Biological evaluation of benzothiazoles obtained by microwave-green synthesis.

Benzothiazole compounds are known as an important bicyclic ring system with multiple applications. These compounds have a wide range of biological activities, including anticancer, antimicrobial, anti-inflammatory and antiviral activities. In this study, benzothiazole compounds were synthesized and their various biological activities were examined. The synthesized benzothiazoles were evaluated for their antimicrobial properties against various bacterial and fungal strains. The compound 6e is most active ligand in the series against bacteria and fungi as compared to standard antibiotics. Especially, this compound significant effect against Staphylococcus aureus (32.00 ± 1.73 mm). These compounds exhibited potent anticancer activity against gastrointestinal cancer cells, demonstrating their potential as therapeutic agents. The lowest antiproliferative response after administration of the compounds was observed in HCT116 cells, while the most effective antiproliferative response was observed in AGS cells (> 10 µg/mL). In all cell lines, 40 and 100 µg/mL application values of the selected compounds showed significant increases in the expression of caspase-3, 8 and 9. We also utilized a computational docking approach to investigate the interaction of these benzothiazoles with VEGFR-2 kinase. Our docking studies showed that compounds 6a and 6d may be promising therapeutic agents against gastrointestinal system cancers due to their ability to bind to VEGFR-2 kinase.

Antimicrobial, Antiproliferative Effects and Docking Studies of Methoxy Group Enriched Coumarin-Chalcone Hybrids.

Methoxy group enriched eight coumarin-chalcone hybrid derivatives were synthesized. Antimicrobial/ antiproliferative activities were tested against eight human pathogenic microorganisms and four cancer cell lines (AGS, HepG2, MCF-7 and PC-3), respectively. Antimicrobial results showed that most of the compounds were almost more active than used standard antibiotics. Cytotoxicity results showed that 2,3,4-trimethoxyphenyl and thiophene containing structures have promising antiproliferative effects against AGS gastric cell lines with ∼5 µg/ml IC50 values. At the same time, 2,4-dimethoxyphenyl bearing derivative exhibited the lowest IC50 values against HepG2 (∼10 µg/ml) and PC-3 (∼5 µg/ml) cell lines. Particularly, the cell viabilities of MCF-7 cell lines were remarkably inhibited by all the compounds with lower IC50 values. Therefore, molecular docking studies between hybrid ligands and quinone reductase-2 enzyme (regulates in MCF-7 cancer cells) were performed. The results demonstrated that all the derivatives can smoothly interact with interested enzyme in agreement with the experimental results. Finally, ADME parameters were studied to reveal drug-likeness potentials of the coumarin-chalcone hybrids.

Thio-Schiff bases derived from 2,2'-disulfanedianiline via nanocerium oxide: antimicrobial effect and antiproliferative effects in melanoma cells.

In this study, the synthesis of dimeric disulfide-Schiff bases was carried out using two methods. The structures of the obtained Schiff bases were elucidated by various spectroscopic methods as well as elemental analysis. The Schiff base derivative compounds (3a-6) were screened for in vitro antibacterial activity against multidrug-resistant microorganisms using microdilution method. All the tested compounds showed varying inhibition zones against the pathogens. According to MIC results, the compound 2 was shown strong inhibitory activity against all the tested microorganisms compared to antibiotics. In addition, all the tested compounds showed different antiproliferative effects on the melanoma cell line (B16F10). Our synthesized dimeric disulfide-Schiff bases have shown significant various effects.

1-Amino-2-hydroxy-4-naphthalenesulfonic acid based Schiff bases or naphtho[1,2-d]oxazoles: selective synthesis and photophysical properties.

A series of Schiff base and naphtho[1,2-d]oxazole derivatives were selectively synthesized via condensation reaction of 1-amino-2-hydroxy-4-naphthalenesulfonic acid and benzaldehyde derivatives at same conditions. The synthesized compounds were then characterized by using (1)HNMR, (13)CNMR, FTIR spectroscopies and elemental analyses. It was seen that the Schiff bases generated in the presence of OH group at ortho position of benzaldehyde derivatives. However, the products were naphtho[1,2-d]oxazoles in other cases. Then, the synthesized compounds were photophysically investigated by UV absorption and fluorescence emission spectroscopies. As a result, these Schiff bases have shown long wavelength absorption (λ(max): 386 nm) and emission (λ(max): 429-437 nm) effect while synthesized naphtho[1,2-d]oxazole derivatives have a set of absorption (λ(max): about 296, 308, 320 nm) and emission maxima (λ(max): 378-395 nm) at lower wavelength.

Synthesis, characterization and electrochemical behavior of some Ni(II), Cu(II), Co(II) and Cd(II) complexes of ONS type tridentate Schiff base ligand.

Tridentate Schiff base (H(2)L) ligand was synthesized via condensation of o-hydroxybenzaldehyde and 2-aminothiophenol. The metal complexes were prepared from reaction of the ligand with corresponding metal salts presence of substituted pyridine in two different solvents (MeOH or MeCN). The ligand and metal complexes were then characterized by using FTIR, TGA, (1)H NMR and (13)C NMR spectroscopies. The FTIR spectra showed that H(2)L was coordinated to the metal ions in tridentate manner with ONS donor sites of the azomethine N, deprotonated phenolic-OH and phenolic-SH. Furthermore, substituted pyridine was coordinated to the central metal atoms. The thermal behavior of the complexes was investigated by using TGA method and dissociations indicated that substituted pyridine and ligand were leaved from coordination. This coordination of the metal complexes was correlated by (1)H NMR and (13)C NMR. Finally, electrochemical behavior of the ligand and a Ni(II) complex were investigated.