COMPOSITION ANALYSIS BY GC-MS OF THREE SAMPLES

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 方法： GC-MS法测定糖基组成 将样品(约20g)放入螺帽管中，以L 2？1 mg/mL肌醇为内标，样品冷冻干燥。干燥后的样品用3M盐酸在甲醇中于100℃下甲醇解2 h，再与吡啶和乙酸酐在甲醇中重新进行N-乙酰化反应，制得甲基糖苷类化合物。将前面的甲烷解和Re-N-乙酰化步骤重复两次。然后，样品用Tri-Sil试剂(Thermo Science)在80℃下进行全O-三甲基硅烷化(TMS)0.5h，在配备Supelco EC-1熔融石英毛细管柱(30m×0.25 mm ID)的Hewlett Packard Series II 5890气相色谱仪上分析TMS甲基糖苷，并与Hewlett Packard 5970 MSD连接。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Methods: Glycosyl composition by GC-MS The samples (~20 ¿g each) were placed in screw-cap tubes, 2 ¿L 1 mg/mL inositol was added as internal standard, and the samples were lyophilized. Methyl glycosides then were prepared from the dried samples by methanolysis with 3 M HCl in methanol at 100 ¿C for 2 h followed by re-N-acetylation with pyridine and acetic anhydride in methanol. The preceding methanolysis and re-N-acetylation steps were repeated two times. The samples then were per-O-trimethylsilylated (TMS) with a Tri-Sil reagent (Thermo Scientific) at 80 ¿C for 0.5 h. Analysis of the TMS methyl glycosides was performed on a Hewlett Packard Series II 5890 gas chromatograph equipped with a Supelco EC-1 fused silica capillary column (30m ¿ 0.25 mm ID) and interfaced to a Hewlett Packard 5970 MSD.