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。子项目的主要支持 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 为子项目列出的总成本可能 表示子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 研究方法： 糖基组成（GC-MS法） 将样品（各约20 μ g）置于螺旋盖试管中，加入2 μ L 1 mg/mL肌醇作为内标物，并将样品冻干。 然后通过用3 M HCl的甲醇溶液在100 ℃下甲醇分解2 h，然后用吡啶和乙酸酐的甲醇溶液进行再N-乙酰化，从干燥的样品制备甲基糖苷。 将前述甲醇分解和再-N-乙酰化步骤重复两次。 然后将样品用Tri-Sil试剂（Thermo Scientific）在80 ℃下全-O-三甲基甲硅烷基化（TMS）0.5小时。TMS甲基糖苷的分析在配备有Supelco EC-1熔融石英毛细管柱（30 m × 0.25 mm ID）并与Hewlett Packard 5970 MSD连接的Hewlett Packard Series II 5890气相色谱仪上进行。

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.