A new series of hybrid compounds with tropinone and thiazole rings in the structure was designed and synthesized as potential anticancer agents. They were tested against human multiple myeloma (RPMI 8226), lung carcinoma (A549), breast adenocarcinoma (MDA-MB-231), and mouse skin melanoma (B16-F10) cell lines. Toxicity was tested on human normal skin fibroblasts (HSF) and normal colon fibroblasts (CCD-18Co). The growth inhibition mechanism of the most active derivative was analyzed through investigation of its effect on the distribution of cell cycle phases and ability to induce apoptosis and necrosis in RPMI 8226 and A549 cancer cells. The tyrosinase inhibitory potential was assessed, followed by molecular docking studies. Compounds 3a–3h show high anticancer activity against MDA-MB-231 and B16-F10 cell lines with IC50 values of 1.51–3.03 µM. Moreover, the cytotoxic activity of the investigated compounds against HSF and CCD-18Co cells was 8–70 times lower than against the cancer cells or no toxicity was shown in our tests, with derivative 3a being particularly successful. The mechanism of action of compound 3a in RPMI 8226 cell was shown to be through induction of cell death through apoptosis. The derivatives show ability to inhibit the tyrosinase activity with a mixed mechanism of inhibition. The final molecular docking results showed for IC50 distinct correlation with experiment.

We have designed novel tropinone-thiazole derivatives that showed high antiproliferative activity against a variety of cancer cell lines via caspase 3/7 activation mechanism. Among the derivatives, compounds 3b-3h were found to exhibit high activity against human leukemia (MV4-11), human lung carcinoma (A549), human breast carcinoma (MCF-7), and skin melanoma (B16-F10) cancer cell lines, with IC50 values of 5.43-11.06 μM. The lead compound 3g increases caspase 3/7 activity in A549 cells 25 times more than the control, and 2 times more than reference drug camptothecin. We have also found that tropinone-thiazole derivatives exhibit high tyrosinase inhibitory activity. The lead compounds 3g and 3h showed tyrosinase inhibition effect, with IC50 values 3.22 and 3.51 μM, respectively. These inhibitory activities are 22 times higher than the activity of kojic acid (IC50 72.27 μM) and 120 times higher than activity of ascorbic acid (IC50 386.5 μM). For compounds 3g and 3h, the experimentally determined lipophilicity correlates very well with their enzymatic activities. These data suggest that presented compounds could constitute lead anticancer drug candidates.

Synthesis, characterization and investigation of antiproliferative activity of nine triazene salts against human cancer cells lines (MV-4-11, MCF-7, JURKAT, HT-29, Hep-G2, HeLa, Du-145 and DAUDI), and normal human mammary epithelial cell line (MCF7-10A) is presented. The structures of novel compounds were determined using H-1 and C-13 NMR, and GC-APCI-MS analyses. Among the derivatives, compound 2c, 2d, 2e and 2f has very strong activity against biphenotypic B myelomonocytic leukemia MV4-11, with IC50 values from 5.42 to 7.69 mu g/ml. The cytotoxic activity of compounds 2c-2f against normal human mammary gland epithelial cells MCF-10A is 6-11 times lower than against cancer cell lines. Our results also show that compounds 2c and 2f have very strong activity against DAUDI and HT-29 with IC50 4.91 mu g/ml and 5.59 mu g/ml, respectively. Their lipophilicity was determined using reversed-phase ultra-performance liquid chromatography and correlated with antiproliferative activity. Our UV-Vis spectroscopic results indicate also that triazene salts tends to interact with negatively charged DNA phosphate chain. To support the experiment, theoretical calculations of the H-1 NMR shifts were carried out within the Density Functional Theory. (C) 2018 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.

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, 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 H-1 and C-13 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.

