Gas chromatographic separation of fatty acid methyl esters on weakly polar capillary columns

Analysis of biodiesel-diesel blends: Does ultrafast gas chromatography provide for similar separation in a fraction of the time?

Ultrafast gas chromatography (UFGC) using a moderately polar column was compared to traditional gas chromatography (GC) for evaluation of biodiesel-diesel blended fuels. Several biodiesel feedstocks (soybean, tallow, canola, palm, camelina) and concentrations (1-20%) were evaluated, with specific attention to the separation of fatty acid methyl esters (FAMEs) from the biodiesel component. UFGC is compared to traditional GC using a similar column chemistry. Principal component analysis (PCA) is performed to identify clustering based on feedstock and concentration. UFGC proves an effective and fast technique, comparable to traditional GC, for the analysis of biodiesel-diesel blended fuels.

Advanced Lipid Technologies® (ALT®): A Proven Formulation Platform to Enhance the Bioavailability of Lipophilic Compounds

Despite recent advances, the drug development process continues to face significant challenges to efficiently improve the poor solubility of active pharmaceutical ingredients (API) in aqueous media or to improve the bioavailability of lipid-based formulations. The inherent high intra- and interindividual variability of absorption of oral lipophilic drug leads to inconsistent and unpredictable bioavailability and magnitude of the therapeutic effect. For this reason, the development of lipid-based drugs remains a challenging endeavour with a high risk of failure. Therefore, effective strategies to assure a predictable, consistent, and reproducible bioavailability and therapeutic effect for lipid-based medications are needed. Different solutions to address this problem have been broadly studied, including the approaches of particle size reduction, prodrugs, salt forms, cocrystals, solid amorphous forms, cyclodextrin clathrates, and lipid-based drug delivery systems such as self-emulsifying systems and liposomes. Here, we provide a brief description of the current strategies commonly employed to increase the bioavailability of lipophilic drugs and present Advanced Lipid Technologies® (ALT®), a combination of different surfactants that has been demonstrated to improve the absorption of omega-3 fatty acids under various physiological and pathological states.

New biobased tetrabutylphosphonium ionic liquids: synthesis, characterization and use as a solvent or co-solvent for mild and greener Pd-catalyzed hydrogenation processes

Phosphonium-based ionic liquids with natural organic derived anions were easily prepared and showed good performance and recyclability in Pd-catalyzed hydrogenation processes at room temperature under atmospheric H₂ pressure.

Comparison of GC stationary phases for the separation of fatty acid methyl esters in biodiesel fuels

The fatty acid methyl ester (FAME) content of biodiesel fuels has traditionally been determined using gas chromatography with a polar stationary phase. In this study, a direct comparison of the separation of FAMEs present in various biodiesel samples on three polar stationary phases and one moderately polar stationary phase (with comparable column dimensions) was performed. Retention on each column was based on solubility in and polarity of the phase. Quantitative metrics describing the resolution of important FAME pairs indicate high resolution on all polar columns, yet the best resolution, particularly of geometric isomers, is achieved on the cyanopropyl column. In addition, the separation of four C18 monounsaturated isomers was optimized and the elution order determined on each column. FAME composition of various biodiesel fuel types was determined on each column to illustrate (1) chemical differences in biodiesels produced from different feedstocks and (2) chemical similarities in biodiesels of the same feedstock type produced in different locations and harvest seasons.

Isolation of alpha-glucosidase inhibitors produced by an endophytic fungus, Colletotrichum sp. TSC13 from Taxus sumatrana

Colletotrichum sp. have potential to act as antidiabetic agent, due to its alpha-glucosidase inhibitory. Therefore, the objective of present study was to isolate and identify the bioactive compounds responsible for the alpha-glucosidase inhibitory activity in Colletotrichum sp. TSC13. The methanol extract of TSC13 mycelia, was partitioned with n-hexane, chloroform and ethyl acetate. The n-hexane fraction exhibited the strongest alpha-glucosidase inhibitory activity. Column chromatography of this fraction resulted in 8 sub-fractions (F1-8). Fraction 3 (F3) which showed 71.4 +/- 2.4% inhibition was analysed further. Analysis using GC-MS after methylation of F3 and comparison to spectra databases and confirmation using authentic sample standards showed that F3 had two saturated fatty acid methyl esters, palmitic acid and stearic acid methyl esters and three unsaturated fatty acid methyl esters, oleic acid, linoleic acid and linoleinic acid methyl esters. Unsaturated fatty acids showed higher activity than the saturated fatty acids and the methyl esters form of unsaturated fatty acids showed slightly less active than the free acids. Further analysis using an ethyl acetate extract, it was confirmed that most of the fatty acids were present in the form of free acids. Therefore, it was concluded that the alpha-glucosidase inhibitor compounds in Colletotrichum sp. TSC13 were unsaturated fatty acids. This is the first report that a Colletotrichum sp. from T. sumatrana has alpha-glucosidase inhibitory activity.

Recent trends in the advanced analysis of bioactive fatty acids

The consumption of dietary fats have been long associated to chronic diseases such as obesity, diabetes, cancer, arthritis, asthma, and cardiovascular disease; although some controversy still exists in the role of dietary fats in human health, certain fats have demonstrated their positive effect in the modulation of abnormal fatty acid and eicosanoid metabolism, both of them associated to chronic diseases. Among the different fats, some fatty acids can be used as functional ingredients such as alpha-linolenic acid (ALA), arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), gamma-linolenic acid (GLA), stearidonic acid (STA) and conjugated linoleic acid (CLA), among others. The present review is focused on recent developments in FAs analysis, covering sample preparation methods such as extraction, fractionation and derivatization as well as new advances in chromatographic methods such as GC and HPLC. Special attention is paid to trans fatty acids due its increasing interest for the food industry.