Synthesis method and application of natural product ivesinol and its derivatives

Abstract

The application discloses a synthesis method and application of a natural product Ivesinol and derivatives thereof, and comprises the following steps: compound 12, 4, 6-trihydroxybenzaldehyde is subjected to methylation and aldehyde group reduction reaction to obtain compound 3, and compound 3 is subjected to a Friedel-Crafts acylation reaction to obtain compound 4; compound 5, phloroglucinol, is subjected to methylation and a Friedel-Crafts reaction to obtain compound 7, and the compound 7 is subjected to a Vilsmeier reaction to introduce an aldehyde group, and the aldehyde group is reduced to obtain compound 9; and compound 4 and 9 are subjected to a coupling reaction to obtain compound IVE-1 and / or IVE-2, i.e. the natural product Ivesinol and derivatives thereof; the application explores and completes a total synthesis route of the natural product Ivesinol and derivatives thereof by reverse synthesis analysis, and constructs a series of compound libraries of Ivesinol derivatives, lays a foundation for further exploring the structure-activity relationship of the natural product and derivatives thereof, and researching the antibacterial activity and drugability of the compounds, and has important significance for treating infectious diseases caused by drug-resistant bacteria.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic synthesis and medicinal chemistry, in particular to a synthetic method and application of natural product Ivesinol and derivatives thereof. BACKGROUND

[0002] In 1928, British doctor Fleming discovered penicillin, which completely changed the treatment method of bacterial infection. Since then, scientists have been constantly searching for new antibiotics to solve various infectious diseases faced by mankind. In the past hundred years, mankind has made important breakthroughs in the treatment of infectious diseases, the prevention and control of animal diseases, and the protection of public health safety using antibiotics, which has greatly reduced the mortality rate caused by infectious diseases. However, the development of new antibiotics is very difficult, and only two new types of antibiotics have been listed in the past 50 years. Most of the antibiotics were discovered before the 1970s. Due to the long use time, combined with the unreasonable use of antibiotics in the medical and breeding industries, and the low awareness of people's rational use of drugs, the existing antibiotics have generally developed drug resistance, and the treatment effect has been greatly reduced. With the continuous enhancement of pathogenic bacteria resistance, super bacteria frequently appears, which seriously threatens human life and health. More and more infectious diseases become more difficult to treat, and mankind may face the "post-antibiotic era" when there is no effective antibiotic available.

[0003] In recent years, antibiotic resistance has risen to one of the three major global health problems, along with a large number of medical and economic impacts. It is estimated that by 2050, 10 million people will die from drug-resistant bacterial infections worldwide each year, and the economic loss will reach 100 trillion US dollars. In view of the current serious situation of bacterial resistance, the WHO announced in 2017 the twelve types of antibiotic-resistant "key pathogens" that are most resistant, pose the greatest threat to human health, and most urgently need new antibiotics for treatment. Among these pathogenic bacteria, E. faecium, S. aureus, K. pneumonia, A. baumannii, P. aeruginosa and Enterobacter spp. six "super bacteria" are collectively known as "ESKAPE". They have strong resistance to existing antibiotics and can "escape" the danger of being killed, causing difficult-to-treat multi-drug resistant bacterial infections, and are the drug-resistant pathogens that the World Health Organization calls for urgent attention.

[0004] In order to cope with the outbreak of infectious diseases caused by multi-drug resistant bacteria, there is an urgent need for new antibiotics with novel mechanisms of action in the clinic. Compared with chemically synthesized antibiotics, the diversity and complexity of natural product antibiotics are particularly prominent. Over the past few decades, about 28,000 antibiotics have been isolated from natural products, of which 200 have been directly marketed as drugs. Based on these marketed natural product antibiotic skeletons, another 200-300 semi-synthetic antibiotics have been marketed, greatly improving the selection range of antibiotics. Currently, most of the first-line drugs used in the clinic to treat infections are derived from natural products, such as β-lactams, aminoglycosides, tetracyclines, rifamycins, and macrolides (as shown below), which are all derived from natural products as lead compounds. However, many natural products containing medicinal ingredients not only have limited distribution in nature, but also have very low content of effective ingredients. Therefore, it is obviously not enough to meet the huge demand for drugs by natural sources alone, and synthetic chemists need to continuously explore more simple and efficient synthetic strategies to more conveniently perform total synthesis and structural modification of natural products through chemical methods, so as to discover more active lead compounds and promote drug discovery.

[0005]

[0006] In 1937, Birch et al. isolated a polyphenolic compound Protokosin from Brayera anthelmintica and identified its structure, but due to the limitation of too little raw material, further derivatization research was not carried out. Until 1952, the team obtained enough raw material and further research found that under alkaline conditions, Protokosin could be converted into a new natural product derivative β-kosin by zinc powder reduction, and its chemical structure was determined by spectroscopy, chemical transformation and other means. In the nearly 60 years since then, there has been no further research on β-kosin reported, until 2014, Marwa H. Ahmed et al. from the University of Mississippi isolated a new polyphenolic natural product from the flowers of a plant Ivesia gordonii in North America, and identified its chemical structure by one-dimensional and two-dimensional nuclear magnetic resonance, mass spectrometry and other means. By comparison, it was found that the natural product and β-kosin had the same chemical structure, and the authors named it Ivesinol in a popular way (as shown below).

[0007]

[0008] Ahmed et al. found through further research that Ivesinol has excellent inhibitory effect on S. aureus, MRSA, VRE, etc. Among them, the inhibitory activity of Ivesinol on MRSA is MIC = 0.31 ug / mL, and the MIC of VRE is 1.25 ug / mL. The inhibitory activity of positive control ciprofloxacin and vancomycin on the two strains of bacteria is weaker than that of Ivesinol, and even has no activity (Table 1). In addition, Ivesinol also shows certain inhibitory activity on the fungus M. intracellulare (MIC = 15.67 ug / mL).

[0009] Table 1. Antimicrobial activity data of Ivesinol

[0010]

[0011] Ivesinol has much better inhibitory activity on drug-resistant E. faecalis and S. aureus than the current first-line clinical drugs, but the safety, stability, etc. of Ivesinol are still missing, the antibacterial mechanism and target are also unclear, and there is no report on the total synthesis of Ivesinol so far, which to some extent hinders the study of the drugability of Ivesinol. Therefore, it is of great significance to complete the total synthesis of Ivesinol, design and synthesize a series of compound libraries, further explore the structure-activity relationship of the natural product, study its antibacterial activity, and investigate the drugability. SUMMARY

[0012] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a synthesis method and application of natural product Ivesinol and its derivatives, to solve the problem that there is no total synthesis method of Ivesinol and its derivatives in the prior art, and to lay an important foundation for further study of the antibacterial activity and drugability of Ivesinol.

[0013] To achieve the above-mentioned purposes and other related purposes, the first aspect of the present application provides a synthesis method of natural product Ivesinol and its derivatives, and the synthesis route of the method is as follows:

[0014]

[0015] The method comprises the following steps:

[0016] (1) Compound 1 2,4,6-trihydroxybenzaldehyde is methylated and subjected to an aldehyde group reduction reaction to obtain compound 3, and compound 3 is subjected to a Friedel-Crafts acylation reaction to obtain compound 4;

[0017] (2) Compound 5 is methylated to obtain compound 7, and an aldehyde group is introduced into compound 7 by Vilsmeier reaction, and compound 9 is obtained by reducing the aldehyde group;

[0018] (3) Compound 4 and 9 are coupled to obtain compound IVE-1 and / or IVE-2;

[0019] wherein,

[0020] R 1 at least one selected from ethyl, isopropyl, n-butyl, n-hexyl and other linear or branched alkyl substituents,

[0021] R 2 at least one selected from ethyl, isopropyl, n-butyl, n-hexyl and other linear or branched alkyl substituents,

[0022] R 3 at least one selected from hydroxyl, methoxy and other linear alkoxy groups,

[0023] R 4 at least one selected from hydroxyl, methoxy and other linear alkoxy groups,

[0024] R 5 at least one selected from acetyl, isobutyl, isobutyryl, tert-pentyl, n-pentyl, n-pentanoyl and other linear or branched alkyl and acyl groups,

[0025] R 6 at least one selected from acetyl, isobutyl, isobutyryl, tert-pentyl, n-pentyl, n-pentanoyl and other linear or branched alkyl and acyl groups.

[0026] Further, the synthesis route of the method is as follows:

[0027]

[0028] The method comprises the following steps:

[0029] (1) Compound 1 2,4,6-trihydroxybenzaldehyde is methylated to obtain compound 2, and compound 2 is reduced by aldehyde group to obtain compound 3, and compound 3 is acylated by Friedel-Crafts reaction to obtain compound 4;

[0030] (2) Compound 5 is methylated to obtain compound 6, and compound 6 is reacted by Friedel-Crafts reaction to obtain compound 7, and an aldehyde group is introduced into compound 7 by Vilsmeier reaction to obtain compound 8, and compound 9 is obtained by reducing the aldehyde group in compound 8;

[0031] (3) Compound 4 and 9 are coupled to obtain compound IVE-1 and / or IVE-2.

[0032] Further, in the steps (1), (2), the methylation reaction is a selective monomethylation reaction, and the methylating agent used is selected from any one of methyl iodide, dimethyl sulfate and dimethyl carbonate.

[0033] Further, in the steps (1), (2), the methylation reaction is carried out at room temperature or at 50-60°C, respectively.

[0034] Further, in the step (1), the aldehyde group in the compound 2 is reduced to a methyl group by sodium cyanoborohydride under acidic conditions to obtain the compound 3.

