Application of N-salicyloyl tryptamine derivative in preparation of medicine for resisting chlamydia psittaci infection diseases

Abstract

The invention provides application of an N-salicyloyl tryptamine derivative in preparation of a medicine for resisting chlamydia psittaci infection diseases, and belongs to the technical field of biological medicines. According to the application of the N-salicyloyl tryptamine derivative provided by the invention in preparation of the medicine for resisting the chlamydia psittaci infection disease, the N-salicyloyl tryptamine derivative comprises NHWL06032. Through screening, the NHWL06032 has specific inhibitory activity on chlamydia psittaci, the MIC90 of the NHWL06032 is 15 mu g / mL, and the NHWL06032 has no obvious toxicity on host cells under effective concentration. According to the technical scheme provided by the invention, the problem of drug resistance in the existing treatment of chlamydia psittaci infection by antibiotics can be solved, and a non-antibiotic treatment scheme is provided for chlamydia psittaci infection.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to the application of an N-salicylic acid tryptophan derivative in the preparation of a drug for treating Chlamydia psittaci infection. Background Technology

[0002] Chlamydia psittaci is an important zoonotic pathogen with a biphasic developmental cycle, consisting of an infectious epithelium (EB) and a replicating reticulum (RB). It primarily infects birds but can also be transmitted to humans via the respiratory tract, causing psittacosis. The clinical manifestations of psittacosis are diverse, ranging from mild flu-like symptoms to severe pneumonia and multiple organ dysfunction.

[0003] While antibiotic treatment (such as tetracyclines and macrolides) plays a crucial role in the management of psittacosis, the complexity of the disease, delayed diagnosis, and the potential risk of antibiotic resistance present new challenges to treatment. Antibiotic overuse can disrupt the gut microbiota, increasing the risk of drug-resistant bacteria. Currently, there are no reports of synthetic drugs specifically targeting psittacosis. Although some studies have shown that synthetic peptides exhibit inhibitory activity in vitro, they generally suffer from poor stability, susceptibility to protease degradation, short in vivo half-life, and high production costs.

[0004] N-Salicylic acid ester derivatives are a class of compounds composed of salicylic acid derivatives and melatonin derivatives. Currently, in clinical practice or existing research, their uses have only been documented in inhibiting neuroinflammation, anti-oxidation, and treating neurodegenerative diseases such as stroke and Parkinson's disease. There are no reports on the use of these specific small molecule derivatives in the treatment of Chlamydia psittaci infection. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an application of N-salicylic acid tryptophan derivative in the preparation of a drug for treating Chlamydia psittaci infection, so as to solve the risks of drug resistance in existing antibiotic treatments for Chlamydia psittaci infection, as well as the problems of poor stability, easy degradation and high cost of existing non-antibiotic therapies (such as synthetic peptides).

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides the use of an N-salicylic acid tryptophan derivative in the preparation of a drug for treating Chlamydia psittaci infection, wherein the N-salicylic acid tryptophan derivative includes NHWL06032.

[0007] Preferably, the N-salicylic acid tryptophan derivative further includes an optically pure stereoisomer of NHWL06032, a pharmaceutically acceptable salt, a solvate, or a prodrug.

[0008] Preferably, the psittacosis-related chlamydia infection includes psittacosis, pneumonia, or multiple organ dysfunction caused by psittacosis.

[0009] Preferably, the drug target of the drug includes the major outer membrane protein of Chlamydia psittaci.

[0010] Preferably, the N-salicylic acid ester derivative in the drug has a mass percentage content of 0.1% to 99%.

[0011] Preferably, the dosage form of the drug includes an injection.

[0012] Preferably, the injectable is a formulation suitable for intraperitoneal injection.

[0013] Preferably, the drug further includes a pharmaceutically acceptable carrier or excipient.

[0014] Preferably, the drug is a non-antibiotic drug.

[0015] The beneficial effects of this invention are: The N-salicylic acid tryptophan derivative provided by this invention exhibits significant specific antibacterial activity in the treatment of Chlamydia psittaci infection. Experimental results show that NHWL06032 has a minimum inhibitory concentration (MIC) against Chlamydia psittaci. 90 The concentration is as low as 15 μg / mL, which can significantly reduce the number and size of Chlamydia inclusion bodies. Unlike traditional antibiotics, the drug mechanism provided by this invention is unique. It can exert its anti-chlamydia effect by inhibiting the expression of the major outer membrane protein (MOMP) of Chlamydia psittaci and effectively blocking the transformation process from the reticulosome (RB) to the EB, and is less likely to cause cross-resistance.

