Separation and Determination of Macaene, Macamides and Phytosterols of Lepidium meyenii (Maca) Collected in Peru by LC-UV and LC-ELSD methods

Maca, Lepidium meyenii Walp. (Cruciferae), a plant only found on the high plateaus (3800–4800 m) of the Junin region in Peru, is one of the oldest crops of the Andeans [1]. Extracts rich in macamides and macaene show promising pharmacological activities and these compounds are therefore used as quality markers [1]. The native Indians used Maca to treat a number of conditions such as anemia, tuberculosis, sterility and fatigue [2]. A reversed phase HPLC method permitting the determination of macaene, four main macamides and phytosterols in Lepidium meyenii was described. A separation was possible by using a C12 stationary phase column, an acidic mobile phase comprising of acetonitrile, and water and a column temperature of 40°C. By monitoring the separation at 210 and 280 nm, the macaene and macamides were detectable as low as 0.2 µg/mL. The four phytosterols were successfully separated within 15 minutes by using a C8 column, a mobile phase comprising of water and methanol detected by evaporative light scattering (ELS). All phytosterols were detectable at concentrations as low as 3.0 µg/mL. The analysis of the 33 samples of Maca showed variations in macamides, macaene and phytosterol contents (campesterol and β-sitosterol) between different hypocotyls of Maca. Acknowledgements: This research is funded in part by “Science Based Authentication of Dietary Supplements” funded by the Food and Drug Administration grant number 2 U01 FD 002071–07 and the United States Department of Agriculture, Agricultural Research Service Specific Cooperative Agreement Number 58-6408-06-067. References: [1] Zheng BL, et al. (2000). Urology 55: 598–602. [2] Ganzera M, et al. (2002) Chem. Pharm. Bull. 50(7): 988–991.

Fig. 1 Content (µg/g dry matter) of total macamides, macaene and phytosterols in four different color types of Maca (sample size: 11 yellow, 7 red, 8 violet and 7 black Maca hypocotyls)