Structural characterizations andα-glucosidase inhibitory activities of four Lepidium meyenii polysaccharides with different molecular weights

Four polysaccharides(MCPa,MCPb,MCPc,MCPd)were obtained from Lepidium meyenii Walp.Their structures were characterized by chemical and instrumental methods including total sugar,uronic acid and protein content determi-nation,UV,IR and NMR spectroscopy,as well as monosaccharide composition determination and methylation analy-ses.Four polysaccharides were a group of glucans with different molecular weights ranging from 3.12 to 14.4 kDa,and shared a similar backbone chain consisting of(1→4)-glucose linkages with branches attached to C-3 and C-6.Furthermore,bioactivity assay showed that MCPs had concentration-dependent inhibitory activity onα-glucosidase.MCPb(Mw=10.1 kDa)and MCPc(Mw=5.62 kDa)with moderate molecular weights exhibited higher inhibitory activ-ity compared with MCPa and MCPd.

Identification and quality evaluation of Lepidium meyenii. (Maca) based on gas chromatographic analysis of its essential oils from roots

Lepidium meyeniiWalp. （Maca）, a perennial herbaceous plant with narrow distdbution in the Andean region, was cultivated by local residents as early as 1600 B.C. It has high nutritional values and multiple medicinal effects. In recent years the plant source of Maca has been greatly scarce since Maca products are increasingly becoming popular in the world. This makes the study urgent on the identification and quality evaluation of Maca materials. In present work, four Mace samples of different origins or handlings and three other natural plants, including radish, odental ginseng and American ginseng, were investigated. Their essential oils （steam distillates） of the hypogeal parts were weighed and analyzed by GC/MS. Through comparison of the characteristics of their chromatograms, it was found that the essential oil of Maca had unique GC/MS behaviors, and the characteristic peaks produced by the major essential oil components （Phenylacetonitrile, Benzaldehyde, 3-Methoxyphenylacetonitrile, etc） were distinct. Furthermore, the chromatograms of several Maca samples showed a similar qualitative pattern except for some differences in the quantitative composition, and the percentage of total essential oils in the samples varied from 0.88 % to 1.59 %. These behaviors and technologies can be applied to the identification of Maca materials in the markets and be a supplement to assess the quality of Maca matedals.

玛咖(Lepidium meyenii.)干粉的营养成分及抗疲劳作用研究

本文对南美药食两用植物玛咖(LepidiummeyeniiWalp.)干粉的营养成分进行了分析,其中蛋白质含量达到8.87%,并发现含有大量的支链氨基酸和一定量的牛磺酸、矿物质锌等多种具有抗疲劳作用的营养成分,且通过动物试验证明了玛咖干粉具有显著抗疲劳功效。

Lepidium meyenii (Maca) improved semen parameters in adult men

Aim:The present study was designed to determine the effect of a 4-month oral treatment with tablets of Lepidiwnmeyenii(Maca)on seminal analysis in nine adult normal men aged 24-44 years old.Methods:Nine men receivedtablets of Maca(1500 or 3000 mg/day)for 4 months.Seminal analysis was performed according to guidelines of theWorld Health Organization(WHO).Serum luteinizing hormone(LH),follicle stimulating hormone(FSH),prolactin(PRL),testosterone(T)and estradiol(E_(2))were measured before and after treatment.Results;Treatment withMaca resulted in increased seminal volume,sperm count per ejaculum,motile sperm count,and sperm motility.Serumhormone levels were not modified with Maca treatment.Increase of sperm count was not related to dose of Maca.Conclusion:Maca improved sperm production and sperm motility by mechanisms not related to LH,FSH,PRL,Tand E_(2).

Effect of Lepidium meyenii(maca)roots on spermatogenesis of male rats

Aim:To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii(maca)on spermatogenesis in adult male rats.Methods;Male rats received an aqueous extract of the root(66.7 mg in onemL)twice a day for 14 consecutive days.Results:Treatment with Lepidium meyenii resulted in an increase in theweights of testis and epididymis but not the seminal vesicle weight.The length and frequency of stages IX-XIV seminif-erous tubules,where mitosis occurred,were increased and stages I-VI were reduced in rats treated with Lepidiummeyenii.Conclusion;The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initialstages(IX-XIV).