[0035] Further, in the step (1), the aldehyde group reduction reaction is carried out at a pH of 2-3.

[0036] Further, in the step (1), the acylation reagent used in the Friedel-Crafts acylation reaction is acyl chloride, and its chemical structural formula is R 1 COCl.

[0037] Further, in the step (2), the Friedel-Crafts reaction includes an acylation reaction and an alkylation reaction, the acylation reagent used in the acylation reaction is acyl chloride, and its chemical structural formula is R 2 COCl;

[0038] The alkylation reagent used in the alkylation reaction is haloalkane, and its chemical structural formula is R 5 Cl and / or R 6 Cl.

[0039] Further, in the steps (1), (2), the reaction temperature of the Friedel-Crafts acylation reaction and the Friedel-Crafts reaction is 60-70°C.

[0040] Further, in the step (2), the aldehyde group is introduced by Vilsmeier reaction of the compound 7 with oxalyl chloride / N,N-dimethylformamide (DMF) system to obtain the compound 8.

[0041] Further, in the step (2), the aldehyde group is reduced to obtain the compound 9 under Pd / C / H2 conditions.

[0042] Further, in the step (3), the compound 4 and the compound 9 are coupled with TsCl / polyformal system to obtain the compound IVE-1 and / or IVE-2.

[0043] Further, in the step (3), the coupling reaction temperature is 40-60°C, preferably 45-55°C.

[0044] The second aspect of the present application provides a compound synthesized according to the method of the first aspect, the structure of the compound is shown in IVE-1 and IVE-2 as follows:

[0045]

[0046] Further, the IVE-1 is selected from at least one of the following structures T-1, T-19, T-21, T-18, T-3, T-4, T-5, T-7, T-10:

[0047]

[0048] Further, the IVE-2 is selected from at least one of the following structures T-6, T-8, T-20, T-9, T-11, T-13, T-2, T-12, T-14, T-15, T-16, T-17:

[0049]

[0050] The third aspect of the present application provides the use of the method according to the first aspect in the synthesis of natural product Ivesinol and its derivatives.

[0051] The fourth aspect of the present application provides the use of the compound according to the second aspect in antibiosis, the compound is selected from at least one of the following structures T-1, T-19, T-21, T-18, T-3, T-4, T-5, T-7, T-10, T-6, T-8, T-20, T-9, T-11, T-13, T-2, T-12, T-14, T-15, T-16, T-17.

[0052] Further, the use is to inhibit the activity of bacteria or fungi, or to treat infectious diseases caused by bacteria or fungi.

[0053] The fifth aspect of the present application provides an antibacterial drug, the drug contains an effective dose of a compound, the compound is selected from at least one of the following structures T-1, T-19, T-21, T-18, T-3, T-4, T-5, T-7, T-10, T-6, T-8, T-20, T-9, T-11, T-13, T-2, T-12, T-14, T-15, T-16, T-17.

[0054] Further, the antibacterial drug is used to inhibit the activity of bacteria or fungi, or to treat infectious diseases caused by bacteria or fungi.

[0055] Further, the bacteria are selected from at least one of E. faecium, S. aureus, K. pneumonia, A. baumannii, P. aeruginosa, Enterobacter spp., MRSA, VRE.

[0056] Further, the fungi are selected from M. intracellulare.

[0057] As described above, the synthesis and application of the natural product Ivesinol and its derivatives of the present application have the following beneficial effects:

[0058] The present application explores and completes the total synthesis route of the natural product Ivesinol and its derivatives by retrosynthetic analysis, using commercial reagents as starting materials, and constructs a series of compound library of Ivesinol derivatives, which lays a foundation for further exploring the structure-activity relationship of the natural product and its derivatives, and studying the antibacterial activity and drugability of such compounds. On this basis, the present application verifies through experiments that the natural product Ivesinol and some of its derivatives have equivalent or better inhibitory activity than clinical drugs for some bacteria or fungi, which is of great significance for further drugability research of this series of compounds, and also has important significance for the treatment of infectious diseases caused by drug-resistant bacteria. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 The figure shows the in vitro cytotoxicity test results of Ivesinol in Example 1 of the present application.

[0060] Figure 2 The figure shows the concentration-bacterial amount curve in Example 1 of the present application.

[0061] Figure 3 The figure shows the antibiofilm experiment results of Ivesinol in Example 1 of the present application.

[0062] Figure 4 The figure shows the drug resistance test results of Ivesinol in Example 1 of the present application.

[0063] Figure 5 The figure shows the hemolytic toxicity experiment results of Ivesinol in Example 1 of the present application.

[0064] Figure 6 The figure shows the pharmacokinetics experiment results of Ivesinol in Example 1 of the present application. Detailed Implementation

[0065] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should also be understood that the following embodiments are only used to specifically illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are only examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0066] Given the current lack of a total synthetic method for Ivesinol and its derivatives, one embodiment of the present invention provides a method for synthesizing the natural product Ivesinol and its derivatives. The synthetic route of the method is as follows:

[0067]

[0068] The method includes the following steps:

[0069] (1) Compound 1, 2,4,6-trihydroxybenzaldehyde, was methylated and reduced to obtain compound 3. Compound 3 was then subjected to Friedel-Crafts acylation to obtain compound 4.

[0070] (2) Compound 5, phloroglucinol, was methylated and Friedel-Crafts reaction to obtain compound 7. Compound 7 was introduced with an aldehyde group by Vilsmeier reaction, and the aldehyde group was reduced to obtain compound 9.

[0071] (3) Compounds 4 and 9 were coupled to give compounds IVE-1 and / or IVE-2;

[0072] in,

[0073] R 1 It is selected from at least one of ethyl, isopropyl, n-butyl, n-hexyl, and other straight-chain or branched alkane substituents.

[0074] R 2 It is selected from at least one of ethyl, isopropyl, n-butyl, n-hexyl, and other straight-chain or branched alkane substituents.

[0075] R 3 At least one selected from hydroxyl, methoxy, and other straight-chain alkoxy groups.

[0076] R 4 at least one selected from the group consisting of hydroxyl, methoxy and other linear alkoxy,

[0077] R 5 at least one selected from the group consisting of acetyl, isobutyl, isobutyryl, tert-butyl, n-pentyl, n-pentanoyl and other linear or branched alkyl and acyl groups,

[0078] R 6 at least one selected from the group consisting of acetyl, isobutyl, isobutyryl, tert-butyl, n-pentyl, n-pentanoyl and other linear or branched alkyl and acyl groups.

[0079] Another embodiment of the present application provides a synthetic method of natural product Ivesinol and its derivatives, the synthetic route of the method is as follows:

[0080]

[0081] The method comprises the following steps:

[0082] (1) Compound 1 2,4,6-trihydroxybenzaldehyde is methylated to obtain compound 2, compound 2 is subjected to an aldehyde group reduction reaction to obtain compound 3, and compound 3 is subjected to a Friedel-Crafts acylation reaction to obtain compound 4;

[0083] (2) Compound 5 phloroglucinol is methylated to obtain compound 6, compound 6 is subjected to a Friedel-Crafts reaction to obtain compound 7, compound 7 is subjected to a Vilsmeier reaction to introduce an aldehyde group, to obtain compound 8, and the aldehyde group in compound 8 is reduced to obtain compound 9;

[0084] (3) Compounds 4 and 9 are subjected to a coupling reaction to obtain compounds IVE-1 and / or IVE-2.

[0085] In some embodiments, in steps (1) and (2), the methylation reaction is a selective monomethylation reaction, and the methylating agent used is any one selected from the group consisting of iodomethane, dimethyl sulfate and dimethyl carbonate.

[0086] In some embodiments, in steps (1) and (2), the methylation reaction is carried out at room temperature or at 50-60°C, respectively.

[0087] In some embodiments, in step (1), the aldehyde group in compound 2 is reduced to a methyl group by sodium cyanoborohydride under acidic conditions to obtain compound 3.

[0088] In some embodiments, in step (1), the aldehyde group reduction reaction is carried out at a pH of 2-3.

[0089] In some embodiments, in the step (1), the acylating agent used in the Friedel-Crafts acylation reaction is an acyl chloride, and the chemical structure of the acyl chloride is R 1 COCl.

[0090] In some embodiments, in the step (2), the Friedel-Crafts reaction includes an acylation reaction and an alkylation reaction, the acylating agent used in the acylation reaction is an acyl chloride, and the chemical structure of the acyl chloride is R 2 COCl;

[0091] The alkylation agent used in the alkylation reaction is a haloalkane, and the chemical structure of the haloalkane is R 5 Cl and / or R 6 Cl.

[0092] In some embodiments, in the steps (1) and (2), the reaction temperature of the Friedel-Crafts acylation reaction and the Friedel-Crafts reaction is 60-70°C.

[0093] In some embodiments, in the step (2), the aldehyde group is introduced by a Vilsmeier reaction of the compound 7 with an oxalyl chloride / N,N-dimethylformamide (DMF) system to obtain the compound 8.

[0094] In some embodiments, in the step (2), the aldehyde group is reduced to obtain the compound 9 under the condition of Pd / C / H2.

[0095] In some embodiments, in the step (3), the compound 4 and the compound 9 are coupled with a TsCl / polyformal system to obtain the compound IVE-1 and / or IVE-2.

[0096] In some embodiments, in the step (3), the coupling reaction temperature is 40-60°C, preferably 45-55°C.

