Examination of the structures of several glycerolipids from marine macroalgae by NMR and GC‐MS

Abstract

Several classes of glycerolipids were isolated from the total lipids of the algae Saccharina cichorioides, Eualaria fistulosa, Fucus evanescens, Sargassum pallidum, Silvetia babingtonii (Ochrophyta, Phaeophyceae), Tichocarpus crinitus, and Neorhodomela larix (Rhodophyta, Florideophyceae). The structures of these lipids were examined by nuclear magnetic resonance (NMR) spectroscopy, including 1D ((1) H and (13) C) and 2D (COSY, HSQC and HMBC) experiments. All of the investigated algae included common galactolipids and sulfonoglycolipids as the major glycolipids. Minor glycolipids isolated from S. cichorioides, T. crinitus, and N. laris were identified as lyso-galactolipids with a polar group consisted of the galactose. Comparison of the (1) H NMR data of minor nonpolar lipids isolated from the extracts of the brown algae S. pallidum and F. evanescens with the (1) H NMR data of other lipids allowed them to be identified as diacylglycerols. The structures of betaine lipids isolated from brown algae were confirmed by NMR for the first time. The fatty acid compositions of the isolated lipids were determined by gas chromatography-mass spectrometry.

Seasonal Composition of Lipids, Fatty Acids Pigments in the Brown Alga <i>Sargassum pallidum</i>: The Potential for Health

“…It is interesting to note that in the summer months we found very small amounts lysoform MGDG, in particular, MGMG (Table 1). Nuclear magnetic resonance spectroscopy (NMR) we earlier confirmed chemical structure of this lipid as 1-O-acyl-3-O-(β-D-galactopyranosyl)-sn-glycerols [73]. Increasing all classes of GL observed again after the reproduction.…”

“…It should be noted, that TLC has previously showed this lipid in S. pallidum [43] [74], but the structure has not been corroborated. The structure of this lipid from S. pallidum was confirmed by NMR as 1,2-diacylglyceryl-3-O-2'(hydroxymethyl)-(N,N,N-trimethyl)-β-alanine by us [73].…”

The lipid biochemistry of eukaryotic algae

“…Although monoacyl-glycosylglycerides have been reported in algae [23], their possible formation during extraction cannot be eliminated if careful precautions to inhibit any endogenous lipases are not taken.…”

Bioprospecting of Marine Macrophytes Using MS-Based Lipidomics as a New Approach

“…However, the NMR does not provide information on the composition of the fatty acids of the individual molecular species. Usually the NMR is associated with GC-MS to achieve the detailed information of lipid species [ 98 , 99 ]. On the other hand, MS provides all information at the molecular species level, providing information on the chain length, degree of unsaturation and positional distribution of fatty acids at sn -1/ sn -2 positions.…”