, a method for the treatment of viruses, in particular RNA viruses, including but not limited to: pharmaceutical compositions of infections with coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERCoV) and 2019 New coronavirus (COVID-19(Corona virus Disease)), Ebola virus, bunyavirus, avian influenza H9N2, H1N1, H7N9, arenavirus, rabies virus, hepatitis C HCV, hepatitis B HBV, human immunodeficiency virus HIV-1, herpes simplex virus HSV-1, HSV-2, and the like, comprising a therapeutically effective amount of a compound of the present invention, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient. In a preferred embodiment, the compounds or pharmaceutical compositions of the invention may be used for the treatment of infections caused by severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and 2019 novel coronavirus (covi-19 (Corona virus Disease)), ebola virus, fever-associated thrombocytopenia syndrome virus (sftsv), avian influenza virus H9N 2.

Examples of pharmaceutically acceptable salts of the compounds of the present invention include, but are not limited to, inorganic and organic acid salts, such as hydrochloride, hydrobromide, sulfate, citrate, lactate, tartrate, maleate, fumarate, mandelate and oxalate salts; and inorganic and organic base salts formed with bases such as sodium hydroxy, TRIS (hydroxymethyl) aminomethane (TRIS, tromethamine) and N-methylglucamine.

Although the requirements vary from person to person, the skilled person can determine the optimal dosage of each active ingredient in the pharmaceutical composition of the invention. Typically, the compounds of the present invention, or pharmaceutically acceptable salts thereof, are administered orally to a mammal daily in an amount of from about 0.0025 to 50 mg/kg body weight. But preferably about 0.01 to 10mg per kg is administered orally. For example, a unit oral dosage may include from about 0.01 to 50 mg, preferably from about 0.1 to 10mg, of a compound of the present invention. A unit dose may be administered one or more times daily in one or more tablets, each tablet containing from about 0.1 to 50 mg, conveniently from about 0.25 to 10mg, of a compound of the invention or a solvate thereof.

The pharmaceutical compositions of the present invention may be formulated in a form suitable for various routes of administration, including but not limited to, administration by parenteral, subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal, buccal, intrathecal, intracranial, nasal or topical routes for the treatment of tumors and other diseases. The amount administered is an amount effective to ameliorate or eliminate one or more symptoms. For the treatment of a particular disease, an effective amount is an amount sufficient to ameliorate or in some way reduce the symptoms associated with the disease. Such amounts may be administered as a single dose or may be administered according to an effective treatment regimen. The amount administered may be sufficient to cure the disease, but is generally administered to ameliorate the symptoms of the disease. Repeated administration is generally required to achieve the desired improvement in symptoms. The dosage of the drug will depend on the age, health and weight of the patient, the type of concurrent treatment, the frequency of treatment, and the desired therapeutic benefit.

The pharmaceutical preparation of the present invention can be administered to any mammals as long as they can obtain the therapeutic effects of the compound of the present invention. Of these mammals, the most important is human. The compounds of the present invention or pharmaceutical compositions thereof are useful for treating ulcerative colitis.

The pharmaceutical preparations of the present invention can be manufactured in a known manner. For example, by conventional mixing, granulating, dragee-making, dissolving, or lyophilizing processes. In the manufacture of oral formulations, solid excipients and active compounds may be combined, optionally grinding the mixture. If desired or necessary after addition of suitable amounts of auxiliaries, the granulate mixture is processed to give tablets or dragee cores.

Suitable adjuvants are, in particular, fillers, for example sugars such as lactose or sucrose, mannitol or sorbitol; cellulose preparations or calcium phosphates, such as tricalcium phosphate or calcium hydrogen phosphate; and binders, such as starch pastes, including corn starch, wheat starch, rice starch, potato starch, gelatin, tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, or polyvinylpyrrolidone. If desired, disintegrating agents such as the starches mentioned above, as well as carboxymethyl starch, cross-linked polyvinylpyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate may be added. Adjuvants are, in particular, flow regulators and lubricants, for example silica, talc, stearates, such as calcium magnesium stearate, stearic acid or polyethylene glycol. If desired, a suitable coating resistant to gastric juices can be provided to the tablet core. For this purpose, concentrated saccharide solutions can be used. Such solutions may contain gum arabic, talc, polyvinyl pyrrolidone, polyethylene glycol and/or titanium dioxide, lacquer solutions and suitable organic solvents or solvent mixtures. For the preparation of coatings resistant to gastric juices, suitable cellulose solutions can be used, for example cellulose acetate phthalate or hydroxypropylmethyl cellulose phthalate. Dyes or pigments may be added to the coating of the tablet or lozenge core. For example, for identifying or for characterizing combinations of active ingredient doses.

