Chemical Structure of a Novel Aminophospholipid from Hydrogenobacter thermophilus Strain TK-6

The phospholipid composition of Hydrogenobacter thermophilus strain TK-6, an obligately chemolithoautotrophic, extremely thermophilic hydrogen bacterium, was analyzed. Two of four phospholipids detected from the strain were assumed to be phosphatidylinositol and phosphatidylglycerol. An aminophospholipid named PX, whose content among the phospholipids was 65%, was found to have a novel chemical structure by analysis of the dilyso form with nuclear magnetic resonance and fast atom bombardment-mass spectrometry (FAB-MS) and by analysis of the intact PX with FAB-MS as 1,2-diacyl-3-O-(phospho-2′-O-(1′-amino)-2′,3′,4′,5′-pentanetetrol)-sn-glycerol. Structurally similar phospholipids have been identified in Methanospirillum hungatei, Methanolacinia paynteri, and Methanogenium cariaci, which all belong to the Archaea.