Quadrupole ion-trap mass spectrometry to locate fatty acids on lipid A from Gram-negative bacteria.

摘要: The structure of lipid A released by mild acid hydrolysis from lipopolysaccharide two strains Shigella flexneri with different degrees acylation was characterized using electrospray ionization (ESI) and ion-trap mass spectrometry. analyzed underivatized ESI in negative-ion mode. With multiple stages fragmentation (MSn), both the degree positions fatty acids on disaccharide backbone could be determined. It possible to determine MSn technique, where each MS stage parent ion an one had been eliminated. One way location identifying cross-ring fragments reducing sugar ions containing numbers acids. Another a charge-driven release situated close phosphate group. were otherwise eliminated charge-remote mechanism. combined data show usefulness spectrometers for this type analysis.