Lately, high-throughput lipid profiling has contributed to understand the biological, physiological and pathological roles of lipids in living organisms. the International Corticotropin-releasing factor (CRF) Lipid Classification and Nomenclature Committee (ILCNC) on the initiative of the Lipid Metabolites and Pathways Strategy (LIPID MAPS) consortium defined lipids as hydrophobic or amphipathic small molecules that originate entirely or in part by carbanion-based Corticotropin-releasing factor (CRF) condensations of thioesters and/or by carbocation-based condensations Corticotropin-releasing factor (CRF) of isoprene units [1,2,3]. Current lipid classification involves eight categories based on chemical functionalities as: (1) glycerolipids (GL), (2) sphingolipids (SP), (3) glycerophospholipids (GP), (4) sterol lipids (ST), (5) fatty acyls (FA), (6) prenol lipids (PR), (7) polyketides (PK), and (8) saccharolipids (SL), where the last two categories are not synthesized by mammals and represent a small proportion of the known lipidome [1,2,3]. Table 1 presents the number of lipid structures per category according to Lipid Maps? Structure Corticotropin-releasing factor (CRF) Database (LMSD) and Figure 1 shows representative structures for each category. Open in a separate window Figure 1 LIPID MAPS categories and representative structures with calculated octanol/water partition coefficient (log P) using ChemAxon. Reported log P of solvents used in lipidomics are indicated below DNM1 [30]. Color code represents relative polarity, non-polar (blue), and polar (red). Example of classes corresponds to Glycerolipids, DG(16:0/16:0/0:0)L02010001; Sphingolipids, SP(16:0/16:0)LMGP01010564; Glicerophospholipids, PC(16:0/16:0)LMGP01010564; Sterol lipids, CholesterolLMST01010001; Fatty acyls, C16:0LMFA01010001; Prenol lipids, 2E,6E-farnesolLMPR0103010001; Polyketides, PinosylvinLMPK13090001; Saccharolipids, 2,3-di-0-hexanoyl–glucopyranoseLMSL05000001. Table 1 Number of lipids structures per representative lipid category. thead th rowspan=”2″ align=”center” valign=”middle” style=”border-top:solid slim;border-bottom:solid slim” colspan=”1″ Lipid Category /th th rowspan=”2″ align=”middle” valign=”middle” design=”border-top:solid slim;border-bottom:solid slim” colspan=”1″ Primary Subclasses /th th rowspan=”2″ align=”middle” valign=”middle” style=”border-top:solid slim;border-bottom:solid Corticotropin-releasing factor (CRF) slim” colspan=”1″ Log P Range a /th th colspan=”3″ align=”middle” valign=”middle” style=”border-top:solid slim;border-bottom:solid slim” rowspan=”1″ LIPID Maps b /th th align=”middle” valign=”middle” design=”border-bottom:solid slim” rowspan=”1″ colspan=”1″ Curated /th th align=”middle” valign=”middle” design=”border-bottom:solid slim” rowspan=”1″ colspan=”1″ Computationally-Generated /th th align=”middle” valign=”middle” design=”border-bottom:solid slim” rowspan=”1″ colspan=”1″ All /th /thead Fatty Acyls [FA]Fatty Acids and Conjugates, Eicosanoids, Docosanoids, Fatty esters, Fatty amides, Fatty nitriles, Fatty ethers, Fatty acyl glycosides, Acylcarnitines.?5C15764417929436Glycerolipids [GL]Monoradylglycerols, Diradylglycerols, Triradylglycerols, Glycosylmonoradylglycerols, Glycosyldiradylglycerols.5C3523273797611Glycerophospholipids [GP]Glycerophosphocholines, Glycerophosphoethanolamines, Glycerophosphoserines, Glycerophosphoglycerols, Glycerophosphoglycerophosphates, Glycerophosphoinositols, Oxidized glycerophospholipids, Cardiolipins.5C25160783129919Sphingolipids [SP]Sphingoid bases, Ceramides, Phosphosphingolipids, Natural glycosphingolipids, Acidic glycosphingolipids, Fundamental glycosphingolipids.5C25141031764586Sterol lipids [ST]Sterols, Steroids, Secosteroids, Bile derivatives and acids, Steroid conjugates.0C202829 2829Prenol lipids [PR]Isoprenoids, Hydroquinones and Quinones, Polyprenols.0C201352 1352Sacccharolipids [SL]Acylaminosugars, Acylaminosugar glycans, Acyltrehaloses.0C302212941316Polyketides [PK]Linear polyketides, Lactone and Macrolides polyketides, Linear tetracyclines, Polyether antibiotics, Aflatoxins, Flavonoids, Aromatic polyketides.0C156810 6810TOTAL21,90621,95343,859 Open up in another window a Octanol/water partition coefficient (log P) determined using ChemAxon. b Data extracted from Lipid Maps? Framework Data source (LMSD) in the 05/02/2020 upgrade. Once considered simple membranes energy and constituents storage space reservoirs, nowadays lipids will also be identified for playing important roles in varied biological actions at mobile and systemic amounts including: cell signaling, transportation, protein trafficking, development, differentiation, and apoptosis [3,4]. To perform these many functions, cells create lipids having a huge structural complexity, plus a differentiated compartmentalization, area, interaction and organization [5]. Consequently, a specific group of lipidsknown as lipidomecharacterize each cell, cells, and biological program [4]. Lipidomes are often are complex mixtures of lipids, with diverse chemical structures that represent the different biological microenvironments where lipids normally play their function in vivo. Therefore, lipidomes are highly susceptible to changes in response to physiological, pathological, and environmental conditions and can indicate an organism status in a particular moment [6]. In fact, abnormalities in the metabolism of lipids have been linked to several human pathologies (e.g., Alzheimers disease [7], cancer [8], diabetes [9]), stress response in plants [10] and antibiotic resistance in infectious bacteria [11,12]. For this reason, the study of lipids has represented a valuable tool to elucidate mechanistic insights into all kingdoms of life. The main analytical platforms for lipid analyses include mass spectrometry (MS) and nuclear magnetic resonance (NMR), where MS-based techniques have been widely used due to their high sensitivity (pM concentrations), availability and speediness in accurate identification, quantification and monitoring of basal lipid profiles in complex biological mixtures [13]. Test planning for MS-lipidomics contains solventCprotein precipitation, lipid removal, and solvent evaporation. Step one of proteins precipitation aims to remove matrix parts that could hinder the accuracy and accuracy from the mass evaluation, such as for example salts and proteins. The subsequent stage of lipid removal takes benefit of the hydrophobic properties of lipids to split up them in a nonpolar solvent program with or without mechanised assistance (e.g., vortex, microwave, ultrasound). Finally, solvent evaporation enables lipid enrichment and resuspension inside a compatible solvent.