Physicochemical properties and biological activities of polysaccharides from the peel of Dioscorea opposita Thunb.extracted by four different methods

Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb.(DTTP).The influences of 4 extraction methods,namely hot water extraction(W),acidic extraction(HA),hot-compressed water extraction(HCW)and enzyme-assisted extraction(EAE),on the yields,physicochemical properties,hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared.Among these DTTP polysaccharides,DTTP-HA was outstanding in several respects.DTTP-HA was the most water soluble;it had the highest total carbohydrate content(85.08%),the highest uronic acid(13.20%)and the highest thermal stability.DTTP-HA and DTTP-W possessed a triple-helix structure.These 4 kinds of polysaccharides have the same types of monosaccharides,but in different molar percentages.Extraction method had a significant impact on the microstructures of the extracted polysaccharides.DTT-HA exhibited irregular structure with many holes.Among the 4 extracted methods,the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities.The better bioactivities of DTTP-HA may be related to the above factors.The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.

Effect of dioscorea opposite waste on growth performance, blood parameters, rumen fermentation and rumen bacterial community in weaned lambs

This study investigated the effects of dioscorea opposite waste(DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs(male,(22.68±2.56) kg initially) were used as the experimental animals. Four levels of concentrate: 0(control, CON), 10%(DOW1), 15%(DOW2) and 20%(DOW3), were replaced with DOW in the basal diet as experimental treatments. The results showed that lambs fed the DOW2 diet had a higher(P<0.05) dry matter intake(DMI) than the other groups. There was no significant difference(P>0.05) among DOW groups in average daily weight gain(ADG), and replacing concentrate with DOW linearly or quadratically increased(P<0.05) the ADG, while lambs fed the DOW2 diet showed greater(P<0.05) ADG than the CON group. The relative plasma concentration of growth hormone(GH), insulin like growth factor-1(IGF-1) and insulin were affected by DOW, replacing concentrate with DOW linearly or quadratically(P<0.05) enhanced the plasma concentration of GH, IGF-1 and insulin, which was significantly higher(P<0.05) in the DOW2 group than in the CON, DOW1 and DOW3 groups. In addition, the DOW treatment showed a lower(P<0.05) concentration of blood urea nitrogen(BUN) than the CON group. Replacing concentrate with DOW quadratically decreased(P<0.05) the ruminal ammonia nitrogen(NH3-N) and increased(P<0.05) the total of volatile fatty acids(TVFAs) at 0 and 4 h after feeding as well as linearly decreased(P<0.05) the NH3-N at 8 h after feeding. Replacing concentrate with DOW linearly decreased(P<0.05) the propionate and increased the aceate before feeding, and linearly decreased(P<0.05) propionate and quadratically increased(P<0.05) the aceate at 4 and 8 h after feeding. Lambs fed the DOW2 diet increased the phylum Firmicutes and genera Succiniclasticum and Ruminococcus_1 groups, whereas decreased(P<0.05) the relative abundance of phylum Deferribacteres and genera intestinimonas and Ruminiclostridium. In summary, replacing the concentrate with 15% DOW was beneficial for improving the rumen fermentation and ADG by increasing the DMI and modulating the rumen microbial community.

Effect of Purple Yam(Dioscorea alata L.) on Nutritional and Physiological Functions of Growing Rats

