Hydrocarbon chain distribution of ether phospholipids of the ascidianHalocynthia roretzi and the sea urchinStrongylocentrotus intermedius

Abstract

The contents and compositions of the 1-O-alk-1'-enyl-2-acyl, 1-O-alkyl-2-acyl, and 1,2-diacyl glycerophospholipids in the muscle and viscera of the ascidian Halocynthia roretzi, and of the gonad of the sea urchin Strongylocentrotus intermedius, which are eaten to some extent in Alaska and in Asia, were analyzed by gas-liquid chromatography. 1-O-Alk-1'-enyl-2-acyl glycerophospholipids were found in all of the samples, accounting for 64.4-69.0% of the ethanolamine glycerophospholipid (EPL). By contrast, the levels of the 1-O-Alk-1'-enyl-2-acyl choline glycerophospholipids (CPL) were low (3.1-5.7%). CPL was rich in the 1-O-alkyl-2-acyl subclass amounting to 12.5-23.9% in the ascidian sample. The level of CPL in the sea urchin gonad was extremely high, amounting to 46.1%. The most prominent alkyl chains in the sn-1 position of CPL from the ascidian muscle were 16:0 (44.6%), 18:1 (26.5%), and 18:0 (10.7%), and of CPL from the sea urchin gonad were 18:0 (36.2%), 16:0 (33.0%), and 18:1 (17.8%). Unusually high levels of odd-numbered alkyl chains, e.g., 19:0 and anteiso 17:0, were detected in the CPL of all samples. The prominent alkenyl chains of EPL were 18:0 (69.4%), 16:0 (10.0%), and 18:1 (8.54%) (not counting the vinyl double bond) for the sea urchin gonad. Relatively high levels of 20:1 alkenyl chains were also present. The glycerol sn-2 positions contained high proportions of polyunsaturated fatty acids. Thus, 20:5n-3 (43.6%) and 22:6n-3 (20.1%) were most abundant in the alkylacyl CPL from the ascidian muscle and 20:5n-3 (54.9%) and 20:4n-6 (30.1%) in alkylacyl CPL from the sea urchin gonad. Despite a possible interconversion of the alkyl and alkenyl chains of each class of the ether phospholipids, they showed few features in common.

Preparation of Marine Plasmalogen and Selective Identification of Molecular Species by LC-MS/MS

“…5 . The plasmalogen level 61.8 of PE of the ascidian viscera analyzed in the present study was about the same as that reported previously, where plasmalogen accounted for 64.4 of PE 8 .…”

Phospholipid Distribution and Phospholipid Fatty Acids of the Tropical Tunicates Eudistoma sp. and Leptoclinides uniorbis

“…Several gelatinous zooplanktonic species also had high PL contents between 40 and 98%, while the non-gelatinous benthic Distaplia cylindrinca had 75% of PL [33]. The muscle and viscera of H. roretzi contained 39.9 and 28.0% of polar lipids respectively, mainly PL [27]. In this report, the most abundant PL was PC at around 49% followed by PE and SPH.…”

“…The lipid content of the edible parts of H. roretzi was studied monthly and found to be between 0.78 and 2.67% [16]. Other results were obtained using a similar extraction procedure for ascidians such as H. roretzi (0.3% of lipids [27]), A. savignyi (0.6% of lipids [19]), Styela sp. (1.0% of lipids [20]), P. atlanticum (5.0-7.0% of lipids [26]).…”

“…Interestingly, high levels of DHA were observed in glycolipids (up to 12% of the FA mixture) and especially in PL (38.2%) from the pelagic colonial tunicate Pyrosoma atlanticum [26]. Ether-linked glycerophospholipids in muscle and viscera, a major PL subclass of H. roretzi, were investigated [27]. Interestingly, the sn-2 glycerol positions of these ether lipids contained high levels polyunsaturated FA (PUFA) including EPA and DHA as major components.…”

Effects of sea squirt (Halocynthia roretzi) lipids on white adipose tissue weight and blood glucose in diabetic/obese KK-Ay mice

“…H. roretzi contains various functional components such as eicosapentaenoic acid (ePa), docosahexaenoic acid (dHa), carotenoids, taurine and plasmalogen (1)(2)(3). in a previous study, Kawasaki reported that hexane extracts from H. roretzi muscle decreased total cholesterol, triglycerides, phospholipids and neFa in the serum of rats (4).…”