Piperazine-substituted quinone compound having antibacterial and antifungal activity, method for synthesising this compound, and molecular modelling thereof

Abstract

The invention relates to a compound having antibacterial and antifungal properties and the chemical structure of Formula X, and to the synthesis method of said compound. Said compound is a piperazine-substituted quinone compound, and the position and orientation of the molecule within DNA and E. coli DNA gyrase B have been determined by means of molecular simulation.

Description

[0001] DESCRIPTION

[0002] PIPERAZINE-SUBSTITUTED QUINONE COMPOUND HAVING ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY, METHOD FOR SYNTHESISING THIS COMPOUND, AND MOLECULAR MODELLING THEREOF

[0003] Technical Field

[0004] The present invention relates to a piperazine-substituted quinone compound having antibacterial and antifungal activity, and to the synthesis of this compound. The molecular simulation of the compound has been conducted to determine the positioning and orientation of the molecule within DNA and E. coli DNA gyrase B.

[0005] State of the Art

[0006] Antibacterial and antifungal drugs play a critical role in the treatment of diseases. Antifungal drugs are used for the treatment of fungal infections. These drugs inhibit the growth and spread of fungal cells by weakening their cell walls or disrupting their cell membranes. They also assist the immune system in combating infection by preventing the spread of fungal infections. Antibacterial drugs, on the other hand, are used to treat bacterial infections. These drugs exert their effect by weakening bacterial cell walls, inhibiting protein synthesis, or disrupting metabolic processes. Among antibacterial drugs, antibiotics are the most widely used, as they prevent the spread of bacterial infections and support the immune system in fighting infection. These drugs play a significant role in protecting public health and in the treatment of serious diseases. Although antifungal and antibacterial drugs provide effective treatment options, they also entail certain disadvantages. Antifungal drugs may cause serious side effects and reduce patients' quality of life, as they may also harm healthy cells. Antibacterial drugs, on the other hand, may lead to antibiotic resistance as a result of misuse or overuse, which complicates the treatment of infections. Moreover, both types of drugs may fail to achieve the intended effect and carry the risk of treatment failure.

[0007] DNA stands out as the main point of interaction in the intracellular activities of drugs. It is believed that most chemotherapeutic drugs interact with DNA

[0001] , Molecular modelling can enhance drug efficacy, enable the design of new drug molecules, and allow further development of existing drugs. Drug design based on molecule-DNA interactions has led to the discovery of anticancer, antibiotic, and antiviral drugs. Determining the most stable geometries of molecules is of great importance in the fields of drug design and protein research. Prokaryotic enzymes (such as DNA gyrase) are selected as targets for antibacterial agents, whereas eukaryotic enzymes are targets for antitumour drugs. Since the DNA gyrase enzyme is found only in bacteria and not in eukaryotes, it is considered an ideal drug target [2], Literature research particularly aims to determine the most stable geometries of piperazine and naphthoquinone derivatives that exhibit anticancer and antibacterial activity through molecular modelling.

[0008] Piperazine is used as a key intermediate in the production of both human and veterinary medicines and stands out as an active ingredient in anthelmintics in the field of veterinary medicine [3], The piperazine scaffold, a simple diazacycloalkane, holds great importance in medicinal chemistry due to its wide range of biological activities. Piperazine derivatives are being investigated for therapeutic applications such as antipsychotic, antidepressant, and anxiolytic effects, owing to their central pharmacological activities involving activation of the monoamine pathway. In addition, these derivatives are also used as intermediates for sedative, antihistaminic, insecticidal, fungicidal, bactericidal, analgesic, antispasmodic, and anthelmintic agents [4], Naphthoquinones, on the other hand, are compounds widely found in nature and exhibit significant pharmacological properties. These compounds possess antibacterial, antifungal, antiviral, insecticidal, anti-inflammatory, and antipyretic properties [5], They may also inhibit replication processes by binding to DNA and interact with various proteins. The anticancer properties and therapeutic potential of naphthoquinones attract the interest of the scientific community; for instance, Tang and colleagues evaluated the antibacterial activities of piperazine-substituted chaicone sulphonamides against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli [6], The piperazine ring system is used in the synthesis of various drug molecules, and many FDA-approved anticancer drugs contain this ring [7, 8],