Effect of alcoholic extract of Lepidium meyenii (Maca) on testicular function in male rats

Aim: To evaluate the effect of the alcoholic extract of Lepidium meyenii (Maca) on the spermatogenesis in male rats. Methods: In Holtzman rats, Maca alcoholic extract (5%) was given by oral route at doses of 48 mg/day or 96 mg/day for 7 days, 14 days and 21 days. Testicular function was assessed by measurements of lengths of different stages of seminiferous epithelia and by epididymal sperm count. Results: Ethanolic extract of Maca increased the length of stages IX-XI of seminiferous epithelium at treatment day 7, day 14 and day 21. Progression of spermatogenesis was evident only after day 21 when lengths of stages XII-XIV of seminiferous epithelium were increased; at day 7 and day 14, no important change in spermatogenesis was observed. Epididymal sperm count was increased with 48 mg/day at all times. With 96 mg/day an increase in sperm count was observed at day 7, but it was reduced at day 14 and day 21 of treatment. Serum testosterone levels were not affected. Conclusion: The alcoholic extract of Maca activates onset ant progression of spermatogenesis at 48 mg/day or 96 mg/day in rats.

Lepidium meyenii (Maca) reduces spermatogenic damage induced by a single dose of malathion in mice

Aim: To observe the effect of the aqueous extract of hypocotyls of the plant Lepidium meyenii (Maca) on spermato-genic damage induced by the organophosphate insecticide malathion in mice. Methods: Mice were treated with 80 mg kg^(-1) of malathion in the presence or absence of an aqueous extract of Maca, which was orally administered 7, 14 or 21 days after injection of the malathion. Stages of the seminiferous epithelium were assessed by transillumination on days 0, 7, 14 and 21. Results: The administration of Maca increased significantly the length of stage 鈪?on days 7, 14 and 21 of treatment compared with the controls. An increase in the length of stage 鈪?occurred on day 14 of treatment. Malathion affected spermatogenesis by reducing the lengths of stage 鈪?on day 7, stages 鈪?and 鈪?鈪?on day 14 and a recovery of stages 鈪?鈪?on day 21. The magnitude of alteration in the length of stage 鈪?produced by malathion was significantly reduced by Maca on days 7 and 14. The length of stage 鈪?was increased when Maca was administered to mice treated with malathion. Assessment of the relative length of stages of the seminiferous epithelium showed that Maca treatment resulted in rapid recovery of the effect of malathion. Conclusion: Maca enhances spermatogenesis following spermatogenic damage caused by the organophosphorous pesticide.

Progress on the Chemical Constituents Derived from Glucosinolates in Maca(Lepidium meyenii)

Maca(Lepidium meyenii Walp.),a famous food supplement,has drawn an unprecedented international interest over the last two decades.It was assumed that glucosinolates,macamides,macaenes,and alkaloids are the main bioactive components of Maca before.Recently,a series of novel thiohydantoins which generally exhibit a variety of activities have been isolated from Maca.This review focuses on the progress on the main bioactive components of Maca and their biosynthetic pathway,which indicates that macamides,thiohydantoins,and some alkaloids may originate from glucosinolates.Interestingly,thiohydantoins from Maca are the first type of thiohydantoin derivatives to be found from a natural source and may contribute to some significant effects of Maca.

独行菜属植物玛咖(Lepidium meyenii)的微形态研究

利用光学显微镜和环境扫描电子显微镜,对不同颜色、不同产地玛咖(Lepidium meyenii)的叶表皮、花粉粒以及种皮进行了微形态学研究。结果表明:(1)不同颜色玛珈的叶表皮、花粉粒微形态具有高度的一致性,但与我国部分独行菜属植物有着明显的差异;(2)不同产地、不同颜色玛珈的种皮微形态有明显的差异。该研究为新植物资源玛咖的种质鉴定、分类提供了一些新的依据。

Qualitative Identification and Semi-Quantitative Comparison of Sucrose in Maca (<i>Lepidium meyenii</i>) by Infrared Spectrum Analysis

Objective: In order to establish a method for qualitative identification and semi-quantitative comparison of sucrose in Macas by infrared spectral analysis. Methods: Six Maca samples with three color types and from two producing areas in Yunnan province (China) were collected. Fourier trans-form infrared spectroscopy (FTIR) of raw Maca, ethyl acetate extracts (EtOAc-E), alcohol extracts (EtOH-E) and extracted residues were recorded selectively. Comparative analysis and analysis-through-separation strategies were used to explore the FTIR analytical method for sucrose in Maca. Results: Sucrose was proved to be a component in the Lijiang purple Maca (LPM) sample by comparative analysis of FTIR and second derivative in-frared spectroscopy (SDIR) with sucrose as a reference substance. Relative higher content of sucrose might be responsible for the distinctive absorption character of FTIR from LPM. With the aid of comparative analysis and analysis-through-separation strategies, conclusions could be drawn that all of the six Maca samples in this research contained some sucrose more or less. Furthermore, relative content of sucrose in the LM was higher than those in HM in general. Conclusion: An infrared spectrum analysis method for qualitative identification and semi-quantitative comparison of sucrose in different Maca samples was developed. Compared with other analytical methods, the developed method shows unparalleled charm for its inherent merits of convenient, fast, low cost, visual, efficient et al.

