Infectious diseases, including bacterial, fungal, and viral, have once again gained urgency in the drug development pipeline after the recent COVID-19 pandemic. Tuberculosis (TB) is an old infectious disease for which eradication has not yet been successful. Novel agents are required to have potential activity against both drug-sensitive and drug-resistant strains of Mycobacterium tuberculosis (Mtb), the causative agent of TB. In this study, we present a series of 2-phenyl-N-(pyridin-2-yl)acetamides in an attempt to investigate their possible antimycobacterial activity, cytotoxicity on the HepG2 liver cancer cell line, and-as complementary testing-their antibacterial and antifungal properties against a panel of clinically important pathogens. This screening resulted in one compound with promising antimycobacterial activity-compound 12, MICMtb H37Ra = 15.625 μg/mL (56.26 μM). Compounds 17, 24, and 26 were further screened for their antiproliferative activity against human epithelial kidney cancer cell line A498, human prostate cancer cell line PC-3, and human glioblastoma cell line U-87MG, where they were found to possess interesting activity worth further exploration in the future.

• Klíčová slova
• antibacterial, antimycobacterial, antiproliferative, drug design, pyridine, tuberculosis,
• MeSH
• acetamidy * chemie   farmakologie   MeSH
• antifungální látky farmakologie   chemie   chemická syntéza   MeSH
• antituberkulotika farmakologie   chemie   MeSH
• buňky Hep G2 MeSH
• lidé MeSH
• mikrobiální testy citlivosti * MeSH
• Mycobacterium tuberculosis * účinky léků   MeSH
• nádorové buněčné linie MeSH
• proliferace buněk * účinky léků   MeSH
• protinádorové látky farmakologie   chemie   MeSH
• pyridiny chemie   farmakologie   MeSH
• SARS-CoV-2 účinky léků   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetamidy * MeSH
• antifungální látky MeSH
• antituberkulotika MeSH
• protinádorové látky MeSH
• pyridiny MeSH

Despite the established treatment regimens, tuberculosis remains an alarming threat to public health according to WHO. Novel agents are needed to overcome the increasing rate of resistance and perhaps achieve eradication. As part of our long-term research on pyrazine derived compounds, we prepared a series of their ortho fused derivatives, N-phenyl- and N-benzyl quinoxaline-2-carboxamides, and evaluated their in vitro antimycobacterial activity. In vitro activity against Mycobacterium tuberculosis H37Ra (represented by minimum inhibitory concentration, MIC) ranged between 3.91-500 µg/mL, with most compounds having moderate to good activities (MIC < 15.625 µg/mL). The majority of the active compounds belonged to the N-benzyl group. In addition to antimycobacterial activity assessment, final compounds were screened for their in vitro cytotoxicity. N-(naphthalen-1-ylmethyl)quinoxaline-2-carboxamide (compound 29) was identified as a potential antineoplastic agent with selective cytotoxicity against hepatic (HepG2), ovarian (SK-OV-3), and prostate (PC-3) cancer cells lines. Molecular docking showed that human DNA topoisomerase and vascular endothelial growth factor receptor could be potential targets for 29.

• Klíčová slova
• Mycobacterium tuberculosis, antimycobacterial, cytotoxicity, molecular docking, pyrazinamide, quinoxaline, tuberculosis,
• Publikační typ
• časopisecké články MeSH

According to the World Health Organization, tuberculosis is still in the top ten causes of death from a single infectious agent, killing more than 1.7 million people worldwide each year. The rising resistance developed by Mycobacterium tuberculosis against currently used antituberculars is an imperative to develop new compounds with potential antimycobacterial activity. As a part of our continuous research on structural derivatives of the first-line antitubercular pyrazinamide, we have designed, prepared, and assessed the in vitro whole cell growth inhibition activity of forty-two novel 5-alkylamino-N-phenylpyrazine-2-carboxamides with various length of the alkylamino chain (propylamino to octylamino) and various simple substituents on the benzene ring. Final compounds were tested against Mycobacterium tuberculosis H37Ra and four other mycobacterial strains (M. aurum, M. smegmatis, M. kansasii, M. avium) in a modified Microplate Alamar Blue Assay. We identified several candidate molecules with micromolar MIC against M. tuberculosis H37Ra and low in vitro cytotoxicity in HepG2 cell line, for example, N-(4-hydroxyphenyl)-5-(pentylamino)pyrazine-2-carboxamide (3c, MIC = 3.91 µg/mL or 13.02 µM, SI > 38) and 5-(heptylamino)-N-(p-tolyl)pyrazine-2-carboxamide (4e, MIC = 0.78 µg/mL or 2.39 µM, SI > 20). In a complementary screening, we evaluated the in vitro activity against bacterial and fungal strains of clinical importance. We observed no antibacterial activity and sporadic antifungal activity against the Candida genus.

