Lemonakis Nikolaos, Gikas Evagelos, Halabalaki Maria, Skaltsounis Alexios-Leandros
Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece.
PLoS One. 2013 Oct 21;8(10):e78277. doi: 10.1371/journal.pone.0078277. eCollection 2013.
Oleuropein (OE) is a secoiridoid glycoside, which occurs mostly in the Oleaceae family presenting several pharmacological properties, including antioxidant, cardio-protective, anti-atherogenic effects etc. Based on these findings OE is commercially available, as Herbal Medicinal Product (HMP), claimed for its antioxidant effects. As there are general provisions of the medicine regulating bodies e.g. European Medicines Agency, the quality of the HMP's must always be demonstrated. Therefore, a novel LC-MS methodology was developed and validated for the simultaneous quantification of OE and its main degradation product, hydroxytyrosol (HT), for the relevant OE claimed HMP's. The internal standard (IS) methodology was employed and separation of OE, HT and IS was achieved on a C18 Fused Core column with 3.1 min overall run time employing the SIM method for the analytical signal acquisition. The method was validated according to the International Conference on Harmonisation requirements and the results show adequate linearity (r(2) > 0.99) over a wide concentration range [0.1-15 μg/mL (n=12)] and a LLOQ value of 0.1 μg/mL, for both OE and HT. Furthermore, as it would be beneficial to control the quality taking into account all the substances of the OE claimed HMP's; a metabolomics-like approach has been developed and applied for the total quality control of the different preparations employing UHPLC-HRMS-multivariate analysis (MVA). Four OE-claimed commercial HMP's have been randomly selected and MVA similarity-based measurements were performed. The results showed that the examined samples could also be differentiated as evidenced according to their scores plot. Batch to batch reproducibility between the samples of the same brand has also been determined and found to be acceptable. Overall, the developed combined methodology has been found to be an efficient tool for the monitoring of the HMP's total quality. Only one OE HMP has been found to be consistent to its label claim.
橄榄苦苷（OE）是一种裂环环烯醚萜苷，主要存在于木犀科植物中，具有多种药理特性，包括抗氧化、心脏保护、抗动脉粥样硬化作用等。基于这些发现，OE作为一种草药产品（HMP）已上市销售，宣称具有抗氧化作用。由于药品监管机构（如欧洲药品管理局）有通用规定，HMP的质量必须始终得到证明。因此，开发并验证了一种新颖的液相色谱 - 质谱方法，用于同时定量相关OE宣称的HMP中的OE及其主要降解产物羟基酪醇（HT）。采用内标（IS）方法，在C18熔融核柱上实现了OE、HT和IS的分离，总运行时间为3.1分钟，采用选择离子监测（SIM）方法采集分析信号。该方法根据国际协调会议要求进行了验证，结果表明在较宽的浓度范围[0.1 - 15μg/mL（n = 12）]内具有良好的线性（r²> 0.99），OE和HT的定量下限（LLOQ）值均为0.1μg/mL。此外，考虑到OE宣称的HMP中的所有物质来控制质量将是有益的；已开发并应用了一种类似代谢组学的方法，通过超高效液相色谱 - 高分辨率质谱 - 多变量分析（MVA）对不同制剂进行全面质量控制。随机选择了四种宣称含有OE的商业HMP，并进行了基于MVA相似性的测量。结果表明，所检测的样品也可以根据其得分图进行区分。还确定了同一品牌样品之间的批次间重现性，发现是可以接受的。总体而言，已发现所开发的组合方法是监测HMP全面质量的有效工具。仅发现一种OE HMP与其标签声明一致。
