Synthesis and antibacterial activity of novel 3-O-arylalkylcarbamoyl-3-O-descladinosyl-9-O-(2-chlorobenzyl)oxime clarithromycin derivatives.

A novel series of 3-O-arylalkylcarbamoyl-3-O-descladinosyl-9-O-(2-chlorobenzyl)oxime clarithromycin derivatives, were designed, synthesized and evaluated for their in vitro antibacterial activity. These derivatives were found to have strong activity against susceptible and resistant bacteria strains. Among them, compounds 7a and 7q showed the most potent activity (0.125 µg/mL) against erythromycin-resistant S. pneumoniae expressing the mefA gene. Moreover, compounds 7f, 7i, 7p and 7z displayed remarkably improved activity (4 µg/mL) against penicillin-resistant S. aureus ATCC31007, and compounds 7a, 7b, 7f, 7p and 7z showed improved activity (8 µg/mL) against erythromycin-resistant S. pyogenes. In particular, compound 7z exhibited potent and balanced activity against the tested drug-susceptible and -resistant bacterial strains.

Synthesis and antibacterial evaluation of novel 11-O-carbamoyl clarithromycin ketolides.

A series of novel 11-O-carbamoyl clarithromycin ketolides were designed, synthesized and evaluated for their in vitro antibacterial activity. The results showed that the majority of the target compounds displayed improved activity compared with references against erythromycin-resistant S. pneumoniae A22072 expressing the mef gene, S. pneumoniae B1 expressing the erm gene and S. pneumoniae AB11 expressing the mef and erm genes. In particular, compounds 9, 18, 19 and 22 showed the most potent activity against erythromycin-resistant S. pneumoniae A22072 with the MIC values of 0.5µg/mL. Furthermore, compounds 11, 18, 19, 24 and 29 were also found to exhibit favorable antibacterial activity against erythromycin-susceptible S. pyogenes with the MIC values of 0.125-1µg/mL, and moderate activity against erythromycin-susceptible S. aureus ATCC25923 and B. subtilis ATCC9372.

Access to Bromo-γ-butenolides via Zwitterion-Catalyzed Rearrangement of Cyclopropene Carboxylic Acids.

γ-Butenolides are useful structural motifs in many pharmaceutically relevant compounds. In particular, halogenated γ-butenolides are attractive building blocks because the halogen handles can readily be manipulated to give various functional molecules. In this study, a catalytic synthesis of halogenated γ-butenolides from cyclopropene carboxylic acids was developed using zwitterionic catalysts and N-haloamides as the halogen sources. The catalytic protocol could also be applied to the synthesis of halogenated pyrrolones by using cyclopropene amides as the starting materials.

Synthesis and Biological Evaluation of Novel FtsZ-targeted 3-arylalkoxy-2,6-difluorobenzamides as Potential Antimicrobial Agents.

Novel series of 3-O-arylalkylbenzamide and 3-O-arylalkyl-2,6-difluorobenzamide derivatives were synthesized and evaluated for their on-target activity and antibacterial activity. The results indicated that the 3-O-arylalkyl-2,6-difluorobenzamide derivatives possessed much better on-target activity and antibacterial activity than the 3-O-arylalkylbenzamide derivatives. Among them, 3-O-chlorobenzyl derivative 36 was the most effective in antibacterial activity (0.5, 4, and 8 µg/mL) against Bacillus subtilis ATCC9372, methicillin-resistant Staphylococcus aureus ATCC29213, and penicillin-resistant Staphylococcus aureus PR, while 3-O-methylbenzyl derivative 41 only exhibited the most potent activity (2 µg/mL) against Staphylococcus aureus ATCC25923.

The Recent Development of Farnesyltransferase Inhibitors as Anticancer and Antimalarial Agents.

Cancer is a serious disease characterized by the uncontrolled growth division of cells, and nowadays it remains a significant challenge for the medical field. Malaria is an infectious disease in the similar situation to cancer. Almost 40% people in the world live in areas with malaria risk and each year there are about 2 to 3 million people dying from malaria. Farnesyltransferase (FTase) that belongs to isoprenyltransferase family can catalyze the initial step of Ras-processing and is identified as a promising target for the treatment of cancer and malaria. During the past decade years, a large number of FTase inhibitors with anticancer or antimalarial activity have been reported and some of them are undergoing clinical development. This review mainly introduces the FTase inhibitors as anticancer and antimalarial agents, with focus on their enzyme inhibitory activity, stability and enzyme selectivity, etc. In particular, the promising new FTase inhibitors among them will be discussed in detail and the inspirations for their design will be highlighted.