• Klíčová slova
• alkylamino derivatives, antibacterial, antifungal, antimycobacterial, cytotoxicity, pyrazinamide,
• MeSH
• antituberkulotika chemická syntéza   chemie   izolace a purifikace   farmakologie   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• Mycobacterium tuberculosis účinky léků   MeSH
• pyrazinamid chemie   MeSH
• pyraziny chemie   MeSH
• racionální návrh léčiv MeSH
• vyvíjení léků MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antituberkulotika MeSH
• pyrazinamid MeSH
• pyraziny MeSH

We prepared a series of substituted N-(pyrazin-2-yl)benzenesulfonamides as an attempt to investigate the effect of different linkers connecting pyrazine to benzene cores on antimicrobial activity when compared to our previous compounds of amide or retro-amide linker type. Only two compounds, 4-amino-N-(pyrazin-2-yl)benzenesulfonamide (MIC = 6.25 μg/mL, 25 μM) and 4-amino-N-(6-chloropyrazin-2-yl)benzenesulfonamide (MIC = 6.25 μg/mL, 22 μM) exerted good antitubercular activity against M. tuberculosis H37Rv. However, they were excluded from the comparison as they-unlike the other compounds-possessed the pharmacophore for the inhibition of folate pathway, which was proven by docking studies. We performed target fishing, where we identified matrix metalloproteinase-8 as a promising target for our title compounds that is worth future exploration.

• Klíčová slova
• Mycobacterium tuberculosis, anti-infectives, pyrazinamide, sulfonamide, target fishing,
• MeSH
• antiinfekční látky chemická syntéza   chemie   farmakologie   MeSH
• antituberkulotika chemická syntéza   chemie   farmakologie   MeSH
• benzensulfonamidy MeSH
• chemické jevy MeSH
• mikrobiální testy citlivosti MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• Mycobacterium tuberculosis účinky léků   MeSH
• sulfonamidy chemická syntéza   chemie   farmakologie   MeSH
• techniky syntetické chemie MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antiinfekční látky MeSH
• antituberkulotika MeSH
• sulfonamidy MeSH

Three series of N-(pyrazin-2-yl)benzamides were designed as retro-amide analogues of previously published N-phenylpyrazine-2-carboxamides with in vitro antimycobacterial activity. The synthesized retro-amides were evaluated for in vitro growth inhibiting activity against Mycobacterium tuberculosis H37Rv (Mtb), three non-tuberculous mycobacterial strains (M. avium, M. kansasii, M. smegmatis) and selected bacterial and fungal strains of clinical importance. Regarding activity against Mtb, most N-pyrazinylbenzamides (retro-amides) possessed lower or no activity compared to the corresponding N-phenylpyrazine-2-carboxamides with the same substitution pattern. However, the active retro-amides tended to have lower HepG2 cytotoxicity and better selectivity. Derivatives with 5-chloro substitution on the pyrazine ring were generally more active compared to their 6-cloro positional isomers or non-chlorinated analogues. The best antimycobacterial activity against Mtb was found in N-(5-chloropyrazin-2-yl)benzamides with short alkyl (2h: R² = Me; 2i: R² = Et) in position 4 of the benzene ring (MIC = 6.25 and 3.13 µg/mL, respectively, with SI > 10). N-(5-Chloropyrazin-2-ylbenzamides with hydroxy substitution (2b: R² = 2-OH; 2d: R² = 4-OH) on the benzene ring or their acetylated synthetic precursors possessed the broadest spectrum of activity, being active in all three groups of mycobacterial, bacterial and fungal strains. The substantial differences in in silico calculated properties (hydrogen-bond pattern analysis, molecular electrostatic potential, HOMO and LUMO) can justify the differences in biological activities between N-pyrazinylbenzamides and N-phenylpyrazine-2-carboxamides.

• Klíčová slova
• antibacterial, antifungal, antimycobacterial, cytotoxicity, linker, pyrazinamide, retro-amide, tuberculosis,
• MeSH
• antibakteriální látky chemická syntéza   chemie   farmakologie   MeSH
• benzamidy chemická syntéza   chemie   farmakologie   MeSH
• buněčné linie MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• Mycobacterium tuberculosis účinky léků   MeSH
• racionální návrh léčiv * MeSH
• techniky syntetické chemie * MeSH
• viabilita buněk účinky léků   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• benzamide MeSH Prohlížeč
• benzamidy MeSH