[0097] In some embodiments, in the step (1), the synthesis process of the compound 2 includes the following steps:

[0098] The compound 1 2,4,6-trihydroxybenzaldehyde powder (1.0 equiv), anhydrous K2CO3 (4.0-6.0 equiv) is dissolved with a mixed solvent (the mixed solvent includes water and acetone in a volume ratio of 1:1), and dimethyl sulfate (1.0-2.0 equiv) dissolved with acetone is added dropwise at room temperature, and the dropwise time is more than 2 h. After the dropwise addition is completed, it is reacted for 1.5-3 h. After the reaction is completed, ethyl acetate (EA) is used for extraction, the combined extract is washed with saturated brine, dried, and the crude product is concentrated under reduced pressure, and then separated and purified by a silica gel column to obtain a yellow-green solid, which is the compound 2.

[0099] In some embodiments, in the step (1), the synthesis process of the compound 3 includes the following steps:

[0100] Compound 2 (1.0 equiv) was dissolved in THF, NaCNBH3 (2.0-4.0 equiv) was added at 0 °C, and then the pH was adjusted with HCl to keep the pH of the reaction solution at about 2-3, and stirred at room temperature for 3-6 h. After the reaction was completed, the solvent was removed under reduced pressure, extracted with ethyl acetate (EA), and the combined extract was washed with saturated brine, dried, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel to obtain a yellow solid, which was compound 3.

[0101] In some embodiments, the synthesis of compound 4 in step (1) includes the following steps:

[0102] Compound 3 (1.0 equiv) and AlCl3 (3.0-5.0 equiv) were placed in a reaction bottle and replaced with nitrogen. PhNO2 was added and stirred for 20-50 min, then acyl chloride (1.0-1.5 equiv) was added dropwise, and the reaction was transferred to an oil bath at 60-70 °C and stirred overnight. After the reaction was completed, H2O was added to quench the reaction, and ethyl acetate (EA) was used to extract the reaction solution. The combined extract was washed with saturated brine, dried, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel to obtain a yellow solid, which was compound 4.

[0103] In some embodiments, the synthesis of compound 6 in step (2) includes the following steps:

[0104] Compound 5 (3.0 equiv) and anhydrous K2CO3 (2.0-4.0 equiv) were dissolved in acetone, and dimethyl sulfate (1 equiv) was slowly added at room temperature. The dropwise addition was completed in more than 15 min, and then the reaction was transferred to an oil bath at 50-60 °C and stirred overnight. After the reaction was completed, HCl was added to quench the reaction, and the solvent was removed under reduced pressure. The reaction solution was extracted with ethyl acetate (EA), and the combined extract was washed with saturated brine, dried, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel to obtain a transparent oil, and the solvent was removed by suction to obtain a white solid, which was compound 6.

[0105] In some embodiments, the synthesis of compound 7 in step (2) includes the following steps:

[0106] Compound 6 (1.0 equiv) and AlCl3(3.0-5.0 equiv) were placed in a reaction flask, and nitrogen was replaced. PhNO2was added and stirred for 20-50 min, then acyl chloride (1.0-1.5 equiv) was added dropwise, the reaction was moved to an oil bath at 60-70℃, and stirred overnight. After the reaction was completed, H2O was added for quenching, ethyl acetate (EA) was extracted, the extract was combined and washed with saturated brine, dried, and the crude product was concentrated under reduced pressure, and then purified by column chromatography on silica gel to obtain intermediate compound 7.

[0107] In some embodiments, the synthesis process of compound 8 in step (2) includes the following steps:

[0108] Compound 7 was placed in a reaction flask, and after nitrogen replacement, anhydrous MeCN was added, and oxalyl chloride (1.0-2.0 equiv) and anhydrous DMF (0.3-1.0 equiv) were slowly added at 0℃. After stirring for 30 min, the reaction was moved to room temperature and stirred for 10-20 h. The reaction solution was filtered, and after stirring at 100℃ for 2 h, it was cooled and filtered to obtain intermediate compound 8.

[0109] In some embodiments, the synthesis process of compound 9 in step (2) includes the following steps:

[0110] Compound 8 was dissolved in 10 mL of ethanol, 10% Pd / C was added, the reaction system was replaced with hydrogen, and stirred at room temperature overnight. After diatomite filtration, the filtrate was concentrated to obtain the target product compound 9.

[0111] In a specific embodiment, the synthesis route of natural product Ivesinol and its derivatives is as follows:

[0112]

[0113] The synthesis of compounds IVE-1 and IVE-2 involved in the embodiments of the present application adopts a convergent synthesis method, and is obtained by coupling two types of compounds, i.e., left fragment compound 4 and right fragment compound 9. In some embodiments, compound 4 and compound 9 are selected from any one of the structures shown in the following structure:

[0114] Compound 4:

[0115]

[0116] Compound 9:

[0117]

[0118] In some embodiments, IVE-1 is preferably at least one of the following structures T-1, T-19, T-21, T-18, T-3, T-4, T-5, T-7, T-10, and IVE-2 is preferably at least one of the following structures T-6, T-8, T-20, T-9, T-11, T-13, T-2, T-12, T-14, T-15, T-16, T-17:

[0119]

[0120] The above embodiments of the present application are analyzed by reverse synthesis, and a full synthesis route of natural product Ivesinol and its derivatives is explored and completed by using commercial reagents as starting materials, and a series of compound libraries of Ivesinol derivatives are constructed. Further, it is found through experiments that the compounds shown in formula IVE-1 and IVE-2 have the ability to inhibit the growth of bacteria such as Staphylococcus aureus and Enterococcus faecium and / or fungi, and can be used for, but not limited to, treating infectious diseases caused by the two types of bacteria.

[0121] Based on this, an embodiment of the present application provides an application of a compound according to the above embodiments in antibiosis, the compound being selected from at least one of the following structures T-1, T-19, T-21, T-18, T-3, T-4, T-5, T-7, T-10, T-6, T-8, T-20, T-9, T-11, T-13, T-2, T-12, T-14, T-15, T-16, T-17. The application is to inhibit the activity of bacteria or fungi, or to treat infectious diseases caused by bacteria or fungi.

[0122] Another embodiment of the present application provides an antibacterial drug, which contains an effective dose of a compound selected from at least one of the following structures T-1, T-19, T-21, T-18, T-3, T-4, T-5, T-7, T-10, T-6, T-8, T-20, T-9, T-11, T-13, T-2, T-12, T-14, T-15, T-16, T-17. Wherein, the antibacterial drug is used to inhibit the activity of bacteria or fungi, or, to treat infectious diseases caused by bacteria or fungi. Further, the drug also includes a pharmaceutically acceptable carrier and / or excipient; the drug can be a single component substance, or a multi-component substance; the form of the drug is not particularly limited, which can be various preparation forms such as solid, liquid, gel, semi-liquid, aerosol, etc.; the main target of the drug is mammals such as rodents, primates, etc.; the drug can be used in combination with other antibacterial drugs. In some embodiments, the bacteria are selected from at least one of the following: E. faecium, S. aureus, K. pneumonia, A. baumannii, P. aeruginosa, Enterobacter spp., MRSA, VRE, but not limited thereto.

[0123] In some embodiments, the fungi are selected from M. intracellulare, but not limited thereto.

[0124] In a specific embodiment, the synthesis method of compounds 4-1, 4-2, 4-3 is as follows:

[0125] Synthesis of compound 3:

[0126] Compound 1 (1.0 g, 6.5 mmol, 1.0 equiv) was added to a 100 mL dry single-necked round-bottom flask, followed by anhydrous K2CO3(4.5 g, 32.5 mmol, 5 equiv), and then ultrapure water (32 mL): acetone (32 mL) = 1:1 was dissolved, and dimethyl sulfate (1.23 g, 9.75 mmol, 1.5 equiv) dissolved in acetone (4 mL) was added dropwise at room temperature, and the dropwise addition took more than 2 h. After the dropwise addition was completed, the reaction was allowed to proceed for another 2 h. After the reaction was completed, EA (3 x 100 mL) was used for extraction, and the combined extract was washed with saturated brine (3 x 100 mL), dried over anhydrous sodium sulfate, and the crude product was concentrated under reduced pressure, and then purified by silica gel column chromatography (PE:EA = 2:1) to obtain compound 2 (390 mg, 35%) as a yellow-green solid.

[0127] Compound 2 (2.21 g, 13.2 mmol, 1.0 equiv) was placed in a 250 mL dry single-necked round-bottom flask, dissolved in 30 mL THF, and then placed in a 0°C bath, followed by the addition of NaCNBH3(2.5 g, 39.5 mmol, 3 equiv), and then 1N HCl was used to adjust the pH, so that the pH of the reaction solution remained at about 4, and then the reaction was stirred at room temperature for 4 h. After the reaction was completed, the solvent was removed under reduced pressure, EA (3 x 150 mL) was used for extraction, and the combined extract was washed with saturated brine (3 x 100 mL), dried over anhydrous sodium sulfate, and the crude product was concentrated under reduced pressure, and then purified by silica gel column chromatography (PE:EA = 6:1) to obtain intermediate compound 3 (430 mg, 22%) as a yellow solid.

[0128] ① Synthesis of compound 4-1:

[0129] Compound 3 (100 mg, 0.65 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry single-necked round-bottom flask, and then nitrogen was replaced. PhNO2(4 mL) was added and stirred for 30 min, and then isobutyryl chloride (83 mg, 0.78 mmol, 1.2 equiv) was added dropwise, and then the reaction was moved to a 65°C oil bath and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, EA (3 x 30 mL) was used for extraction, and the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and the crude product was concentrated under reduced pressure, and then purified by silica gel column chromatography (PE:EA = 5:1) to obtain intermediate compound 4-1 (110 mg, 76%) as a yellow solid.

