Many species from the genus Citrus are used in traditional medicine and contain polymethoxylated flavonoids. These compounds show anti-inflammatory and chemopreventive activities, among others, and therefore have a big potential to be developed as therapeutic agents or dietary supplements. Citrus species are different in their profile and yield of polymethoxylated flavonoids. Therefore, polymethoxylated flavonoids were identified and quantified in seven different Citrus species, including wild-type and commercially available species. All species were profiled using UPLC-QTOF-MS/MS analysis combined with mass spectral molecular networking. A total of 38 polymethoxylated flavonoids were detected and 8 of them were present in every species. As the yield of polymethoxylated flavonoids was different for each species, a generally applicable HPLC-diode array detection method was developed and validated according to the ICH guidelines to quantify the amount of nobiletin and the total amount of polymethoxylated flavonoids expressed as nobiletin. Analysis of the seven samples showed evidence that wild-type Citrus species (e.g., Citrus depressa) contain higher yields of polymethoxylated flavonoids compared to commercially available species (e.g., Citrus limon). Qualitative analysis revealed the broadest variety of different PMFs in C. depressa, Citrus reticulata, and Citrus reticulata × Citrus sinensis, which makes them interesting sources of polymethoxylated flavonoids for future development as therapeutic agents or dietary supplements.

中文翻译：

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使用 UPLC-QTOF-MS/MS 和 HPLC-DAD 鉴定和定量不同柑橘品种中的多甲氧基黄酮

柑橘属的许多物种用于传统医学并含有多甲氧基黄酮类化合物。这些化合物显示出抗炎和化学预防活性等，因此具有作为治疗剂或膳食补充剂开发的巨大潜力。柑橘类的多甲氧基黄酮类化合物的特征和产量不同。因此，在包括野生型和市售品种在内的七种不同柑橘品种中鉴定和量化了多甲氧基化黄酮类化合物。使用 UPLC-QTOF-MS/MS 分析结合质谱分子网络分析所有物种。共检测到 38 种多甲氧基黄酮类化合物，其中 8 种存在于每个物种中。由于每个物种的多甲氧基黄酮类化合物的产量不同，根据 ICH 指南，开发并验证了一种普遍适用的 HPLC 二极管阵列检测方法，以量化 nobiletin 的量和以 nobiletin 表示的多甲氧基化黄酮类化合物的总量。对七个样品的分析表明，与市售品种（如柠檬柑橘）相比，野生型柑橘品种（如 Citrus depressa）含有更高产量的多甲氧基化黄酮类化合物。定性分析揭示了 C. depressa、Citrus reticulata 和 Citrus reticulata × Citrus sinensis 中最广泛的不同 PMF，这使得它们成为多甲氧基化黄酮类化合物的有趣来源，可用于未来作为治疗剂或膳食补充剂的开发。