Synthesis of pyrazoline fatty chain derivatives and its effects on melanoma cells.

Skin cancer is the most common type of cancer in Brazil, representing 30% of all cases. Among these, melanoma represents only 3% of malignant neoplasms; however, it is the most serious and has a high capacity for metastasis. For this reason, it is extremely important to identify more efficient compounds and treatments that stop or decrease the proliferation of melanoma, even in its more advanced stages. This work reports the synthesis and biological evaluation of two homologous series of pyrazoline fatty chain derivatives as potent antitumoral agents in the melanoma B16F10 cell line. Cells were treated with pyrazoline fatty chain compounds (3, 30, 300, and 3000 µM) for 0, 24, 48, and 72 h. Decreased cell viability was observed when using most compounds at different concentrations and times. The structure-activity relationship (SAR) between antitumoral activity and the number of carbons and lipophilicity, as well as the oxygen-sulfur bioisosteric exchange, was evaluated. Among the tested derivatives, the lipophilic compounds 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-carboxamide (2d) and 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-thiocarboxamide (3d) showed the best results in the B16F10 cell line, as they produced the best cell viability decrease effects. The presence of fatty unbranched undecyl chain in the molecular structure appears to be important for its antimelanoma properties.

New Polymorph Form of Dexamethasone Acetate.

A new monohydrated polymorph of dexamethasone acetate was crystallized and its crystal structure characterized. The different analytical techniques used for describing its structural and vibrational properties were: single crystal and polycrystal X-ray diffraction, solid state nuclear magnetic resonance, infrared spectroscopy. A Hirshfeld surface analysis was carried out through self-arrangement cemented by H-bonds observed in this new polymorph. This new polymorph form appeared because of self-arrangement via classical hydrogen bonds around the water molecule.

Fatty-monastrol derivatives and its cytotoxic effect against melanoma cell growth.

Melanoma is the most dangerous type of skin cancer due to the occurrence of metastases. This work is aimed at studying the effects of the insertion of palmitic and oleic acid chain into monastrol in the melanoma cell line, B16F10. Cells were treated with monastrol, palmitic-monastrol or oleic-monastrol for periods of 0, 24, 48 and 72 h, and the cytotoxic effect was observed for palmitic-monastrol and oleic-monastrol after 24 h. For monastrol the effects were observed in 48 h on B16F10 cells, and in 24 h for a non-tumour cell line, melan-a. In this cell line, fatty-monastrol derivatives were cytotoxic after 24 h of exposure in the same concentrations as B16F10. However, oleic-monastrol inhibited cell growth at 20µM only after 72 h, in contrast to the B16F10 cell line, in which oleic-monastrol inhibited cell growth at 48 h, showing that at least in this structural modification, melan-a was less sensitive than B16F10. The ability of compounds to induce apoptosis and/or necrosis was measured, and it was observed that monastrol induces apoptosis within 24 h. However, the cells treated with fatty-monastrol derivatives did not remain adhered on the well plate after 3 h of treatment. At this time point, these cells still emitted fluorescence indicating viable cells, suggesting a possible effect of palmitic- and oleic-monastrol in the adhesion proteins found on the cell membrane.