[0130] ② Synthesis of compound 4-2:

[0131] Compound 3 (100 mg, 0.65 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry single-necked round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added to stir the reaction for 30 min, and then n-pentanoyl chloride (93.6 mg, 0.78 mmol, 1.2 equiv) was added dropwise. The reaction was moved to a 65 °C oil bath and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was used to extract, and the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 4:1) to obtain yellow solid intermediate compound 4-2 (96 mg, 62%).

[0132] iii. Synthesis of compound 4-3:

[0133] Compound 3 (100 mg, 0.65 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry single-necked round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added to stir the reaction for 30 min, and then n-pentanoyl chloride (93.6 mg, 0.78 mmol, 1.2 equiv) was added dropwise. The reaction was moved to a 65 °C oil bath and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was used to extract, and the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 4:1) to obtain yellow solid intermediate compound 4-2 (96 mg, 62%).

[0134] In a specific embodiment, the synthesis method of compounds 9-1, 9-2, 9-3, 9-4, 9-5, 9-6, 9-7 is as follows:

[0135] Synthesis of compound 6:

[0136] Phloroglucinol (compound 5) (7.0 g, 55.5 mmol, 3.0 equiv) was added to a 250 mL dry single-necked round-bottom flask, followed by anhydrous K2CO3 (7.7 g, 55.5 mmol, 3 equiv), acetone (60 mL), and dimethyl sulfate (2.334 g, 18.5 mmol, 1 equiv) was added slowly at room temperature over 15 min. After the dropwise addition was complete, the reaction was transferred to a 55 °C oil bath and stirred overnight. After the reaction was completed, the reaction was quenched with 1 N HC1, the solvent was removed under reduced pressure, and the crude product was extracted with EA (3 x 150 mL), combined, washed with saturated brine (3 x 100 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel (PE:EA = 10:1-2:1) to obtain a transparent oil, and the solvent was removed by suction to obtain white solid intermediate compound 6 (2.5 g, 32%).

[0137] i. Synthesis of compound 9-1:

[0138] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AlCl3 (346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask and replaced with nitrogen. PhNO2 (4 mL) was added and the reaction was stirred for 30 min, followed by dropwise addition of acetyl chloride (61 mg, 0.78 mmol, 1.2 equiv). The reaction was transferred to a 65 °C oil bath and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was used to extract the reaction, which was combined, washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel (PE:EA = 5:1) to obtain intermediate compound 7 (56 mg), which was placed in a 10 mL dry single-necked round-bottom flask, replaced with nitrogen, and anhydrous MeCN (8 mL) was added. Oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C, and the reaction was stirred for 30 min at room temperature. The reaction was filtered, 5 mL of water was added, and the mixture was stirred at 100 °C for 2 h, cooled, and filtered to obtain intermediate compound 8, which was dissolved in 10 mL of ethanol, 10% Pd / C was added, the reaction system was replaced with hydrogen, and the reaction was stirred at room temperature overnight. The reaction was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-1 (39 mg, 20%).

[0139] ii. Synthesis of compound 9-2:

[0140] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added, and the reaction was stirred for 30 min, then isobutyryl chloride (83 mg, 0.78 mmol, 1.2 equiv) was added dropwise, the reaction was moved to a 65 °C oil bath, and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was added to extract the reaction, the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 8:1) to obtain intermediate compound 7 (43 mg), which was placed in a 10 mL dry single-neck round-bottom flask, and replaced with nitrogen. Anhydrous MeCN (8 mL) was added, and oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C. The reaction was stirred for 30 min, then moved to room temperature and stirred for 15 h. The reaction was filtered, 5 mL of water was added, and the mixture was stirred at 100 °C for 2 h, then cooled and filtered to obtain intermediate compound 8, which was dissolved in 10 mL of ethanol, and 10% Pd / C was added. The reaction system was replaced with hydrogen, and the reaction was stirred at room temperature overnight. The reaction was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-2 (40 mg, 18%).

[0141] ③ Synthesis of compound 9-3:

[0142] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AICI3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added, and the reaction was stirred for 30 min, then pivaloyl chloride (94 mg, 0.78 mmol, 1.2 equiv) was added dropwise, the reaction was moved to a 65 °C oil bath, and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was added to extract the reaction, the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 3:1) to obtain intermediate compound 7 (61 mg), which was placed in a 10 mL dry single-neck round-bottom flask, and replaced with nitrogen. Anhydrous MeCN (8 mL) was added, and oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C. The reaction was stirred for 30 min, then moved to room temperature and stirred for 15 h. The reaction was filtered, and 5 mL of water was added. The reaction was stirred at 100 °C for 2 h, then cooled and filtered to obtain intermediate compound 8, which was dissolved in 10 mL of ethanol, and 10% Pd / C was added. The reaction system was replaced with hydrogen, and the reaction was stirred at room temperature overnight. The reaction was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-3 (67 mg, 28%).

[0143] (IV) Synthesis of compound 9-4:

[0144] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added, and the reaction was stirred for 30 min, then n-valeryl chloride (94 mg, 0.78 mmol, 1.2 equiv) was added dropwise, the reaction was moved to a 65 °C oil bath, and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was added to extract the reaction, the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 10:1) to obtain intermediate compound 7 (61 mg), which was placed in a 10 mL dry single-neck round-bottom flask, and replaced with nitrogen. Anhydrous MeCN (8 mL) was added, and oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C. The reaction was stirred for 30 min, then moved to room temperature and stirred for 15 h. The reaction was filtered, 5 mL of water was added, and the mixture was stirred at 100 °C for 2 h, then cooled and filtered to obtain intermediate compound 8, which was dissolved in 10 mL of ethanol, and 10% Pd / C was added. The reaction system was replaced with hydrogen, and the reaction was stirred at room temperature overnight. The reaction was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-4 (78 mg, 33%).

[0145] 5. Synthesis of compound 9-5:

[0146] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added, and the reaction was stirred for 30 min, then propionyl chloride (72 mg, 0.78 mmol, 1.2 equiv) was added dropwise, the reaction was moved to a 65 °C oil bath, and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was added to extract the reaction, the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 5:1) to obtain intermediate compound 7 (56 mg), which was placed in a 10 mL dry single-neck round-bottom flask, and replaced with nitrogen. Anhydrous MeCN (8 mL) was added, and oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C. The reaction was stirred for 30 min, then moved to room temperature and stirred for 15 h. The reaction was filtered, 5 mL of water was added, and the mixture was stirred at 100 °C for 2 h, then cooled and filtered to obtain intermediate compound 8, which was dissolved in 10 mL of ethanol, and 10% Pd / C was added. The reaction system was replaced with hydrogen, and the reaction was stirred at room temperature overnight. The reaction was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-5 (61 mg, 29%).

[0147] (6) Synthesis of compound 9-6:

[0148] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added, and the reaction was stirred for 30 min, then isobutyryl chloride (83 mg, 0.78 mmol, 1.2 equiv) was added dropwise, the reaction was moved to a 65 °C oil bath, and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench the reaction, and EA (3 x 30 mL) was added to extract the reaction, the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 8:1) to obtain intermediate compound 7 (58 mg), which was placed in a 10 mL dry single-neck round-bottom flask, and replaced with nitrogen. Anhydrous MeCN (8 mL) was added, and oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C. The reaction was stirred for 30 min, then moved to room temperature and stirred for 15 h. The reaction was filtered, 5 mL of water was added, and the mixture was stirred at 100 °C for 2 h. After cooling, the mixture was filtered to obtain intermediate compound 8, which was placed in a high-pressure hydrogenation kettle, dissolved in 10 mL of ethanol, and 10% Pd / C was added. The reaction system was filled with hydrogen gas (0.2 MPa), and stirred at room temperature for 3 h. After the reaction was completed, the mixture was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-6 (44 mg, 21%).

[0149] ⑦Synthesis of compound 9-7:

[0150] Compound 6 (140 mg, 1.0 mmol, 1.0 equiv) and AlCl3(346.34 mg, 2.6 mmol, 4.0 equiv) were placed in a 50 mL dry round-bottom flask, and replaced with nitrogen. PhNO2(4 mL) was added, and the reaction was stirred for 30 min, then n-valeryl chloride (94 mg, 0.78 mmol, 1.2 equiv) was added dropwise, and the reaction was moved to a 65 °C oil bath and stirred overnight. After the reaction was completed, H2O (10 mL) was added to quench it, and EA (3 x 30 mL) was used to extract it, and the combined extract was washed with saturated brine (3 x 20 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was separated and purified by column chromatography on silica gel (PE:EA = 10:1) to obtain intermediate compound 7 (55 mg), which was placed in a 10 mL dry single-neck round-bottom flask, and replaced with nitrogen. Anhydrous MeCN (8 mL) was added, and oxalyl chloride (55 mg, 0.43 mmol, 1.4 equiv) and anhydrous DMF (11 mg, 0.16 mmol, 0.5 equiv) were slowly added at 0 °C. After stirring for 30 min, the reaction was moved to room temperature and stirred for 15 h. The reaction solution was filtered, and 5 mL of water was added. After stirring at 100 °C for 2 h, it was cooled and filtered to obtain intermediate compound 8, which was placed in a high-pressure hydrogenation kettle, dissolved in 10 mL of ethanol, and 10% Pd / C was added. The reaction system was filled with hydrogen gas (0.2 MPa), and the reaction was stirred at room temperature for 3 h. After the reaction was completed, it was filtered through diatomite, and the filtrate was concentrated to obtain the target product compound 9-7 (72 mg, 21%).