[0009] In the patent application numbered WO2015172076A1 , which is part of the state of the art, various new compounds and their pharmaceutically acceptable salts, solvents, hydrates, polymorphs, co-crystals, tautomers, stereoisomers, etc. are disclosed. These compounds are intended for pharmaceutical compositions and methods designed for the treatment of proliferative diseases such as various types of cancer (e.g. leukaemia, breast cancer, melanoma, metastatic cancer). The patent emphasises their effectiveness in inhibiting disease progression by targeting cellular mechanisms. Although the present invention is innovative and comprehensive, it lacks efficacy data against specific types of cancer. In particular, although it has been stated that some compounds inhibit the growth and proliferation of fungal cells, it is also noted that these effects may vary depending on the specific fungal species and may be less effective against certain fungal types. However, there are shortcomings such as insufficient information about safety and toxicity profiles, as well as limitations regarding clinical application.

[0010] A study included in the prior art, conducted by Baglayan et al., examines the vibrational spectra, DFT calculations, and conformational stabilities of the 1 -butylpiperazine (1 bpa) molecule, and also discusses piperazine and quinone structures [9], In the study, four possible conformations (e-e, e-a, a-a, a-e) were analysed, and the e-e form was found to be the most stable. Optimised geometric parameters were obtained using the DFT / B3LYP method. Among the strengths are comprehensive DFT applications and detailed spectral analyses, while the shortcomings include the fact that the study was conducted only in the gas phase and that experimental geometric data are not available in the literature.

[0011] The limitations and inadequacies of the existing solutions in the art, such as the insufficient antibacterial and antifungal effects of commonly used compounds, and the insufficiency of studies on the geometric stabilities and DNA interactions of the compounds in the state of the art, have made it necessary to introduce improvements in this field.

[0012] Brief Description and Aims of the Invention

[0013] The invention discloses a piperazine-substituted quinone compound having antibacterial and antifungal activity, as well as a method for synthesising the compound. The synthesised compound, having the chemical structure of Formula X (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1 -yl)-5,8-dihydroxynaphthalene-1 ,4-dione), exhibits strong antibacterial and antifungal properties.

[0014] Formula X

[0015] The main aim of the invention is to provide a compound with antibacterial and antifungal properties. The compound that is the subject of the invention (Formula X) not only possesses strong antibacterial properties but also exhibits antifungal properties. The most stable molecular geometry of said compound, as well as its position and orientation within DNA and E. coli DNA gyrase B, have been determined by means of molecular modelling. In addition, it has been found that the investigated compound shows strong molecule-DNA and molecule-E. coli DNA gyrase B interactions according to the molecular docking analysis used in the invention.

[0016] Description of Drawings

[0017] Figure 1: The most stable optimised geometry of the compound (2-chloro-3-(4-(2- ethoxyethyl)piperazin-1-yl)-5,8-dihydroxynaphthalene-1 ,4-dione) obtained at the DFT / wB97XD / 6-311 ++G(d,p) theory level.

[0018] Detailed Description of the Invention

[0019] The invention relates to a piperazine-substituted quinone compound having antibacterial and antifungal activity, namely the compound of Formula X (2-chloro-3- (4-(2-ethoxyethyl)piperazin-1 -yl)-5,8-dihydroxynaphthalene-1 ,4-dione), and the synthesis thereof.

[0020] The compound that is subject of the invention is a piperazine-substituted quinone compound with the chemical structure of Formula X and with antibacterial and antifungal activity.

[0021] Formula X

[0022] The most stable molecular geometries of compounds can be determined by means of molecular modelling. The most probable molecular structure of the compound that is the subject of the invention has been determined at the DFT / wB97XD / 6-311 ++G(d,p) theory level using the Gaussian16 program

[0010] (Figure 1 ). A molecular docking simulation of the optimised piperazine-substituted naphthoquinone with DNA and E. coli DNA gyrase B was conducted using the YASARA program [11-12], Thus, based on the interaction between piperazine-substituted naphthoquinone and DNA, and between piperazine-substituted naphthoquinone and E. coli DNA gyrase B, the position and orientation of the molecule within DNA and E. coli DNA gyrase B have been determined. As a result of the molecular docking calculations of piperazine- substituted naphthoquinone with DNA, it was found that the molecule forms a stable docking by interacting with the Cytosine 9, Guanine 10, Cytosine 11 , Cytosine 15, Guanine 16, and Adenine 18 nucleotides. As a result of the molecular docking calculation of piperazine-substituted naphthoquinone with E. coli DNA gyrase B, it was found that the molecule forms a stable docking by interacting with the Asparagine 46, Alanine 47, Glutamic acid 50, Aspartic acid 73, Isoleucine 78, and Proline 79 amino acids.

