| BackgroundMaca Lepidium meyenii Walp),an annual herb of Brassicaceae family growing originally at 4000 4500 meters' altitude in the Andean region of Peru,has been cultivated by the indigenous people as staple food and a traditional medicine for centuries.Maca was found to possess many pharmacological activities,such as enhancing libido and fertility,increasing immunity function,anti-fatigue,inhibition prostate hyperplasia,and reducing menopause.In recent years,maca has been popularized almost all around the world as a dietary supplement because of its potential bioactivity,the consumption quantity of Maca has been increasing.However,the territory suitable for planting maca in Peru is less and less,resulting in a shortage of market supply of maca.The Food and Agriculture Organization of the United Nations FAO)recommended to promote the cultivation of maca around the world,many countries,such as USA,Japan,and so on,have introduced and planted maca,China has been planted maca,too,and the main growing area is in unnan,XinOiang,Xizang,Jilin.Maca contains various types of secondary metabolites,mainly including macaenes,macamides,glucosinolates,sterols,and alkaloids,among which macaenes and macamides are the characteristic components of maca.However,its clinical study is main on crude extract,and lack of the systerm study on the isolation,active functions for one single chemical composition.In order to further elucidate the mechanism of maca,elucidate its constituents,exploiting and utilizing it,we havecarried through the studies of systemic chemical constituents of the ethanol extract from maca produced in Heqing.So as to enhance the development of resources and control the quality of maca,this study mainly focused on fingerprint of 16 batches of the tuber of maca from different origin and varieties.ObjectiveStudy of the chemical constituents of maca can further clarify the basis of its efficacy substance and find new active ingredient resources,which lay the foundation for its further development and utilization.At the same time,the fingerprint of the maca from different origin and varieties were studies by HPLC,which can provide the basis of quality control reference for maca.Methods1.To investigate the chemical constituents of maca produced in Heqing.Eighteen compounds were isolated from the petrol ether extract and the n-BuOH extract of maca using combination of column chromatographies on MCI resin,silica gel,C18 bonded silica gel,and Sephadex LH-20,followed by semi-preparative HPLC and recrystallization.The purified compounds were identified on the basis of their physicochemical properties and spectral data UV,IR,1D-NMR,2D-NMR,MS).2.To establish the HPLC fingerprint and to research the quality of maca,we have study of 16 bactches of maca from different habitats.The chromatographic conditions were optimizedE Shimadzu LC-20 AD high-performance liquid chromatogramphy combined UV detector,Inertsil C18 column 5?m,4.6×150 mm),mobile AE 0.3%phosphoric acid,mobile BE acetonitrile,using a binary gradient elution program;Flow rate is 1.0 mLˇmin-1;The detection wavelength is 220 nm;The column temperature is30 ?.In Oection volume is 10 ?L.Results1.By various methods of isolation,eighteen compounds were isolated,which elucidated as macaolidine 1),tryptophan 2),daucosterol 3),3S)-1,2,3,4-tetrahydro-?-carboline-3-carboxylicacid 4),chlorogenic acid 5),luteolin 6),hyperoside 7),apigenin 8),palmitic acid 9),amber acid 10),?-sitosterol 11),N-benzylheptadecanamide 12),N-m-Methoxybenzyl)hexadecanamide 13),hexadecanoic acid,2-oxiranylmethyl ester 14),benzylamine 15),monasfluore B 16),macaridine 17),4-dimethylamino)-benzoic acid 18).2.16 batches of maca have a total of 13 peaks,the results showed that the similarity of the 16 batches of samples was above 0.9,and the highest similarity was0.998.The results of the methodology survey and the consequences of the fingerprints assessment are in accordance with the national standard of fingerprints of traditional Chinese medicine,so the method for establishing the chromatography fingerprints by HPLC can be used to reflect the characteristics of maca,which can be used as a reliable means for appraisal and assessment the quality of maca.Conclusions1.Compound 1 was a new phenylacetamide alkaloid,and compounds 4,14,16 were isolated from maca for the first time.2.The best extraction and chromatographic conditions were optimized by using single-factor optimization,which the 16 batches of maca HPLC fingerprint were established by optimized conditions,the results showed that a reliable analytical method has been established and it provides a quality control reference for maca and related products. |
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