[0016] Furthermore, at effective antibacterial concentrations, NHWL06032 exhibits no significant toxicity to host cells and demonstrates good safety in in vivo animal experiments. Compared to easily degradable synthetic peptides, the small molecule compound NHWL06032 described in this invention possesses better stability and drug-like properties, providing a new non-antibiotic treatment strategy for addressing the increasingly serious problem of antibiotic resistance in clinical practice, and is an ideal candidate molecule for developing novel anti-psittacosis drugs. Attached Figure Description

[0017] Figure 1 This image shows the immunofluorescence detection of four N-salicylic acid tryptophan derivatives with anti-Chlamydia psittaci (Cps) activity screened in this invention. In the image, A represents the treatment group treated with compound NHWL06032, B represents the treatment group treated with compound NHWL05079, C represents the treatment group treated with compound NHWL05073, and D represents the treatment group treated with compound NHWL05066. In the image, green fluorescence indicates Chlamydia inclusion bodies, and blue fluorescence indicates cell nuclei.

[0018] Figure 2 This is a statistical chart showing the inhibitory effect of different concentrations of NHWL06032 on the number and size of Cps inclusion bodies in embodiments of the present invention. In the chart, A is an immunofluorescence micrograph of different drug concentrations; B is a bar chart of the number of inclusion bodies (IFUs / mL) based on chart A; C is a high-power microscopic observation of the morphology of inclusion bodies in some groups; and D is a bar chart of the area of ​​inclusion bodies in different groups. , , , ns indicates no significant difference (compared to the control group).

[0019] Figure 3 This is a graph showing the cytotoxicity test results of NHWL06032 in an embodiment of the present invention. In the graph, A is a statistical graph of HeLa cell viability at different concentrations detected by the CCK-8 assay; B is a staining result graph of the cell colony formation assay. (Compared to the Blank Control group).

[0020] Figure 4 This is a statistical chart showing the changes in the ultrastructure of Cps inclusion bodies and the number of EB / RB bodies after treatment with NHWL06032, observed by transmission electron microscopy (TEM) in an embodiment of the present invention. In the chart, A is an image of the ultrastructure of inclusion bodies under TEM (black arrows indicate EB, white arrows indicate RB), with a scale bar of 1 μm; B is a statistical chart showing the total number of EB and RB bodies within the inclusion bodies; and C is a statistical chart showing the proportion of EB and RB bodies within the inclusion bodies. , (Compared to the 0 μg / mL group).

[0021] Figure 5 This is a statistical graph showing the differential expression of key Cps genes after NHWL06032 treatment detected by RT-qPCR in an embodiment of the present invention. In the graph, A represents the relative expression level of the ompA gene; B represents the relative expression level of the omcB gene; and C represents the relative expression level of the euo gene. 5, , ns indicates no significant difference (compared to the control group).

[0022] Figure 6 This image shows an electrophoresis diagram and grayscale analysis of the expression level of the major outer membrane protein (MOMP) of Cps after treatment with NHWL06032, as detected by Western Blot in an embodiment of the present invention. In the image, A is the Western Blot electrophoresis band diagram; B is the grayscale analysis statistical diagram of the relative expression level of MOMP protein. , ns indicates no significant difference (compared to the control group).

[0023] Figure 7 This is a graph showing the change in mouse body weight during Cps infection and drug treatment in an embodiment of the present invention.

[0024] Figure 8 This figure shows the detection results of Cps load in mouse lungs in an embodiment of the present invention. In the figure, A is an immunofluorescence (IFA) graph of lung tissue homogenate supernatant; B is a bar chart of the number of lung Cps inclusion bodies (IFUs / mL) based on graph A; and C is a statistical graph of the lung Cps 16S rRNA gene copy number detected by qPCR. In the figure, , , , (Compared to the NC group).

[0025] Figure 9 This is an H&E staining image of a mouse lung tissue pathological section from an embodiment of the present invention. The scale bar in the image is 100 μm in length.