[0023] The IR (ATR) spectrum of the compound that is the subject of the invention comprises v (cm-1) = 2972, 2931 , 2913, 2865, 2824, 2804 (-CH), 1603 (C=O), 1556 (C=C) peaks.

[0024] The1H NMR (499.74 MHz, CDCI3) spectrum of the compound that is the subject of the invention comprises 5 = 12.67, 12.23 (s, 2H, -OH), 1.12-1 .33 (m, 3H, -CH3), 2.59-2.69 (s, 4H, -NCH2), 2.58-2.59 (m, 4H, -NCH2), 3.44-3.46 (m, 2H, -NCH2), 3.52-3.55 (m, 2H, -OCH2), 3.60-3.61 (t, 2H, -OCH2), 7.06-7.18 (m, 2H, Ch_arom) peaks. The13C NMR (125.66 MHz, CDCI3) spectrum of the compound that is the subject of the invention comprises 5 = 14.09, 28.63 (-CH2, -CH3), 50.58, 53.19, 56.86 (-NCH2), 66.91 , 65.47 (-OCH2), 157.25, 155.58, 149.37, 128.99, 121.26, 110.43, 109.47 (C_arom, CH_arom), 183.74, 180.40 (C=O) peaks.

[0025] The UV-vis (C2H5OH) spectrum of the compound that is the subject of the invention comprises A (logs) = 519 (4.05), 308 (3.68), 273 (4.30), 206 (4.58) nm peaks, while the UV-vis (CHCI3) spectrum comprises A (logs) = 524 (4.66), 309 (4.40), 274 (4.99), 239 (4.84) nm peaks.

[0026] The MS(+ESI) spectrum of the compound that is the subject of the invention comprises the peak 381.2 [M+H]+, while the MS / MS (+ESI) spectrum comprises the peak 335.1 [M-EtO]+ (M = 380.82 g / mol).

[0027] The antibacterial activity of the compound that is the subject of the invention (Formula X) was determined using the disc diffusion method. For antibacterial analysis, 6 mm antimicrobial susceptibility test discs were used. For antimicrobial activity, the compound that is the subject of the invention (Formula X) was tested against Grampositive bacteria Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Micrococcus luteus, Enterococcus faecalis, Pseudomonas aeruginosa, and against Gram-negative bacteria Salmonella typhimurium and Escherichia coli. All pathogenic bacteria were activated on Nutrient Agar at 37°C, and bacterial cultures containing approximately 10sCFU / ml were enriched in Nutrient Broth and used. Said compound (Formula X) was diluted to 20 mg / ml using dimethyl sulphoxide. Discs containing the compound that is the subject of the invention (Formula X) were placed on the surface of Nutrient Agar (standard medium comprising peptone from meat 5.0 g / L; meat extract 3.0 g / L; agar-agar 12.0 g / L). The plates were then incubated at 37 °C ± 1 °C for 24 hours. After incubation, the diameter of growth inhibition zones around the discs was measured and expressed in millimetres.

[0028] The antifungal activity of the compound that is the subject of the invention (Formula X) was also determined using the disc diffusion method. For antifungal analysis, 6 mm antimicrobial susceptibility test discs were used. For the antifungal activity test, moulds were activated on Potato Dextrose Agar (PDA) at 30 °C. The PDA standard medium comprises potato infusion 4.0 g / L; D(+) glucose 20.0 g / L; agar-agar 15.0 g / L. Said compound (Formula X) was diluted to 20 mg / ml using dimethyl sulphoxide. Discs coated with the diluted compound (Formula X) were placed on the PDA agar surface containing spores. The plates were incubated at 28-30 °C for 48-72 hours. The results were recorded by measuring the zones surrounding the disc.

[0029] In the study, the in vitro antimicrobial activity of the compound that is the subject of the invention (Formula X) on Gram-positive and Gram-negative bacteria on the plates is presented in Table 1 .

