Laboratoire de Pharmacognosie, LDRI, Université catholique de Louvain, Av. E. Mounier, 72, B1.72.03, 1200, Brussels, Belgium.
Anal Bioanal Chem. 2013 Nov;405(28):9235-49. doi: 10.1007/s00216-013-7325-z. Epub 2013 Oct 18.
Euterpe oleracea fruits have gained much attention because of their phenolic constituents that have shown potential health benefits. The aim of this work was to quantify the major non-anthocyanin flavonoids (NAF) in the fruit juice by an accurate method coupling ultra-high pressure liquid chromatography with a linear ion trap-high resolution Orbitrap mass spectrometry system (UHPLC-LTQ-Orbitrap MS). Fruits were processed to juice, and then the juice was lyophilized and defatted. The residue was then extracted in the presence of methanol by sonication. The extraction time was optimized and recovery rates of the extraction were >90%. The extracts were dried and solubilized again in 40% MeOH, which showed the best compromise for MS detection. For the UHPLC quantification, a HSS C18 column (1.8 μm) was used with a gradient elution of methanol and water both with 0.1% formic acid. Total error and accuracy profiles were used as validation criteria. Seven compounds and their isomers were successfully separated, including the major NAF. Calibration in the matrix was found to be more accurate than calibration without matrix. Trueness (<15% relative bias), repeatability, and intermediate precision (<13% RSD), selectivity, response function, linearity, LOD (ranged from 0.04 to 0.81 μg/mL) and LOQ (0.15-5.78 μg/mL) for 12 compounds were evaluated and the quantification method was validated. Its applicability was demonstrated on real samples from different suppliers. Their qualitative and quantitative profiles were similar and some compounds were for the first time quantified. In addition, eriodictyol was identified for the first time in this fruit along with five other flavonoids for which possible structures were proposed.
杨桃果实因其酚类成分而备受关注，这些成分显示出潜在的健康益处。本工作旨在通过一种准确的方法定量分析果汁中的主要非花青素类黄酮（NAF），该方法将超高压液相色谱与线性离子阱-高分辨率轨道阱质谱系统（UHPLC-LTQ-Orbitrap MS）相结合。将果实加工成果汁，然后将果汁冻干并脱脂。然后在甲醇存在下通过超声提取残留物。优化了提取时间，提取回收率>90%。提取物干燥后再次溶解在 40%甲醇中，这是 MS 检测的最佳折衷方案。对于 UHPLC 定量分析，使用 HSS C18 柱（1.8 μm），甲醇和水均以 0.1%甲酸作为流动相进行梯度洗脱。总误差和准确度曲线被用作验证标准。成功分离出包括主要 NAF 在内的七种化合物及其异构体。在基质中进行校准比不使用基质进行校准更准确。准确度（<15%相对偏差）、重复性和中间精密度（<13%RSD）、选择性、响应函数、线性、LOD（范围为 0.04-0.81 μg/mL）和 LOQ（0.15-5.78 μg/mL）用于 12 种化合物进行了评估，并验证了定量方法。该方法已应用于不同供应商的实际样品，其定性和定量谱图相似，并且首次定量了一些化合物。此外，首次在该果实中鉴定出圣草酚，并提出了其他五种黄酮类化合物的可能结构。
