Bowser D V, Teece R G, Somani S M
Biomed Mass Spectrom. 1978 Nov;5(11):627-33. doi: 10.1002/bms.1200051107.
Amino sugars isolated from lipopolysaccharides of Brucella suis, Brucella abortus and Neisseria gonorrhoeae colony types 1 and 4 were identified using gas chromatography electron impact and chemical ionization mass spectrometry. Lipopolysaccharides were obtained by aqueous ether or aqueous phenol extraction. Isolated lipopolysaccharides were hydrolyzed in 1% acetic acid followed by hydrolysis of the polysaccharide moiety in 2 NHCl for 6 h at 100 degrees C. Amino sugars were first isolated by elution from Dowex 50 H+ and then N-acetylated, followed by trimethylsilylation. Trimethylsilyl ethers of 2-acetamido-2-deoxysugars; N-acetylglucosamine, N-acetylmannosamine, N-acetylgalactosamine, and a 2-acetamido-2.6-dideoxysugar, N-acetylquinovosamine, were identified by their fragmentation patterns. In the electron impact mode, N-acetylglucosamine and N-acetyl-galactosamine were distinguished from one another by comparing peak intensities at m/e 233 and 305. However, N-acetylglucosamine and N-acetylmannosamine could not be differentiated by electron impact mass spectrometry. In the chemical ionization mode, N-acetylglucosamine and N-acetylmannosamine both with base peaks at m/e 494, could be distinguished from N-acetylgalactosamine and N-acetylquinovosamine by their base peaks at m/e 420 and 332, respectively. N-Acetylglucosamine and N-acetylmannosamine were differentiated from one another by comparing peak intensities at m/e 330, 404, 420, and 510 [MH]+. This is the first report of chemical ionization mass spectrometry applied to the identification of amino sugars in bacterial lipopolysaccharides and shows that some 2-amino-2-deoxysugars can be differentiated by both electron impact and chemical ionization mass spectrometry.
利用气相色谱电子轰击和化学电离质谱法对从猪布鲁氏菌、流产布鲁氏菌以及淋病奈瑟菌1型和4型脂多糖中分离出的氨基糖进行了鉴定。脂多糖通过水相乙醚或水相苯酚萃取获得。分离出的脂多糖在1%乙酸中水解，然后在2N盐酸中于100℃水解多糖部分6小时。氨基糖首先通过从Dowex 50 H+上洗脱进行分离，然后进行N - 乙酰化，接着进行三甲基硅烷化。通过其碎片模式鉴定了2 - 乙酰氨基 - 2 - 脱氧糖（N - 乙酰葡糖胺、N - 乙酰甘露糖胺、N - 乙酰半乳糖胺）以及一种2 - 乙酰氨基 - 2,6 - 二脱氧糖（N - 乙酰奎诺糖胺）的三甲基硅烷基醚。在电子轰击模式下，通过比较m/e 233和305处的峰强度来区分N - 乙酰葡糖胺和N - 乙酰半乳糖胺。然而，电子轰击质谱法无法区分N - 乙酰葡糖胺和N - 乙酰甘露糖胺。在化学电离模式下，N - 乙酰葡糖胺和N - 乙酰甘露糖胺的基峰均在m/e 494，它们可分别通过m/e 420和332处的基峰与N - 乙酰半乳糖胺和N - 乙酰奎诺糖胺区分开来。通过比较m/e 330、404、420和510 [MH]+处的峰强度来区分N - 乙酰葡糖胺和N - 乙酰甘露糖胺。这是关于化学电离质谱法应用于鉴定细菌脂多糖中氨基糖的首次报道，表明一些2 - 氨基 - 2 - 脱氧糖可通过电子轰击和化学电离质谱法进行区分。
