Constituents of Lepidium meyenii ‘maca’ Ilias Muhammad a, *,JianpingZhao a ,D.ChuckDunbar a ,IkhlasA.Khan a,b a National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA b Department of Pharmacognosy, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA Received 8 May 2001; received in revised form 23 August 2001 Abstract The tubers of Lepidium meyenii contain the benzylated derivative of 1,2-dihydro-N-hydroxypyridine, namedmacaridine, together with the benzylated alkamides (macamides), N-benzyl-5-oxo-6E,8E-octadecadienamideand N-benzylhexadecanamide, as well as the acyclicketoacid,5-oxo-6E,8E-octadecadienoicacid.Thestructureelucidationoftheisolatedcompoundswasbasedprimarilyon1D and2DNMRspectroscopicanalyses,including 1 H– 1 HCOSY, 1 H– 13 CHMQC, 1 H– 13 CHMBCand 1 H– 1 HNOESYexperiments,as well as from 1 H– 15 N NMR HMBC correlations for macaridine and N-benzylhexadecanamide. # 2002 Published by Elsevier Science Ltd. Keywords: Lepidium meyenii;Brassicaceae;1,2-Dihydro-N-hydroxypyridine;Macaridine;Macamide; N-Benzyl-5-oxo-6E,8E-octadecadienamide; N- Benzylhexadecanamide; 5-Oxo-6E,8E-octadecadienoicacid;2DNMR; 1 H– 15 NNMR 1. Introduction Lepidium meyenii Walp. (Brassicaceae), commonly known as ‘maca’, is a nutritionally valuable native Per- uvianplantthatisusedintheAndeandiet(Leon,1964). This plant was domesticated at least two centuries ago in the Andean mountains, where natives used its tubers as food and as a folk medicine. L. meyenii is known to contain valuable nutritional ingredients (Dini et al., 1994)andisusedlocallyfortheenhancementoffertility andsexualbehaviorinmenandwomen,andasatradi- tional remedy of menopausal symptoms. The aphrodi- siac activity of L. meyenii after oral administration in mice has recently been reported by Zheng et al. (2000). Earlierchemicalworkontherootsofthisplantyielded mainly macaenes, macamides (alkamides), fatty acids, sterols and benzyl isothiocyanate (Zheng et al., 2000). However, other species of the genus Lepidium exhibit the presence of flavonoids, flavonoid glycosides (Fursa et al., 1970; KurKin et al., 1981) and alkaloids, includ- ingthe bis-benzyl imidazole derivatives from L. sativum (Maieretal.,1998). Several ‘maca’ dietary supplements 1 are currently available in the United States for the nutritional supple- mentofvarioussexualdysfunctionsinmenandwomen. As part of our continuing program to isolate marker compounds from traditional medicine and dietary sup- plements (Ganzera et al., 2001; Muhammad et al., 2001 a,b),thepresentstudydealswiththeisolationandchar- acterization of a 1,2-dihydro-N-hydroxypyridine deriva- tive,macaridine(1),togetherwiththehithertounreported constituents N-benzyl-5-oxo-6E,8E-octadecadienamide (2), N-benzylhexadecanamide (3) and 5-oxo-6E,8E- octadecadienoic acid (4),fromthetubersof L. meyenii. 2. Results and discussion The petroleum ether extract of L. meyenii tubers was subjectedtocolumnchromatography(CC),followedby a short flash-CC and centrifugal preparative TLC (see 0031-9422/02/$ - see front matter # 2002 Published by Elsevier Science Ltd. PII:S0031-9422(01)00395-8 Phytochemistry 59 (2002) 105–110 www.elsevier.com/locate/phytochem 1 MacaPure TM (Patentpending),PureWorldBotanicals,Inc.,375 Huyler Street, South Hackensack, NJ 07606, USA, Web address < http://www.madis.com/news/macapure_spec.html > ; Maca 750 TM , MedicinePlants,Webaddress: < http://www.maca750.com> . * Corresponding author: Tel.: +1-662-915-1051; fax: +1-662-915- 7989. E-mail address: milias@sunset.backbone.olemiss.edu (I. Muhammad).