The method of administration of the pharmaceutical composition includes, but is not limited to, various methods of administration known in the art, and can be determined according to the actual condition of the patient. These methods include, but are not limited to, parenteral, subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal, buccal, intrathecal, intracranial, nasal, or topical routes of administration.

In addition to the compounds of the present invention, the pharmaceutical compositions of the present invention may further comprise other antiviral agents which may be selected from one or more of lopinavir, ritonavir, ribavirin, ridciclovir, oseltamivir, tamiflu, lanimivir, peramivir and chloroquine (chloroquine phosphate); one or more of lopinavir, ritonavir, ribavirin, rituxivir, and chloroquine (chloroquine phosphate) are preferred. In a preferred embodiment, the compound that may be used in combination with other antiviral drugs in the pharmaceutical composition of the present invention is compound No. 1 or compound No. 16.

THE ADVANTAGES OF THE PRESENT INVENTION

1. The invention discovers a series of thiazole derivatives with broad-spectrum and excellent anti-RNA virus, especially coronavirus activity for the first time;

2. the compounds of the invention have low toxicity to normal cells;

3. the compound of the invention lays a material foundation for researching and developing a new generation of anti-RNA virus, in particular coronavirus drugs, thereby having important academic value and practical significance.

The technical solution of the present invention is further described below with reference to specific embodiments, but the following examples are not intended to limit the present invention, and all of the various application methods adopted according to the principles and technical means of the present invention belong to the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out under conventional conditions or conditions recommended by the manufacturers. Unless otherwise indicated, percentages and parts are by weight.

Example 1: reference for the preparation of compounds

Referring to CN107459496A, the following compounds were prepared.

Example 2 Activity evaluation

Inhibitory activity of the compound of the present invention against 2019 novel coronavirus (COVID-19(Corona virus Disease)), Ebola virus, avian influenza virus A/guangZHou/99(H9N2), and cytotoxicity evaluation thereof

The material and the method are as follows: compound 16(S312) and Compound 1(S416)

The detection method and the result are as follows:

1. the experiment for detecting the drug effect of the 2019-resistant novel coronavirus by the fluorescent quantitative PCR method comprises the following steps:

the cells were infected with 2019BetacoV/Wuhan/WIV04/2019 strain (isolated from Wuhan virus, academy of sciences, China) MOI of 0.05 on Vero E6 cells (ATCC-1586), and co-cultured by adding drugs of various dilution concentrations, which were diluted with DMSO, and DMSO dilutions were used as controls. The infection solution is DMEM + 0.2% BSA, and after 48 hours of infection, the cell supernatant is collected, the viral RNA in the supernatant is extracted by a viral RNA extraction kit (Qiagen), and real-time quantification is performedReverse transcription PCR (qRT-PCR) (Qiagen) measures the copy number of viral RNA in the cell supernatant, thereby reflecting the replication efficiency of the virus. Data processing was performed using Graphpad prism software to determine the half inhibitory concentration (EC) of a compound against viruses₅₀)。

2. Drug effect experiment of Bright-Glo detection of anti-Ebola virus replicon

Ebola virus replication subsystem (EBOV-NP, EBOV-VP35, EBOV-VP30, EBOV-MG, EBOV-L)

As can be known from the name list of pathogenic microorganisms infected among people, the hazard degree of the Ebola virus is classified into the first class, the first class needs to be operated in a laboratory with a BSL-4 biological safety level, in order to reduce the biological safety risk, an Ebola virus replication subsystem is selected for carrying out an antiviral efficacy test, the system can completely reflect the replication efficiency of the Ebola virus, and the system is a common system for screening anti-Ebola virus medicaments. The Ebola virus replication system consists of a mini genome expression plasmid MG for recombining and expressing a T7 promoter and a luciferase gene and 4 auxiliary plasmids for respectively expressing L, NP, VP35 and VP30 proteins, and when the replication system enters cells for replication through transfection, T7 RNA polymerase induces the T7 promoter to start so as to drive the luciferase gene to express. The replication efficiency of the replicon is positively correlated with the expression quantity of the luciferase gene, so that the replication efficiency of the replicon can be measured by the expression quantity of the luciferase gene in a cell system treated by the drug in drug evaluation, and the inhibition degree of the drug on the Ebola replicon can be evaluated. Bright-Glo reagent (Promega) was used to measure the amount of luciferase expressed. The number of the planks is 2 multiplied by 10⁴The BSR T7/5 cells (stably transfected with a gene expressing T7 RNA polymerase in cell culture medium MEM + 10% FBS + 1% L-Glutamine + 2% MAA + 1% P/S) were used in 96-well white-bottomed plates until the cells were 80% full. The ebola virus five plasmid replication system was prepared as follows:

transfection: the plasmids of the above-mentioned system were dissolved in 25. mu.L of Opti-MEM serum-free medium and recorded as tube A(ii) a mu.L of Lipo 2000 was dissolved in 25. mu.L of Opti-MEM serum free medium and recorded as tube B. A, B tubes were mixed together and recorded as tube C, and left at room temperature for 20 min. mu.L/well was added to the treated 96-well plate using a line gun (negative control used a system without EBOV-L plasmid). Shaking at 800rpm for 2 hr, 3-fold dilution of the compound using Opti-MEM serum-free medium, 8 gradient, 3 multiple wells, 50. mu.L per well in shaken white-bottomed 96-well plates, placing at 37 ℃ in 5% CO₂After incubation in an incubator for 24 hours, 50. mu.L of Bright-Glo reagent was added to each well, shaken in the dark for 3min, mixed well, and then allowed to stand for 10 min. Reading in a microplate reader, recording Luminescence (Luminescence) value, and performing data processing by Graphpad prism software to obtain half inhibitory concentration EC of the compound on viruses₅₀。

3. Cell Titer-Glo test for drug effect of anti-avian influenza virus capable of infecting human

The experiment is based on a Cell Titer-Glo reagent luminescence detection method, and the inhibitory activity of the compound on avian influenza virus A/guangZhou/99(H9N2) (virus is given by the national influenza center) which can infect people is detected. The number of the planks is 2 multiplied by 10⁴After the cells grow into a monolayer, the original culture solution is discarded, 50 mu L of 20 TCID 50H 9N2 avian influenza virus suspension and 50 mu L of diluted drug solution are added at the same time, each concentration is at least 3 multiple wells, and the virus infection solution is DMEM + 0.2% BSA +25mM HEPES +1 mu g/mL TPCK. Meanwhile, a normal cell control group and a virus control group are set. The 96-well cell culture plate is placed at 37 ℃ and 5% CO₂In the incubator, CPE caused by virus was observed under a microscope every day. The virus control group was removed from the incubator when 75% -100% CPE appeared. Add 25. mu.l per wellShaking the reagent for 3min in dark place, and standing for 10 min. The plate is placed in a microplate reader for reading, and the value of Luminescence (Luminescence) is recorded. Data processing was performed by Graphpad prism software to determine the half inhibitory concentration IC of the compound against the virus₅₀。

4. CellTiter-Glo test for drug toxicity (CC)₅₀)

Adenosine Triphosphate (ATP) participates in a plurality of enzymatic reactions in organisms, is an index of living cell metabolism, can detect the survival condition of cells by detecting the ATP content in the cells, and the CellTiter-Glo living cell detection adopts luciferase as a detection object, wherein the luciferase needs the participation of ATP in the luminescence process, and only the respiration action and other life activity processes of metabolic activity cells can generate ATP. Adding equal volume of CellTiter-Glo reagent into the cell culture medium, measuring the cold light value, wherein the light signal is in direct proportion to the ATP amount in the system, and the ATP is in positive correlation with the number of living cells, thereby determining the survival condition of the cells. The number of the planks is 2 multiplied by 10⁴The cells are put in a 96-well plate with a white background, after the cells grow into a monolayer, the original culture solution is discarded, the compound is diluted into different concentrations by using an infection solution (DMEM + 0.2% BSA +25mM HEPES +1 mu g/mL TPCK) in a multiple ratio, and the diluted compounds are added into the 96-well plate; 100 μ l per well, 5 duplicate wells per concentration, with only 0.1mL of infected cells as a normal control; placing at 37 ℃ and 5% CO₂And taking the incubator out of the incubator after 72 hours, cooling the incubator to room temperature, adding 25 mu l of CellTiter-Glo reagent into each well, shaking the incubator for 3min in a dark place, uniformly mixing the reagents, standing the mixture for 10min, placing the mixture in a microplate reader for reading, and recording the value of Luminescence (Luminescence). The semi-toxic concentration (CC) of the compound to the cells was determined by data processing using Graphpad prism software₅₀) And a nontoxic limit concentration (MNCC); percent cell viability ═ test/control wells Luminescence values x 100%.

