Monocyclic ß-Lactam: A Review on Synthesis and Potential Biological Activities of a Multitarget Core.

A monocyclic ring in their structure characterizes monobactams, a subclass of ß-lactam antibiotics. Many of these compounds have a bactericidal mechanism of action and acts as penicillin and cephalosporins, interfering with bacterial cell wall biosynthesis. The synthesis of novel ß-lactams is an emerging area of organic synthesis research due to the problem of increasing bacterial resistance to existing ß -lactam antibiotics, and, in this way, new compounds have been presented with several structural modifications, aiming to improve biological activities. Among the biological activities studied, the most outstanding are antibacterial, antitubercular, anticholesterolemic, anticancer, antiinflammatory, antiviral, and anti-enzymatic, among others. This review explores the vast number of works related to monocyclic ß-lactams, compounds of great importance in scientific research.

Lopinavir, an HIV-1 peptidase inhibitor, induces alteration on the lipid metabolism of Leishmania amazonensis promastigotes.

The anti-leishmania effects of HIV peptidase inhibitors (PIs) have been widely reported; however, the biochemical target and mode of action are still a matter of controversy in Leishmania parasites. Considering the possibility that HIV-PIs induce lipid accumulation in Leishmania amazonensis, we analysed the effects of lopinavir on the lipid metabolism of L. amazonensis promastigotes. To this end, parasites were treated with lopinavir at different concentrations and analysed by fluorescence microscopy and spectrofluorimetry, using a fluorescent lipophilic marker. Then, the cellular ultrastructure of treated and control parasites was analysed by transmission electron microscopy (TEM), and the lipid composition was investigated by thin-layer chromatography (TLC). Finally, the sterol content was assayed by gas chromatography-mass spectrometry (GC/MS). TEM analysis revealed an increased number of lipid inclusions in lopinavir-treated cells, which was accompanied by an increase in the lipophilic content, in a dose-dependent manner. TLC and GC-MS analysis revealed a marked increase of cholesterol-esters and cholesterol. In conclusion, lopinavir-induced lipid accumulation and affected lipid composition in L. amazonensis in a concentration-response manner. These data contribute to a better understanding of the possible mechanisms of action of this HIV-PI in L. amazonensis promastigotes. The concerted action of lopinavir on this and other cellular processes, such as the direct inhibition of an aspartyl peptidase, may be responsible for the arrested development of the parasite.

Synthesis of platinum complexes from N-benzyl-2-aminoethanethiol derivatives.

Twelve new platinum(II) complexes, analogs of cisplatin, containing a 2-aminoethanethiol N-substituted by several benzyl groups have been prepared and characterized in good yields. The ligands were obtained by reaction between 2-aminoethanethiol hydrochloride and different benzyl halides