[0030] Table 1. Antimicrobial and antifungal activity test results of said compound (Formula X)

[0031] The antibacterial activity zones observed against Gram -positive bacteria ranged between 9.5-20.25 mm, while for Gram-negative bacteria they were determined to be between 10.92-11 .08 mm. The highest antibacterial activity was observed against the Gram-positive bacterium Micrococcus luteus, with a zone of 20.25 mm. Said compound (Formula X) exhibited an antibacterial effect of 22.3 mm against Enterococcus faecalis, and was determined to have a notably strong antibacterial effect. In the study, it was observed that said compound (Formula X) exhibited 13.75 mm of antibacterial activity against Listeria monocytogenes. Said compound (Formula X) is of importance for controlling the spread of Listeria monocytogenes and the associated human disease. Said compound (Formula X) was found to exhibit an antibacterial effect of 15.33 mm against B. cereus. Said compound (Formula X) was found to have no antibacterial effect against Pseudomonas aeruginosa. As a result, said compound (Formula X) exhibited antibacterial activity against pathogenic Grampositive and Gram-negative bacteria. Said compound (Formula X) was determined to have antibacterial properties against the pathogenic bacteria Staphylococcus aureus and Salmonella spp.

[0032] The results of the tests regarding the antifungal effect of the compound that is the subject of the invention (Formula X) are presented in Table 1. The compound, subject of the invention (Formula X), exhibited a 24 mm effect against the mould Aspergillus niger, which poses a threat to human health, and demonstrated antifungal activity. It was determined to possess a notably high antifungal effect by exhibiting a 28.5 mm zone against the mould Alternaria alternata.

[0033] In the study, in vitro antimicrobial activity tests were carried out on the plates using the compound (Formula X) and the molecule 2,3-Dichloro-5,8-dihydroxy-1 ,4- naphthoquinone (DDN). The effects of the DDN structure, which was used in the synthesis of the compound, subject of the invention (Formula X), on Gram-positive and Gram-negative bacteria are presented in Table 2.

[0034] Table 2. Comparison of the antibacterial and antifungal activities of said Formula X compound and the DDN molecule

[0035] The antibacterial activity zone of the compound that is the subject of the invention (Formula X) against Gram-positive bacteria was found to range between 9.5-20.25 mm, while for Gram-negative bacteria it was found to range between 10.92-11 .08 mm. The DDN molecule, on the other hand, showed activity ranging from 8.00-13.00 mm against Gram-positive bacteria and from 6.8-7.5 mm against Gram-negative bacteria. The highest antibacterial activity was observed against the Gram-positive bacterium Micrococcus luteus as 20.25 mm with the compound, subject of the invention (Formula X). The compound, subject of the invention (Formula X) exhibited antibacterial activity that was twice as high as that of the DDN molecule. The compound, subject of the invention (Formula X) showed a 22.3 mm effect against Enterococcus faecalis, while the DDN compound showed an effect of 13 mm. It was determined that the compound, subject of the invention (Formula X) demonstrated significantly stronger antibacterial activity compared to the DDN compound. In the study conducted within the scope of the invention, the synthesised compound that is the subject of the invention (Formula X) exhibited 13.75 mm of antibacterial activity against Listeria monocytogenes, whereas the DDN compound showed 9.25 mm. The compound (Formula X) is important for controlling the spread of Listeria monocytogenes and the related human disease. The compound (Formula X) was found to exhibit an antibacterial effect of 15.33 mm against B. cereus. The DDN compound, on the other hand, had an antibacterial effect of 10.5 mm. The compound in question (Formula X) has a stronger effect against B. cereus compared to the DDN compound. It was determined that neither the compound in question (Formula X) nor the DDN molecule exhibited antibacterial activity against Pseudomonas aeruginosa. The compound in question (Formula X) exhibited 11.08 mm of antibacterial activity against S. typhimurium, whereas the DDN molecule showed 6.8 mm. It was determined that the compound that is the subject of the invention (Formula X) has antibacterial properties against these important pathogenic bacteria. As a result, the compound that is the subject of the invention (Formula X) exhibited higher antibacterial activity against pathogenic Grampositive and Gram-negative bacteria compared to the DDN molecule.

[0036] The antifungal effects of the compound (Formula X) and the DDN molecule are presented in Table 1 . The compound in question (Formula X) exhibited a 24 mm effect against the Aspergillus niger mold, which poses a threat to human health, and possesses antifungal activity. It was determined that the compound (Formula X) exhibited a 28.5 mm effect against the mold Alternaria alternata and had notably high antifungal activity. The DDN molecule exhibited an effect of 13.8 mm against Aspergillus niger and 14.5 mm against Alternaria alternata. The compound, subject of the invention (Formula X) has higher antifungal activity than the DDN compound. The antifungal activity of the compound (Formula X) was found to be higher than that of the DDN molecule and in fact showed nearly 2 times greater efficacy.