[0151] Example 1:

[0152] I. Synthesis of natural product Ivesinol:

[0153] Compound 4-1 (22.4 mg, 0.1 mmol, 1.0 equiv) and 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, and p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added in sequence. CHCl3(3 mL) was added as a solvent, and the tube was tightly sealed and stirred at 50 °C for 2 h. After the reaction was completed, the solvent was removed under reduced pressure, and the product was separated and purified by column chromatography on silica gel to obtain yellow solid Ivesinol (9.7 mg, 21%). 1HNMR (400 MHz, CDC13) δ 13.54 (s, 1H), 12.67 (s, 1H), 8.91 (s, 1H), 8.78 (s, 1H), 3.99 (d, J = 0.7 Hz, 3H), 3.96 (s, 1H), 3.94 (d, J = 0.7 Hz, 3H), 3.71 (d, J = 7.5 Hz, 3H), 2.15-2.10 (m, 3H), 2.07-2.04 (m, 3H), 1.15 (t, J = 6.8 Hz, 13H). 13 C NMR (100 MHz, CDC13) δ 212.12, 209.84, 163.07, 162.08, 160.54, 159.55, 156.10, 154.74, 110.90, 110.38, 110.01, 107.90, 107.84, 106.04, 65.17, 61.93, 39.92, 38.90, 36.30, 34.72, 19.46, 19.18, 17.76, 8.85, 7.99.

[0154] After the synthesis of natural product Ivesinol, this embodiment also carries out biological activity research on Ivesinol, including a wide range of MIC screening against various bacteria, in vitro cytotoxicity test, bactericidal curve experiment, antibiofilm experiment, drug resistance experiment, minimum bactericidal concentration (MBC) experiment, cell hemolysis toxicity experiment and pharmacokinetic experiment, to perfect the research data and lay a foundation for further new drug research and development.

[0155] II. Results and discussion of Ivesinol biological experiments

[0156] 2.1 Ivesinol minimum inhibitory concentration experiment

[0157] Minimum inhibitory concentration (MIC) is an index for quantitatively determining the in vitro bacteriostatic activity of a drug, and is also a key index for studying the interaction between bacteria and drugs. In order to kill or inhibit pathogenic bacteria in the body, the drug must reach an effective concentration in the target tissue or organ and maintain it for a certain period of time. In this experiment, according to the related biological activity reports of Ivesinol, the bacteriostatic activity screening of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (E. faecium) was carried out, and the results are shown in Table 2.

[0158] Table 2 Ivesinol minimum inhibitory concentration experiment results

[0159] Table 3.2 Results of Ivesinol minimum inhibitory concentration experiment

[0160]

[0161]

[0162]

[0163] Experimental results showed that Ivesinol's bactericidal activity against MRSA ranged from 1 to 0.5 μg / mL, comparable to that of Vancomycin and Ciprofioxacin. The best activity against VER was 1 μg / mL (Ef 2006295036), which was not as good as reported in the literature. Subsequently, bactericidal activity against Gram-negative bacteria was determined, including Staphylococcus aureus (SA 1405 and SA186286), Escherichia coli (E. coli 25922), and Klebsiella pneumoniae (KPN 3026), with results shown in Table 3. However, regrettably, the experimental results indicated virtually no inhibitory activity against Gram-negative bacteria.

[0164] Table 3. Experimental results of the minimum inhibitory concentration of Ivesinol against Gram-negative bacteria.

[0165] Table 3.3 Results of minimal inhibitory concentration of Ivesinol onGram-negative bacteria

[0166]

[0167] 2.2 Ivesinol in vitro cytotoxicity test

[0168] Cytotoxicity assays are a simple, efficient, and quantitative in vitro method for evaluating the safety of compounds. The principle behind these assays is that the toxicity of the analyte affects cell homeostasis, disrupting cell integrity and basic functions, leading to apoptosis. Commonly used cytotoxicity assays include the MTT assay, CCK-8 assay (Cell Counting Kit-8), MEM elution assay, and direct contact assay. This experiment used the MTT cytotoxicity assay to perform cytotoxicity tests on three cell types: L02 (normal hepatocytes), Huvec (human umbilical vein endothelial cells), and 293T (normal kidney cells). The results are as follows: Figure 1 As shown, with increasing Ivesinol concentration, cytotoxicity increases and viable cell count decreases. The Ivesinol IC50 value for L02 cells was calculated. 50 =9.7890.5 μg / mL, Ivesinol IC50 in 293T cells 50= 0.4068 μg / mL, IC of Huvec cell Ivesinol 50 = 0.351 μg / mL, from the data, the cytotoxicity is large, the activity window is small, and it does not show the low toxicity reported in the literature.

[0169] 2.3 Ivesinol bactericidal curve experiment

[0170] The relationship between the concentration of antibacterial drugs and the rate and degree of bactericidal activity can be explained by determining the bactericidal curve of the compound, all antibacterial drugs have concentration-dependent and non-dependent zones on their concentration-bacterial amount curves, which are manifested by the slope of the curve, and non-concentration-dependent drugs have steeper concentration-bacterial amount curves than concentration-dependent drugs. MRSA 300 was selected as the experimental strain in this experiment. The bactericidal effect of Ivesinol was determined by different concentrations and times, and the results are shown in Figure 2 . The MIC, 2xMIC, 4xMIC, and 8xMIC of Ivesinol were determined at 4 time points, and the results showed that the bactericidal effect was better with increasing concentration of the compound, and Ivesinol belongs to a concentration-dependent compound. 2.4 Ivesinol antibiofilm experiment.

[0171] There are mainly two kinds of antibiofilm experiments: one is to prevent the formation of biofilm, and the other is to interfere with the biofilm after the biofilm has been formed. This experiment is the first kind of compound affecting the formation of biofilm. From Figure 3, it can be observed that Ivesinol at a concentration of 2xMIC has an inhibitory effect on biofilm, but there is basically no effect from the MIC value, but the positive control ciprofloxacin has a certain effect on biofilm even at 1 / 2xMIC, indicating that the bactericidal effect of Ivesinol is not caused by the effect on biofilm.

[0172] 2.5 Ivesinol resistance test

[0173] The increase of the MIC value of the compound by 1-5 times is low resistance; 5-15 is moderate resistance; and more than 15 is high resistance. The resistance experiment of Ivesinol has been done to 26 generations Figure 4 ), from the initial 0.5 μg / mL to the 26th generation, which increased to 2 μg / mL, and remained low resistance. The positive control drug ciprofloxacin increased from 0.5 μg / mL to 32 μg / mL at the 24th generation, which was 64 times higher than the initial MIC value, showing high resistance. Compared with the positive control, we found that the compound Ivesinol has the characteristics of resistance to drugs.

[0174] 2.6 Minimum bactericidal concentration experiment of Ivesinol

[0175] Minimum bactericidal concentration (MBC): the minimum drug concentration required to kill 99.9% (reducing 3 orders of magnitude) of test microorganisms, in order to better show the killing of the drug on bacteria. When the number of colonies on the agar plate is less than 10, the concentration can be judged as the minimum bactericidal concentration of the compound. As shown in Table 4, the minimum bactericidal concentration of Ivesinol is 16 μg / mL, and the minimum bactericidal concentration of the positive control drug ciprofloxacin is 1 μg / mL.

[0176] Table 4. Colony count of Ivesinol at each concentration

[0177] Table 3.4 Colony count of Ivesinol at each concentration

[0178]

[0179] 2.7 Hemolytic toxicity experiment of Ivesinol

[0180] Hemolysis generally refers to the destruction of the red blood cell membrane, or the appearance of many small pores, or the outflow of hemoglobin from the red blood cells due to extreme extension, and is accompanied by the gradual increase in the transparency of the red blood cell free liquid and the gradual deepening of the red color, which is one of the important indicators of pre-market research of drugs. In this experiment, the OD 600 was determined by a microplate reader, and the results were calculated by the hemolysis rate formula, as shown in Figure 5 . It can be seen that the concentration of the compound increased from 0.125 μg / mL to 8 μg / mL, and the hemolysis rate was less than 5%, and when it increased to 16 μg / mL, it rose to 5.8%. Through the experiment, it can be known that the compound Ivesinol has no hemolytic toxicity in the active range.

[0181] 2.8 Pharmacokinetic experiment of Ivesinol

[0182] Pharmacokinetic experiment mainly studies the dynamic change process of the drug in the animal body, which is an important part of preclinical research of drugs. In this experiment, BALB / c mice were selected as experimental objects, and blood was collected at set time points by tail vein injection of the test substance, and the experimental results were analyzed by HPLC, as shown in Figure 6 . The T 1 / 2= 4.92 min, Ivesinol has a fast elimination time in mice. Example 1 carried out a comprehensive biological activity evaluation on the antibacterial effect of ivesinol, and found that the antibacterial activity of the compound did not reach the level reported in the literature, and there is still room for further improvement. Cell toxicity, antibiofilm activity and pharmacokinetics experiments showed that the water solubility, safety and other indicators of the compound were difficult to meet the requirements of drug production. Therefore, the present application carries out structural modification on Ivesinol, carries out further structure-activity relationship research, clarifies the pharmacophore, optimizes the drugability, and obtains a lead compound with stable structure and simplified structure. The drugability evaluation of this kind of compound has important significance. Specifically, examples 2-22 of the present application still follow the synthesis strategy of ivesinol, and the compound is synthesized by dividing it into left and right two fragments, and then coupling to complete assembly.

[0183] First, the left part is designed to remain unchanged, and the acyl fragment in the right fragment is changed, hoping to clarify whether the alkyl chain in the acyl group will affect the biological activity. Finally, three compounds T-3 / 4 / 5 are successfully obtained. Then, the right side is kept unchanged, and the structure of the left fragment is changed. By changing the acyl fragment and the phenolic hydroxyl group on the benzene ring, six compounds T-6-T-11 are designed and synthesized.

