First-time Isolation of Flavonoids and Cytotoxic Potential of the Amazonian Shrub Ptychopetalum olacoides Benth

In the present study, three flavonoids, 3-O-methylquercetin (1), 3,4'-O-dimethylquercetin (2) and 3,7-O-dimethylquercetin (3) were isolated and characterized for the first time from a methanol extract obtained from the species Ptychopetalum olacoides. The structures of compounds were identified by spectroscopic methods (1D-, 2D-NMR, MS and UV) and confirmed by comparison with the respective literature data. The cytotoxic effect of crude extract was evaluated in vitro against three human cancer cell lines. The results showed a mild cytotoxic activity (IC50 = 45.16 mu g/mL) against breast cancer (MCF-7). However, crude extract did not exhibit any cytotoxic effect against normal cell human fibroblast (MRC-5).FAPERJCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Fluminense, Inst Quim, Dept Quim Organ, Campus Valonguinho, BR-24020141 Niteroi, RJ, BrazilUniv Fed Para, Inst Ciencias Biol, BR-66075110 Belem, Para, BrazilUniv Fed Sao Paulo, Dept Ciencias Mar, BR-11070100 Santos, SP, BrazilUniv Fed Rural Rio de Janeiro, Dept Quim, BR-23897000 Seropedica, RJ, BrazilUniv Fed Sao Paulo, Dept Ciencias Mar, BR-11070100 Santos, SP, BrazilWeb of Scienc

Fármacos no combate à tuberculose: passado, presente e futuro

Approximately every minute, somewhere in the world four people die from tuberculosis (TB), an infection of Mycobacterium tuberculosis with about 3 million deaths per year. In spite of these problems, unfortunaly, it is about 40 years that a novel drug was last introduced on the market. Due to the rapid spread of multi-drug resistant TB strains, resistant against all major anti-tuberculosis drugs, and the recent resurgence of the incidence of tuberculosis in association with the human immunodeficiency virus (HIV) infection and AIDS, we need urgently the development of new drugs to fight tuberculosis. This is covered in the present article

Synthesis and Biological Evaluation of Novel 6-Hydroxy-benzo[d][1,3]oxathiol-2-one Schiff Bases as Potential Anticancer Agents

With the aim of discovering new anticancer agents, we have designed and synthesized novel 6-hydroxy-benzo[d][1,3]oxathiol-2-one Schiff bases. The synthesis started with the selective nitration at 5-position of 6-hydroxybenzo[d][1,3]oxathiol-2-one (1) leading to the nitro derivative 2. The nitro group of 2 was reduced to give the amino intermediate 3. Schiff bases 4a–r were obtained from coupling reactions between 3 and various benzaldehydes and heteroaromatic aldehydes. All the new compounds were fully identified and characterized by NMR (1H and 13C) and specifically for 4q by X-ray crystallography. The in vitro cytotoxicity of the compounds was evaluated against cancer cell lines (ACP-03, SKMEL-19 and HCT-116) by using MTT assay. Schiff bases 4b and 4o exhibited promising cytotoxicity against ACP-03 and SKMEL-19, respectively, with IC50 values lower than 5 μM. This class of compounds can be considered as a good starting point for the development of new lead molecules in the fight against cancer