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, characterization and investigation of antiproliferative activity of ten thiazole-based nitrogen mustard against human cancer cells lines (MV4-11, A549, MCF-7 and HCT116) and normal mouse fibroblast (BALB/3T3) is presented. The structures of novel compounds were determined using H-1 and C-13 NMR, FAB(+)-MS, and elemental analyses. Among the derivatives, 5b, 5c, 5e, 5f and 5i were found to exhibit high activity against human leukaemia MV4-11 cells with IC50 values of 2.17-4.26 mu g/ml. The cytotoxic activity of compound 5c and 5f against BALE/3T3 cells is up to 20 times lower than against cancer cell lines. Our results also show that compounds 5e and 5i have very strong activity against MCF-7 and HCT116 with IC50 values of 3.02-4.13 mu g/ml. Moreover, spectroscopic characterization and cellular localization for selected compound were performed. In order to identify potential drug targets we perform computer simulations with DNA-binding site of hTopol and hTopoll and quantum chemical calculation of interaction and binding energies in complexes of the five most active compounds with guanine. (c) 2016 Elsevier B.V. All rights reserved.

Synthesis, characterization and investigation of antimicrobial activity of 11 novel adamantanyl-thiazoles are presented. Their structures were determined using H-1 and C-13 NMR, EI(+)-MS, HRMS, and elemental analyses. Among the derivatives, compound 3c showed very strong activity, especially against Candida albicans ATCC 10231 and Candida parapsilosis ATCC 22019 with minimal inhibitory concentration (MIC) values ranging from 1.95 to 7.81 mu g/ml. Compounds 3a and 3b showed good antifungal activity. Among the examined compounds, the widest spectrum of antibacterial activity possessed 3f that showed good activity, especially against Staphylococcus epidermidis ATCC 12228, Micrococcus luteus ATCC 10240, Bacillus subtilis ATCC 6633 with MIC values ranging from 31.25 to 62.5 mu g/ml. Molecular docking studies of all compounds on the active sites of microbial enzymes indicated possible targets sterol 14-demethylase, secreted aspartic proteinase (SAP), N-myristoyltransferase (NMT), and topoisomerase II. Thiazoles 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k showed more favorable affinity to SAP and NMT than the native ligand.

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 and investigation of antimicrobial activities of novel thiazoles and selenazoles is presented. Their structures were determined using NMR, FAB(+)-MS, HRMS and elemental analyses. To support the experiment, theoretical calculations of the H-1 NMR shifts were carried out for representative systems within the DFT B3LYP/6-311++G** approximation which additionally confirmed the structure of investigated compounds. Among the derivatives, compounds 4b, 4h, 4j and 4l had very strong activity against reference strains of Candida albicans ATCC and Candida parapsilosis ATCC 22019 with MIC = 0.49 -7.81 mu g/ml. In the case of compounds 4b, 4c, 4h - 4j and 4l, the activity was very strong against of Candida spp. isolated from clinical materials, i.e. C. albicans, Candida krusei, Candida inconspicua, Candida famata, Candida lusitaniae, Candida sake, C. parapsilosis and Candida dubliniensis with MIC = 0.24 -15.62 mu g/ml. The activity of several of these was similar to the activity of commonly used antifungal agent fluconazole. Additionally, compounds 4m - 4s were found to be active against Gram-positive bacteria, both pathogenic staphylococci Staphylococcus aureus ATCC with MIC = 31.25-125 mu g/ml and opportunistic bacteria, such as Staphylococcus epidermidis ATCC 12228 and Micrococcus luteus ATCC 10240 with MIC = 7.81-31.25 mu g/ml. (C) 2015 Elsevier B.V. All rights reserved.

Novel disulfide analogues of isophosphoramide mustard (iPAM) were designed and synthesised. All compounds were hydrolytically stable and underwent reduction by L-glutathione with different kinetic parameters. Based on the HPLC-MS analysis a mechanism of activation by glutathione obtained disulfide analogues of iPAM was proposed. The compounds were tested for cytotoxic activity against human promyelocytic leukaemia HL-60, human lymphoblastic leukaemia MOLT-4, human lymphoblastic leukaemia CCRF/CEM, human bladder cancer HCV29T, murine melanoma B16-F0 and murine fibroblasts Balb3T3 cell lines. The most promising anticancer activity was exhibited by compound 4, which proved to be more active than the reference cisplatin against all cancer cell lines.

