超高效液相色谱-光电二极管阵列检测-串联四级杆质谱法测定红洋葱中黄酮醇及其糖苷类化合物

Determination of Flavonols and Flavonol Glycosides in Red Onion by Ultra High Performance Liquid Chromatography-Photodiode Array Detection-Tandem Quadrupole Mass Spectrometry

采用ACQUITY UPLC HSS T3色谱柱,以含0.1%甲酸的乙腈-水为流动相,0.3 mL/min梯度洗脱方式辅以光电二极管阵列检测-串联四级杆质谱进行定性与定量分析,建立了种同时测定红洋葱中13种黄酮醇及其糖苷类化合物的方法,其中包含6种槲皮素及其糖苷、4种异槲皮素及其糖苷和3种山奈素及其糖苷。结果表明,红洋葱中主要的黄酮醇及黄酮醇糖苷类化合物是槲皮素-4'-葡萄糖糖苷、槲皮素-3,4'-二葡萄糖糖苷、槲皮素和异槲皮素-4'-葡萄糖糖苷。红洋葱的不同部位黄酮醇及其糖苷的含量和分布并不致,以干燥品计算,在相同质量的各部位中,外两层、第三层和内层中总黄酮醇及其糖苷含量的比例为60.3∶33.0∶6.7,其中各部位槲皮素及槲皮素糖苷占黄酮总量的92.1%以上;外两层中黄酮醇单糖糖苷含量大,第三层中黄酮醇苷元含量大,而内层中黄酮醇二糖糖苷含量大。另外,在红洋葱中还发现了少量的山奈素及其糖苷,主要存在于洋葱外层中。本方法简单快速、准确性好,可用于洋葱产品中黄酮醇及其糖苷类化合物的分析。

An ultra high performance liquid chromatography-photodiode array detection-tandem quadrupole mass spectrometry （UPLC-PAD-MS/MS） method was developed for the determination of total 13 flavonols and flavonol glycosides in red onion which including 6 quercetin and its glycosides, 4 isorhamnetin and its glycosides, 3 Kaempferol and its glycosides. The chromatographic separation was carried out by used a UPLC HSS T3 column and eluted under gradient with mobile phases of acetonitrile and water both contained 0.1% formic acid at a flow rate of 0.3 mL/min. The results showed that the major flavonols and flavonol glycosides in red onion were quercetin-4＇-glueoside, quercetin-3, 4＇-diglucoside, quercetin and Isorhamnetin-4＇- glucoside. The amounts and distributions of flavonols and flavonol glycosides among different parts of red onion were different. For the same amount of dry materials, the content ratio of total flavonols and flavonol glycosides in the outer two layers, the third layer and the inner layer was 60.3： 33.0： 6.7, the amount of quercitin and its glycosides accounts above 92.1% of total flavonols and flavonol glycosides for each part. In the outer two layers, the amount of flavonol monoglycosides are the highest, in the third layer, the amount of flavonol aglycones were the highest, but in the inner layer, the amount of flavonol diglycosides were the highest. Small amounts of Kaempferol and its glycosides were found in red onion, and mostly were found in outer layers. This method is simple, fast, accurate and convenient, and can be used to analyze flavonols and flavonol glycosides in onion product.