Konrad Misiura

Synthesis and In Vitro Antiproliferative Activity of Thiazole-Based Nitrogen Mustards: The Hydrogen Bonding Interaction between Model Systems and Nucleobases

Synthesis, characterization and investigation of antiproliferative activity of eight thiazole-based nitrogen mustard against human cancer cells lines (MV4-11, A549, HCT116 and MCF-7) and normal mouse fibroblast (BALB/3T3) are presented. Their structures were determined using NMR, FAB MS, HRMS and elemental analyses. Among the derivatives, 3a, 3b, 3e and 3h were found to exhibit high activity against human leukemia MV4-11 cells with IC50 values of 0.634-3.61 µg/ml. The cytotoxic activity of compound 3a against BALB/3T3 cells is up to 40 times lower than against cancer cell lines. Our data indicated also that compound 3e had very strong activity against MCF-7 and HCT116 with IC50 equal to 2.32 µg/ml and 2.81 µg/ml, respectively. Their activity was similar to the activity of cis-platin, which is clinically used as anticancer drug in the treatment of human solid tumours. We also perform quantum chemical calculation of interaction and binding energies in complexes of model systems and 3e with DNA bases. Interaction of real drug 3e with guanine is much stronger than with the remaining nucleobases, and the strongest among all investigated complexes. Computer simulations were performed with ATP-binding domain and DNA-binding site of hTopoII. Compounds 3a-h were recognized as potential inhibitors of hTopoII.

Synthesis and anticonvulsant activities of novel 2-(cyclopentylmethylene)hydrazinyl-1,3-thiazoles in mouse models of seizures

Abstract Synthesis, characterization and investigation of in vivo anticonvulsant activities of 13 novel cyclopentanecarbaldehyde-based 2,4-disubstituted 1,3-thiazoles are presented. Their structures were determined using 1H and 13C NMR, FAB(+)-MS, HRMS and elemental analyses. The results of anticonvulsant screening reveal that seven intraperitoneally administered compounds: 3a, 3b, 3d, 3e, 3f, 3k and 3m containing F-, Cl-, Br-, CF3-, CH3- and adamantyl substituents demonstrated significant anticonvulsant activity in the pentylenetetrazole model with median effective doses (ED50) ≤ 20 mg/kg, respectively, which was approximately seven-fold lower than that reported for the reference drug, ethosuximide. Noteworthy, none of these compounds impaired animals’ motor skills in the rotarod test.

Discovery and evaluation of efficient selenazoles with high antifungal activity against Candida spp.

Synthesis, characterization and investigation of antifungal and antibacterial activities of fourteen 2,4- disubstituted 1,3-selenazoles is presented. Their structures were determined using (1)H and (13)C NMR, FAB MS and HRMS analyses. Among the derivatives, compounds 5, 6, 8, 9, 12, 13 and 15 had very strong activity against reference strains of C. albicans ATCC 10231 and C. parapsilosis ATCC 22019 with MIC = 0.24-7.81 µg/ml. The compounds 5, 6, 8, 13 and 15 showed also very strong activity against clinical isolates belonging to non-albicans Candida spp. strains, i.e. C. krusei, C. inconspicua, C. famata, C. lusitaniae, C. sake, C. parapsilosis, C. dubliniensis with MIC = 0.24-7.81 µg/ml. The activity of several of these was similar to the activity of most commonly used antifungal agents fluconazole. The compounds 9 and 16 indicate also very strong antibacterial activity against S. epidermidis and M. luteus with MIC = 1.95-3.91 µg/ml. Additionally, the compound 11 is strong active against M. luteus with MIC = 3.91 µg/ml.