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.

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 H-1 NMR, C-13 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 mu g/mL.

Synthesis, characterization and investigation of antimicrobial activities of ten novel tetrahydroindazolyl-thiazoles is presented. Their structures were determined using H-1 and C-13 NMR, FAB(+)-MS and HRMS analyses. Among the derivatives, compound 3f shows strong antibacterial activity against S. aureus ATCC 43300, S. aureus ATCC 25923, and S. epidermidis ATCC 12228 with MIC 7.81 mu g/ml, and good activity against S. aureus ATCC 6538 with MIC 31.25 mu g/ml. Compounds 3a-e and 3j show good antifungal activity with MIC values ranging from 31.25 mu g/ml to 250 mu g/ml.

Synthesis, characterization and investigation of antibacterial and antifungal activities of twelve camphor based 2,4-disubstituted 1,3-thiazoles is presented. Their structures were determined using NMR, IR, FAB MS and HRMS analyses. Among the derivatives, 3i and 5 were found to exhibit antifungal and antibacterial activities comparable to that of fluconazole and ciprofloxacin against yeast belonging to Candida spp., MIC 0.12-0.98 μg/ml and Gram-positive bacteria including both pathogenic S. aureus and opportunistic S. epidermidis, MIC 0.98-7.81 μg/ml, B. subtilis and B. cereus, MIC 3.91-31.25 μg/ml, and M. luteus, MIC 0.98 μg/ml species, respectively. Molecular docking studies of all compounds into the active sites of microbial enzymes indicated a possible targets SAP and NMT, thiazoles 3a-j, 4, 5 showed more favourable affinity than the native ligand.

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.

Cyclophosphamide (CPA) and ifosfamide (IFO) belong to oxazaphosphorine drugs and for a few decades have been widely used for treatment of solid tumours and haematological malignancies. Both drugs are administered in pharmacologically inactive form and require metabolic activation by cytochrome P-450 (CYP). Metabolic transformations taking place under the action of specific CYP isoenzymes lead to the formation of therapeutically essential metabolites and some toxic compounds affecting quality of therapy. The first stage of these conversions is connected with hydroxylation reactions occurring on the C-4 carbon atom within a ring and C-1 atoms of 2-chloroethyl chains. As a result of C-4 hydroxylation 4-hydroxy derivatives (4-OH-CPA and 4-OH-IFO) are formed and remain in tautomeric equilibrium with aldo compounds which in cancer cells spontaneously release cytotoxic phosphoramide mustards and urotoxic acrolein. At the same time hydroxychloroethyl compounds formed during hydroxylation of side-chains are unstable and collapse with the release of inter alia nephro- and neurotoxic chloroacetaldehyde (CAA). Due to formation of toxic metabolites it is essential to use some preventive agents such as mesna and recently examined agmatine. Since CPA and IFO are widely used anticancer drugs, their efficacy is limited not only by their toxicity but also due to occurring resistance. This resistance seems to be a result of changes of expression and activity of enzymes such as CYP and aldehyde dehydrogenase (ALDH) and increase of intracellular levels of glutathione (GSH) and glutathione S-transferase (GST). At present a few methods of overcoming this resistance are being examined including the use of metabolism modulators, antisense oligonucleotides selectively inhibiting gene expression, and introducing genes of some CYP isoenzymes to a cancer tissue.

A series of new prodrugs: [bis(2-chloroethylamino)phosphoryloxy]methyl acetate, [bis(2-chloroethylamino)phosphoryloxy]methyl pivalate and [bis(2-chloroethylamino)phosphoryloxy]methyl benzoate, was obtained in the reaction of isophosphoramide mustard (iPAM) with the corresponding acyloxymethyl halides. The cytotoxic activity of these new compounds is also shown. All compounds were highly active in the inhibition of cancer cell proliferation against the human lung (A594), prostate (PC-3) and breast (MCF-7) cancer cell lines.