[Objective] This study was to explore the effect of purple yam on the nutritional and physiological functions of rats.[Method] Forty SD rats were randomly divided into four groups with ten rats in each group which were reared with artificial semisynthetic feed added with 10% steamed yam powder.The four groups,the casein（CK） group which was used as the control,the purple yam（PY） group,the Tiegun yam（TY） group and common Huai yam（HY） group,were supplied with feed of equal content of energy,protein and fat.The rats were pair-fed for 56 days to observe changes of relevant nutritional and physiological indices.[Result] There were no significant differences of body weight,food conversion rate and organ indices between rats in PY group and CK group.Mean corpuscular hemoglobin in PY group was significantly lower than that in CK group;hemoglobin showed no significant difference with that in CK group;eosnophils was lower than that in CK group.Low density lipoprotein-cholesterol,total cholesterol and atherogenic index in PY group were lower than that in the other three groups;anti-atherogenic index was the highest among the four groups,while showing no significant difference;triglyceride content was lower than that in CK group.Among the antioxidant indices,the activity of catalase and superoxide dismutase were higher than that in CK group,while malondialdehyde content was lower than that in CK group.[Conclusion] Purple yam showed the trend of reducing the content of blood glucose,total cholesterol,low density lipoprotein-cholesterol,triglyceride,malondialdehyde,and raising the activity of glutathione peroxidase,superoxide dismutase and catalase,thus having certain antioxidative function.

叶喷水杨酸对山药(Dioscorea alata L.)地下块茎蔗糖—淀粉转化影响(英文)

【目的】阐明叶喷水杨酸(SA)对山药地下块茎蔗糖—淀粉转化的影响,为了解山药蔗糖转化机制、提高其淀粉形成提供参考。【方法】设置SA 0.0(对照)、0.5、1.0和5.0 mmol/L 4个处理,在山药(Dioscorea alata L.)"白扁"地下块茎形成的早期和后期分别进行叶面喷施,定期采样测定地下块茎主要碳水化合物含量和蔗糖裂解与淀粉形成的相关酶活性。【结果】除5.0 mmol/L SA处理的后期地下块茎总可溶性糖(TSS)含量急剧增加外,地下块茎的TSS、蔗糖、葡萄糖、果糖、淀粉、直链淀粉(AM)、支链淀粉(AP)和纤维素的含量在其他处理间的变化趋势相同。与对照相比,0.5mmol/L与5.0 mmol/L SA处理对山药地下块茎的影响作用相反,前者不仅显著提高了蔗糖合成酶(SuSase)、酸性转化酶(SAInv)、细胞壁结合酸性转化酶(CWBAInv)、中性转化酶(NInv)等酶的活性,而且显著增加腺苷二磷酸焦磷酸化酶(AGPase)、可溶性淀粉合成酶(SSS)、颗粒结合淀粉合成酶(GBSS)、淀粉分支酶(SBE)等酶的活性,1.0 mmol/L仅在块茎发育中期对上述酶有微小的促进作用。所有SA处理中,虽然蔗糖含量与SuSase及淀粉合成相关酶的活性呈不显著正相关,但蔗糖与总可溶性糖含量的比率与这些酶活性及淀粉含量成显著正相关。葡萄糖、果糖含量及它们所占总可溶性糖的比率与上述酶的活性分别呈显著负相关,葡萄糖与果糖的比率与上述酶的活性无显著相关性,蔗糖与葡萄糖、果糖的比率均与AGPase、SSS、GBSS的活性呈显著正相关。【结论】叶面喷施SA在山药地下块茎发育过程中通过作用于蔗糖裂解和淀粉合成相关酶的活性来影响蔗糖的运输和流向,小于1.0 mmol/L的SA通过提高酶活性来促进蔗糖转运入山药地下块茎并转化成淀粉,而其他浓度SA具有相反的作用。

Total Saponins from Dioscorea Septemloba Thunb Reduce Serum Uric Acid Levels in Rats with Hyperuricemia through OATP1A1 Up-regulation

The aim of this study is to evaluate the efficacy of total saponins of Dioscorea（TSD）, an extract of the Chinese herbal Bi Xie, on hyperuricemia and to elucidate the underlying mechanisms. The rat hyperuricemia model was established by administration of adenine. Thirty-two rats were randomly allocated into 4 groups： model group, low/high-dose TSD-treated groups, and allopurinol-treated group. Meanwhile, 8 rats were used as normal controls. Serum uric acid（UA）, blood urea nitrogen（BUN）, serum creatinine（Scr）, and organic anion transporting polypeptide 1A1（OATP1A1） levels were measured. Comparison between the model group and treatment（allopurinol and TSD） groups showed the serum UA levels were significantly decreased in treatment groups. TSD had similar effects to allopurinol. It was found that the OATP1A1 protein expression levels in treatment groups were higher than in model group and normal controls. And different from the allopurinol-treated groups, TSD-treated group had elevated OATP1A1 expression levels in the stomach, liver, small intestine and large intestine tissues. It was suggested that TSD may facilitate the excretion of UA and lower UA levels by up-regulating OATP1A1 expression.

