Antibacterial compounds and uses thereof

Abstract

The application discloses an antibacterial compound and application thereof, and is characterized by a structural formula: (6R, 7R)-7-(2-(5-amino-1, 3, 4-thiadiazol-2-yl) acetylamino)-8-oxo-3-((S)-tetrahydrofuran-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, which is named as (6R, 7R)-7-(2-(5-amino-1, 3, 4-thiadiazol-2-yl) acetylamino)-8-oxo-3-((S)-tetrahydrofuran-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid. The application is based on the pet anti-infection drug cefovecin sodium, retains the 3-position tetrahydrofuran ring advantage structure, and modifies the 7-position amide side chain, introduces the acetylamino side chain containing heteroatoms (containing heterocyclic ring), so as to control the antibacterial activity and antibacterial spectrum of the cephalosporin nucleus, and improve the inhibition effect on clinical gram-positive bacteria (staphylococcus and drug-resistant staphylococcus, etc.), so as to develop a new type of veterinary antibiotic with clinical application value.

Description

Technical Field

[0001] This invention relates to the field of biomedicine, specifically to an antibacterial compound and its applications. Background Technology

[0002] Antimicrobial agents (including antibiotics, antiviral drugs, antifungal drugs, and antiparasitic drugs) are medications used to prevent and treat infections in humans, animals, and plants. Antimicrobial resistance occurs when bacteria, viruses, fungi, and parasites change over time and no longer respond to drugs. Antimicrobial resistance leads to increasingly more difficult-to-treat infections. The misuse and overuse of antimicrobial agents are major drivers of the development of drug-resistant pathogens.

[0003] Antimicrobial resistance occurs when bacteria, viruses, fungi, and parasites cease to respond to antimicrobial drugs. Because drug resistance renders antibiotics and other antimicrobial treatments ineffective, treating infections becomes more difficult, and may even become impossible. This can lead to the emergence of superbugs, bacteria that are not inhibited by the first-line drugs used to treat these pathogens, thus increasing the risk of disease transmission, disability, and death. This problem is considered one of the top ten global public health threats.

[0004] In recent years, the widespread use, especially the overuse, of antibiotics has led to severe resistance in many pathogens to clinical antibiotics, posing a serious threat to public health. However, the development of new antibiotics is slow; therefore, the search for novel antibiotics and new antibacterial strategies to address the global "antibiotic crisis" is urgently needed.

[0005] Cefavirenz sodium is a novel third-generation cephalosporin antibiotic specifically for animals. Its structural feature is the addition of a tetrahydrofuran heterocycle linked to the C-position of the cephalosporin nucleus via a C-C bond, thus endowing the product with broad-spectrum antibacterial activity and stability against β-lactamases. As an antibacterial agent, cefavirenz sodium exhibits a broad antibacterial spectrum and advantages in dogs and cats, including rapid absorption, slow elimination, high bioavailability, good safety profile, and a high therapeutic index. It is an ideal long-acting antibiotic for dogs and cats and has shown promising applications in veterinary clinical practice. It is primarily used to treat skin, digestive tract, genitourinary tract, bone, and soft tissue infections in dogs and cats caused by susceptible bacteria, as well as pyoderma in dogs caused by Staphylococcus aureus carrying the mecA gene. It can also be used to prevent postoperative infections in dogs and cats after surgery.

[0006]

[0007] The number of cephalosporin derivatives containing tetrahydrofuran heterocyclic compounds at the C-3 position reported in the literature is limited, and apart from cefotaxime, there is no further research and development of new derivatives with similar structures. Summary of the Invention

[0008] To address the aforementioned technical problems, the first objective of this invention is to provide an antibacterial compound, and the second objective is to provide its application, thereby enhancing its inhibitory effect against clinical Gram-positive bacteria.

[0009] To achieve the first objective mentioned above, the present invention provides the following technical solution: an antibacterial compound, characterized in that it has the following structural formula:

[0010] ;

[0011] Named as: (6R,7R)-7-(2-(5-amino-1,3,4-thiadiazol-2-yl)acetamido)-8-oxo-3-((S)-tetrahydrofuran-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid.

[0012] The antimicrobial compound is used in the preparation of drugs for treating diseases in livestock caused by Gram-positive bacteria.

[0013] In the above scheme: the Gram-positive bacteria is Staphylococcus aureus ( Staphylococcus aureus ), methicillin-resistant Staphylococcus aureus ( Staphylococcus aureus ), Pseudomonas intermedia ( Staphylococcus pseudo-intermediate Streptococcus suis ( Streptococcus suis ).

