Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai, PR China.
J Sep Sci. 2011 Jun;34(11):1347-54. doi: 10.1002/jssc.201100024. Epub 2011 Apr 13.
Dalbergia odorifera contains high concentrations of flavonoid aglycones and trace flavonoid glycosides. In this study, trace flavonoid glycosides were separated from D. odorifera by titania with matrix solid-phase dispersion (MSPD). Before the MSPD experiment, four standards, including two isoflavone glycosides (genistin and formononetin-8-C-apiosyl (1-6)-glucoside) and their aglycones (genistein and formononetin), were used to compare their retention on a titania column. The effect of acetonitrile concentration and pH on their retention was investigated and a conclusion was drawn that high acetonitrile concentration and pH lead to the greatest difference in the retention of flavonoid as glycosides and aglycones. Besides hydrophilic interaction and ligand-exchange interaction may exist between sugar moiety of flavonoid glycoside and titania, so that flavonoid glycosides have stronger retention than that of aglycones. Based on the chromatographic rule of flavonoid as glycosides and aglycones on the titania column, the MSPD method was optimized to elute high concentration flavonoid aglycones first with 90% acetonitrile and 10% water containing 100 mM ammonium acetate buffer, and then to elute trace flavonoid glycosides with 20% acetonitrile and 80% water containing 1% trifluoroacetate (TFA). Isolated flavonoid glycosides were further analyzed by UPLC-MS/MS, and their fragmentation in MS(2) showed they are C-glycosyl flavonoids.
降香含有高浓度的黄酮苷元和痕量黄酮糖苷。本研究采用钛硅分子筛（TiO2）基质固相分散（MSPD）法从降香中分离痕量黄酮糖苷。在 MSPD 实验之前，使用四种标准品，包括两种异黄酮糖苷（染料木苷和芒柄花苷-8-C-（1-6）-吡喃葡萄糖苷）及其苷元（染料木素和芒柄花素），来比较它们在 TiO2 柱上的保留情况。考察了乙腈浓度和 pH 值对它们保留的影响，得出结论：高乙腈浓度和 pH 值导致糖苷和苷元形式的黄酮类化合物保留的差异最大。此外，黄酮糖苷的糖基部分与 TiO2 之间可能存在亲水相互作用和配体交换相互作用，使得黄酮糖苷比苷元具有更强的保留能力。基于黄酮糖苷和苷元在 TiO2 柱上的色谱规律，优化了 MSPD 方法，先用 90%乙腈和 10%水（含 100mM 乙酸铵缓冲液）洗脱高浓度的黄酮苷元，然后用 20%乙腈和 80%水（含 1%三氟乙酸（TFA））洗脱痕量黄酮糖苷。分离得到的黄酮糖苷进一步通过 UPLC-MS/MS 进行分析，其 MS(2)中的碎片表明它们是 C-糖苷黄酮。
