Diastereoselective Sonochemical Synthesis of Spirocyclopropaneoxindoles and Evaluation of Their Antioxidant and Cytotoxic Activities.

An efficient diastereoselective synthesis of spirocyclopropaneoxindoles is reported using three-component reactions of various phenacylidenetriphenylphosphorane, isatins and phenacyl bromide under ultrasonic irradiation. The structures of synthesized spirocyclopropaneoxindoles were characterized by their spectral data. The antioxidant activities of the synthesized compounds were evaluated by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. Among the products, those with NH group in their structure exhibited higher antioxidant activities than other derivatives. Also, in vitro cytotoxicity of compounds 4b, 4e, 4j, 4k were examined against heLa cancer cell lines using MTT assay. The results revealed that compound 4j with chlorine substituent on phenyl group displayed higher cytotoxicity activity (IC50 =4.50±0.30 µg/mL) after 48 h.

Synthesis and Characterization of Novel Thiazolo[3,2-a]pyrimidine Derivatives and Evaluation of Antioxidant and Cytotoxic Activities.

A series of novel thiazolo[3,2-a]pyrimidines were synthesized and characterized by FT-IR, 1 H, 13 C-NMR and mass techniques. Their antioxidant activities were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and the results showed that all the synthesized compounds exhibit good antioxidant activity. In addition, it was found that any substituent on the aromatic ring of the products plays an important role in their antioxidant activity. In vitro cytotoxicity of compounds 4a-4j was investigated using MTT cell viability assay. Among these compounds, 6-ethyl 2,3-dimethyl 5-(4-chlorophenyl)-7-methyl-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-2,3,6-tricarboxylate (4e) bearing a chlorine substituent displayed the highest cytotoxic effect (IC50 =6.26±0.6 µm) in comparison with doxorubicin (IC50 =0.68±0.1 µm) as a standard after 72 h. Therefore, it is assumed that these compounds could be used as effective antioxidant and cytotoxic agents.