Studies On The Chemical Constituents And Activities Of Lepidium Meyenii Walp.

Lepidium meyenii Walp.belongs to Lepidium L.which is an annual or biennial herb.Traditionally,Lepidium meyenii Walp.has the effects of invigorating the kidney and impotence,replenishing and restoring lung qi.Modern medical research shows that Lepidium meyenii Walp.has the effects of improving sexual function and fertility,anti-oxidation and anti-fatigue,improving memory and learning ability,regulating endocrine and enhancing immunity,inhibiting osteoporosis,treating menopause and anti-tumor.Objectives: The Objective is to separate the chemical compositions and identify the structures of the compounds from the rhizome of Lepidium meyenii Walp.The isolated compounds were screened for anti-oxidation,anti-bacterial and anti-tumor activity for the development and application of Lepidium meyenii Walp.Methods: Ethanol was used to extract the rhizome of Lepidium meyenii Walp.and obtained the ethanol extraction,then the extraction were extracted with petroleum ether,ethyl acetate,and n-butanol respectively to get three different polarity extractions.The chemical constituents were isolated and purified with silica gel column chromatography,ODS reversed-phase column chromatography,HP-20 macroporous adsorption resin column chromatography,Sephadex LH-20,HPLC and recrystallization.The structures of the compounds were identified by physicochemical properties and spectrum data.The anti-oxidant activity of alcohol extract and some compounds was determined by DPPH method.The minimum inhibitory concentration(MIC)of alcohol extraction and some compounds was determined by tube double dilution method.The inhibitory activities of some compounds on the proliferation of tumor cells HT-29,A549,and Hep G 2 were investigated by MTT method.Results: Seventeen compounds were isolated from the dried rhizome of Lepidium meyenii Walp.and their structures were identified as N-benzyl-hexadecanamide(I),benzeneacetamide(II),vanillic acid(III),nicotinic acid(IV),palmitic acid(V),coniferin(VI),pinoresinol-O-?-D-glucose(VII),?-sitosterol(VIII),daucosterol(IX),flazine(X),succinic acid(XI),niacinamide(XII),prunasin(XIII),5-(3-hydroxypropyl)-2-methoxyphenyl-?-D-glucopyranoside(XIV),adenine(XV),luteolin(XVI),quercitrin(XVII).Compounds VI,X,XII,XIII,XIV were isolated from Lepidium L.for the first time and compounds V,XV,XVII were isolated from the rhizome of Lepidium meyenii Walp.for the first time.Alcohol extract,pinoresinol-O-?-D-glucose and vanillic acid have a strong ability to remove free radicals.Some compounds of maca have different degrees of inhibition on Bacillus subtilis,Staphylococcus aureus,Candida albicans and Aspergillus niger.Flazine and5-(3-hydroxypropyl)-2-methoxyphenyl-?-D-glucopyranoside have inhibitory activity on Hep G 2 cell.And as the concentration of compound increases,the inhibition rate increases.Conclusion: Seventeen compounds were isolated from the dried rhizome of Lepidium meyenii Walp.Compounds VI,X,XII,XIII,XIV were isolated from the Lepidium L.for the first time and compounds V,XV,XVII were isolated from rhizome of Lepidium meyenii Walp.for the first time.Lepidium meyenii Walp.contains anti-oxidant active substances,and pinoresinol-O-?-D-glucose and vanillic acid are the material basis for Lepidium meyenii Walp.to exert anti-oxidant activity.Benzeneacetamide,nicotinic acid,flazine,pinoresinol-O-?-Dglucose and coniferin have bacteriostasis.Flazine and 5-(3-hydroxypropyl)-2-methoxyphenyl-?-D-glucopyranoside have inhibitory activity on Hep G 2 cell.The above experiments provide a theoretical basis for the development and use of Lepidium meyenii Walp.