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1H qNMR-based quantitative analysis of total macamides in five maca (Lepidium meyenii Walp.) dried naturally

Xing-Rong Peng, Yan-Jie Huang, Jun-Hong Liu, Ran-Ran Zhang, Zhong-Rong Li, Lin Zhou, Ming-Hua Qiu
Journal of food composition and analysis 2021 v.100 pp. 103917
Lepidium meyenii, air drying, food composition, medicine, quality control, quantitative analysis, China, Peru
Macamides are considered bioactive markers of maca, and they have been used as food and medicine for centuries. In the present study, a ¹H qNMR method was developed, and the analyses of the specificity, linearity, sensitivity, accuracy, and precision further indicate the validity of this method. Furthermore, the ¹H qNMR method was applied for the quantification of total macamides in five naturally air-dried maca samples with different origins and colors. The results showed that the content of total macamides was correlated with the origins and colors: China purple maca (1845.75 ± 3.45 μg g⁻¹) > China yellow maca (1090.20 ± 2.07 μg g⁻¹) > Peru yellow maca (393.30 ± 2.42 μg g⁻¹) > China and Peru black maca (each 269.10 ± 1.03 μg g⁻¹). In addition, a new macamide, N-benzyl-(9-carboxymethyl)-octanamide (2), which is the first example of a macamide with an azelaxyl motif, was identified from Chinese purple maca. Our research not only provides a valid method to determine the content of total macamides in different maca samples but also offers a reference for quality control of maca.