Structural Relationships of 1, 2-Diacylglycerol Residues in Glycerolipid Classes from Seeds, Leaves and Roots of Adzuki bean (Vigna angularis)

Abstract

Major glycerolipid classes such as triacylglycerol (TG), monoglycosyldiacylglycerol (MGDG), diglycosyldiacylglycerol (DGDG), phosphatidylcholine (PC), phosphatidylethanol-amine (PE) and phosphatidylinositol (PI) were isolated from seeds, leaves and the roots of Adzuki bean (Vigna angularis), and their molecular species of 1, 2-diacylglycerol residues were investigated. Not only the relative proportions but also molecular species compositions of these glycerolipids differed among the organs. However, the major molecular species, based on the degree of unsaturation of the component 1, 2-diacylglycerol residues, were generally dienoic to pentaenoic types (i.e. 16 : 0-18 : 2, 16 : 0-18 : 3, 18 : 2-18 : 2, and 18 : 2-18 : 3) in TG, PC and PE, dienoic and trienoic in PI, and hexaenoic (i.e. 18 : 3-18 3) in MGDG and DGDG. Thus, the degree of unsaturation in the DG species of Adzuki glycerolipids was moderate for TG, PC and PE, lower for PI, and higher for MGDG and DGDG.