[0026] Figure 10 This is a graph showing the change in body weight in mice during an acute toxicity experiment in this embodiment of the invention.

[0027] Figure 11 These are H&E stained pathological sections of major organs (heart, liver, spleen, lung, and kidney) in mice during the acute toxicity experiment in this embodiment of the invention. Detailed Implementation

[0028] This invention provides the use of an N-salicylic acid oxytryptamine derivative in the preparation of a drug for treating Chlamydia psittaci infection, wherein the N-salicylic acid oxytryptamine derivative includes NHWL06032, or a pharmaceutically acceptable salt, stereoisomer, solvate, or prodrug thereof.

[0029] In this invention, the diseases caused by Chlamydia psittaci infection preferably include psittacosis, pneumonia, or multiple organ dysfunction caused by Chlamydia psittaci. Chlamydia psittaci is an obligate intracellular parasite that can cause zoonotic diseases. The drug provided by this invention can effectively inhibit the growth and reproduction of Cps and improve lung inflammation and systemic pathological damage caused by its infection.

[0030] In this invention, the drug target preferably includes the major outer membrane protein (MOMP) of Chlamydia psittaci. MOMP is the most abundant protein on the outer membrane of Chlamydia psittaci and is crucial for maintaining the structural integrity and pathogenicity of Chlamydia. The drug provided by this invention can significantly inhibit MOMP expression, thereby disrupting the normal physiological function of Chlamydia. Furthermore, the drug preferably exerts its antibacterial effect by inhibiting the transformation of Chlamydia psittaci reticular form (RB) into EB. RB is the reproductive form of Chlamydia, and EB is the infectious form; blocking this transformation process can effectively interrupt the infection cycle of Chlamydia.

[0031] In the drug of the present invention, the mass percentage of the N-salicylic acid ester derivative is preferably 0.1% to 99%, more preferably 2% to 96%. The drug of the present invention also preferably includes a pharmaceutically acceptable carrier or excipient. The present invention does not impose any particular limitation on the type of carrier or excipient; conventional pharmaceutical excipients in the art can be used, such as water for injection, physiological saline, buffer solutions, solubilizers, stabilizers, etc.

[0032] In this invention, the dosage form of the drug preferably includes an injection. The route of administration of the injection preferably includes intraperitoneal injection. In animal experiments, the drug provided by this invention has shown good therapeutic efficacy and safety when administered via intraperitoneal injection.

[0033] In this invention, the drug is preferably a non-antibiotic drug. Compared with traditional antibiotics (such as tetracyclines and macrolides), the drug provided by this invention has a unique chemical structure and mechanism of action, is less prone to cross-resistance, and has low toxicity to host cells at effective doses, thus having a high safety window.

[0034] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0035] Unless otherwise specified, the following embodiments are all conventional methods.

[0036] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0037] The N-salicylic acid hydroxytryptamine derivatives (including NHWL06032 and other screened compounds) in the following examples were all prepared according to the method disclosed in Chinese patent application CN 118791419 A.

[0038] Example 1 The use of an N-salicylic acid oxytryptamine derivative in the preparation of a medicament for treating Chlamydia psittaci infection, wherein the N-salicylic acid oxytryptamine derivative includes NHWL06032.

[0039] The preparation method of NHWL06032 is carried out in accordance with the method described in Chinese patent application CN 118791419 A.

[0040] The obtained compound NHWL06032 was a white solid with a yield of 57%.

[0041] Its 1H NMR data are as follows: 1 H NMR(500MHz, CDCl3)δ7.95(s,1H), 7.20(dd,J=8.7, 2.5Hz, 1H), 7.02–6.94(m, 2H), 6.80–6.74(m, 2H), 6.66(dt, J=8.7, 2.5Hz, 1H), 6.55(d, J=8.2Hz, 1H), 6.41(d, J=6.4Hz, 1H), 3.75(dd, J=6.3, 2.5Hz, 2H), 3.03(td, J=6.6, 2.4Hz, 2H), 2.83(d, J=2.5Hz, 3H), 2.30(d, J=2.5Hz, 3H).