A New Furostanol Saponin from the Water-extract of Dioscorea nipponica Mak.,the Raw Material of the Traditional Chinese Herbal Medicine Wei Ao Xin

O-a-D-Glucopyranosyl-furost-5(6),20(22)-dien-3a,26-diol 1, a new furostanol saponin, was isolated from the water-extract of Dioscorea nipponica Mak., the raw material of a traditional Chinese herbal medicine Wei Ao Xin. The structure of 1 was determined on the basis of its spectral data especially by NMR spectroscopy. The result provides the first example of naturally occurring furostanol saponins with a single saccharide chain at the C-26 position.

Interspecific Crossing between Yam Species (Dioscorea rotundata and Dioscorea bulbifera) through in Vitro Ovule Culture

In the present study, in vitro ovule culture technique was used to obtain interspecific cross combination of Dioscorea rotundata ufenyi and Dioscorea bulbifera wild. Ten days after pollination, ovules were excised and cultured onto 1/2 strength Murashige and Skoog (MS) medium (Basal salt mixture + Vitamins) supplemented with 6% sucrose, 0.7% agar and plant growth hormones such as GA3, BAP, Picrolam and TDZ. Cultured ovules were transferred on 1/2 MS medium with 3% sucrose and 0.7% agar after three weeks. 40 days after pollination, germination was observed from 7 months cultured ovule between D. rotundata ufenyi x D. bulbifera wild. Hybridity of the regenerated plant was checked by flow cytometric method. A close relation was observed between the fluorescence intensity of the obtained progeny with one of the parents’ fluorescence. The observed progeny can be closely correlated with an apomictic tissue from an ovule parent of D. rotundata ufenyi. Plantlets derived from ovule culture were proliferated through in vitro shoot multiplication with hormonal concentration (0.5 mg/l BAP) supplemented with 1/2 strength MS medium. Obtained ovule culture derived in vitro plantlets were successfully hardened, acclimatized and transferred to the field, where they survived and grew normally. In plant breeding, interspecific crossing is very important technique, enabling the time needed to produce homozygous lines to be shortened as compared to the conventional plant breeding techniques.

Farmer Participatory Breeding - The Foster Parent in the Breeding of Dioscorea spp. in Ghana

Yam （Dioscorea spp.）, has been aptly described as an orphan crop. It has suffered institutional neglect from time immemorial. Until this study there were no formally released yam varieties in Ghana. The farmer participatory breeding approach was adapted to fast-track the development and release of three new yam varieties in Ghana. This paper uses the breeding process as a case study and conducts a SWOT analysis to provide guidelines for breeding for crops in Low External Input Agriculture. It was faster than conventional breeding in varietal development. Scientific quality of Farmer Participatory Breeding is as good as conventional breeding. Farmer Participatory Breeding is a must for breeding yam in Ghana. Ultimately, three genotypes 2000/001, KUP2000/001 and TDr89/02665 were accepted and released as new varieties ＂CRIKukrupa＂, ＂CRIPona＂ and ＂Mankrong Pona＂ respectively in March 2005. Danger of omission of some promising genotypes in the course of varietal development and danger of opinion group cabalizing the group discussions were identified as potential threats to the approach. Effective research-extension-farmer linkage was identified as extremely vital to the success of the approach. Farmer participatory breeding process was also sustainable and more efficient than conventional breeding in varietal selection in yam breeding.