Identification of maca(Lepidium meyenii Walp.) and its adulterants by a DNA-barcoding approach based on the ITS sequence

Maca(Lepidium meyenii) is an herbaceous plant that grows in high plateaus and has been used as both food and folk medicine for centuries because of its benefits to human health. In the present study, ITS(internal transcribed spacer) sequences of forty-three maca samples, collected from different regions or vendors, were amplified and analyzed. The ITS sequences of nineteen potential adulterants of maca were also collected and analyzed. The results indicated that the ITS sequence of maca was consistent in all samples and unique when compared with its adulterants. Therefore, this DNA-barcoding approach based on the ITS sequence can be used for the molecular identification of maca and its adulterants.

Lepithiohydimerins A-D:Four Pairs of Neuroprotective Thiohydantoin Dimers Bearing a Disulfide Bond from Maca(Lepidium meyenii Walp.)

Main observation and conclusion An HPLC-UV-guided separation was performed and four pairs of unprecedented macathiohydantoin dimers,lepithiohydimerins A—D(1—4)bearing a rare disulfide bond were isolated from the tubers of Maca.Their structures were unambiguously confirmed by NMR spectroscopic,X-ray crystallographic and electronic circular dichroism(ECD)analyses.At the concentration of 20μmol/L,compounds 2-1,2-2,and 4-1 increased the viability of PC12 cells with the cell viability at(72.06±1.14)%,(72.64±1.49)%,and(70.93±1.22)%,respectively.Furthermore,the serial concentration experiment showed that they can protect PC12 cells in a dose-dependent manner.

有机肥与氮磷钾配施对玛咖产量和质量的影响

探讨有机肥与氮磷钾配施对玛咖品质和产量的影响,为优质玛咖种植及合理施肥提供参考依据。以玛咖优良品种“乌蒙黑玛咖”为材料,田间试验设置6个处理:CK、M(有机肥)、F1(常规施肥)、F1+M、F2(50%常规施肥)、F2+M。施肥显著提高玛咖地上部和根农艺性状、产量和品质。在8—9月以促进地上部生长为主,而在10月以加快玛咖根生长为主;玛咖前期生长对磷钾需求较高,而对氮的需求在整个生育期都高;施肥显著提高玛咖酰胺类化合物、玛咖烯、芥子油苷类化合物和灰分的含量,其中F1+M处理在酰胺类化合物、玛咖烯和灰分含量上均表现出最高,分别为192.79、7.93和3.97 mg/100 g,而芥子油苷类化合物含量则在F1处理最高,为2.47 mg/100 g;所有施肥处理中表现为F1+M处理产量最高,为11708 kg/hm^(2)。试验结果表明,F1+M处理下,即每公顷施用化肥N 120 kg、P_(2)O_(5)90 kg、K_(2)O 120 kg,同时配施精制有机肥7500 kg,可使玛咖产量和品质达到最佳。

玛咖脂溶性成分的GC-MS指纹图谱的构建及溯源

采用超声辅助法和气相色谱-质谱联用法对7个不同产地的玛咖的脂溶性成分进行了提取检测.计算了91种脂溶性成分中15个特征成分异氰酸苄酯、苯乙腈、苯乙酸、3-甲氧基苯乙腈、2-苯基乙酰胺、N-乙酰苄胺、棕榈酸甲酯、2-甲基-4-苯甲氧基吡啶氮氧化物、亚油酸甲酯、(Z,Z)-9,12-十八烯酸苄酯、十八烷-9,12,15-三烯酸苄酯、芥酸酰胺、N-苄基-(9Z,12Z)-十八碳二烯酰胺、N-苄基十六烷酰胺和(9Z)-N-苄基-9-十八碳烯酰胺的相对含量;通过对获得的数据进行比对分析,构建了玛咖的指纹图谱.采用主成分分析法提取得到3-甲氧基苯乙腈、亚油酸甲酯和N-苄基十六烷酰胺3个主要成分,它们总累计百分比达到88.947%.根据玛咖中三种主要的脂溶性成分的相对含量采用主成分分析法清晰的区分了7个产地的玛咖.

