No abstract

A new series of azetidinone (Z2a-Z2e, Z2g), thiazolidinone and selenazolidinone derivatives (Z2B, Z2E, Z2B', Z2E') based on sulfonamide have been synthesized and characterized by different instrumental techniques, such as elemental analyses, FTIR, multinuclear NMR (1H, 13C) and mass spectrometry. The tested compound containing selenium (Z2E') was less toxic than its analogs containing sulfur (Z2E) based on the LD50 value determined by Dixon's up and down method. All compounds showed antibacterial properties, however, Z2E' was more active against Gram-negative bacteria: Escherichia coli and Pseudomonas aeruginosa than Gram-positive ones: Streptococcus aureus and Bacillus, with the lowest MIC value of 5 mg/mL. All compounds showed good antioxidant activity at a lower rate than the standard compound BHT (82%). More precisely, Z2b was the main compound that possess strong activity as an antioxidant (73%). MTT viability assay showed that all tested compounds had cytotoxic effects on MCF-7 cells after 72 h of treatment. Our results revealed that Z2E' and Z2E compounds possessed strong activity (IC50 = 24.8 and 90.9 µg/mL, respectively) against MCF-7 cells at a higher rate than the standard compound 5-FU (IC50 = 97.47 µg/mL). Our results indicated that Z2E' had a promising bioactive scaffold of great medicinal interest due to their numerous pharmacological and biological activities.

Several new and know sulfonamide Schiff bases were prepared by the condensation reaction of sulfonamide (i.e.2-amino-4chlorobenzenesulfonamide, sulfamerazine, sulfanilamide, sulfamethazine, sulfathiazole and sulfadiazine) with vanillin and salicylaldehyde, respectively in an acidic medium. These Schiff bases were used to a new series of β-lactam (azetidin-2-one) compounds (i.e. 4-chloro-2-(2-(4-hydroxy-3-methoxyphenyl)-3-mercapto-4-oxoazetidin-1-yl)benzenesulfonamide , 4-[2-aryl-3-mercapto (or 3-hydroseleno)-4-oxoazetidin-1-yl]-N-substituted benzenesulfonamide; Z5A1-Z5A6, Z5A9-Z5A12, Z5A2', Z5A9'-Z5A11') by their reactions with thioglycolic acid and 2-seleno-glycolic acid, respectively, in presences of phosphorus oxychloride and triethylamine. Cyclocondensation of the Schiff bases with 2-mercaptobutanoic acid in presence of zinc chloride afforded 4-thiazolidinone derivatives (i.e. 4-[5-ethyl-2-aryl-4-oxothiazolidin-3-yl]-N-substituted benzenesulfonamide; ZZ5A2-ZZ5A6, ZZ5A9-ZZ5A12). All new azetidin-2-one and 1,3-thiazolidin-4-onederivatives were characterized by IR, 1 H NMR, 13 C NMR, mass spectroscopic techniques and elemental analysis. The toxicity of new compounds was assayed via the determination of their LD50 value by using Dixon ' s up and down method. The antibacterial activity of azetidin-2-onecompounds were tested in vitro against Staphylococcus aureus, Bacillus, Escherichia coli and Pseudomonas aeruginosa. Furthermore, the antioxidant and anticancer efficiency of compounds were evaluated.

5-hexenyl 1-naphthyl telluride (1) and 5-hexenyl (1,1’-binaphthyl-2-yl) telluride (2) were prepared from the reaction of 1-bromonaphthalene and 2-bromobinaphthalene with di(5-hexenyl) ditelluride in presence of lithium metal. Reaction of 1 and 2 with K2PtCl4 afforded the platinum(II) complexes 3 and 4, respectively in good yields. Silica-bound telluride-platinum complexes were directly synthesized from fumed silica, triethoxysilane and platinum complexes (i.e. 3 and 4). The catalytic activities of polysiloxane-supported platinum complexes were examined with 1-hexene, 1-decene and 1-dodecene at different temperature. It was found that these catalysts are efficient for hydrosilylation of olefins with triethoxysilane.