E classes are dominant in brown macroalgae (11.3 ?9.3 of total PLs). Phosphatidic acid (PA) and phosphatidylinositol (PI) are also found in high amounts, whereas PS’s are present as a minor PL class [61?3]. Moreover, Vaskovsky [63] and Khotimchenko [64] also detected inositol phosphorylceramide (IPC) in red macroalgae. Both authors isolated IPC from Gracilaria verrucosa [65], the FA composition in its acyl chains being: myristic (9.8 ), palmitic (51.7 ), stearic (23.2 ), oleic (9.8 ) and palmitoleic acids. PLs, in contrast to GLs, contain high Necrosulfonamide price amounts of n-6 PUFA, except PGs, which contain -linolenic acid. The major FAs in PLs are palmitic (16:0), STA (18:0), oleic (18:1), AA (20:4) and EPA (20:5). More recently, Melo et al. [37] also detected IPC in the red macroalgae Chondrus crispus, particularly fifteen molecular species of IPC with most abundant molecular species being d18:0/26:0. Due to the dual hydrophilic and hydrophobic properties of PLs, they are mainly known for their role as building blocks for cell membranes in most organisms. In addition to their role in cellular structure and functions, they are also important for lipoproteins, which transport lipids to tissues via the blood stream. Additionally, certain PLs metabolites serve as important molecules within several signalling systems. During the last several years, more attention has been given to the beneficial health effects of PLs in animals in general and humans in particular [66]. Besides the benefit of the n-3 PUFAs of PLs, namely PC, they also alleviate senescence and are beneficial for cognitive functions, counter inflammatory diseases and can increase sports performance, among other beneficial properties [67]. PLs from marine macrophytes display the capacity to inhibit Hep; PLs containing n-3 PUFAs have more potent effects on liver and blood plasma lipid levels, compared to PLs without n-3 PUFAs that have been shown to increase the levels of HDL [67]. The antitumor and antiviral activities of PLs may be related to PUFAs and phosphate groups. However, the activity associated with PLs, as well as related metabolic pathways, are still not well understood. In spite of the important roles of PLs, the full identification of their profile and their Doravirine side effects variation with external conditions are still far from being fully known. The development of modern analytical methods combining various chromatographic techniques with sensitive detection systems and MS, as well as new derivatization procedures, has led to significant progress in the deep identification of lipid profiles, as well as on the identification of new and unusual classes of lipids and FA in marine macrophytes in recent years. This knowledge is crucial to exploring the bioactive properties of polar lipids. 3.4. Betaine Lipids Betaine lipids are a class of acylglycerolipids that have a quarternary amine alcohol ether-linked to a diacylglycerol moiety and lack phosphorous. They are zwitterionic at neutral pH due to their positively charged trimethylammonium group and negatively charged in carboxyl group. They can be found in lower plants and algae. Currently, three types of betaine are known to occur in macroalgae: diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) and its structural isomer diacylglycerylhydroxymethyl-N,N,N-trimetyl -alanine (DGTA) and diacylglycerylcarboxyhydroxymethylcholine (DGCC) (Figure 5). It has been suggested that green macroalgae contain relatively higher amounts of betaine lipid DGTS (5.2 ?6.5 o.E classes are dominant in brown macroalgae (11.3 ?9.3 of total PLs). Phosphatidic acid (PA) and phosphatidylinositol (PI) are also found in high amounts, whereas PS’s are present as a minor PL class [61?3]. Moreover, Vaskovsky [63] and Khotimchenko [64] also detected inositol phosphorylceramide (IPC) in red macroalgae. Both authors isolated IPC from Gracilaria verrucosa [65], the FA composition in its acyl chains being: myristic (9.8 ), palmitic (51.7 ), stearic (23.2 ), oleic (9.8 ) and palmitoleic acids. PLs, in contrast to GLs, contain high amounts of n-6 PUFA, except PGs, which contain -linolenic acid. The major FAs in PLs are palmitic (16:0), STA (18:0), oleic (18:1), AA (20:4) and EPA (20:5). More recently, Melo et al. [37] also detected IPC in the red macroalgae Chondrus crispus, particularly fifteen molecular species of IPC with most abundant molecular species being d18:0/26:0. Due to the dual hydrophilic and hydrophobic properties of PLs, they are mainly known for their role as building blocks for cell membranes in most organisms. In addition to their role in cellular structure and functions, they are also important for lipoproteins, which transport lipids to tissues via the blood stream. Additionally, certain PLs metabolites serve as important molecules within several signalling systems. During the last several years, more attention has been given to the beneficial health effects of PLs in animals in general and humans in particular [66]. Besides the benefit of the n-3 PUFAs of PLs, namely PC, they also alleviate senescence and are beneficial for cognitive functions, counter inflammatory diseases and can increase sports performance, among other beneficial properties [67]. PLs from marine macrophytes display the capacity to inhibit Hep; PLs containing n-3 PUFAs have more potent effects on liver and blood plasma lipid levels, compared to PLs without n-3 PUFAs that have been shown to increase the levels of HDL [67]. The antitumor and antiviral activities of PLs may be related to PUFAs and phosphate groups. However, the activity associated with PLs, as well as related metabolic pathways, are still not well understood. In spite of the important roles of PLs, the full identification of their profile and their variation with external conditions are still far from being fully known. The development of modern analytical methods combining various chromatographic techniques with sensitive detection systems and MS, as well as new derivatization procedures, has led to significant progress in the deep identification of lipid profiles, as well as on the identification of new and unusual classes of lipids and FA in marine macrophytes in recent years. This knowledge is crucial to exploring the bioactive properties of polar lipids. 3.4. Betaine Lipids Betaine lipids are a class of acylglycerolipids that have a quarternary amine alcohol ether-linked to a diacylglycerol moiety and lack phosphorous. They are zwitterionic at neutral pH due to their positively charged trimethylammonium group and negatively charged in carboxyl group. They can be found in lower plants and algae. Currently, three types of betaine are known to occur in macroalgae: diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) and its structural isomer diacylglycerylhydroxymethyl-N,N,N-trimetyl -alanine (DGTA) and diacylglycerylcarboxyhydroxymethylcholine (DGCC) (Figure 5). It has been suggested that green macroalgae contain relatively higher amounts of betaine lipid DGTS (5.2 ?6.5 o.