Vertically Band-based Orientation Cultivation for Dioscorea opposita

The author made innovation on cultivation technology of Dioscorea oppo- site based on orientation tuberization. According to large furrow, big tuber, and lots of soils, a tuber bed is established suitable for yam growth, and a vertically band- based orientation is introduced. Specifically, soils are ground and colored bands are paved in bottom of furrows where tubers can be cultivated. At harvest, band soils can be removed to collect tubers. It is simple and easy. The yield can be as high as 75 000 kg/hm2. It is applicable in a variety of lands, especially for arid areas, mountains areas or under-forest lands with slopes from 10°to 25°. Semi-mechanical or mechanical planting and harvest can be applied with promising prospects.

野生盾叶薯蓣(Dioscorea zingiberensis C.H. Wrigh)资源储量精度估算

为保护野生濒危药源植物—盾叶薯蓣 (DioscoreazingiberensisC .H .Wrigh) ,笔者就其资源储量和地理分布进行了调查研究 ,将盾叶薯蓣在我国的地理分布划分为两个区 ,绘出该资源的地理分布示意图 ,我们对第I分布区资源储量进行了精度估算 ,结果为 :从总体上第I分布区平均蓄积量可估计为 44.0 5 3g/m2 ,此种估计产生的误差限为 7.1 47克 ,相对误差限 0 .1 62 ,作这种估计的精度为 0 .838,可靠性为 0 .95。此结果为保护生物学工作提供了有价值的资料。

黄独(Dioscorea bulbifera L.)不同居群叶表皮微形态特征的比较观察

应用扫描电子显微镜（SEM）对15个黄独（Dioscorea bulbifera L.）居群（11个野生居群及4个栽培居群）植株的叶表皮微形态特征（包括气孔器、表皮毛和气孔周围表皮细胞的特征）进行了观察和测量,并据此编制了15个黄独居群的检索表。观察结果表明：15个黄独居群植株叶片在气孔器外拱盖内缘类型,气孔器旋转方向,气孔长轴长度及密度和深度,叶片表皮毛的有无及类型,叶肉腺毛的长、短轴长度及密度,气孔周围表皮细胞垂周壁和平周壁的形态以及平周壁表面颗粒形状等特征上均有明显差异。气孔器外拱盖内缘有光滑和浅波状2种类型;气孔器的旋转方向分为不定向旋转、左旋和右旋3种方式;气孔长轴长度和密度的变化幅度分别为18.59~31.93μm和86~356 mm-2。叶片表皮毛均仅存在于下表皮,可分为乳突和多细胞头单细胞柄腺毛2种类型,乳突主要分布于主脉,腺毛主要分布于二级脉和叶肉;叶肉腺毛的长、短轴长度的变化幅度分别为25.00~55.00和24.86~44.29μm,大部分居群腺毛密度的变化幅度为6~29 mm-2。叶片气孔周围表皮细胞垂周壁的形状有平直、平直隆起、平直脊状隆起、弯曲、弯曲脊状隆起和弯曲拱状隆起6种类型;表皮细胞平周壁的表面纹饰有具瘤条纹和光滑条纹2种形态,其扩散方式也有2种形式：一种为不环绕气孔且四方扩散,另一种为环绕气孔2~3周后扩散但扩散方向不定;平周壁上的颗粒形状有簇晶状、屑状、密集粉状、粉状、粒状和片状6种类型。比较分析结果显示：黄独不同居群叶表皮微形态特征的多态性较为丰富,地理分布相近的居群微形态特征的相似性较高,这些特征与黄独的各种下分类群相对应。

与黄独(Dioscorea bulbifera)性别相关的RAPD-SCAR标记研究

对黄独(Dioscorea bulbiferaL.)14个居群42个单株的总DNA进行RAPD分析,并根据测序结果合成1对特异的SCAR引物,即5′-GGCTTCTGTCACTACATGGG-3′和5′-GGCTTCTGTCCAGTGCATCT-3′,对42个单株的总DNA进行检测,扩增到1条长681 bp的与雄性相关的特异片段。除形态上有一定变异的4个单株外,这个与雄性相关的RAPD-SCAR标记在黄独原变种的29个单株中验证准确,在可能为其变种的9个单株中部分验证准确,表明该RAPD-SCAR标记能够准确标记黄独的原变种及一些变种的雄性性别。

