Maca is a Peruvian tuberous root of the Brassicaceae family grown in the central Andes between altitudes of 4000 and 4500 m. The medicinal plant is a nutraceutical with important biological activities and health effects. In this study, we report a rapid high‐performance thin layer chromatography (HPTLC)‐(−)desorption electrospray ionization (DESI)‐mass spectrometry (MS) method to profile and separate intact glucosinolates without prior biochemical modifications from the hydromethanolic extracts of two phenotypes, red and black Maca (Lepidium peruvianum) seeds. In the first stage of the plant's life cycle, aromatic glucosinolates were the main chemical constituents whereby six aromatic, three indole, and one aliphatic glucosinolate were tentatively identified. At the seedling stage, glucolepigramin/Glucosinalbin was the most predominant precursor, rather than Glucotropaeolin, which is mainly found in hypocotyls and roots. These findings lead us to suggest that glucolepigramin/glucosinalbin play a major role as active precursors in the biosynthetic pathways of other secondary metabolites in the early stages of plant development. Between red and black Maca seeds, only minor differences in the relative abundances of glucosinolates were observed rather than different plant metabolites. For the first time, we report six potential plant antibiotics, phytoanticipins: glycosylated ascorbigens and dihydroascorbigens from Maca seeds. We also investigated a targeted reverse phase C₁₈ functionalized TLC‐DESI‐MS method with high sensitivity and specificity for Brassicaceae fatty acids in Maca seeds and health supplements such as black Maca root lyophilized powder and tinctures. The investigation of secondary metabolites by normal and reverse phase TLC‐DESI‐MS methods, described in this study, can aid in their identification as they begin to emerge in later stages of development in plant tissues such as leaves, hypocotyls, and roots.

中文翻译：

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通过正相和反相薄层色谱结合解吸电喷雾电离质谱法对玛卡（Lepidium peruvianum）中的生物活性次级代谢物进行化学分析和分离

玛卡是秘鲁十字花科的块根，生长在海拔 4000 至 4500 米之间的安第斯山脉中部。药用植物是一种营养保健品，具有重要的生物活性和保健作用。在这项研究中，我们报告了一种快速高效薄层色谱 (HPTLC)-(-) 解吸电喷雾电离 (DESI)-质谱 (MS) 方法来分析和分离完整的硫代葡萄糖苷，而无需事先生化修饰从两种氢甲醇提取物中表型，红色和黑色玛卡（Lepidium peruvianum) 种子。在植物生命周期的第一阶段，芳香族芥子油苷是主要化学成分，由此初步鉴定出六种芳香族、三种吲哚和一种脂肪族芥子油苷。在幼苗阶段，葡糖苷元/葡糖苷元是最主要的前体，而不是主要存在于下胚轴和根中的葡糖苷元。这些发现使我们认为，在植物发育的早期阶段，葡糖苷元/葡糖苷元在其他次生代谢物的生物合成途径中作为活性前体发挥着重要作用。在红色和黑色玛卡种子之间，仅观察到硫代葡萄糖苷相对丰度的微小差异，而不是不同的植物代谢物。我们首次报告了六种潜在的植物抗生素，植物抗生素：来自玛卡种子的糖基化抗坏血酸和二氢抗坏血酸。我们还研究了一个有针对性的反相 C₁₈功能化 TLC-DESI-MS 方法对玛卡种子和保健品（如黑玛卡根冻干粉和酊剂）中的十字花科脂肪酸具有高灵敏度和特异性。本研究中描述的通过正相和反相 TLC-DESI-MS 方法对次生代谢物的研究有助于识别它们，因为它们开始出现在植物组织（如叶、下胚轴和根）发育的后期阶段。