Antiproliferative activity of synthetic fatty acid amides from renewable resources

AbstractIn 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

Effect of harvesting processes on the lipid yield and fatty acid profile of the marine microalga Nannochloropsis oculata

The effect of different methods of biomass concentration and salt removal on the lipid yield and fatty acid profile of the marine microalga Nannochloropsis oculata was evaluated. The microalgae were subjected to nine treatments: (1) centrifugation, (2) centrifugation + washing with H2O, (3) centrifugation + washing with ammonium formate, (4) flocculation with NaOH, (5) flocculation with NaOH + washing with H2O, (6) flocculation with NaOH + washing with ammonium formate, (7) flocculation with NaOH and neutralization with HCl, (8) flocculation with NaOH, neutralization with HCl + washing with H2O, and (9) flocculation with NaOH, neutralization with HCl + washing with ammonium formate. Flocculation with the addition of NaOH was effective at concentrating biomass (>90%) but interfered with lipid extraction because it exhibited a lower lipid yield (4.40 ± 0.1%) compared with centrifugation (45.4 ± 0.8%). Moreover, important polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA C20:5) and eicosatetraenoic acid (ETA C20:4), disappeared when NaOH was used. Centrifugation plus washing the biomass with ammonium formate was more effective than other treatments, leading to higher lipid yields, as well as larger amounts of the polyunsaturated fatty acids EPA and ETA. However, it is a very expensive harvesting method. Thus, the main finding of the present study is that microalgae concentration processes can affect lipid and fatty acid extraction in massive microalgae production; therefore, it is necessary to carefully choose the harvest process to be used in large-scale microalgae production

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

Sulfamic acid: An efficient acid catalyst for esterification of FFA

Esterification is one of the most fundamental reactions in organic chemistry. It has a great application in both laboratory work and industrial processes on account of its versatility. In this study sulfamic acid (H2NSO3H, SA) was used as an efficient catalyst for the synthesis of fatty acid methyl and ethyl esters (FAEEs and FAMEs) under different conditions (fatty acid type, molar ratio, temperature, and % catalyst). Esterification using methanol and ethanol resulted in a higher fatty acid alkyl ester yield. The best result was obtained with ethanol, which yielded 91.2–97.7% FAEEs. However, in the same conditions the FAMEs were obtained with lower yields. These results demonstrate that this green methodology has high potential for the synthesis of fatty acid alkyl ester

Production of FAMEs from several microalgal lipidic extracts and direct transesterification of the Chlorella pyrenoidosa

In this study different methods were applied for lipids extraction from the dry biomass of Chlorella pyrenoidosa. The survey was carried under different conditions seeking comparative assessment of extraction methods. The method using chloroform:methanol (2:1 v/v) showed the highest lipid extraction followed by methanol, chloroform, ethanol, and hexane. Afterward, we also assessed the relative influence of the solvent extractor selectivity on the overall FAMEs (Fatty Acids Methyl Esters) yield. The application of the transesterification process on the several lipidic extracts was compared with direct transesterification process from dry biomass. In the extraction using chloroform:methanol system a larger amount of lipids was obtained but the conversion to FAMEs using transesterification process was the lowest from lipids. However, despite the amount of extracted lipids with methanol being smaller, its conversion to FAMEs was higher from lipids. In addition, the extraction with methanol followed by transesterification process also resulted in a higher FAMEs yield from biomass than direct transesterification process using methanol