Distribution of Very-Long-Chain Fatty Acids between Molecular Species of Different Phospholipid Classes of Two Soft Corals

Abstract

Fatty acids (FAs) of soft corals contain two very-long-chain tetracosapolyenoic acids (TPA, 24:5n-6 and 24:6n-3), which are chemotaxonomic markers of all species of the subclass Octocorallia. The distribution of TPA in molecular species of different phospholipid (PL) classes was investigated for the first time in the soft corals Sinularia macropodia and Capnella sp. From shallow waters of Vietnam. Phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylinositol (PI) were the major PL classes of S. macropodia and Capnella sp. More than thirty two molecular species of these four PL classes were determined by high resolution tandem mass spectrometry.

Comparative lipidomic analysis of phospholipids of hydrocorals and corals from tropical and cold-water regions

“…The MS 2 spectra of the [M−H] − ions of diacyl PI molecules were also complex and contained at least six diagnostic peeks ([M−H−keten 2 ] − , [M−H−FA 2 ] − , [M−H−C 6 H 10 O 5 −FA 1 ] − , [M−H−C 6 H 10 O 5 −FA 2 ] − , [FA 1 −H] − , and [FA 2 −H] − (Fig 3D). The spectra and fragmentations of the major GLP classes were discussed in detail in our previous publications [46,48,49].…”

“…The proportions of hydrocoral GPL forms were compared with those of five soft coral species described earlier (the tropical species: Sinularia macropodia , Capnella sp., and Xenia sp. [46,48]; the cold-water species: Gersemia fruticosa and G . rubiformis [49,50]) (Fig 4).…”

“…A set of all lipid molecular species present in an organism is defined as lipidome, and the quantitative description of the lipidome is one of the main tasks of lipidomics. Lipidomic analyses started in the early 2000s and have recently been applied to mollusks [42,43], sea anemones [44], hard corals [45], soft corals and their SDs [46,47], but data on lipidomes of marine invertebrates still remain very limited. In addition to common analyses of lipids, the lipidomic approach opens up new opportunities for marine ecological studies [44].…”

“…In addition to common analyses of lipids, the lipidomic approach opens up new opportunities for marine ecological studies [44]. A comparison of lipid molecular species from the different taxonomic groups provides new knowledge of cnidarian lipid biochemistry [46]. Polar structural lipids, such as phosphono- and phospholipids, are a relatively conserved part of lipidome and are influenced by the environment and food sources to a much lesser extent than non-polar storage lipids [17].…”

“…To date, the polar lipidomes of three tropical soft corals ( Xenia sp., Capnella sp., and Sinularia macropodia ) and two cold-water soft coral ( Gersemia rubiformis , G . fruticosa ) [46,48–50], as well as the glycerophosphocholine molecular species profile of the tropical hard coral Seriatopora caliendrum [45], have been described. Information on lipids of hydrocorals is much less than on coral lipids.…”