Analysis of Galactolipids of Eukaryotic Algae by LC/MS/MS

Introduction

Galactolipids are a type of glycolipid, which accounts for nearly 80% (molar ratio) of the chloroplast membrane lipids of higher plants and is found abundantly in nature. Instead of using phospholipids, plants and other photosynthetic autotrophs use galactolipids, which do not contain phosphorus, as the major component of the thylakoid membrane of their chloroplasts. The following significant findings on the biological activities of galactolipids have been obtained by researches conducted in the past few decades: 1. Direct involvement in thylakoid biosynthesis 2. Indispensable for photosynthetic electron transport reaction 3. Partially substitutes for phospholipids during phosphorus starvation 4. The role in flower development 5. Contribution to the anti-inflammatory properties and antitumor activities of medicinal plants A galactolipid is composed of at least one galactose head group attached to the sn-3 position of the glycerol backbone via an ether bond and two fatty acid chains attached to the sn-1 position and sn-2 position via an ester bond. Galactolipids are amphiphilic because galactose has a hydroxyl group. Galactolipids are classified by the types of sugars into groups, including monogalactosyl diacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and sulfoquinovosyldiacylglycerol (SQDG). The ratio of MGDG and DGDG as well as their fatty acid composition and distribution are important indicators for research on chloroplast formation. Euglena gracilis are one type of euglenids which are a group of eukaryotic unicellular algae; they have chloroplasts and can proliferate photoautotrophically and heterotrophically. As wax esters formed in Euglena gracilis under low oxygen conditions are considered as excellent raw materials for biofuel production, Euglena gracilis have been gaining more attention in recent years. This article introduces an example analysis of galactolipids in Euglena gracilis powder using a high performance liquid chromatograph and triple quadrupole mass spectrometer system (Shimadzu LCMS-8060), as part of analyzing lipids of Euglena gracilis.

March 26, 2019 GMT