title: New alkamides from maca (Lepidium meyenii).
abstract: Maca (Lepidium meyenii) has been used as a food in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements, with claims of anabolic and aphrodisiac effects, although the biologically active principles are not fully known. In an earlier chemical investigation, two new alkamides and a novel fatty acid, as well as the N-hydroxypyridine derivative, macaridine, were isolated from L. meyenii. Further examination has led to the isolation of five additional new alkamides, namely, N-benzyl-9-oxo-12Z-octadecenamide (1), N-benzyl-9-oxo-12Z,15Z-octadecadienamide (2), N-benzyl-13-oxo-9E,11E-octadecadienamide (3), N-benzyl-15Z-tetracosenamide (4), and N-(m-methoxybenzyl)hexadecanamide (5). Their structures were established by spectrometric and spectroscopic methods including ESI-HRMS, EI-MS, (1)H, (13)C, and 2D NMR, as well as (1)H-(15)N 2D HMBC experiments. In addition, the identity of N-benzyl-15Z-tetracosenamide (4) was confirmed by synthesis. These compounds have been found from only L. meyenii and could be used as markers for authentication and standardization.
authors.affiliation: Department of Pharmacognosy and National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA.
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhao
authors.forename: Ilias
authors.initials: I
authors.lastname: Muhammad
authors.forename: D Chuck
authors.initials: DC
authors.lastname: Dunbar
authors.forename: Jamal
authors.initials: J
authors.lastname: Mustafa
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
mesh_terms: D000577:Amides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D005227:Fatty Acids / Q000032:analysis; D029686:Lepidium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D035281:Plant Tubers / Q000737:chemistry*; D011725:Pyridines / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000577:Amides; D005227:Fatty Acids; D011725:Pyridines; C450176:macaridine