[0014] Beneficial effects

[0015] This invention is based on the pet anti-infective drug cefotaxime sodium. It retains the dominant structure of the tetrahydrofuran ring at the 3-position and modifies the amide side chain at the 7-position by introducing an acetaminophen side chain containing heteroatoms. This modifies the antibacterial activity and antibacterial spectrum of the cefotaxime nucleus, with a focus on enhancing the inhibitory effect on clinical Gram-positive bacteria (such as Staphylococcus spp. and drug-resistant Staphylococcus), thus developing a novel veterinary antibiotic with clinical application value. Attached Figure Description

[0016] Figure 1 For the present invention 1 H NMR spectrum. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0018] Example 1

[0019] An antibacterial compound, characterized by having the following structural formula:

[0020] ;

[0021] Named as: (6R,7R)-7-(2-(5-amino-1,3,4-thiadiazol-2-yl)acetamido)-8-oxo-3-((S)-tetrahydrofuran-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (code F50-123).

[0022] Preparation of F50-123:

[0023] 1. Preparation of intermediate 2-(5-amino-1,3,4-thiadiazol-2-yl)acetic acid

[0024]

[0025] 3.4 g (18.16 mmol) of ethyl 2-(5-amino-1,3,4-thiadiazol-2-yl)acetate, 5 mL of methanol, and 15 mL of 10% sodium hydroxide aqueous solution were added to a 50 mL reaction flask and stirred at room temperature for 30 min. The pH was adjusted to 2.8-3.2 with 5% hydrochloric acid, and a solid precipitated. The solid was collected by filtration and dried under reduced pressure at 35-45 °C to give 2 g of orange solid, with a yield of 69.20%.

[0026] 2. Preparation of p-nitrobenzyl (6R,7R)-7-(2-(5-amino-1,3,4-thiadiazol-2-yl)acetamido)-8-oxo-3-((S)-tetrahydrofuran-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-en-2-carboxylic acid)

[0027]

[0028] At room temperature, 1.0 g (6.27 mmol) 2-(5-amino-1,3,4-thiadiazol-2-yl)acetic acid and 2.31 g (5.23 mmol) 7-amino-nucleus p-nitrobenzyl ester hydrochloride were dissolved in 10 mL DMF; 3.38 g DIPEA and 2.38 g HATU were added, and the mixture was reacted at room temperature for 30 min.

[0029] 20 mL of dichloromethane and 15 mL of water were added to the reaction system, and the mixture was stirred and allowed to stand to separate into layers. The organic phase was washed twice with 15 mL of saturated brine each time, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The mixture was then subjected to rapid silica gel column chromatography (eluting with dichloromethane-methanol) and concentrated to give 1 g of yellow solid, with a yield of 34.98%.

[0030] 3. Preparation of the target product F50-123

[0031]

[0032] 1.0 g (1.83 mmol) of the above p-nitrobenzyl ester intermediate (C 22H 22 Sodium dithionite (N6O7S2) was dissolved in 4 mL of acetone and 6 mL of water. 1.43 g of sodium dithionite was added with stirring, and the pH was adjusted to 7.8-8.2 with 5% ammonia. The reaction was carried out at room temperature for 30 min. 20 mL of dichloromethane was added for extraction to remove organic impurities. The aqueous phase was cooled to 0-5 °C, and the pH was adjusted to 2.5-3.0 with 5% hydrochloric acid solution, causing a solid to precipitate. The solid was filtered, and the wet product was dried under reduced pressure at 35-45 °C to give 0.3 g of a white solid, with a yield of 39.84%.

[0033] 1 H NMR (400 MHz, DMSO- d 6) δ 9.14 (d, J = 8.3 Hz, 1H), 7.04 (s, 2H), 5.47(dd, J = 8.4, 4.7 Hz, 1H), 4.96 (d, J = 4.7 Hz, 1H), 4.92 (dd, J = 9.0, 6.5 Hz,1H), 3.85 (s, 2H), 3.80 (t, J = 7.3 Hz, 1H), 3.61 (td, J = 7.8, 5.5 Hz, 1H), 3.36(s, 1H), 3.20 (d, J = 17.4 Hz, 1H), 2.11 (ddd, J = 16.2, 8.4, 4.0 Hz, 1H), 1.95 –1.69 (m, 2H), 1.52 (dq, J = 11.9, 8.9 Hz, 1H). Figure 1 ).

[0034] LCMS (-ESI): m / z 410.2.

