Brazilian red propolis has been proposed as a new source of compounds with cytotoxic activity. Red propolis is a resinous material of vegetal origin, synthesized from the bees of the Appis mellifera family, with recognized biological properties. To obtain actives of low polarity and high cytotoxic profile from red propolis, in this work, we proposed a new solvent accelerated extraction method. A complete 2³ factorial design was carried out to evaluate the influence of the independent variables or factors (e.g., temperature, number of cycles, and extraction time) on the dependent variable or response (i.e., yield of production). The extracts were analyzed by gas chromatography coupled with mass spectrometry for the identification of chemical compounds. Gas chromatography analysis revealed the presence of hydrocarbons, alcohols, ketones, ethers, and terpenes, such as lupeol, lupenone, and lupeol acetate, in most of the obtained extracts. To evaluate the cytotoxicity profile of the obtained bioactives, the 3-(4,5-dimethyl-2-thiazole)-2,5-diphenyl-2-H-tetrazolium bromide colorimetric assay was performed in different tumor cell lines (HCT116 and PC3). The results show that the extract obtained from 70 °C and one cycle of extraction of 10 min exhibited the highest cytotoxic activity against the tested cell lines. The highest yield, however, did not indicate the highest cytotoxic activity, but the optimal extraction conditions were indeed dependent on the temperature (i.e., 70 °C).

By the classical definition naphthenic acids (NAs) are a complex mixture of monocarboxylic acids containing one or more alkyl-substituted alicyclic rings or only aliphatic carbon chains. Based on the great interest of the oil industry in the elucidation and characterization of naphthenic acids in petrochemical samples, and the lack of efficient methodologies for the total characterization of these compounds, the goal of this study is to compare three techniques (GC/qMS, ESI-MS/MS and GC × GC/TOF-MS) for the analysis of two technical mixtures of NAs. The results presented here demonstrate the applicability of these techniques and the main advantages of each one. GC/qMS is widely used in the naphthenic acid analysis and still presents a good performance; however the ESI-MS-MS allowed a very quick analysis that provided a general profile of each sample, very useful in preliminary classification of petrochemical mixtures, while GC × GC/TOF-MS delivered a thorough evaluation of the different components of each sample. Technical mixtures analyzed showed different profiles confirmed through the three techniques applied. The mixture SA (Sigma Aldrich) presented a predominance of aliphatic acids (Z = 0) while the mixture MN (Miracema-Nuodex) was composed mainly of naphthenic monocyclic acids.