School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 100029, China.
J Agric Food Chem. 2012 Sep 12;60(36):9023-34. doi: 10.1021/jf302713c. Epub 2012 Sep 4.
A sensitive HPLC-DAD-ESI-MS/MS method was established to screen and identify the polymethoxylated flavonoids (PMFs) in the peels of 'Shatangju' mandarin ( Citrus reticulata Blanco). Eight PMF standards, including four polymethoxylated flavones, two polymethoxylated flavanones, and two polymethoxylated chalcones, were first to be analyzed in positive mode by CID-MS/MS. On the basis of the ESI-MS(n) characteristics of PMFs and the results of EIC-MS/MS experiment, 32 PMFs including 24 flavones and 8 flavanones or chalcones were screened from the complex extract of the peels of 'Shatangju' mandarin. Among them, 10 PMFs were hydroxylated polymethoxyflavonoids (OH-PMFs), and the rest were all permethoxylated PMFs. This was the first systematic report of the presence of PMFs in the peels of 'Shatangju' mandarin, especially for polymethoxylated flavanones and chalcones. Meanwhile, the contents of the three main PMFs and total flavonoids in the peels of 'Shatangju' were determined by HPLC and UV spectrophotometry, respectively. The results indicated that the developed analytical method could be employed as an effective technique for the characterization of PMFs.
建立了一种灵敏的 HPLC-DAD-ESI-MS/MS 方法，用于筛选和鉴定‘沙糖桔’果皮中的多甲氧基黄酮（PMFs）。首次在正离子模式下通过 CID-MS/MS 对 8 种 PMF 标准品（包括 4 种多甲氧基黄酮、2 种多甲氧基黄烷酮和 2 种多甲氧基查耳酮）进行了分析。基于 PMFs 的 ESI-MS(n)特征和 EIC-MS/MS 实验结果，从‘沙糖桔’果皮的复杂提取物中筛选出 32 种 PMFs，包括 24 种黄酮类和 8 种黄烷酮或查耳酮。其中，10 种 PMFs 为羟基化多甲氧基黄酮（OH-PMFs），其余均为全甲氧基 PMFs。这是首次系统报道‘沙糖桔’果皮中存在 PMFs，特别是多甲氧基黄烷酮和查耳酮。同时，采用 HPLC 和紫外分光光度法分别测定了‘沙糖桔’果皮中三种主要 PMFs 和总黄酮的含量。结果表明，所建立的分析方法可用于 PMFs 的特征描述。
