Marcelo G. Montes D’Oca

Synthesis and antituberculosis activity of new fatty acid amides

This work reports the synthesis of new fatty acid amides from C16:0, 18:0, 18:1, 18:1 (OH), and 18:2 fatty acids families with cyclic and acyclic amines and demonstrate for the first time the activity of these compounds as antituberculosis agents against Mycobacterium tuberculosis H(37)Rv, M. tuberculosis rifampicin resistance (ATCC 35338), and M. tuberculosis isoniazid resistance (ATCC 35822). The fatty acid amides derivate from ricinoleic acid were the most potent one among a series of tested compounds, with a MIC 6.25 microg/mL for resistance strains.

Synthesis and antimycobacterial activity of isoniazid derivatives from renewable fatty acids.

This work describes the synthesis of a series of fatty acid hydrazide derivatives of isoniazid (INH). The compounds were tested against Mycobacterium tuberculosis H37Rv (ATCC 27294) as well as INH-resistant (ATCC 35822 and 1896 HF) and rifampicin-resistant (ATCC 35338) M. tuberculosis strains. The fatty acid derivatives of INH showed high antimycobacterial potency against the studied strains, which is desirable for a pharmaceutical compound, suggesting that the increased lipophilicity of isoniazid plays an important role in its antimycobacterial activity.

Investigation of major and trace element distribution in the extraction-transesterification process of fatty acid methyl esters from microalgae Chlorella sp.

This work reports, for the first time, the determination of major and trace elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Se, Sn, Sr, Ti, Tl, U, V, and Zn) in the fractions of the synthesis of fatty acid methyl esters (FAMEs). These include fresh microalgae, residual biomass, lipid fraction, crude FAMEs, insoluble fraction and purified FAMEs from microalgae Chlorella sp. A microwave-assisted digestion procedure in closed vessels was applied for sample digestion and subsequent element determination by inductively coupled plasma-based techniques. The proposed method was suitable for the multielement determination in FAMEs and its fractions obtained from microalgae. The element concentration was compared with results found in the literature and a careful discussion about the use of residual biomass for different applications was performed.

Antiproliferative activity of synthetic fatty acid amides from renewable resources

In the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line-the most aggressive CNS cancer.

Protective role of the novel hybrid 3,5-dipalmitoyl-nifedipine in a cardiomyoblast culture subjected to simulated ischemia/reperfusion

This work investigated the acute effects of the calcium channel blocker nifedipine and its new fatty hybrid derived from palmitic acid, 3,5-dipalmitoyl-nifedipine, compared to endocannabinoid anandamide during the process of inducing ischemia and reperfusion in cardiomyoblast H9c2 heart cells. The cardiomyoblasts were treated in 24 or 96-well plates (according to the test being performed) and maintaining the treatment until the end of hypoxia induction. The molecules were tested at concentrations of 10 and 100μM, cells were treated 24h after assembling the experimental plates and immediately before the I/R. Cell viability, apoptosis and necrosis, and generation of reactive oxygen species were evaluated. Nifedipine and 3,5-dipalmitoyl-nifedipine were used to assess radical scavenging potential and metal chelation. All tested molecules managed to reduce the levels of reactive oxygen species compared to the starvation+vehicle group. In in vitro assays, 3,5-dipalmitoyl-nifedipine showed more antioxidant activity than nifedipine. These results indicate the ability of this molecule to act as a powerful ROS scavenger. Cell viability was highest when cells were induced to I/R by both concentrations of anandamide and the higher concentration of DPN. These treatments also reduced cell death. Therefore, it was demonstrated that the process of hybridization of nifedipine with two palmitic acid chains assigns a greater cardioprotective effect to this molecule, thereby reducing the damage caused by hypoxia and reoxygenation in cardiomyoblast cultures.

N-Alkylated Sulfamic Acid Derivatives as Organocatalyst in Multicomponent Synthesis of Fatty Dihydropyrimidinones

In this work, N-alkylated sulfamic acid derivatives are introduced as promising acidic organocatalysts with convenient acidity and easy synthesis. The new organocatalysts derived from different nitrogenated compounds (amines, chitosan, urea and thiourea) were applied in multicomponent reactions to synthesize several dihydropyrimidinones (DHPMs). All tested organocatalysts resulted in good DHPM yields, using classic 1,3-dicarbonyl compounds and long-chain 1,3-dicarbonyl derivatives, demonstrating catalytic efficiency. N-Alkylated sulfamic acid derived from benzylamine showed good results (ca. 80% yields). In addition, excellent results were obtained with organocatalysts based on sulfamic acid and thiourea (ca. 80-97% yields), demonstrating the catalytic efficiency of new derivatives of thiourea organosulfamic catalysts.

Involvement of reactive oxygen species in the oleoylethanolamide effects and its pyrazonilic analogue in melanoma cells

The search for more substances that effectively fight melanoma is extremely important, because of its aggressive nature. In this sense, the molecular hybridization is a promising strategy. The aim of this work is to evaluate whether the antiproliferative effect of the endocannabinoid oleoylethanolamide can be improved with the addition of a trifluoromethylated pyrazolinic nucleus on its structure in B16F10 cell line. The pyrazolinic analog was named oleoyl pyrazoline. We also compared the effects of oleoylethanolamide and that of the classic endocannabinoid anandamide (AEA). The cell viability was evaluated by MTT assay, the intracellular reactive oxygen species generation by fluorimetry, and apoptosis/necrosis by fluorescent microscopy. Also, α-tocopherol antioxidant was used to evaluate the involvement of reactive oxygen species in the cellular response. Although the effects of AEA occur in smaller concentrations, the results show that the effects of AEA and oleoylethanolamide were similar. The results showed a decrease in cell viability, induction of apoptosis and necrosis, and increased generation of reactive oxygen species by the oleoylethanolamide, while the oleoyl pyrazoline increased cell proliferation and decreased reactive oxygen species. Additionally, the effects of oleoylethanolamide in cell viability were decreased by inhibiting the generation of reactive oxygen species by α-tocopherol. Therefore, it is possible to suggest the involvement of reactive oxygen species in the effect of oleoylethanolamide in the B16F10 cells. Considering the great need to find substances that can fight melanoma and the lack of greater elucidation in the action mechanisms of cannabinoids and their analogs, this work provides important new information that could serve as reference to other studies.

Toxocara canis: Larvicidal activity of fatty acid amides

Considering the therapeutic potential of fatty acid amides, the present study aimed to evaluate their in vitro activity against Toxocara canis larvae and their cytotoxicity for the first time. Linoleylpyrrolidilamide was the most potent, with a minimal larvicidal concentration (MLC) of 0.05 mg/mL and 27% cytotoxicity against murine peritoneal macrophages C57BL/6 mice, as assessed by the MTT assay.