Hybrid compounds based on a combination of the first-line antitubercular pyrazinamide (PZA) and a formerly identified antimycobacterial scaffold of 4-arylthiazol-2-amine were designed. Eighteen compounds were prepared, characterized and tested for in vitro growth inhibition activity against M. tuberculosis H37Rv, M. kansasii, M. avium and M. smegmatis by Microplate Alamar Blue Assay at neutral pH. Active compounds were tested for in vitro cytotoxicity in the human hepatocellular carcinoma cell line (HepG2). The most active 6-chloro-N-[4-(4-fluorophenyl)thiazol-2-yl]pyrazine-2-carboxamide (9b) also had the broadest spectrum of activity and inhibited M. tuberculosis, M. kansasii, and M. avium with MIC = 0.78 μg mL-1 (2.3 μM) and a selectivity index related to HepG2 cells of SI > 20. Structure-activity relationships within the series are discussed. Based on its structural similarity to known inhibitors and the results of a molecular docking study, we suggest mycobacterial beta-ketoacyl-(acyl-carrier-protein) synthase III (FabH) as a potential target.

• Publikační typ
• časopisecké články MeSH

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) has become a frequently deadly infection due to increasing antimicrobial resistance. This serious issue has driven efforts worldwide to discover new drugs effective against Mtb. One research area is the synthesis and evaluation of pyrazinamide derivatives as potential anti-TB drugs. In this paper we report the synthesis and biological evaluations of a series of ureidopyrazines. Compounds were synthesized by reacting alkyl/aryl isocyanates with aminopyrazine or with propyl 5-aminopyrazine-2-carboxylate. Reactions were performed in pressurized vials using a CEM Discover microwave reactor with a focused field. Purity and chemical structures of products were assessed, and the final compounds were tested in vitro for their antimycobacterial, antibacterial, and antifungal activities. Propyl 5-(3-phenylureido)pyrazine-2-carboxylate (compound 4, MICMtb = 1.56 μg/mL, 5.19 μM) and propyl 5-(3-(4-methoxyphenyl)ureido)pyrazine-2-carboxylate (compound 6, MICMtb = 6.25 μg/mL, 18.91 μM) had high antimycobacterial activity against Mtb H37Rv with no in vitro cytotoxicity on HepG2 cell line. Therefore 4 and 6 are suitable for further structural modifications that might improve their biological activity and physicochemical properties. Based on the structural similarity to 1-(2-chloropyridin-4-yl)-3-phenylurea, a known plant growth regulator, two selected compounds were evaluated for similar activity as abiotic elicitors.

• Klíčová slova
• Mycobacterium tuberculosis, abiotic elicitors, anti-infectives, callus culture, ester, pyrazinoic acid, ureidopyrazine,
• MeSH
• antituberkulotika chemická syntéza   chemie   farmakologie   MeSH
• buňky Hep G2 MeSH
• Fagopyrum chemie   MeSH
• fyziologický stres účinky léků   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• molekulární struktura MeSH
• Mycobacterium tuberculosis účinky léků   MeSH
• proliferace buněk účinky léků   MeSH
• pyrazinamid chemie   farmakologie   MeSH
• pyraziny chemická syntéza   chemie   farmakologie   MeSH
• regulátory růstu rostlin chemická syntéza   chemie   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antituberkulotika MeSH
• propyl 5-(3-(4-methoxyphenyl)ureido)pyrazine-2-carboxylate MeSH Prohlížeč
• propyl 5-(3-phenylureido)pyrazine-2-carboxylate MeSH Prohlížeč
• pyrazinamid MeSH
• pyraziny MeSH
• regulátory růstu rostlin MeSH

Aminodehalogenation of 3-chloropyrazine-2-carboxamide with variously substituted benzylamines yielded a series of fifteen 3-benzylaminopyrazine-2-carboxamides. Four compounds possessed in vitro whole cell activity against Mycobacterium tuberculosis H37Rv that was at least equivalent to that of the standard pyrazinamide. MIC values ranged from 6 to 42 μM. The best MIC (6 μM) was displayed by 3-[(4-methylbenzyl)amino]pyrazine-2-carboxamide (8) that also showed low cytotoxicity in the HepG2 cell line (IC50 ≥ 250 μM). Only moderate activity against Enterococcus faecalis and Staphylococcus aureus was observed. No activity was detected against any of tested fungal strains. Molecular docking with mycobacterial enoyl-ACP reductase (InhA) was performed to investigate the possible target of the prepared compounds. Active compounds shared common binding interactions of known InhAinhibitors. Antimycobacterial activity of the title compounds was compared to the previously published benzylamino-substituted pyrazines with differing substitution on the pyrazine core (carbonitrile moiety). The title series possessed comparable activity and lower cytotoxicity than molecules containing a carbonitrile group on the pyrazine ring.