Synthesis, antimicrobial and anticonvulsant screening of small library of tetrahydro-2H-thiopyran-4-yl based thiazoles and selenazoles

Abstract Synthesis and investigation of antimicrobial activity of 22 novel thiazoles and selenazoles derived from dihydro-2H-thiopyran-4(3H)-one are presented. Additionally, anticonvulsant activity of six derivatives is examinated. Among the derivatives, compounds 4a–f, 4i, 4k, 4 l, 4n, 4o–s and 4v have very strong activity against Candida spp. with MIC = 1.95–15.62 μg/ml. In the case of compounds 4a–f, 4i, 4k, 4 l, 4n, 4o, 4r and 4s, the activity is very strong against some strains of Candida spp. isolated from clinical materials, with MIC = 0.98 to 15.62 μg/ml. Additionally, compounds 4n-v are found to be active against Gram-positive bacteria with MIC = 7.81–62.5 μg/ml. The results of anticonvulsant screening reveal that compounds 4a, 4b, 4m and 4n demonstrate a statistically significant anticonvulsant activity in the pentylenetetrazole model, whereas compounds 4a and 4n showed protection in 6-Hz psychomotor seizure model. Noteworthy, none of these compounds impaired animals’ motor skills in the rotarod test. We also performed quantum chemical calculation of interaction and binding energies in complex of 4a with cyclodextrin.

Synthesis and antimicrobial activities of novel 6-(1,3-thiazol-4-yl)-1,3-benzoxazol-2(3H)-one derivatives

Abstract Synthesis, characterization and investigation of antimicrobial activities of seven new 6-(1,3-thiazol-4-yl)-1,3-benzoxazol-2(3H)-ones are presented. Their structures were determined using 1H NMR, 13C NMR and elemental analyses. The compounds possess some biological activity against Gram-positive bacteria, especially against Micrococcus luteus belonging to opportunistic pathogens, with an MIC of 31.25 μg/mL.

Synthesis, Antibacterial Activity, Interaction with Nucleobase and Molecular Docking Studies of 4-Formylbenzoic Acid Based Thiazoles

BACKGROUND Synthesis, characterization and investigation of antibacterial activity of ten novel Schiff base derivatives of 4-formylbenzoic acid is presented. Their structures were determined using 1H and 13CNMR, EI(+)-MS and elemental analyses. Additionally, DFT calculations of interaction energies in complexes of the novel drugs and DNA bases are carried out. OBJECTIVE Design and synthesis of thiazole derivatives with benzoic acid scaffold to obtain compounds with an improved antibacterial activity. METHOD The examined compounds were screened in vitro for antibacterial activity using the broth microdilution method. Geometrical parameters of the investigated complexes were optimized within the Density Functional Theory (DFT) approximation using the B3LYP functional and the 6-311G** basis set. The docking simulations were performed using the FlexX docking module. RESULTS Among the derivatives, compound 4b showed very strong bacterial activity against staphylococci, MIC 1.95-3.91 µg/ml, micrococci, MIC 0.98 µg/ml, and Bacillus spp., MIC 7.81-15.62 µg/ml. The compounds 4c, 4d, 4e and 4j also showed high bioactivity against staphylococci, MIC 3.91-31.25 µg/ml, and micrococci, MIC 0.98-15.62 µg/ml. Interaction energy values for investigated guanine complexes are about 2 kcal/mol lower than for the corresponding cytosine complexes. Molecular docking studies of all compounds on the active sites of bacterial enzymes indicated gyrase B as possible target. CONCLUSION To conclude, an efficient and economic method for the synthesis of thiazoles containing benzoic acid moiety has been developed. The results of antibacterial screenings reveal that some obtained compounds show high to very strong antibacterial activity. The DFT calculations showed that interaction of the obtained drugs with guanine is stronger than with cytosine. Molecular docking studies of all compounds on the active sites of bacterial enzymes indicated gyrase B as possible target.

Synthesis and biological evaluation of novel 2-(1H-imidazol-2-ylmethylidene)hydrazinyl- 1,3-thiazoles as potential antimicrobial agents

Abstract Synthesis, characterization, and investigation of antimicrobial activities of nine novel imidazolylthiazoles are presented. Their structures were determined using 1H NMR, 13C NMR, and elemental analysis. Compounds 3e and 3i show very strong or strong bacteriostatic or bactericidal activity [minimal bactericidal concentration/minimal inhibitory concentration (MIC)=2–64] against Staphylococcus spp. (MIC=7.81–15.62 μg/mL), Micrococcus luteus ATCC 10240 (MIC=1.95–3.91 μg/mL), and Bacillus spp. (MIC=3.91–15.62 μg/mL). Compounds 3e and 3i also show the highest fungicidal effect (minimal fungicidal concentration/MIC=2–4) against reference strains of fungi belonging to Candida spp. with MIC ranging from 3.91 to 31.25 μg/mL.