[0042] Example 2 Screening of anti-Chlamydia psittaci activity of 30 N-salicylic acid tryptophan derivatives: Screening Method: HeLa cells were infected with the Cps 6BC standard strain at a multiplicity of infection (MOI) of 1 to construct an in vitro Cps infection model. Two hours after infection, cells were treated with different test compounds. The experimental groups were added to culture media containing different test compounds, with different concentration gradients (5 μg / mL, 25 μg / mL, 45 μg / mL) for screening (the control group received 0.1% DMSO). After culturing at 37°C for 46 hours, cells were fixed with fixative and subjected to indirect immunofluorescence (IFA). Chlamydia inclusion bodies (shown as green fluorescence) were observed under a fluorescence microscope, and the antibacterial activity of the compounds was evaluated based on the number and size of the inclusion bodies. Evaluation criteria were: - (No activity): No significant difference in the number and size of inclusion bodies compared to the control group; + (Moderate activity): Reduced number or smaller size of inclusion bodies; ++ (Strong activity): Significantly reduced number of inclusion bodies, with only a very small number or no obvious inclusion bodies visible in the field of view.

[0043] Some of the screening results are shown in Table 1 and Figure 1 As shown in the figure. The results indicate that among the 30 N-salicylic acid ester derivatives tested, the vast majority of compounds did not exhibit inhibitory activity against Chlamydia psittaci.

[0044] Table 1. Screening results of anti-Cps activity of some N-salicylic acid ester derivatives.

[0045] Depend on Figure 1 As can be seen, the four compounds NHWL06032, NHWL05079, NHWL05073, and NHWL05066 exhibited visible antibacterial effects. Among them, the NHWL06032 treatment group showed the most significant antibacterial effect (++), with almost no large Chlamydia inclusion bodies observed in the field of view, and only a very small number of tiny fluorescent spots. It significantly reduced the size and number of Cps inclusion bodies.

[0046] Example 3 To further evaluate the anti-chlamydia activity of NHWL06032 and determine its minimum inhibitory concentration, experiments were conducted with different drug concentration gradients.

[0047] Experimental Methods: A Cps-infected HeLa cell model (Cps 6BC, MOI=1) was constructed. Two h after infection, the supernatant was aspirated, and D10 medium containing different concentrations of NHWL06032 (5 μg / mL, 7 μg / mL, 10 μg / mL, 12 μg / mL, 15 μg / mL) was added. A solvent control group containing 0.1% DMSO was also included. After further culturing at 37℃ for 46 h, cells were fixed with 4% paraformaldehyde and subjected to indirect immunofluorescence (IFA) detection. Cell nuclei were stained with DAPI (blue), and Chlamydia inclusion bodies were labeled with anti-CpsMOMP antibody (green). Five fields of view were randomly selected under a fluorescence microscope to count the number of inclusion bodies, and the size of the inclusion bodies was observed and statistically analyzed using a confocal microscope.

[0048] Depend on Figure 2 As shown in Figure A, with increasing NHWL06032 concentration, the number of Cps inclusion bodies in HeLa cells gradually decreased, and the area of ​​the inclusion bodies significantly decreased. Figure 2 As shown in B, compared with the control group, the number of inclusion bodies (IFUs / mL) in each treatment group was significantly reduced, exhibiting a clear dose-dependent effect. Figure 2 C and Figure 2 As shown in Figure D, with increasing drug concentration, the morphology of the remaining Cps inclusion bodies shrank, and their average area decreased significantly. This indicates that the drug not only inhibited the number of Chlamydia infections but also suppressed their intracellular growth and development. When the effective concentration of NHWL06032 reached 15 μg / mL, both the number and area of ​​Cps inclusion bodies were significantly inhibited, with an inhibition rate exceeding 90%. Therefore, the MIC of NHWL06032 against Chlamydia psittaci was determined. 90It is approximately 15 μg / mL.

[0049] Example 4 The toxicity of compound NHWL06032 to HeLa cells was detected using the CCK-8 assay and cell colony formation assay, and the selectivity index (SI) was calculated to assess its safety to host cells.

[0050] Detection method: HeLa cells were seeded in 96-well plates and cultured overnight to allow cell adhesion. The old culture medium was then removed, and fresh culture medium containing different concentrations of NHWL06032 was added to each well. The concentrations were set at 0 μg / mL (control group), 5 μg / mL, 10 μg / mL, 15 μg / mL, and 30 μg / mL. After 24 hours of drug treatment, 10 μL of LCK-8 solution was added to each well, and the cells were incubated for another 2 hours. The absorbance (OD value) at 450 nm was measured using a microplate reader, and cell viability was calculated.

