Analysis of intact hopanoids and other lipids from the bacterium Zymomonas mobilis by high-performance liquid chromatography.

Hopanoids and other lipids were extracted from Zymomonas mobilis and quantitatively analyzed by high-performance liquid chromatography. Previous methods for hopanoid analysis required derivatization of the hopanoids via periodate oxidation or acetylation. The current method employs a normal-phase silica gel column, a ternary gradient of hexane-isopropanol-water-triethylamine, and detection with a flame ionization detector. Three major hopanoid classes were separated and quantified by this new method, and together they comprised 30 to 40% of the total lipid in these cells. Mass spectrometry confirmed that chemical structures of these hopanoids were consistent with those previously proposed. In addition, several other common lipid classes (free fatty acids and six classes of common phospholipids), comprising the remaining 60 to 70% of the total lipids, were also separated and quantified. This new chromatographic method represents the first technique for the analysis and purification of intact hopanoids. This method should be useful for the analysis and purification of hopanoids from other bacterial species.