[0035] Example 2

[0036] Bioactivity evaluation

[0037] Cefavirenzin is a long-acting third-generation veterinary cephalosporin with a C-3 position linked to an (S)-tetrahydrofuran ring, which significantly prolongs its half-life in vivo. A single dose can maintain an effective blood concentration for a long time. It has been approved in many countries for the treatment of bacterial infections in dogs and cats. In the United States, its approved indications are mainly for skin and soft tissue infections in dogs and cats induced by Staphylococcus, Group G Streptococcus, and Pasteurella multocida. In the United Kingdom, its approved indications are broader, including skin and soft tissue infections, urinary tract infections, and periodontal infections, covering β-hemolytic streptococci, Staphylococcus, Pasteurella multocida, Escherichia coli, Proteus, and some anaerobes.

[0038] However, cefotaxime has significant drawbacks: although it has excellent pharmacokinetic properties, its overall antibacterial activity is only slightly improved, and it exhibits cross-resistance with other third-generation cephalosporins; ESBL- and AmpC enzyme (CMY-2, DHA-1) producing strains are generally resistant to it, which limits its clinical application.

[0039] This invention uses cefavirenz sodium as a positive control to conduct in vitro drug susceptibility evaluation on the newly synthesized derivatives, focusing on evaluating its inhibitory activity against common pathogenic bacteria in veterinary clinics.

[0040] 1. Tested strain

[0041] 1) Gram-positive and Gram-negative standard strains and clinical isolates were used to evaluate basic antibacterial activity.

[0042] Gram-positive bacteria: Staphylococcus aureus ( Staphylococcus aureus ATCC 29213, methicillin-resistant Staphylococcus aureus (MRSA) Staphylococcus aureus ATCC43300, Enterococcus faecalis ( Enterococcus fecal ATCC29212, Pseudomonas intermedia ( Staphylococcus pseudintermediaus Clinical strains, Streptococcus pyogenes ( Streptococcus pyogenes Streptococcus suis ( Streptococcus suis ).

[0043] Gram-negative bacteria: Escherichia coli ( Escherichia coli ATCC 25922, Klebsiella pneumoniae ( Klebsiella pneumoniae ATCC13883, Proteus mirabilis ( Miraculous Proteus ATCC12453, Riemerella anatipestifer ( Riemerella anatipestifer Salmonella ( Salmonella spp. Pasteurella multocida ( ) Pasteurella multocida ).

[0044] Anaerobic bacteria: Bacteroides fragilis ( Bacteroides fragilis ATCC25285.

[0045] 2) Pseudomonas aeruginosa ( Pseudomonas aeruginosaATCC 27853: This bacterium is naturally resistant to cefavirenz and is used to evaluate whether derivatives improve its activity against Pseudomonas aeruginosa.

[0046] 3) β-lactamase-resistant strains, assessing the ability of compounds to resist enzymatic hydrolysis.

[0047] AmpC-producing Enterobacteriaceae ( Escherichia coli Escherichia coli carrying plasmids AmpC (DHA-1, CMY-2);

[0048] ESBL-producing Enterobacteriaceae ( Escherichia coli ): Escherichia coli carrying CTX-M enzyme, Klebsiella pneumoniae carrying SHV-18 ( Klebsiella pneumoniae ATCC700603.

[0049] 2. Experimental Methods

[0050] The minimum inhibitory concentrations (MICs) of F50-094, F50-121, F50-123, F50-128, and ceftriaxone against each tested bacterial strain were determined using the agar dilution method; the drug test concentration gradient was set to 0.0625-128 mg / L.

[0051] 3. In vitro drug sensitivity results

[0052] Table 1. MIC results (mg / L) of each compound against the tested strains.

[0053]

[0054] The structural formula for F50-094 is:

[0055]

[0056] The structural formula for F50-121 is:

[0057] .

[0058] The structural formula for F50-128 is:

[0059] .

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An antibacterial compound, characterized in that, The structural formula is: ； Named as: (6R,7R)-7-(2-(5-amino-1,3,4-thiadiazol-2-yl)acetamido)-8-oxo-3-((S)-tetrahydrofuran-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid.

2. The use of the antibacterial compound of claim 1 in the preparation of a medicament for treating diseases in livestock caused by Gram-positive bacteria.

3. The application according to claim 2, characterized in that: The Gram-positive bacteria is Staphylococcus aureus (Staphylococcus aureus) Staphylococcus aureus ), methicillin-resistant Staphylococcus aureus ( Staphylococcus aureus ), Pseudomonas intermedia ( Staphylococcus pseudintermedius Streptococcus suis ( Streptococcus suis ).

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