[0051] Simultaneously, a cell colony formation experiment was conducted. HeLa cells were seeded in 6-well plates. The experimental group was given medium containing 15 μg / mL NHWL06032, while the control group was given medium containing an equal amount of DMSO. After continuous culture for 48 hours, the medium was discarded, the cells were washed with PBS, fixed with 4% paraformaldehyde for 15 minutes, stained with crystal violet for 15 minutes, and after washing away excess stain, the colony formation was recorded by photograph.

[0052] The results are as follows Figure 3 As shown in Figure A: 24 hours after drug treatment, NHWL06032 exhibited extremely low toxicity to HeLa cells. Cell viability remained above 95% at concentrations of 5 μg / mL, 10 μg / mL, and 15 μg / mL. Even at the highest tested concentration of 30 μg / mL (approximately 100 μM), cell viability remained above 90%. Figure 3 As shown in B, after culturing at a concentration of 15 μg / mL for 48 hours, the cells in the NHWL06032 treatment group were still able to form clear colonies, and compared with the control group, the cell proliferation ability was not significantly inhibited, but instead showed a certain promoting trend.

[0053] Based on the CCK-8 assay results, the half-maximal cytotoxic concentration (CC50) of NHWL06032 against HeLa cells was greater than 30 μg / mL, which, combined with the minimum inhibitory concentration (MIC) determined in Example 3, indicates a cytotoxic effect. 90 = 15 μg / mL), calculate the selectivity index: SI = CC 50 / MIC 90≥2. This indicates that NHWL06032 is safe and non-toxic to host cells at concentrations that effectively kill Chlamydia psittaci, and maintains good cell compatibility at higher concentrations, demonstrating a good safety window.

[0054] Example 5 The mechanism of action of NHWL06032 was explored from three levels: ultrastructure, gene transcription, and protein expression, using transmission electron microscopy (TEM), RT-qPCR, and Western blotting.

[0055] Specific procedures: HeLa cells were seeded in culture plates and infected with Cps 6BC strain for 2 hours. The experimental groups were then treated with medium containing 12 μg / mL NHWL06032 (for transmission electron microscopy observation, based on the sublethal concentration determined in previous experiments to observe morphology); the gene and protein detection groups were treated with medium containing 5 μg / mL, 10 μg / mL, and 15 μg / mL NHWL06032, respectively, to observe changes at different drug concentrations; the control group was treated with medium containing 0.1% DMSO. After culturing at 37℃ for 45 hours, cells were collected. The ultrastructure of inclusion bodies was observed under transmission electron microscopy in one group of cells, and the number of blast bodies (EB) and reticular bodies (RB) was counted; total RNA was extracted from another group of cells and detected using RT-qPCR. ompA , euo and omcB The relative expression levels of genes were determined; total protein was extracted from the remaining cells, and the expression level of major outer membrane protein (MOMP) was detected by Western blotting.

[0056] Depend on Figure 4 As shown in Figure A, the inclusion bodies in the control group were filled with dense protozoa (EB, indicated by black arrows) and larger reticular formations (RB, indicated by white arrows), exhibiting a compact structure. However, after treatment with NHWL06032, the total number of EB and RB within the inclusion bodies was significantly reduced, and the structure was... Figure 4 As shown in B and C, the proportion of EB in the inclusion bodies was significantly reduced, indicating that the drug treatment effectively inhibited the developmental transformation of RB into EB and blocked the infection cycle of Chlamydia.

[0057] Depend on Figure 5 As shown, after processing with NHWL06032, Cps' ompA (Encoding major outer membrane proteins) euo (Early transcription genes) and omcB The mRNA expression levels of the three key genes (encoding outer membrane complex proteins) were significantly lower than those of the control group, and the downregulation trend was more significant with increasing drug concentration (5-15 μg / mL).

[0058] Depend on Figure 6As shown in Figure A, compared with the control group, the MOMP protein band in the treatment group was significantly lighter in color, from... Figure 6 As shown in Figure B, NHWL06032 significantly inhibited the expression of MOMP protein. In summary, NHWL06032 exerts its anti-chlamydia effect by downregulating the transcription and protein expression of key genes and blocking the transformation of Chlamydia from the replicating (RB) to the infectious (EB) form.