[0037] The synthesis method of a piperazine-substituted quinone compound having antibacterial and antifungal activity, which is the subject of the invention, comprises the process steps of: i. dissolving 2,3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone and 1-(2- ethoxyethyl)piperazine in chloroform (CHCI3), ii. mixing sodium carbonate (Na2COs) with chloroform (CHCI3), iii. adding the mixture prepared in step (ii) into the solution prepared in step (i), and stirring at room temperature, iv. then allowing the mixture to stand at room temperature and filtering to obtain the organic phase, and v. drying the organic phase with sodium sulphate (Na2SO4) and filtering it, thereby obtaining the compound with the chemical structure of Formula X, (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1-yl)-5,8-dihydroxynaphthalene-1 ,4- dione).

[0038] Formula X

[0039] In one embodiment of the invention, the synthesis method of a piperazine-substituted quinone compound having antibacterial and antifungal activity comprises the process steps of: i. dissolving 0.2-0.4 g of 2,3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone and 0.125-0.250 g of 1 -(2-ethoxyethyl)piperazine in 30-50 ml of chloroform (CHCI3), ii. mixing 0.25-0.52 g of sodium carbonate (Na2COs) with 10-30 ml of chloroform (CHCI3), iii. adding the solution prepared in step (ii) to the solution prepared in step (i), and stirring at room temperature for 30-45 minutes, iv. then allowing the mixture to stand at room temperature for 30-45 minutes and filtering to obtain the organic phase, and v. drying the organic phase with 0.2-0.4 g of sodium sulphate (Na2SO4) and filtering it, thereby obtaining the compound with the chemical structure of Formula X, (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1 -yl)-5,8- dihydroxynaphthalene-1 ,4-dione).

[0040] Formula X

[0041] In another embodiment of the invention, the synthesis method of a piperazinesubstituted quinone compound having antibacterial and antifungal activity comprises the process steps of: i. dissolving 0.2 g of 2,3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone and 0.125 g of 1 -(2-ethoxyethyl)piperazine in 30 ml of chloroform (CHCh), ii. mixing 0.25 g of sodium carbonate (Na2COs) with 10 ml of chloroform (CHCh), iii. adding the solution prepared in step (ii) to the solution prepared in step (i), and stirring at room temperature for 30-45 minutes, iv. then allowing the mixture to stand at room temperature for 30 minutes and filtering to obtain the organic phase, and v. drying the organic phase with 0.2 g of sodium sulphate (Na2SO4) and filtering it, thereby obtaining the compound with the chemical structure of Formula X, (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1 -yl)-5,8-dihydroxynaphthalene- 1 ,4-dione).

[0042] Formula X

[0043] In one embodiment of the invention, a solution of 0.2 g (0.77 mmol) of 2,3-dichloro-5,8- dihydroxy-1 ,4-naphthoquinone and 0.125 g (0.77 mmol) of 1 -(2-ethoxyethyl)piperazine in chloroform (CHCh) is mixed with a solution of sodium carbonate (Na2COs) in chloroform (CHCh), and the resulting mixture is stirred at room temperature for 30-45 minutes. The reaction mixture turns violet in colour and, after being left to stand at room temperature overnight, is filtered. Said reaction is shown in Reaction 1. The organic phase is dried with sodium sulphate (Na2SO4) and filtered. The final compounds are purified by column chromatography.

[0044] Reaction 1 Synthesis of (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1-yl)-5,8- dihydroxynaphthalene-1 ,4-dione) [1 : 2,3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone; 2: 1-(2-ethoxyethyl)piperazine; and 3: 2-chloro-3-(4-(2-ethoxyethyl)piperazin-1-yl)-5,8- dihydroxynaphthalene-1 ,4-dione]

[0045] REFERENCES

[0046] [1] Lerman, L. S. (1961 ). Structural considerations in the interaction of DNA and acridines. Journal of molecular biology, 3(1 ), 18IN13-30IN14.

