Suitable simple and fast methods for selective isolation of phospholipids as a tool for their analysis

Abstract

Lipids are gaining relevance over the last 20 years, as our knowledge about their role has changed from merely energy/structural molecules to compounds also involved in several biological processes. This led to the creation in 2003 of a new emerging research field: lipidomics. In particular the phospholipids have pharmacological/food applications, participate in cell signalling/homeostatic pathways while their analysis faces some challenges. Their fractionation/purification is, in fact, especially difficult, as they are amphiphilic compounds. Moreover, it usually involves SPE or TLC procedures requiring specific materials hampering their suitableness for routine analysis. Finally, they can interfere with the ionization of other molecules during mass spectrometry analysis. Thus, simple high-throughput reliable methods to selectively isolate these compounds based on the difference between chemical characteristics of lipids would represent valuable tools for their study besides that of other compounds. The current review work aims to describe the state-of-the-art related to the extraction of phospholipids using liquid-liquid methods for their targeted isolation. The technological and biological importance of these compounds and ion suppression phenomena are also reviewed. Methods by precipitation with acetone or isolation using methanol seem to be suitable for selective isolation of phospholipids in both biological and food samples.

Peanut Oil Body Composition and Stability

“…The polar regions of phospholipid molecules are oriented toward the water phase, while nonpolar parts form a hydrophobic phase separating two aqueous regions. The polar head group imparts a phospholipid with a strong ionic character, while the long alkyl chain makes it extremely hydrophobic (Pimentel et al., ).…”

Symposium review: The relevance of bovine milk phospholipids in human nutrition—Evidence of the effect on infant gut and brain development

“…The concentration and composition (polar head and fatty acid tail) of glycerophospholipids and sphingolipids in bovine raw milk are greatly affected by different factors, including breed of the cow, stage of lactation, season of the year, nutrition and diet, and processing and treatment. Interestingly, the analytical methods of extraction and analysis add variation in determining the content of the polar lipid fraction (Bitman and Wood, 1990;Avalli and Contarini, 2005;Rombaut and Dewettnick, 2006;Graves et al, 2007;Rombaut et al, 2007;Lopez et al, 2008;Contarini and Povolo, 2013;Pimentel et al, 2018). Overall, the concentration of the polar lipid fraction ranges between 9 and 40 mg/100 g of raw milk (Table 1).…”

Bioactive Sugarcane Lipids in a Circular Economy Context

“…Other extraction techniques using isopropanol, acetone, ethanol, methanol and acetonitrile have been identified for their lipophilic selectivity depending on the solvent proportions, applied extraction temperatures and sample preparation [ 61 , 62 ].…”

“…For reliable lipid analysis, previous fractionation steps are commonly required in order to focus on specific molecules or to avoid ionic suppression. Thus, thin-layer chromatography (TLC) and solid-phase extraction (SPE) are widely used; however, they are considered time- and sample-consuming, involving specific materials [ 62 ]. Regarding chromatography techniques, a variety of column-packing materials, eluents and detectors have been used for lipid class separation and further analysis by high-performance liquid chromatography (HPLC) and/or gas chromatography (GC) [ 45 ].…”

“…The complex mixture of different compounds in the lipid extracts, as well as their interactions with the containing matrix, have to be specifically adapted to the studied material [ 61 , 62 , 110 , 111 ].…”