云南栽培玛咖的营养成分分析与评价

对云南栽培的玛咖营养成分进行了分析,并与文献报道的秘鲁产玛咖进行了比较。结果表明:云南栽培玛咖含有16.7×104mg.kg-1的蛋白质、21.5×104mg.kg-1粗纤维、9.30%氨基酸、多种无机元素、多种维生素等营养成分,脂肪含量低;所含营养成分的种类与秘鲁产玛咖类似,其中对人体有益的蛋白质、粗纤维、钙、铁、锌、VC等成分的含量较高,表明云南栽培玛咖的营养丰富,具有开发利用价值。

云南玛卡营养成分分析

为探明从国外引进种植的玛卡的营养成分,采用国标方法对云南玛卡进行分析。结果表明:云南玛卡干样中含蛋白质12.31%、粗纤维32.57%、脂肪0.92%、VC314.97mg/kg、钙1818mg/kg、铁81.2mg/kg、锌23.8mg/kg、钾18.7mg/kg、磷1895mg/kg等多种营养成分,脂肪酸中含有38.64%亚油酸、26.46%亚麻酸、17.73%棕榈酸,同时富含14.04%氨基酸。玛卡营养成分丰富,可以进一步开发利用。

云南栽培3种颜色玛咖中总生物碱含量分析

建立云南栽培玛咖的总生物碱含量的分析方法,分析评价3种色型玛咖的总生物碱含量。分别采用酸性染料比色法和酸碱滴定法对云南栽培的3种色型玛咖的总生物碱含量进行测定。结果表明:酸性染料比色法灵敏度高,相对标准偏差较小,是玛咖总生物碱含量测定的适宜方法;紫色、白色和黄色3种色型玛咖的总生物碱含量分别为4.4078、2.9193、2.2241mg/g,差异达到极显著水平(P<0.01);其中紫色玛咖的总生物碱含量最高,并与相关文献测定的来源于秘鲁的玛咖干粉的总生物碱含量相近。

三种色型玛咖芥子油苷组分及含量分析

【目的】分析和评价云南栽培的3种色型玛咖中芥子油苷的组成及含量,为其功能及活性物质基础的进一步研究提供理论依据和技术手段。【方法】以紫色、黄色和白色等3种色型玛咖块根的鲜样、真空干燥样品和自然干燥样品为原料,采用甲醇提取液,应用HPLC及LC-ESI/MS技术分别对原料中的芥子油苷组分及含量进行分析。【结果】3种色型玛咖中均含有两种芳香族芥子油苷:苄基芥子油苷(benzyl glucosinolate)和甲氧基芐基芥子油苷(methoxybenzyl glucosinolate),样品中苄基芥子油苷含量均明显高于甲氧基苄基芥子油苷。紫色、黄色和白色玛咖鲜样中的总芥子油苷含量分别为50.14、46.35、84.57μmol.g-1,自然干燥样品的总含量分别为13.05、14.35、14.94μmol.g-1,而真空干燥样品含量分别只有0.24、0.05、0.29μmol.g-1。【结论】云南栽培的3种色型玛咖中的芥子油苷组分相同,与文献报导的秘鲁产原料的芥子油苷组分基本一致。3种原料鲜样中的各组分芥子油苷含量及总含量均存在显著差异(P<0.01),其中白色玛咖的芥子油苷含量较高,3种色型样品均明显高于文献报导的秘鲁产原料。干燥样品的含量显著低于鲜样(P<0.01),粉碎干燥加工使玛咖中的芥子油苷发生了严重水解。

新疆产玛咖的挥发油成分研究

目的:检测新疆玛咖(Maca,Lepidium meyenii Walp.)挥发油成分及探讨提取过程中挥发油主成分的变化规律。方法:采用水蒸气蒸馏法和气质联用技术对新疆引种玛咖中的挥发油成分进行分析,并研究提取时间、缓冲液浓度对玛咖挥发油主成分的影响。结果:分离鉴定了新疆玛咖挥发油成分32种,用外标面积归一化法测得其总挥发油含量为1.72%,其中异硫氰酸苄酯、苯乙腈为其主要成分。通过对提取过程中挥发油成分的转化分析,发现提取时间和缓冲液浓度对所得的挥发油主成分有显著影响。结论:气质联用技术可用于引种玛咖的快速鉴别及品质分析,而提取过程中要对提取时间和盐浓度严格控制。

玛咖醇提取物对小鼠的抗衰老作用

目的探讨玛咖醇提取物的抗衰老作用及其机制。方法采用自然衰老小鼠为模型,连续ig给予玛咖醇提取物60 d后,测定小鼠血清、肝脏、心脏组织中谷胱甘肽过氧化物酶(G SH-Px)、超氧化物歧化酶(SOD)活性和丙二醛(M DA)的水平以及皮肤羟脯氨酸水平,免疫功能实验采用PHA刺激淋巴细胞转化及免疫器官指数的方法。结果玛咖醇提取物能显著提高老龄小鼠心脏和肝脏中G SH-Px活性及血清和肝脏中SOD活性,降低血清及肝脏中M DA水平,增加皮肤羟脯氨酸水平,提高PHA刺激的淋巴细胞转化率。结论玛咖醇提取物可能通过改善自由基代谢、增强细胞免疫发挥其抗衰老作用。