[0184] Then, another series of analogues are designed, and the substituents on both sides are changed simultaneously to obtain 10 compounds T-12-T-21. In this series of compounds, the present application directly changes the acyl group of some compounds to alkane, or changes the position of phenolic hydroxyl and methoxy on both sides of the benzene ring, changes the acyl form, and expects to realize the optimization of activity and toxicity.

[0185] The specific synthesis methods of Ivesinol derivatives T-1-T-21 are as follows:

[0186] Example 2:

[0187] Synthesis of derivative T-1:

[0188] Compound 4-1 (44.8 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, and p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), polyformal (29 mg, 0.2 mmol, 1.0 equiv) were added in turn, and CHCl3 (3 mL) was added as a solvent, and the tube was sealed at 50℃ and stirred for 2h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the compound T-1 (32.7 mg, 71%) was separated and purified by silica gel column chromatography. 1H NMR (400 MHz, CDC13) δ 12.64 (d, J = 1.4 Hz, 2H), 8.73-8.59 (m, 3H), 3.93 (s, 6H), 3.75 (q, J = 6.8 Hz, 2H), 3.69 (s, 2H), 2.06 (s, 6H), 1.18 (s, 6H), 1.16 (s, 6H). 13 C NMR (100 MHz, CDC13) δ 210.32, 162.06, 159.47, 154.91, 110.70, 109.46, 106.42, 65.13, 38.83, 29.67, 19.68, 17.63, 7.99.

[0189] Example 3:

[0190] Synthesis of derivative T-2:

[0191] Compound 4-2 (47.6 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to obtain compound T-2 (38.6 mg, 81%). 1 H NMR (400 MHz, CDC13) δ 13.08 (s, 2H), 8.68 (s, 2H), 3.95 (s, 6H), 3.69 (s, 2H), 3.04 (t, J = 7.5 Hz, 4H), 2.06 (s, 6H), 1.64 (q, J = 7.6 Hz, 4H), 1.36 (q, J = 7.5 Hz, 4H), 0.93 (t, J = 7.3 Hz, 6H). 13 C NMR (100 MHz, CDC13) δ 205.90, 162.33, 159.65, 155.21, 110.73, 109.55, 107.49, 64.87, 42.31, 27.47, 22.57, 17.56, 13.96, 7.95. M.p: 173-175 °C. HRESIMS (m / z): 487.23374 [M+H] + (calcd for C 27 H 35 O8 + : 487.23326).

[0192] Example 4:

[0193] Synthesis of derivative T-3:

[0194] Compound 4-3 (53.2 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-3 (41.5 mg, 81%). 1 H NMR (400 MHz, CDC13) δ 13.09 (s, 2H), 8.68 (s, 2H), 3.95 (s, 6H), 3.69 (s, 2H), 3.03 (d, J = 7.9 Hz, 4H), 2.06 (s, 6H), 1.69-1.62 (m, 4H), 1.32 (d, J = 19.5 Hz, 12H), 0.88 (d, J = 6.2 Hz, 6H). 13 C NMR (100 MHz, CDC13) δ 205.90, 162.35, 159.66, 155.22, 110.73, 109.54, 107.48, 64.88, 53.53, 42.63, 31.71, 29.15, 25.35, 22.49, 14.06, 7.95. HRESIMS (m / z): 543.29634 [M+H] + , (calcd for C 31 H43O8 + : 543.29675).

[0195] Example 5:

[0196] Synthesis of derivative T-4:

[0197] Compound 4-2 (23.8 mg, 0.1 mmol, 1.0 equiv) and compound 9-4 (23.8 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv), paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-4 (8.8 mg, 18%). 1HNMR (400 MHz, CDC13) δ 13.69 (s, 1H), 13.05 (s, 1H), 8.94 (s, 1H), 8.76 (s, 1H), 3.98 (s, 3H), 3.96 (s, 3H), 3.69 (s, 2H), 3.11 (t, J = 7.4 Hz, 2H), 3.03 (t, J = 7.5 Hz, 2H), 2.12 (s, 3H), 2.05 (s, 3H), 1.64 (q, J = 7.6 Hz, 5H), 1.38-1.31 (m, 4H), 0.92 (d, J = 7.0 Hz, 6H). 13 C NMR (100 MHz, D20) δ 205.34, 203.29, 160.27, 159.72, 157.26, 156.68, 153.99, 152.58, 108.21, 107.64, 107.45, 105.98, 105.13, 104.66, 62.41, 59.41, 41.97, 39.68, 27.13, 25.06, 24.00, 19.90, 15.15, 11.44, 11.27, 6.27, 5.39. HRESIMS (m / z): 487.23374 [M+H] + (calcd for C 27 H 35 O8 + : 487.23341).

[0198] Example 6:

[0199] Synthesis of derivative T-5:

[0200] Compound 4-1 (22.4 mg, 0.1 mmol, 1.0 equiv) and compound 9-1 (19.6 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as a solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was separated and purified by silica gel column chromatography to obtain compound T-5 (6.9 mg, 16%). 1HNMR (500 MHz, CDC13) δ 9.93 (s, IH), 9.93 (s, IH), 8.97 (s, IH), 8.97 (s, IH), 8.51 (s, IH), 8.51 (s, IH), 5.42 (s, IH), 5.42 (s, IH), 4.38 (hept, J = 12.8 Hz, IH), 3.98 (s, 2H), 3.91 (s, 3H), 3.77 (s, 3H), 2.61 (s, 3H), 2.16 (s, 6H), 1.16 (d, J = 6.4 Hz, 6H).

[0201] Example 7:

[0202] Synthesis of derivative T-6:

[0203] Compound 4-1 (22.4 mg, 0.1 mmol, 1.0 equiv) and compound 9-4 (23.8 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as a solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed as monitored by TLC, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-6 (7.1 mg, 15%). 1 HNMR (500 MHz, CDC13) δ 9.93 (s, IH), 9.93 (s, IH), 8.97 (s, IH), 8.97 (s, IH), 8.51 (s, IH), 8.51 (s, IH), 5.42 (s, IH), 5.42 (s, IH), 4.38 (hept, J = 12.8 Hz, IH), 3.98 (s, 2H), 3.91 (s, 3H), 3.77 (s, 3H), 2.61 (s, 3H), 2.16 (s, 6H), 1.16 (d, J = 6.4 Hz, 6H).

[0204] Example 8:

[0205] Synthesis of derivative T-7:

[0206] Compound 4-1 (22.4 mg, 0.1 mmol, 1.0 equiv) and compound 4-3 (26.6 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to give compound T-7 (9.0 mg, 18%). 1 HNMR (400 MHz, CDC13) δ 13.67 (s, 1H), 12.73 (s, 1H), 8.90 (s, 1H), 8.77 (s, 1H), 3.99 (s, 3H), 3.95 (s, 3H), 3.78-3.71 (m, 1H), 3.69 (s, 2H), 3.08 (t, J = 7.4 Hz, 2H), 2.12 (s, 3H), 2.06 (s, 4H), 1.65 (p, J = 7.5 Hz, 3H), 1.41 (d, J = 4.9 Hz, 2H), 1.34-1.27 (m, 10H), 1.17 (d, J = 6.8 Hz, 9H), 0.90-0.82 (m, 10H). 13 C NMR (100 MHz, CDC13) δ 209.85, 207.94, 162.81, 162.14, 159.55, 159.26, 156.56, 154.73, 110.85, 110.21, 109.97, 108.57, 107.70, 106.02, 65.22, 61.98, 44.82, 38.93, 31.66, 29.70, 29.06, 24.48, 22.59, 19.52, 17.72, 14.10, 8.82, 8.01. HRESIMS (m / z): 501.24939 [M+H] + (calcd for C 28 H 37 O8 + : 501.24996)

[0207] Example 9:

[0208] Synthesis of derivative T-8:

[0209] Compound 4-2 (23.8 mg, 0.1 mmol, 1.0 equiv) and compound 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to obtain compound T-8 (6.6 mg, 14%). 1 HNMR (400 MHz, CDC13) δ 13.56 (s, 1H), 13.03 (s, 1H), 8.97 (s, 1H), 8.76 (s, 1H), 3.99 (s, 3H), 3.96 (s, 3H), 3.70 (s, 2H), 3.02 (t, J = 7.6 Hz, 2H), 2.12 (s, 3H), 2.05 (s, 3H), 1.65 (d, J = 7.5 Hz, 3H), 1.33 (p, J = 7.7 Hz, 3H), 1.15 (d, J = 6.7 Hz, 6H), 0.90 (t, J = 7.4 Hz, 4H). 13 C NMR (100 MHz, CDC13) δ 212.21, 205.89, 163.06, 162.28, 159.84, 159.20, 156.08, 155.14, 110.81, 110.38, 110.06, 107.94, 107.84, 107.20, 64.99, 61.97, 42.32, 39.90, 29.70, 27.74, 22.47, 19.23, 17.76, 13.74, 8.90, 7.96. HRESIMs (m / z): 473.21809 [M+H] + (calcd for C 26 H 33 O8 + : 473.21865).

[0210] Example: 10:

[0211] Synthesis of derivative T-9:

[0212] Compound 4-3 (26.6 mg, 0.1 mmol, 1.0 equiv) and compound 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as a solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to obtain compound T-9 (6.5 mg, 13%). 1 HNMR (400 MHz, CDC13) δ 13.66 (s, 1H), 13.56 (s, 1H), 9.04 (s, 1H), 8.94 (s, 1H), 3.99 (s, 6H), 4.03-3.96 (m, 7H), 3.68 (s, 2H), 2.71 (s, 3H), 2.12 (s, 3H), 2.12 (s, 3H), 1.16 (s, 3H), 1.14 (s, 3H).

