Institute for Macromolecular Studies, NMR Laboratory, National Research Council, Milan, Italy.
Laboratory of Chemistry, Department of Food Science and Human Nutrition, School of Food, Biotechnology and Development, Agricultural University of Athens, Athens, Greece.
Phytochem Anal. 2018 Sep;29(5):476-486. doi: 10.1002/pca.2753. Epub 2018 Feb 26.
The increasing interest on Crocus sativus L. over the last decades is caused by its potential employment as a source of biologically active molecules, endowed with antioxidant and nutraceutical properties. These molecules are present mainly in stigmas and tepals, these last generally considered as byproducts.
To characterise bioactive compounds in stigmas, stamens, and tepals of Crocus sativus L. for quality, cross-contamination of tissues or fraudulent addition, joining spectroscopic and chromatographic techniques.
Fourier transform infrared (FT-IR) and Raman spectroscopies were initially employed, being very rapid in response; volatiles were more appropriately investigated by gas chromatography with mass spectrometry (GC-MS), while finally nuclear magnetic resonance (NMR) and high-performance liquid chromatography with a diode array detector (HPLC-DAD) were adopted for a more thorough characterisation of secondary metabolites. NMR was also used to investigate the anthocyanins content in tepals upon acid extraction.
The results obtained highlighted the drying method as the dominant factor affecting the content of volatile constituents and contributing to the quality of saffron, while only slight differences were observed in the most abundant metabolites of stigmas, as well as in the anthocyanin content of tepals. In particular, for the first time, delphinidin and petunidin were detected by NMR in this latter tissue.
The integrated analytical methodology here proposed, allowed to achieve a deeper level of compositional and structural details of secondary metabolites in Crocus sativus L. flowers.
近几十年来，藏红花（Crocus sativus L.）因其作为具有抗氧化和营养特性的生物活性分子的潜在用途而引起了越来越多的关注。这些分子主要存在于柱头和花瓣中，而后者通常被认为是副产物。
采用光谱和色谱技术，对藏红花（Crocus sativus L.）的柱头、雄蕊和花瓣中的生物活性化合物进行定性分析，以确保其质量、组织间的交叉污染或防止掺假。
傅里叶变换红外（FT-IR）和拉曼光谱技术最初被采用，因为它们的响应非常迅速；气相色谱与质谱联用（GC-MS）更适合用于分析挥发性物质，而最终采用核磁共振（NMR）和二极管阵列检测器高效液相色谱（HPLC-DAD）对次生代谢物进行更全面的分析。NMR 还用于研究酸提取后花瓣中的花色苷含量。
结果表明，干燥方法是影响挥发性成分含量和藏红花质量的主要因素，而柱头中最丰富的代谢物以及花瓣中花色苷的含量仅存在轻微差异。特别是，首次通过 NMR 检测到花色苷在花瓣中存在于飞燕草素和锦葵素。
本文提出的综合分析方法，使我们能够更深入地了解藏红花（Crocus sativus L.）花中次生代谢物的组成和结构细节。