• Klíčová slova
• antibacterials, antifungals, benzylamines, cytotoxicity, microwave-assisted, pyrazinamide, tuberculosis,
• MeSH
• amidy chemie   MeSH
• antibakteriální látky chemická syntéza   farmakologie   MeSH
• antifungální látky chemická syntéza   farmakologie   MeSH
• antiinfekční látky chemická syntéza   farmakologie   MeSH
• antituberkulotika chemická syntéza   farmakologie   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• molekulární struktura MeSH
• pyrazinamid chemická syntéza   farmakologie   MeSH
• pyraziny chemie   MeSH
• simulace molekulového dockingu MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amidy MeSH
• antibakteriální látky MeSH
• antifungální látky MeSH
• antiinfekční látky MeSH
• antituberkulotika MeSH
• pyrazinamid MeSH
• pyraziny MeSH

Two novel thiosemicarbazones and eight novel 2-{[1-(5-alkyl/arylalkylpyrazin-2-yl)ethylidene]hydrazono}-1,3-thiazolidin-4-ones were prepared and tested against a panel of eight fungal strains-Candida albicans ATCC 44859, Candida tropicalis 156, Candida krusei E 28, Candida glabrata 20/I, Trichosporon asahii 1188, Aspergillus fumigatus 231, Lichtheimia corymbifera 272, and Trichophyton interdigitale 445. 1,3-Thiazolidin-4-ones exhibited activity against all strains, the most potent derivative was 2-{[1-(5-butylpyrazin-2-yl)ethylidene]hydrazono}e-1,3-thiazolidin-4-one. Susceptibility of C. glabrata to the studied 1,3-thiazolidin-4-ones (minimum inhibitory concentrations (MICs) were in the range 0.57 to 2.78 mg/L) is of great interest as this opportunistic pathogen is poorly susceptible to azoles and becomes resistant to echinocandins. Antifungal potency of thiosemicarbazones was slightly lower than that of 1,3-thiazolidin-4-ones.

• Klíčová slova
• 1,3-thiazolidin-4-ones, Candida glabrata, acetylpyrazine, antifungal, thiosemicarbazones,
• MeSH
• antifungální látky chemická syntéza   chemie   farmakologie   MeSH
• Aspergillus účinky léků   MeSH
• Candida účinky léků   MeSH
• mikrobiální testy citlivosti MeSH
• molekulární struktura MeSH
• Mucorales účinky léků   MeSH
• thiazolidindiony chemická syntéza   chemie   farmakologie   MeSH
• thiosemikarbazony chemická syntéza   chemie   farmakologie   MeSH
• Trichophyton účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antifungální látky MeSH
• thiazolidindiony MeSH
• thiosemikarbazony MeSH

A series of N-alkyl-3-(alkylamino)pyrazine-2-carboxamides and their N-alkyl-3-chloropyrazine-2-carboxamide precursors were prepared. All compounds were characterized by analytical methods and tested for antimicrobial and antiviral activity. The antimycobacterial MIC values against Mycobacterium tuberculosis H37Rv of the most effective compounds, 3-(hexylamino)-, 3-(heptylamino)- and 3-(octylamino)-N-methyl-pyrazine-2-carboxamides 14‒16, was 25 μg/mL. The compounds inhibited photosystem 2 photosynthetic electron transport (PET) in spinach chloroplasts. This activity was strongly connected with the lipophilicity of the compounds. For effective PET inhibition longer alkyl chains in the 3-(alkylamino) substituent in the N-alkyl-3-(alkylamino)pyrazine-2-carboxamide molecule were more favourable than two shorter alkyl chains.

• Klíčová slova
• alkylation, aminodehalogenation, antimycobacterial activity, inhibition of photosynthetic electron transport, pyrazinamide, pyrazine, structure-activity relationships,
• MeSH
• antituberkulotika chemická syntéza   farmakologie   MeSH
• bakteriální proteiny antagonisté a inhibitory   metabolismus   MeSH
• chloroplasty metabolismus   MeSH
• mikrobiální testy citlivosti MeSH
• Mycobacterium tuberculosis účinky léků   metabolismus   MeSH
• pyrazinamid chemická syntéza   chemie   farmakologie   MeSH
• pyraziny chemická syntéza   farmakologie   MeSH
• Spinacia oleracea metabolismus   MeSH
• syntázy mastných kyselin antagonisté a inhibitory   metabolismus   MeSH
• transport elektronů účinky léků   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antituberkulotika MeSH
• bakteriální proteiny MeSH
• fatty acid synthase I, mycobacteria MeSH Prohlížeč
• pyrazinamid MeSH
• pyraziny MeSH
• syntázy mastných kyselin MeSH