[0213] Example 11:

[0214] Synthesis of derivative T-10:

[0215] Compound 9-1 (19.6 mg, 0.1 mmol, 1.0 equiv) and compound 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as a solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to obtain compound T-10 (6.5 mg, 15%). 1 HNMR (400 MHz, CDC13) δ 13.66 (s, 1H), 13.56 (s, 1H), 9.04 (s, 1H), 8.94 (s, 1H), 3.99 (s, 6H), 4.03-3.96 (m, 7H), 3.68 (s, 2H), 2.71 (s, 3H), 2.12 (s, 3H), 2.12 (s, 3H), 1.16 (s, 3H), 1.14 (s, 3H). 13C NMR (100 MHz, CDC13) δ 212.45, 205.34, 162.94, 162.76, 159.70, 159.25, 157.04, 156.22, 110.05, 109.80, 108.76, 108.30, 108.25, 108.03, 61.97, 39.82, 33.78, 30.27, 29.69, 19.27, 17.97, 8.91, 8.77. M.p: 152-154 °C. HRESIMS (m / z): 431.17114 [M+H] + (calcd for C 23 H 27 O8 + : 431.16965).

[0216] Example 12:

[0217] Synthesis of derivative T-11:

[0218] Compound 9-3 (23.8 mg, 0.1 mmol, 1.0 equiv) and compound 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv), paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After TLC monitoring reaction was completed, the solvent was removed under reduced pressure, and compound T-11 (9.5 mg, 20%) was obtained by silica gel column separation and purification. 1 HNMR (400 MHz, CDC13) δ 13.56 (d, J = 1.5 Hz, 1H), 9.03 (s, 1H), 8.60 (s, 1H), 7.57 (s, 1H), 4.01 (td, J = 6.7, 1.1 Hz, 1H), 3.96 (d, J = 1.3 Hz, 3H), 3.95 (d, J = 1.2 Hz, 3H), 3.67 (s, 2H), 2.12 (d, J = 1.3 Hz, 3H), 2.10 (d, J = 1.2 Hz, 4H), 1.26 (d, J = 1.3 Hz, 10H), 1.17 (d, J = 1.2 Hz, 3H), 1.15 (d, J = 1.2 Hz, 3H). 13C NMR (100 MHz, CDC13) δ 216.36, 212.47, 162.83, 159.37, 156.26, 156.22, 151.72, 114.14, 110.07, 110.05, 109.48, 108.66, 108.08, 62.07, 61.85, 45.51, 39.79, 27.29, 19.28, 18.16, 9.05, 8.87. HRESIMS (m / z): 473.21809 [M+H] + (calcd for C 26 H 33 O g + : 473.21869).

[0219] Example 13:

[0220] Synthesis of derivative T-12:

[0221] Compound 9-4 (47.6 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-12 (37.1 mg, 76%). 1 H NMR (400 MHz, CDC13) δ 13.71 (s, 2H), 8.99 (s, 2H), 3.99 (s, 6H), 3.68 (s, 2H), 3.13 (t, J = 7.3 Hz, 4H), 2.13 (s, 6H), 1.68-1.62 (m, 4H), 1.41-1.33 (m, 4H), 0.93 (t, J = 7.3 Hz, 6H). 13 C NMR (100 MHz, CDC13) δ 208.10, 162.71, 159.32, 156.70, 109.89, 108.70, 108.25, 61.95, 44.56, 29.69, 26.56, 22.46, 14.06, 8.85. M.p: 125-127 °C. HRESIMS (m / z): 487.23374 [M+H] + (calcd for C 27 H 35 O8 + : 487.23327).

[0222] Example 14:

[0223] Synthesis of derivative T-13:

[0224] Compound 9-4 (23.8 mg, 0.1 mmol, 1.0 equiv) and compound 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as a solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to obtain compound T-13 (7.8 mg, 17%). 1 HNMR (500 MHz, CDC13) δ 9.24 (s, 1H), 6.05 (s, 1H), 5.21 (s, 1H), 4.09-3.86 (m, 3H), 3.78 (s, 3H), 3.72 (s, 3H), 3.12-2.74 (m, 2H), 2.16 (s, 3H), 1.54-1.30 (m, 4H), 1.19 (t, J = 26.3 Hz, 6H), 1.00-0.83 (m, 3H).

[0225] Example 15:

[0226] Synthesis of derivative T-14:

[0227] Compound 9-5 (21.0 mg, 0.1 mmol, 1.0 equiv) and compound 9-2 (22.4 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, and CHCl3(3 mL) was added as a solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to obtain compound T-14 (7.1 mg, 16%). 1 HNMR (500 MHz, CDC13) δ 9.13 (s, 1H), 5.35 (d, J = 10.8 Hz, 2H), 4.06-3.84 (m, 3H), 3.78 (s, 6H), 3.54 (q, J = 13.4 Hz, 2H), 2.16 (s, 6H), 1.22 (t, J = 13.4 Hz, 3H), 1.17 (s, 3H), 1.15 (s, 3H).

[0228] Example 16:

[0229] Synthesis of derivative T-15:

[0230] Compound 9-1 (19.6 mg, 0.1 mmol, 1.0 equiv) and compound 9-3 (23.8 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to give compound T-15 (9.8 mg, 22%). 1 HNMR (400 MHz, CDC13) δ 13.67 (s, 1H), 9.08 (s, 1H), 8.58 (s, 1H), 7.60 (s, 1H), 3.97 (s, 3H), 3.96 (s, 3H), 3.67 (s, 2H), 2.73 (s, 3H), 2.12 (d, J = 10.2 Hz, 6H), 1.27 (s, 10H). 13 C NMR (100 MHz, CDC13) δ 216.38, 205.36, 162.70, 159.75, 157.00, 156.27, 153.93, 151.76, 114.02, 109.95, 109.89, 109.51, 108.81, 108.50, 62.07, 61.89, 45.54, 33.79, 27.31, 18.11, 9.09, 8.78. M.p: 198-200 °C. HRESIMS (m / z): 445.18679 [M+H] + (calcd for C 24 H 29 O8 + : 445.18640).

[0231] Example 17:

[0232] Synthesis of derivative T-16:

[0233] Compound 9-2 (44.8 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv) and paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to give compound T-16 (36.8 mg, 80%).1 H NMR (400 MHz, CDC13) δ 13.55 (s, 2H), 8.98 (s, 2H), 3.99 (s, 6H), 3.69 (s, 2H), 3.72-3.65 (m, 3H), 2.13 (s, 6H), 1.16 (s, 7H), 1.15 (s, 7H). 13 CNMR (100 MHz, CDC13) δ 212.44, 162.93, 159.30, 156.25, 110.01, 108.38, 108.09, 61.95, 39.80, 29.67, 19.26, 8.89.

[0234] Example 18:

[0235] Synthesis of derivative T-17:

[0236] Compound 9-6 (42.0 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The tube was sealed and stirred at 50 °C for 2 h. After TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-17 (35.4 mg, 82%). 1 H NMR (400 MHz, CDC13) δ 8.33 (s, 2H), 4.66 (s, 2H), 3.90 (s, 6H), 3.69 (s, 2H), 2.43 (d, J = 7.3 Hz, 4H), 2.13 (s, 6H), 0.92 (d, J = 6.6 Hz, 13H). 13 CNMR (100 MHz, CDC13) δ 152.72, 152.33, 152.18, 112.10, 110.52, 107.31, 61.93, 32.92, 28.43, 22.76, 18.96, 9.14. M.p: 195-197 °C. HRESIMS (m / z): 431.24391 [M+H] + (calcd for C 25 H 35 O6 + : 431.24215).

[0237] Example 19:

[0238] Synthesis of derivative T-18:

[0239] Compound 9-7 (44.8 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to give compound T-18 (35.0 mg, 76%). 1 H NMR (400 MHz, CDC13) δ 8.36 (s, 2H), 4.66 (s, 2H), 3.90 (s, 6H), 3.69 (s, 2H), 2.54 (t, J = 7.9 Hz, 4H), 2.12 (s, 6H), 1.47 (q, J = 7.3 Hz, 4H), 1.37-1.30 (m, 8H), 0.93-0.82 (m, 7H). 13 C NMR (100 MHz, CDC13) δ 152.56, 151.95, 151.90, 113.16, 110.60, 107.35, 61.94, 32.20, 28.93, 23.86, 22.66, 18.91, 14.10, 9.07.

[0240] Example 20:

[0241] Synthesis of derivative T-19:

[0242] Compound 9-1 (19.6 mg, 0.1 mmol, 1.0 equiv) and compound 9-4 (23.8 mg, 0.1 mmol, 1.0 equiv) were placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 1.0 equiv), paraformaldehyde (29 mg, 0.2 mmol, 2.0 equiv) were added successively, CHCl3(3 mL) was added as solvent, the tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by silica gel column chromatography to give compound T-19 (7.1 mg, 16%). 1 H NMR (400 MHz, CDC13) δ 13.72 (s, 1H), 13.68 (s, 1H), 9.03 (s, 1H), 8.96 (s, 1H), 4.00 (s, 3H), 3.99 (s, 3H), 3.68 (s, 2H), 3.13 (t, J = 7.3 Hz, 2H), 2.72 (s, 3H), 2.13 (d, J = 1.1 Hz, 7H), 1.65 (q, J = 7.4 Hz, 3H), 1.44-1.33 (m, 2H), 0.94 (t, J = 7.3 Hz, 3H).13 C NMR (100 MHz, CDC13) δ 208.09, 205.36, 162.78, 162.73, 159.67, 159.27, 157.02, 156.68, 109.92, 109.83, 108.77, 108.68, 108.23, 108.17, 61.98, 44.58, 33.81, 26.55, 22.46, 17.95, 14.09, 8.87, 8.81. M.p: 176-178 °C. HRESIMS (m / z): 445.18679 [M+H] + (calcd for C 24 H 29 O8 + : 445.18629).