不同倍性盾叶薯蓣(Dioscorea zingiberensis)叶表皮形态的比较

通过对二倍体(2x=20)、三倍体(3x=30)、四倍体(4x=40)盾叶薯蓣植株叶片上下表皮细胞密度、细胞形状系数,气孔器大小、气孔指数、气孔密度,以及气孔器保卫细胞叶绿体数与倍性相关性的比较,探讨多倍体在盾叶薯蓣倍性育种上的前景。结果表明:随着倍性增加,盾叶薯蓣表皮细胞密度、气孔器面积、长、宽、以及保卫细胞宽、保卫细胞叶绿体数均明显增大。气孔器面积和保卫细胞宽与倍性成正比,且差异显著,可以作为倍性鉴定的手段之一。

野生及栽培盾叶薯蓣(Dioscorea zingiberensis)的性别特征观察

对野生和栽培盾叶薯蓣（Dioscorea zingiberensis C.H.Wright）的性别特征及变异状况进行了观察,并对栽培盾叶薯蓣母根状茎和子根状茎萌发植株的性别特征进行了比较。观察结果显示,在湖北武当山6个样地717株野生盾叶薯蓣中共有155株开花植株,其中雌株、雄株和雌雄同株分别有60、94和1株,雌雄株比例1∶1-1∶3,平均雌雄株比例1∶1.57,每个根状茎一般具有1支缠绕茎。2004年至2006年的观察结果显示,2004年153株栽培盾叶薯蓣基株中雄株、雌株和雌雄同株分别有78、62和13株;2005年存活的基株中雌株和雄株数量明显减少,雌雄同株数量大幅增加,雄株、雌株和雌雄同株分别有35、19和88株;2006年成活的137株基株中有80株开花,其中雄株、雌株和雌雄同株分别有38、9和33株,雌株和雌雄同株数量大幅下降。随栽培年限的增加,每个基株的缠绕茎数由1-2支增加至5-6支。栽培过程中盾叶薯蓣的性别有较大幅度变异,雄株和雌株多数转变为雌雄同株,反向转变却较少,雄株和雌株间相互转变也较少。2005年存活并开花的基株中共有100株发生变异,在2006年有13株返变回原性别,有26株保持了2005年变异的性别,有11株变异为另一种性别;雄株、雌株和雌雄同株3年的总变异率分别达到80.77%、100.00%和46.14%。子根状茎萌发植株的性别与母根状茎有较大差异,总变异率达到约50%,其中母根状茎为雄性的其子根状茎萌发植株的性别总变异率最高（59.09%）。研究结果表明,野生盾叶薯蓣可能以有性繁殖为主要繁殖方式,性系统简单清晰;栽培盾叶薯蓣复杂的性系统及大幅度的性别变异可能是由外部环境因子的影响造成的。

Polarographic Analysis of Diosgenin in Dioscorea zingiberensis C.H.Wright

目的:研究采用线性扫描极谱技术,测定薯蓣皂苷元(C_(27)H_(42)O_3,简称皂素)的分析方法。方法:用硫酸水解黄姜粉末,以乙醇提取薯蓣皂苷元,再用线性扫描极谱法进行测定。结果:在 pH=5.3±0.5的 B-R 缓冲溶液和0.1 mol·L^(-1)氯化钾底液中,薯蓣皂苷元产生极谱还原波,其一阶导数波的峰电位在-1.05 V(vs.SCE)处,峰电流与薯蓣皂苷元的浓度在一定浓度范围内有良好的线性关系,r=0.9989。建立了薯蓣皂苷元的极谱分析方法,成功地测定了黄姜中的薯蓣皂苷元,并讨论了极谱波的产生机理。结论:方法简便可行,结果准确可靠。本方法对黄姜中薯蓣皂苷元的测定结果与 Liebermann-Barcharad 光度法一致。

