Simultaneous structural identification of diacylglyceryl‐N‐trimethylhomoserine (DGTS) and diacylglycerylhydroxymethyl‐N,N,N‐trimethyl‐β‐alanine (DGTA) in microalgae using dual Li⁺/H⁺ adduct ion mode by ultra‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry

Abstract

This is the first report to achieve the ambiguous structural identification of DGTS and DGTA by UPLC/QTOF MS using dual Li /H adduct ion mode, which has remained a challenge in the past. It could provide new insights into their phylogeny and be helpful to characterize the natural phytoplankton communities as intact polar lipid biomarkers. Copyright © 2017 John Wiley & Sons, Ltd.

Mixotrophy in a Local Strain of Nannochloropsis granulata for Renewable High-Value Biomass Production on the West Coast of Sweden

“…Overall, betaine lipids were shown to be the major clusters detected in the bioactive fractions, with betaine diacylglycerols being almost exclusively present in fraction E and betaine monoacylglycerols being the most abundant metabolite in fraction D. Betaine lipids, structural components of cell membranes and chloroplasts, are acylglycerolipids bearing an ether-linked quaternary amine alcohol moiety at the sn -3 position, which may be represented by a 2′-(hydroxymethyl)-( N , N , N -trimethyl)-β-alanine, a carboxy-(hydroxymethyl)-choline, or a 4′-( N , N , N -trimethyl)-homoserine. The product ion spectra generated from the [M + H] + ions of betaine lipids from fractions D and E were all characterized by the presence of the diagnostic fragment ion at m / z 236.1492 (C 10 H 22 NO 5 + ), which is indicative of diacyl- and monoacyl-glycerol-trimethylhomoserine (DGTS and MGTS) or diacyl- and monoacyl-glyceryl-hydroxymethyl- N , N , N -trimethyl-β-alanine (DGTA and MGTA) [ 25 ]. Therefore, betaine lipids from the bioactive fractions were predicted to be DGTS and MGTS and/or DGTA and MGTA.…”

A Multi-Omics Analysis Suggests Links Between the Differentiated Surface Metabolome and Epiphytic Microbiota Along the Thallus of a Mediterranean Seaweed Holobiont

“…For some of them, these lipid families were characterized through specific fragment ions, such as m/z 236.1494 [C10H22NO5] + for DGTAs and m/z 184.0722 [C 5 H 15 NO 4 P] + for PCs. DGTAs were distinguished from their structural isomers diacylgycerol-N-trimethylhomoserines (DGTSs) based on the absence of a characteristic loss of m/z 87 (Roche and Leblond, 2010), even if it is matter of controversy (Li et al, 2017). Clusters B and F consisted of terpenoids, including several sesquiterpenes and geranylgeranylglycerol (GGG) previously purified from T. atomaria (Othmani et al, 2016a,b).…”

Effect of Temperature and Light Intensity on the Polar Lipidome of Endophytic Brown Algae Streblonema corymbiferum and Streblonema sp. In Vitro

“…The negative ion mode was applied for quantitative analysis of PI and the positive mode was applied for analyzing others lipid classes. Previously described fragmentation reactions were used for sn-position of acyl chains determination in all polar lipid classes [ 56 , 57 , 58 , 59 , 60 ], except GlcADG and PHEG. For the identification of MGDG, DGDG and PC, [M + Li] + ions were used, in this case 5mM LiOH in methanol with 0.02 mL/min flow was added postcolumn.…”