[0243] Example 21:

[0244] Synthesis of derivative T-20:

[0245] Compound 9-3 (47.6 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry sealed tube, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The tube was sealed and stirred at 50 °C for 2 h. After the reaction was completed by TLC monitoring, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-20 (35.1 mg, 72%). 1 H NMR (400 MHz, CDC13) δ 8.63 (s, 2H), 7.56 (s, 2H), 3.93 (s, 6H), 3.66 (s, 2H), 2.10 (s, 6H), 1.26 (s, 19H). 13 C NMR (100 MHz, CDC13) δ 216.51, 156.29, 153.63, 151.68, 114.10, 110.30, 109.54, 61.97, 45.53, 27.30, 18.26. M.p: 229-231 °C. HRESIMS (m / z): 487.23374 [M+H] + (calcd for C 27 H 35 O8 + : 487.23389).

[0246] Example 22:

[0247] Synthesis of derivative T-21:

[0248] Compound 9-1 (39.2 mg, 0.2 mmol, 1.0 equiv) was placed in a 20 mL dry vial, p-TsCl (19 mg, 0.1 mmol, 0.5 equiv), paraformaldehyde (29 mg, 0.2 mmol, 1.0 equiv) were added successively, and CHCl3(3 mL) was added as solvent. The vial was sealed and stirred at 50 °C for 2 h. After TLC monitoring, the reaction was completed, the solvent was removed under reduced pressure, and the product was purified by column chromatography on silica gel to give compound T-21 (33.5 mg, 83%). 1 H NMR (400 MHz, CDC13) δ 13.64 (s, 2H), 8.97 (s, 2H), 3.99 (d, J = 1.0 Hz, 6H), 3.68 (s, 2H), 2.71 (d, J = 1.0 Hz, 6H), 2.13 (d, J = 1.0 Hz, 6H). 13 CNMR (100 MHz, CDC13) δ 205.33, 162.78, 159.64, 156.99, 109.86, 108.76, 108.17, 61.97, 33.77, 17.92.

[0249] Example 23:

[0250] Activity of natural product Ivesinol and its derivatives against S. aureus and E. faecium:

[0251] Minimum inhibitory concentration determination method: 96-well dilution method was used to detect the MIC of the compound against S. aureus and E. faecium to evaluate its activity against drug-resistant bacteria. First, the test compound was dissolved in DMSO to prepare a high-concentration stock solution, and then the compound stock solution was diluted by 2 times in gradient, a total of 10 times, to prepare 11 10x working solutions; then the compound gradient dilution was transferred to a 96-well round-bottom plate, the first to eleventh wells contained 10 μL of the prepared 10x working solution, and the twelfth well contained 10 μL of water as a solvent control. Fresh monoclonal strains were picked and prepared into a bacterial suspension in sterile saline, and the concentration was adjusted to 0.5 McFarland turbidity. The bacterial suspension was diluted 1:200 with 7H9 medium, and then 90 μL of the bacterial suspension was added to the prepared drug-containing 96-well plate. The inoculated 96-well plate was incubated in a biochemical incubator (37 °C) for 16 h, and the experimental results were recorded. Ciprofloxacin, a first-line clinical drug, was used as a positive control. The antibacterial activity of the compounds is shown in Table 5:

[0252] Table 5 Antimicrobial activity of Ivesinol and its derivatives

[0253]

[0254]

[0255] From the data in Table 5, it can be found that the antibacterial activity of compound T-18 is the best, and the difference between T-18 and the natural product is that the acyl side chain of two fragments is different, the side chain of Ivesinol is isobutyryl, and the number of carbon atoms is 4, and the number of carbon atoms of T-18 is 5. In addition, it is found that by changing the symmetry relationship of the left and right fragments, or increasing or decreasing the number of carbon atoms of the acyl side chain, the antibacterial activity is reduced, so it is indicated that the optimal carbon chain length is 5 carbons, and the activity is better when the left and right fragments are asymmetric.

[0256] In summary, the embodiment of the present application first conducts more comprehensive biological activity determination on Ivesinol, and the results show that the activity of Ivesinol is not as good as reported in the literature. The derivative design idea and the finally successfully obtained derivative structure are carried out. First, according to the position of each group on the benzene ring, the length of the acyl side chain, and the existence of the carbonyl group in the acyl side chain, the synthesis of the derivative is carried out. In the case of keeping the left and right fragments unchanged, the other fragment is obtained by changing the number of carbon atoms of the acyl side chain or reducing the carbonyl group in the acyl side chain, and after combination and coupling, 9 derivatives are obtained. The fragments obtained by changing are randomly combined to obtain 10 derivatives. Finally, through the antibacterial activity verification, it is found that changing the symmetry relationship of the left and right fragments, or increasing or decreasing the number of carbon atoms of the acyl side chain will affect the antibacterial activity of the compound, the optimal carbon chain length is 5 carbons, and the activity is better when the left and right fragments are asymmetric, that is, the antibacterial activity of compound T-18 is the best.

[0257] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method for synthesizing the natural product Ivesinol and its derivatives, characterized in that, The synthetic route of the method is as follows: The method includes the following steps: (1) Compound 1, 2,4,6-trihydroxybenzaldehyde, was methylated and reduced to obtain compound 3. Compound 3 was then subjected to Friedel-Crafts acylation to obtain compound 4. (2) Compound 5 was methylated and Friedel-Crafts reaction to obtain compound 7. Compound 7 was given an aldehyde group by Vilsmeier reaction, and the aldehyde group was reduced to obtain compound 9. (3) Compounds 4 and 9 were coupled to give compounds IVE-1 or IVE-2; The IVE-1 is selected from at least one of the following structures T-4, T-7 or T-18, and the IVE-2 is selected from at least one of the following structures T-9 or T-20: 。 2. The synthesis method according to claim 1, characterized in that, The synthetic route of the method is as follows: The method includes the following steps: (1) Compound 1 was methylated to obtain compound 2, compound 2 was reduced to obtain compound 3, and compound 3 was acylated to obtain compound 4. (2) Compound 5 was methylated to obtain compound 6, compound 6 was reacted with Friedel-Crafts to obtain compound 7, compound 7 was introduced with an aldehyde group by Vilsmeier reaction to obtain compound 8, and the aldehyde group in compound 8 was reduced to obtain compound 9. (3) Compounds 4 and 9 are coupled to give compounds IVE-1 or IVE-2.

3. The synthesis method according to claim 2, characterized in that: In steps (1) and (2), the methylation reaction is a selective monomethylation reaction, and the methylating agent used is selected from any one of iodomethane, dimethyl sulfate and dimethyl carbonate.

4. The synthesis method according to claim 2, characterized in that: In steps (1) and (2), the methylation reaction is carried out at room temperature and 50~60℃, respectively.

5. The synthesis method according to claim 2, characterized in that: In step (1), under acidic conditions, the aldehyde group in compound 2 is reduced to a methyl group by sodium cyanoborohydride to obtain compound 3.

6. The synthesis method according to claim 2, characterized in that: In step (1), the aldehyde reduction reaction is carried out at a pH of 2 to 3.

7. The synthesis method according to claim 2, characterized in that: In step (1), the acylation reagent used in the Friedel-Crafts acylation reaction is an acyl chloride with the chemical structural formula R1COCl.

8. The synthesis method according to claim 2, characterized in that: In step (2), the Friedel-Crafts reaction includes acylation and alkylation reactions. The acylation reaction uses an acyl chloride as the acylation reagent, which has the chemical structural formula R2COCl. The alkylation reaction uses a haloalkane as the alkylation reagent, which has the chemical structural formula R5Cl or R6Cl.

9. The synthesis method according to claim 2, characterized in that: In steps (1) and (2), the reaction temperature of the Friedel-Crafts acylation reaction and the Friedel-Crafts reaction is 60~70℃.

10. The synthesis method according to claim 2, characterized in that: In step (2), compound 7 is reacted with oxaloyl chloride / N,N-dimethylformamide DMF system to introduce aldehyde groups, thereby preparing compound 8.

11. The synthesis method according to claim 2, characterized in that: In step (2), the aldehyde group is reduced to obtain compound 9 under Pd / C / H2 conditions.

12. The synthesis method according to claim 2, characterized in that: In step (3), compounds 4 and 9 are coupled with the TsCl / paraformaldehyde system to obtain compounds IVE-1 or IVE-2.

13. The synthesis method according to claim 2, characterized in that: In step (3), the coupling reaction temperature is 40~60℃.

14. A compound, characterized in that: The compound is synthesized according to any one of claims 1 to 13, wherein the compound is selected from at least one of the following structures: T-4, T-7, T-9, T-18, or T-20. 。 15. The use of the compound according to claim 14 in antibacterial applications, wherein the use is not for disease treatment or diagnostic purposes, characterized in that, The bacteria in question is Staphylococcus aureus.

16. The use of compounds T-7 and T-20 according to claim 14 in the treatment of Enterococcus faecalis, wherein the use is not for disease treatment or diagnostic purposes.

17. An antibacterial drug, characterized in that, The drug contains an effective dose of the compound as described in claim 14.

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