A New Steroidal Saponin from Dioscorea deltoidea Wall var. orbiculata

Bioactivity-guided fractionation led to the isolation of a new steroidal saponin, orbiculatoside B, together with a pair of furostanol saponins, protobioside and methyl protobioside, from the fresh rhizomes of Dioscorea deltoidea Wall var. orbiculata. The new compound was identified to be isonarthogenin 3 O - a - L - rhamnopyranosyl (12) - [ a - L - rhamnopyranosyl - ( 1 4 ) ] - b - D - glucopyranoside by various NMR techniques in combination with chemical methods. The three saponins showed strong activity against Pyricularia oryzae, and were cytotoxic to cancer cell line K562, HCT-15, A549, and A2780a in vitro.

A New Spirostanol Saponin from Dioscorea futshauensis

A new spirostanol saponin presenting strong activity of inducing morphological deformation of Pyricularia oryzae mycelia was isolated from Dioscorea futshauensis R. Kunth by bioactivity-guided fractionation. The structure was established as (25S)-spirost-5-en-3 beta, 27-diol-3-O- [alpha -L-rhamnopyranosyl (1 -->2)-beta -D glucopyranosyl (1 -->3)]-beta -D-glucopyranoside on the basis of chemical evidences and spectral analysis, especially by 2D-NMR techniques.

Three New Diarylpropanes from Dioscorea composita

Three new diarylpropanes were isolated from the dried rhizomes of Dioscorea composita Hemsl., and their structures were determined as 1, 3-bis-(2-hydroxy-4-methoxyphenyl) propane (1), 1, 3-bis-(2, 4-dihydroxyphenyl)propane (2), 1-(2′-hydroxy-4′-O-β-D- glucopyranosy- phenyl)-3-(2′′, 4′′-dihydroxyphenyl)propane (3), by spectroscopic analysis, respectively.

Identification of Polysaccharides from Chinese Yam(Dioscoreae opposite “Qi”) by Infrared Spectroscopy

In this study, the structure of polysaccharides from Chinese yam （Dioscoreae opposite ＂Qi＂） was analyzed and identified by infrared spectroscopy within an infrared spectral range of 400-4 000 cm^-1, Characteristic absorption peaks were observed at 840 cm^-1 （α-glucosidic bond）, 759.21 cm^-1 （xylose）, 830.87 cm^-1 （rhamnose）, 812.81 cm^-1, 876.60 cm^-1 （mannose） and 842.64 cm^-1 （arabinose） in infrared spectra of polysaccharides from D. opposite ＂Qi＂, indicating that D. opposite ＂Qi＂ polysaccharides exist mainly in the form of α-glucosidic bonds, including xylose, rhamnose, mannose and arabinose. The experimental results could provide the basis for quantitative analysis, development and application of polysaccharides from D. opposite ＂Qi＂.

In vitro modulation of TH1 and TH2 cytokine expression by edible tuber of Dioscorea alata and study of correlation patterns of the cytokine expression

The underground tuber of Dioscorea alata is a palatable food and is also claimed to have therapeutic effects.Various groups of researchers demonstrated different activities of this tuber such as antioxidant,hepatoprotective,anti-ulcer and anti-diabetic activities.Therefore,the aim of the present study was to evaluate the immunomodulatory potentialities of 70%hydro-methanolic extract of D.alata underground tubers by investigating different parameters like the expression of interferon gamma(IFN-),interleukin(IL)-2,IL-4 and IL-10,in addition to its effect on the proliferation of murine splenic T-lymphocytes in vitro.Results demonstrated that D.alata can actively polarize the TH0 lymphocyte population towards the expression of TH1 immune response by up-regulating the IFN-and IL-2 expression and down-regulating the IL-4 and IL-10 expression.The tuber extract also proved to possess mitogenic activity as evidenced by the proliferation of lymphocytes in vitro.©2014 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.