National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation.
Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
PLoS One. 2019 Apr 29;14(4):e0215759. doi: 10.1371/journal.pone.0215759. eCollection 2019.
To expand our knowledge of lipid and fatty acid (FA) biosynthesis in marine cnidarians, polar lipidomes of hydrocorals were studied for the first time and then compared with those of soft corals from tropical and boreal regions. The structure and content of FAs and molecular species of ethanolamine, choline, serine, and inositol glycerophospholipids (PE, PC, PS, and PI, respectively), and ceramide aminoethylphosphonate (CAEP) in tropical hydrocorals (Millepora platyphylla, M. dichotoma) and the cold-water hydrocoral Allopora steinegeri were determined by chromatography and mass spectrometry. All soft corals and cold-water hydrocorals are characterized by a considerable amount of C20 polyunsaturated FAs (PUFAs) elongated into C22 PUFAs. In the Millepora species, the high level of 22:5n-6 and 22:6n-3 against the background of the extremely low level of C20 PUFAs may be explained by a high activity of rare Δ4 desaturase. In contrast to hydrocorals, soft corals are able to elongate and further desaturate C22 PUFAs into C24 PUFAs. Allopora and soft corals use C20 PUFAs mainly for the synthesis of PE and PC. The molecular species of PS of soft corals concentrate C24 PUFAs, while in Allopora and Millepora the PS molecules are mainly based on 22:4n-6 and 22:5n-6 acyl groups, respectively. Short acyl groups (C14) dominate the CAEP molecules of Allopora. In all the animals compared, most molecular species of PE and PC are ether lipids, but diacyl molecular species dominate PI. Hydrocorals and tropical soft corals contain diacyl and ether PS molecules, respectively, whereas cold-water soft corals contain a mixture of these PS forms. The high similarity of the alkyl/acyl compositions indicates a possible biosynthetic relationship between PS and PI in hydrocorals. The data obtained in our study will provide a resource to further investigate the lipid metabolism in marine invertebrates.
为了拓展我们对海洋刺胞动物类脂和脂肪酸（FA）生物合成的认识，我们首次研究了水螅珊瑚的极性脂类，并与热带和寒带地区的软珊瑚进行了比较。通过色谱和质谱法，确定了热带水螅珊瑚（Millepora platyphylla、M. dichotoma）和冷水水螅珊瑚 Allopora steinegeri 中乙醇胺、胆碱、丝氨酸和肌醇甘油磷脂（PE、PC、PS 和 PI 分别）以及神经酰胺氨基乙基磷酸酯（CAEP）的 FA 结构和含量，以及分子种类。所有的软珊瑚和冷水水螅珊瑚的特点是含有大量的 C20 多不饱和脂肪酸（PUFA）延伸成 C22 PUFAs。在 Millepora 物种中，22:5n-6 和 22:6n-3 的高水平与 C20 PUFAs 的极低水平相对应，这可能是由于罕见的 Δ4 去饱和酶活性高所致。与水螅珊瑚不同的是，软珊瑚能够将 C22 PUFAs 延伸并进一步去饱和成 C24 PUFAs。Allopora 和软珊瑚主要使用 C20 PUFAs 合成 PE 和 PC。软珊瑚 PS 的分子种类集中了 C24 PUFAs，而在 Allopora 和 Millepora 中，PS 分子主要基于 22:4n-6 和 22:5n-6 酰基。短酰基（C14）主导 Allopora 的 CAEP 分子。在所比较的所有动物中，大多数 PE 和 PC 的分子种类都是醚脂，但二酰基分子种类占主导地位的是 PI。水螅珊瑚和热带软珊瑚分别含有二酰基和醚 PS 分子，而冷水软珊瑚则含有这些 PS 形式的混合物。烷基/酰基组成的高度相似性表明，水螅珊瑚中 PS 和 PI 之间可能存在生物合成关系。本研究获得的数据将为进一步研究海洋无脊椎动物的脂类代谢提供资源。