5. Determination of the in vivo Activity of Compounds against H1N1 Virus and novel Coronaviridae

5.1 Compounds S312 and S416 anti-A/WSN/33 (H1N1) Virus efficacy test

The experiment evaluates the anti-influenza efficacy of the drug based on a mouse influenza virus infection model. The used mice are BALB/c female mice, 6-8 weeks old and 18-22 g in weight, and are purchased from Beijing Wintolite laboratory animal technology Limited company, and all animal experiments are carried out in ABSL-2 laboratories. The mice were adapted to ABSL-2 environment 2-3 days later for experiments with A/WSN/33(H1N1)2LD₅₀All mice were infected by nasal drops at a toxic dose of 2000 pfu/mouse. Early administration is for 3 hoursAdministration was followed 1 time daily for 14 consecutive days. The middle and late administration is the days of administration marked in the figure, starting on day 5 post-infection, for either 5 or 9 consecutive days. Mouse body weight and survival data body weight change and survival curves were plotted using Graphpad prism software, expressed as mean ± standard deviation (mean ± s.e.m.), and statistically analyzed using two-way ANOVA. All are compared with a control group when P is<A score of 0.05 was considered statistically significant.

5.2 Compound S416 test for efficacy against New coronavirus in hACE2 transgenic mouse model

The mouse used in the experiment is K18-hACE male mouse, is purchased from Jiangsu Jiejiangaokang Biotech limited company, 19-28g in 6-8 weeks, and all animal experiment operations are carried out in ABSL-3 laboratory. The experiment was performed 2-3 days after the mice were acclimated to the ABSL-3 environment, and the mice were divided into the following 2 groups: model group: non-treatment; experimental groups: s416-0.5 mg/kg; 10 to 12 pieces per group. After anesthetizing the mice, the new coronavirus 2.5x 10 was administered at 2019²The toxic dose of (A) is dripped into a nasal infection. Mice were administered intraperitoneally 2 hours prior to infection for 3 (fig. 6) or 5 (fig. 7) days, once a day; weight and survival curves for each group of mice were plotted using Graphpad prism software. On day 4 and day 7, respectively, lungs of mice were euthanized, and after RNA extraction by grinding, fluorescence quantification was performed to compare the copy numbers of the E and N genes of lung tissues of mice in each group.

5.3 Compound S416 efficacy test against New coronavirus in hamster model

The hamster used in the experiment is male Syrian hamster, 6-8 weeks, 100-120g, purchased from Beijing Wintolite laboratory animal technology, Inc., and all animal experimental procedures were performed in ABSL-3 laboratory. The experiments were performed 2-3 days after the hamsters were acclimated to the ABSL-3 environment, and the hamsters were divided into the following 3 groups: model group: non-treatment; experimental groups: 416-0.25mg/kg administered intraperitoneally (i.p.), 416-0.5mg/kg administered nasally (i.n.); each group had 6. After anesthetizing hamster, new coronavirus 1x 10 was administered at 2019⁷The virus of (1) is infected by nasal drops. The administration is continued for 5 days, once a day; weight and survival curves for each group of hamsters were plotted using Graphpad prism software. On day 7, the lungs were harvested after euthanizing a portion of hamsters, and groundAfter RNA extraction, fluorescence quantification was performed to compare the copy numbers of the hamster lung tissue virus ORF1ab and the N gene in each group. Mouse body weight data are expressed as mean ± standard deviation (mean ± s.e.m.) and statistical analysis is performed using two-way ANOVA. Pulmonary viral titers were statistically analyzed using t-test. All are compared with a control group when P is<A score of 0.05 was considered statistically significant.

The experimental results are as follows:

TABLE 1 summary of antiviral efficacy of Compound 16(S312), Compound 1(S416) against 2019 novel coronaviruses, Ebola replicons, human avian influenza infection H9N2

The above EC50 activity assay is exemplified as follows:

the activity of S312 and S416 on COVID-19(Corona virus Disease) is that when the concentration of S312 is 1.55 mu M, S416 and the concentration is 0.017 mu M, the inhibition rate of 2019 novel coronavirus replication efficiency in Vero E6 cells can reach 50 percent. As shown in fig. 1.