[0047] [2] Heddle, J. G., Barnard, F. M., Wentzell, L. M., & Maxwell, A. (2000). The interaction of drugs with DNA gyrase: a model for the molecular basis of quinolone action. Nucleosides, nucleotides & nucleic acids, 19(8), 1249-1264.

[0048] [3] Brandwene, D. (2005). Piperazine, Encyclopedia of Toxicology (Second Edition) 440-442.

[0049] [4] Tudor, D. C. (1962). A review of piperazine and piperazine compounds as poultry ascaracides. Avian Diseases, 6(4), 493-499.

[0050] [5] Guilhon, J. (1951 ). Un nouvel anthelminthique: le Diethylene diamine. Bulletin de I'Academie Veterinaire de France, 104(4), 243-245.

[0051] [6] Tang, Y. L., Li, Y. K., Li, M. X., Gao, H., Yang, X. B., & Mao, Z. W. (2020). Synthesis of new piperazine substituted chaicone sulphonamides as antibacterial agents. Current Organic Synthesis, 17(2), 136-143.

[0052] [7] Walayat, K., MOHSIN, N. U. A., Aslam, S., & Ahmad, M. (2019). An insight into the therapeutic potential of piperazine-based anticancer agents. Turkish Journal of Chemistry, 43(1 ), 1 -23.

[0053] [8] Romanelli, M. N., Braconi, L., Gabellini, A., Manetti, D., Marotta, G., & Teodori, E. (2023). Synthetic Approaches to Piperazine-Containing Drugs Approved by FDA in the Period of 2011-2023. Molecules, 29(1 ), 68.

[0054] [9] Baglayan, O., Kaya, M. F., Gune§, E., & §enyel, M. (2016). Vibrational spectra, DFT calculations, conformational stabilities and assignments of the fundamentals of the 1 -butylpiperazine. Journal of Molecular Structure, 1122, 324-330.

[0055]

[0010] Gaussian 16, Revision C.01 , Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Petersson, G. A.; Nakatsuji, H.; Li, X.; Caricato, M.; Marenich, A. V.; Bloino, J.; Janesko, B. G.; Gomperts, R.; Mennucci, B.; Hratchian, H. P.; Ortiz, J. V.; Izmaylov, A. F.; Sonnenberg, J. L.; Williams-Young, D.; Ding, F.; Lipparini, F.; Egidi, F.; Goings, J.; Peng, B.; Petrone, A.; Henderson, T.; Ranasinghe, D.; Zakrzewski, V. G.; Gao, J.; Rega, N.; Zheng, G.; Liang, W.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Throssell, K.; Montgomery, J. A., Jr.; Peralta, J. E.; Ogliaro, F.; Bearpark, M. J.; Heyd, J. J.; Brothers, E. N.; Kudin, K. N.; Staroverov, V. N.; Keith, T. A.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A. P.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Millam, J. M.; Kiene, M.; Adamo, C.; Cammi, R.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Farkas, 0.; Foresman, J. B.; Fox, D. J. Gaussian, Inc., Wallingford CT, 2016.

[0056]

[0011] Krieger, E., Koraimann, G., & Vriend, G. (2002). Increasing the precision of comparative models with YASARA NOVA — a self-parameterizing force field. Proteins: Structure, Function, and Bioinformatics, 47(3), 393-402.

[0057]

[0012] Krieger, E., & Vriend, G. (2014). YASARA View — molecular graphics for all devices — from smartphones to workstations. Bioinformatics, 30(20), 2981 -2982.

Claims

CLAIMS1. A piperazine-substituted quinone compound having antibacterial and antifungal properties with the chemical structure of Formula X.Formula X2. A piperazine-substituted quinone compound according to claim 1 , wherein its IR (ATR) spectrum comprises v (cm-1) = 2972, 2931 , 2913, 2865, 2824, 2804 (- CH), 1603 (C=O), 1556 (C=C) peaks.

3. A piperazine-substituted quinone compound according to claim 1 , wherein its 1H NMR (499.74 MHz, CDCIs) spectrum comprises 5 = 12.67, 12.23 (s, 2H, - OH), 1.12-1.33 (m, 3H, -CH3), 2.59-2.69 (s, 4H, -NCH2), 2.58-2.59 (m, 4H, - NCH2), 3.44-3.46 (m, 2H, -NCH2), 3.52-3.55 (m, 2H, -OCH2), 3.60-3.61 (t, 2H, -OCH2), 7.06-7.18 (m, 2H, Ch_arom) peaks.