[0059] Example 6 By establishing an acute Cps infection model in mice, we monitored changes in mouse body weight during drug administration to evaluate the effect of NHWL06032 on improving the overall health of infected mice.

[0060] Specific procedures: Thirty 6-week-old female BALB / c mice were randomly divided into 6 groups of 5 mice each: a blank control group (uninfected), a negative control group (NC group) infected but not treated, a positive control group (Doxycycline group), and low (50 mg / kg), medium (100 mg / kg), and high (200 mg / kg) dose groups of NHWL06032. Except for the Blank group, the other groups received 5 × 10 5 Mice were infected nasally with Cps 6BC bacterial suspension containing IFUs. Treatment began on day 5 post-infection. NHWL06032 dose groups received intraperitoneal injections of the corresponding doses, the positive control group received intraperitoneal injections of 10 mg / kg doxycycline, and the NC and Blank groups received an equal volume of PBS. Treatment continued for 7 days. The mice's mental status and body weight changes were recorded daily throughout the experiment.

[0061] Experimental results are as follows Figure 7 As shown, the Blank group mice maintained good mental condition and showed a steady weight gain throughout the experiment. In contrast, the NC group mice exhibited symptoms such as ruffled fur and arched backs after infection, and their weight dropped sharply, indicating that the infection model was successfully established and the infection was severe. After treatment, the weight loss trend of mice in each NHWL06032 dosage group was halted and began to recover, with the recovery effect showing a dose-dependent effect. Among them, the 200 mg / kg dosage group showed the fastest weight recovery curve, and its growth trend was very close to that of the positive control doxycycline group, indicating that NHWL06032 can effectively alleviate the systemic consumption caused by infection and improve the overall health of mice.

[0062] The in vivo efficacy of NHWL06032 against Chlamydia psittaci was further evaluated by detecting pathogen load and pathological morphological changes in mouse lung tissue. Specific procedures: Mice in each group were sacrificed on day 12 post-infection, and lung tissue was harvested under aseptic conditions. A portion of the lung tissue was homogenized, and the supernatant was used for separate tests: firstly, the number of Chlamydia inclusion bodies (IFUs / mL) in the lung tissue was detected using IFA technology; secondly, total DNA was extracted from the tissue, and the copy number of the Cps 16S rRNA gene was detected using real-time quantitative PCR. Another portion of the lung tissue was sectioned pathologically and stained with H&E, and the pathological structural changes in the lung tissue were observed under a microscope.

[0063] Depend on Figure 8 The lung load test results showed that, compared with the NC group, the number of Chlamydia inclusion bodies in the lungs of mice in the NHWL06032 treatment group and the positive control (Doxycycline) group was significantly lower. Figure 8 Both A and B in the results were significantly reduced. The reduction in inclusion body number was most significant in the 200 mg / kg dose group, followed by the 100 mg / kg group; this reduction in Cps inclusion body number showed a clear dose-dependent effect. From... Figure 8 According to the real-time quantitative PCR results for C, the gene copy number reduction was most significant in the Doxycycline group, followed by the 100 mg / kg group. Notably, the gene copy number detected in the 200 mg / kg group was slightly higher than that in the 100 mg / kg group. This may be because real-time quantitative PCR detects the total bacterial load in the lungs, which cannot distinguish between live and dead bacteria, while IFA detects the number of infectious inclusion bodies in lung tissue. Therefore, at the high dose of 200 mg / kg, a large number of Cps in the mice were effectively killed and cleared, resulting in a very low number of inclusion bodies shown by IFA, while the higher copy number detected by qPCR may originate from residual DNA of dead bacteria that had been killed but not completely degraded. Combining the results of IFA and qPCR, NHWL06032 treatment has a significant effect on inhibiting Cps growth and replication and clearing pathogens from the body.

[0064] Depend on Figure 9 Pathological sections of lung tissue revealed that the lung tissue of the Blank group mice had clear structure, intact alveoli, and no inflammatory cell infiltration; while the lung tissue of the NC group mice showed extensive alveolar wall thickening, accompanied by a large number of neutrophils and lymphocytes infiltrating, with severe alveolar structural damage, presenting typical pathological features of severe pneumonia. After treatment with NHWL06032 (especially the 100 mg / kg and 200 mg / kg groups), lung inflammation was significantly reduced, inflammatory cell infiltration was significantly decreased, alveolar septa thinned, and lung tissue structure recovered well, with a morphology close to that of the Blank group. These results confirm that NHWL06032 can effectively clear lung infection foci in vivo and significantly repair lung tissue damage caused by Chlamydia psittaci.

