No abstract

Two types of regioisomeric chromene-based chalcones namely, 1-(6-methoxy-2H-chromen-3-yl)-3-phenylpropen-1-ones and 3-(6-methoxy-2H-chromen-3-yl)-1-phenylpropen-1-ones were prepared and investigated for their antileishmanial activity against promastigotes form of Leishmania major. The obtained results from in vitro biological assays indicated that chloro-substituted 1-(6-methoxy-2H-chromen-3-yl)-3-phenylpropen-1-ones exhibited excellent activity against Leishmania major at non-cytotoxic concentrations.

Novel levofloxacin-containing hybrids carrying a 5-(nitroaryl)-1,3,4-thiadiazol-2-yl group were synthesized and evaluated in vitro against Gram-positive and Gram-negative bacteria. Preliminary data indicated that levofloxacin-nitrofuran and levofloxacin-nitroimidazole hybrids have a potent activity against Gram-positive organisms with enhanced anti-staphylococcal activity compared with the parent quinolone (N-desmethyl levofloxacin).

Helicobacter pylori infection is the main cause of gastritis and gastroduodenal ulcer disease, and is associated with gastric cancer. In order to develop new potential anti-Helicobacter pylori candidates, we have investigated the antimicrobial activity of some 2-substituted-5-nitroheterocycles against H. pylori. The anti-Helicobacter pylori activity of selected compounds along with commercially available antibacterial metronidazole was evaluated by comparing the inhibition zone diameters determined using the paper disc diffusion bioassay. The compounds that exhibited strong anti-H. pylori activity at concentration of 8-32 microg/disc (average of inhibition zone >20 mm) were further tested against 20 clinical isolates of H. pylori at lower concentrations. In general, we have identified a series of 5-nitroheterocyles including nitrofurans, nitrothiophenes and nitroimidazoles bearing a carboxaldehyde thiosemicarbazone or 2-substituted-1,3,4-thiadiazole residues in the 2-position of the 5-nitroheteroaryl ring as potent anti- Helicobacter pylori agents. It was found that chloro-/ amino-/ mercapto-substituted 1,3,4-thiadiazole moiety attached to 5-nitroheteroaryl ring served as promising C-2 substituents for 2-substituted-5-nitroheterocycles. The Structure-activity relationship of this series indicates that both the structure of the nitroaryl scaffold and the C-2 attached residue have dramatic impact on anti-Helicobacter pylori activity.

brids. -Preliminary results of in vitro tests indicate that title compounds (III) exhibit potent activity against Gram-positive bacteria. -(FOROUMADI*, A.; MANSOURI, S.; EMAMI, S.; MIRZAEI, J.; SORKHI, M.; SAEID-ADELI, N.; SHAFIEE, A.; Arch.