Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden, The Netherlands.
Anal Chim Acta. 2011 Oct 10;703(2):179-86. doi: 10.1016/j.aca.2011.07.036. Epub 2011 Jul 29.
Although metabolomics aims at profiling all the metabolites in organisms, data quality is quite dependent on the pre-analytical methods employed. In order to evaluate current methods, different pre-analytical methods were compared and used for the metabolic profiling of grapevine as a model plant. Five grape cultivars from Portugal in combination with chemometrics were analyzed in this study. A common extraction method with deuterated water and methanol was found effective in the case of amino acids, organic acids, and sugars. For secondary metabolites like phenolics, solid phase extraction with C-18 cartridges showed good results. Principal component analysis, in combination with NMR spectroscopy, was applied and showed clear distinction among the cultivars. Primary metabolites such as choline, sucrose, and leucine were found discriminating for 'Alvarinho', while elevated levels of alanine, valine, and acetate were found in 'Arinto' (white varieties). Among the red cultivars, higher signals for citrate and GABA in 'Touriga Nacional', succinate and fumarate in 'Aragonês', and malate, ascorbate, fructose and glucose in 'Trincadeira', were observed. Based on the phenolic profile, 'Arinto' was found with higher levels of phenolics as compared to 'Alvarinho'. 'Trincadeira' showed lowest phenolics content while higher levels of flavonoids and phenylpropanoids were found in 'Aragonês' and 'Touriga Nacional', respectively. It is shown that the metabolite composition of the extract is highly affected by the extraction procedure and this consideration has to be taken in account for metabolomics studies.
尽管代谢组学旨在描绘生物体中的所有代谢物，但数据质量在很大程度上取决于所采用的预处理方法。为了评估当前的方法，本研究比较和使用了不同的预处理方法来对葡萄进行代谢组学分析。本研究结合化学计量学分析了来自葡萄牙的 5 个葡萄品种。对于氨基酸、有机酸和糖等初级代谢物，发现使用氘化水和甲醇的共同提取方法是有效的。对于酚类等次级代谢物，C-18 固相萃取小柱显示出良好的效果。应用主成分分析与 NMR 光谱相结合，结果表明品种间有明显的区别。胆碱、蔗糖和亮氨酸等初级代谢物被发现可用于区分“阿尔巴利诺”（Alvarinho），而“阿连特茹”（Arinto）（白葡萄品种）中丙氨酸、缬氨酸和乙酸盐水平较高。在红葡萄品种中，“国产多瑞加”（Touriga Nacional）中柠檬酸和 GABA 的信号较高，“阿ragonês”（Aragonês）中琥珀酸和富马酸的信号较高，而“Trincadeira”（Trincadeira）中苹果酸、抗坏血酸、果糖和葡萄糖的信号较高。根据酚类物质的特征，发现“阿连特茹”的酚类物质含量高于“阿尔巴利诺”（Alvarinho）。“Trincadeira”的酚类物质含量最低，而“阿ragonês”和“国产多瑞加”的黄酮类和苯丙素类物质含量较高。结果表明，提取物的代谢物组成受提取程序的影响很大，因此在代谢组学研究中必须考虑这一因素。