[0065] Example 7 To evaluate the acute toxicity of high-dose NHWL06032 in mice.

[0066] Specific procedures: Twenty 6-week-old BALB / c mice, half male and half female (10 females and 10 males), were randomly divided into four groups (n=5 per group): Male Treated, Male Untreated, Female Treated, and Female Untreated. The Treated group received a single intraperitoneal injection of 500 mg / kg of NHWL06032 (referred to as Treated or 500 mg / kg), while the Control group received an equal volume of PBS (referred to as Untreated or Control). The mice were observed for 14 consecutive days, and their weight changes and mental status were recorded. After the experiment, the mice were sacrificed, and major organs such as the heart, liver, spleen, lungs, and kidneys were collected for H&E staining to observe their pathological structures.

[0067] Depend on Figure 10 It was observed that during the 14-day observation period after drug administration, the body weight of both male and female mice did not decrease significantly and maintained a steady upward trend. There were no significant differences in body weight changes between the male drug-treated group and the male control group, or between the female drug-treated group and the female control group. All mice were in good spirits and no deaths were observed. Figure 11 Organ sections revealed that in the treated mice, the myocardial fibers were intact, the hepatocyte cords were regularly arranged, the spleen structure was clear, the alveolar structure was intact, and the glomeruli were morphologically normal, with no pathological changes such as congestion, necrosis, or inflammatory infiltration. These results indicate that NHWL06032 has no significant acute toxicity to female and male mice at doses far exceeding therapeutic levels, demonstrating extremely high in vivo safety.

[0068] In summary, the application of the N-salicylic acid tryptophan derivative NHWL06032 provided by this invention in the preparation of drugs against Chlamydia psittaci infection, through rigorous structure-activity relationship screening, has confirmed that NHWL06032 possesses unexpected anti-chlamydial activity. Experimental results show that NHWL06032 can effectively inhibit the growth of Chlamydia psittaci (MIC) in vitro. 90The concentration is 15 μg / mL. Its mechanism involves inhibiting the expression of the key outer membrane protein MOMP and blocking the conversion of the reticulum to the protozoan. In vivo, it significantly reduces the pathogen load in the lungs of infected mice, improves lung tissue pathological damage, and promotes weight recovery. Simultaneously, this compound exhibits low cytotoxicity to host cells, a wide safety window, and no risk of acute toxicity. This invention successfully develops a non-antibiotic small molecule drug with a novel mechanism of action, effectively overcoming the drug resistance problems of existing antibiotic therapies and the stability defects of synthetic peptide therapies, providing a promising new approach for the clinical treatment of psittacosis.

[0069] The above description is merely a preferred embodiment of the present invention. It should be noted that for those with ordinary technical skills, the specific embodiments described herein are not necessarily those of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. The use of an N-salicylic acid tryptophan derivative in the preparation of a drug for treating Chlamydia psittaci infection, characterized in that, The N-salicyloyl tryptamine derivative includes NHWL06032.

2. Use according to claim 1, characterized in that, The N-salicyloyl tryptamine derivative also includes optically pure stereoisomers, pharmaceutically acceptable salts, solvates or prodrugs of NHWL06032.

3. Use according to claim 1, characterized in that, The chlamydophila psittaci infection disease includes psittacosis, pneumonia or multi-organ dysfunction caused by chlamydophila psittaci.

4. Use according to claim 1, characterized in that, The drug target of the drug includes the major outer membrane protein of chlamydophila psittaci.

5. The use according to claim 1, characterized in that, In the drug, the mass percentage content of the N-salicyloyl tryptamine derivative is 0.1% to 99%.

6. Use according to claim 1, characterized in that, The dosage form of the drug includes an injection.

7. Use according to claim 6, characterized in that, The injection is a preparation suitable for intraperitoneal administration.

8. The use according to claim 1, characterized in that, The drug also includes a pharmaceutically acceptable carrier or excipient.

9. The use according to claim 1, characterized in that, The drug is a non-antibiotic drug.

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