4. A piperazine-substituted quinone compound according to claim 1 , wherein its 13C NMR (125.66 MHz, CDCI3) spectrum comprises 5 = 14.09, 28.63 (-CH2, - CH3), 50.58, 53.19, 56.86 (-NCH2), 66.91 , 65.47 (-OCH2), 157.25, 155.58, 149.37, 128.99, 121.26, 110.43, 109.47 (C_arom, CH_arom), 183.74, 180.40 (C=O) peaks.

5. A piperazine-substituted quinone compound according to claim 1 , wherein its UV-vis (C2H5OH) spectrum comprises A (logs) = 519 (4.05), 308 (3.68), 273 (4.30), 206 (4.58) nm peaks, while its UV-vis (CHCI3) spectrum comprises A (logs) = 524 (4.66), 309 (4.40), 274 (4.99), 239 (4.84) nm peaks.

6. A piperazine-substituted quinone compound according to claim 1 , wherein its MS(+ESI) spectrum comprises the peak 381.2 [M+H]+, and its MS / MS (+ESI) spectrum comprises the peak 335.1 [M-EtO]+.

7. A piperazine-substituted quinone compound according to claim 1 , wherein it is effective against the bacteria Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Salmonella typhimurium, Escherichia coli, and the fungi Aspergillus niger and Alternaria alternata.

8. The synthesis method of a piperazine-substituted quinone compound having antibacterial and antifungal activity, comprising the process steps of: i. dissolving 2,3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone and 1-(2- ethoxyethyl)piperazine in chloroform (CHCls), ii. mixing sodium carbonate (Na2COs) with chloroform (CHCI3), iii. adding the solution prepared in step (ii) into the solution prepared in step (i), and stirring at room temperature, iv. then allowing the mixture to stand at room temperature and filtering to obtain the organic phase, and v. drying the organic phase with sodium sulphate (Na2SO4) and filtering it, thereby obtaining the compound with the chemical structure of Formula X, (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1 -y l)-5, 8- dihydroxynaphthalene-1 ,4-dione).Formula X9. The synthesis method of a piperazine-substituted quinone compound having antibacterial and antifungal activity according to Claim 8, comprising the process steps of: i. dissolving 0.2-0.4 g of 2, 3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone and 0.125-0.250 g of 1 -(2-ethoxyethyl)piperazine in 30-50 ml of chloroform (CHCI3), ii. mixing 0.25-0.52 g of sodium carbonate (Na2COs) with 10-30 ml of chloroform (CHCI3),iii. adding the solution prepared in step (ii) to the solution prepared in step (i), and stirring at room temperature for 30-45 minutes, iv. then allowing the mixture to stand at room temperature for 30 minutes and filtering to obtain the organic phase, and v. drying the organic phase with 0.2-0.4 g of sodium sulphate (Na2SO4) and filtering it, thereby obtaining the compound with the chemical structure of Formula X, (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1 -yl)-5,8- dihydroxynaphthalene-1 ,4-dione).Formula X10. The synthesis method of a piperazine-substituted quinone compound having antibacterial and antifungal activity according to Claim 8, comprising the process steps of: i. dissolving 0.2 g of 2,3-dichloro-5,8-dihydroxy-1 ,4-naphthoquinone and 0.125 g of 1 -(2-ethoxyethyl)piperazine in 30 ml of chloroform (CHCh), ii. mixing 0.25 g of sodium carbonate (Na2COs) with 10 ml of chloroform (CHCh), iii. adding the solution prepared in step (ii) to the solution prepared in step (i), and stirring at room temperature for 30-45 minutes, iv. then allowing the mixture to stand at room temperature for 30 minutes and filtering to obtain the organic phase, and v. drying the organic phase with 0.2 g sodium sulphate (Na2SO4) and filtering it, thereby obtaining the compound with the chemical structure of Formula X, (2-chloro-3-(4-(2-ethoxyethyl)piperazin-1 -yl)-5,8- dihydroxynaphthalene-1 ,4-dione).Formula X11. An antibacterial and antifungal piperazine-substituted quinone compound synthesised by a method according to any one of claims 8 to 10.

12. A piperazine-substituted quinone compound according to claim 11 , wherein it is effective against the bacteria Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Salmonella typhimurium, Escherichia coli, and the fungi Aspergillus niger and Alternaria alternata.

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