The inhibition activity of S312 and S416 on the Ebola replicon is that when the concentration of S312 is 14.96 mu M and the concentration of S416 is 0.018 mu M, the inhibition rate of virus replication efficiency can reach 50%. As shown in fig. 2.

The H9N2 avian influenza virus inhibiting activity of S312 and S416 is that the virus replication efficiency can reach 50% inhibition rate when the concentration of S312 is 13.17 μ M and the concentration of S416 is 0.020 μ M. As shown in fig. 3.

EXAMPLE 3 evaluation of Activity of series of Compounds

The series of compounds of the invention have inhibitory activity (same as above) on 2019 novel coronavirus (COVID-19(Corona virus Disease)), Ebola virus and avian influenza virus A/guangZHou/99(H9N2)

"-" indicates the compound EC₅₀Value to be detected。

Example 4 evaluation of antiviral Activity of Compounds of the present invention in combination with other antiviral drugs (2019 New coronavirus (COVID-19(Corona virus Disease)), Ebola virus, avian influenza A/guangZhou/99(H9N2)) (same procedure as above)

The present inventors have further tested the combination of the compounds of the present invention with other antiviral drugs of the prior art, including one or more of lopinavir, ritonavir, ribavirin, ridciclovir, oseltamivir, tamiflu, lanimivir, peramivir, and chloroquine (chloroquine phosphate).

As a result, it was found that compound 16(S312), compound 1(S416) of the present invention can produce better therapeutic effects in combination with these antiviral agents; wherein the combination with lopinavir, ritonavir, ribavirin, rituxivir and chloroquine (chloroquine phosphate) has relatively better treatment effect.

Example 5 evaluation of the efficacy of the Compounds of the invention against influenza Virus in a mouse model of infection, alone or in combination with other antiviral Agents

The inventor further tests the efficacy of the compound of the invention on influenza virus in a mouse infection model, and the compound is separately administered in the early stage and the combined administration in the middle and late stages of the mouse infection on influenza virus so as to verify the efficacy of the compound on influenza in the early stage and the middle and late stages.

As a result, in a complete lethal model of mice, 50% -100% of mice can be treated by early-stage intraperitoneal administration of S312(2.5-10mg/kg), and more than 50% of mice can be treated by early-stage intraperitoneal administration of S416(0.25-0.5 mg/kg). As shown in fig. 4.

S312(10mg/kg) in the middle and late stages, 50% of mice can be treated by intraperitoneal administration, and 100% of mice can be treated by combining with oseltamivir. S416(0.5mg/kg) can treat 28.6% of mice by intraperitoneal administration at the middle and late stages, and can treat more than 42.9% of mice by combining with oseltamivir. As shown in fig. 5.

Example 6 evaluation of the efficacy of the Compounds of the invention against New coronavirus in a mouse and hamster infection model

The present inventors further tested the efficacy of the compounds of the present invention against the new corona virus in mouse and hamster models, and administered the compounds at an early stage of infection of mice and hamsters with the new corona virus to verify the early efficacy of the compounds against the new corona.

In a complete death model of mice, the condition of weight loss and death caused by virus infection cannot be obviously improved after the intraperitoneal administration of 0.5mg/kg at 4 days after infection, but the virus load in lung tissues can be obviously reduced by more than 56 percent. As shown in fig. 6. On day 7 after infection, the viral load in lung tissue was significantly reduced by more than 45% although the weight loss and death caused by viral infection could not be significantly improved by intraperitoneal administration of 0.5mg/kg at S416. As shown in fig. 7.

In a non-lethal model of hamster infection, S416 administration significantly slowed the weight loss caused by viral infection and significantly reduced the viral load in lung tissues by more than 100-fold. As shown in fig. 8.

Discussion of the related Art

The above results show that the series of compounds of the invention have very high inhibitory activity against 2019 novel coronavirus (COVID-19(Corona virus Disease)), Ebola virus and avian influenza virus A/guangZhou/99(H9N2), especially high activity of compound 16(S312) and compound 1(S416), and EC (EC) of the series of compounds₅₀Reaches dozens of nM, has excellent safety and good application prospect. In particular, for 2019 new coronavirus, the application research of the compound of the invention needs to be accelerated.

All documents referred to herein are incorporated by reference into this application as if each were individually incorporated by reference. Furthermore, it should be understood that various changes and modifications of the present invention can be made by those skilled in the art after reading the above teachings of the present invention, and these equivalents also fall within the scope of the present invention as defined by the appended claims.