Synthesis of Alkyl-Glycerolipids Standards for Gas Chromatography Analysis: Application for Chimera and Shark Liver Oils

Abstract

Natural O-alkyl-glycerolipids, also known as alkyl-ether-lipids (AEL), feature a long fatty alkyl chain linked to the glycerol unit by an ether bond. AEL are ubiquitously found in different tissues but, are abundant in shark liver oil, breast milk, red blood cells, blood plasma, and bone marrow. Only a few AEL are commercially available, while many others with saturated or mono-unsaturated alkyl chains of variable length are not available. These compounds are, however, necessary as standards for analytical methods. Here, we investigated different reported procedures and we adapted some of them to prepare a series of 1-O-alkyl-glycerols featuring mainly saturated alkyl chains of various lengths (14:0, 16:0, 17:0, 19:0, 20:0, 22:0) and two monounsaturated chains (16:1, 18:1). All of these standards were fully characterized by NMR and GC-MS. Finally, we used these standards to identify the AEL subtypes in shark and chimera liver oils. The distribution of the identified AEL were: 14:0 (20–24%), 16:0 (42–54%) and 18:1 (6–16%) and, to a lesser extent, (0.2–2%) for each of the following: 16:1, 17:0, 18:0, and 20:0. These standards open the possibilities to identify AEL subtypes in tumours and compare their composition to those of non-tumour tissues.

The Impact of Short-Term Shark Liver Oil Supplementation on the Fatty Acid Composition of Erythrocyte Membranes

“…Research on SLO attributes its multiple health benefits to the high content of AKGs, squalene, lipid-soluble vitamins and PUFAs. AKGs are ether-linked glycerols containing such substances as batyl alcohol (AKG18/0), chimyl alcohol (AKG16/0) and selachyl alcohol (AKG18/1) [11,12]. AKGs are considered to be important immune-stimulating factors, able to increase the number of leucocytes, lymphocytes and platelets [10].…”

Gas-Phase Catalytic Dehydration of Glycerol with Methanol to Methyl Glyceryl Ethers over Phosphotungstic Acid Supported on Alumina

“…MAGE can be applied in immunostimulatory, antimicrobial, and antitumor applications and anesthesia due to its special biological characteristics . Moreover, it can be used as additives in drugs, , cosmetics, liquid detergents, herbicides, lubricants, and solvents . DAGE and TAGE can be used as fuel additives for diesel, biodiesel, and ethanol gasoline, which can effectively improve fuel quality and reduce pollutant emissions of respirable particles, hydrocarbons, carbon monoxide, and unregulated aldehydes. − …”

Enzymatic Synthesis of Ether Lipids Rich in Docosahexaenoic Acid with Squalene as Reaction Medium

“…1‐ O ‐alkylglycerols (AKG) are ether‐linked glycerols of few species varying by length and unsaturation of the alkyl chains. AKG are found abundant in liver and flesh oils of shark or dogfish, which can also be chemically synthesized (Pinault et al, ). Diacylglycerol ethers (DAGE) or 1‐ O ‐alkyl‐2,3‐diacyl‐sn‐glycerols are the major constituents available in the liver oils of various species of shark and dogfish (Bakes and Nichols, ; Bordier et al, ; Deprez et al, ).…”