黑龙江省野生大豆、栽培大豆高异黄酮种质资源筛选

利用改进的高效液相色谱法(HPLC)检测了黑龙江省野生大豆(Glycine soja)、栽培大豆(G. max) 60份种质资源的异黄酮含量.结果表明,不同类型大豆种质资源异黄酮含量有明显遗传差异,变幅为416.2～6808.2μg/g,野生大豆高于栽培大豆,筛选出高异黄酮野生大豆种质资源4份、高异黄酮栽培大豆种质资源2份.     

黄淮海大豆异黄酮含量分析与特异种质遴选

以黄淮海生态区181份栽培大豆与32份野生大豆为材料,采用高效液相色谱法测定其籽粒异黄酮及组分含量,分析该地区大豆籽粒异黄酮含量遗传变异,遴选高异黄酮特异种质,为相关基因克隆表达、RIL群体构建和专用型品种选育提供资源。结果表明,供试栽培大豆异黄酮含量在1462.6-6115.5 μg/g,平均为3558.2 μg/g,最大差异可达4.2倍;供试野生大豆异黄酮含量在3896.1-7440.4 μg/g,平均为5182.4 μg/g,最大差异可达1.9倍。可见,黄淮海生态区大豆资源异黄酮及组分含量存在较大遗传变异,且野生大豆异黄酮平均含量显著高于栽培大豆。从供试资源中遴选出异黄酮含量超过6000 μg/g特异种质4份（超过7000 μg/g种质1份）。     

代表性大豆种质异黄酮主要组分含量鉴定

采用HPLC检测方法,对100份不同来源的代表性大豆种质进行异黄酮含量分析,结果显示大豆种质中主要含有6种异黄酮组分,分别为黄豆苷（D）、黄豆黄苷（GL）、染料木苷（G）、丙二酰基黄豆苷（MD）、丙二酰基黄豆黄苷（MGL）和丙二酰基染料木苷（MG）,且异黄酮含量在不同生态区间和品种间均存在显著差异,变异丰富;南方产区大豆品种的异黄酮总含量最高（2465.48ug/g）,黄淮大豆产区次之（2308.48ug/g）,北方大豆产区最低（1705.89ug/g）;6 种主要异黄酮组分含量的变异系数变化范围为33.44%～52.03%。相关分析表明异黄酮总含量与各主要组分含量之间均呈极显著正相关,与脂肪含量呈极显著负相关（r = -0.323**）。在此基础上,筛选出高异黄酮含量的大豆种质2份,分别为平顶黑豆（4459.91 ug/g）和PI-567479（4073.95 ug/g）,低异黄酮含量的大豆种质2份,分别为茶色豆（857.74 ug/g）和牡丰1号（922.82 ug/g）,可以用于大豆异黄酮育种或遗传研究。     

豆粕营养成分对蝙蝠蛾拟青霉发酵产物的影响

为探索培养基中的豆粕以及制备豆粕的原材料大豆对蝙蝠蛾拟青霉发酵产物的影响,我们比较了不同品种大豆和用其制成的豆粕的主要营养成分含量,包括粗蛋白、粗脂肪、6种微量元素（钙、镁、铜、锌、铁、锰）和总异黄酮（大豆苷、黄豆黄苷、染料木苷、大豆苷元、黄豆黄素、染料木素）,以及豆粕作为培养基对蝙蝠蛾拟青霉发酵产物的生物量和有效成分含量包括腺苷、腺嘌呤、虫草素和麦角甾醇的影响,结果表明大豆中钙和大豆苷与发酵产物中腺苷含量正相关。豆粕中钙、大豆苷、大豆苷元、染料木素与发酵产物中腺苷含量正相关;豆粕中钙、镁、大豆苷、大豆苷元、染料木素、总异黄酮与发酵产物中腺嘌呤含量负相关;豆粕中铁与菌丝体干重值正相关。结果表明,培养基中的豆粕和原料大豆主要营养成分含量对蝙蝠蛾拟青霉发酵产物品质有显著影响。     

高效液相色谱法测定大豆乳清提取物中大豆异黄酮的含量

建立了大豆乳清提取物中大豆异黄酮含量的高效液相色谱测定方法。采用Nova-Pak C₁₈（3.9×150 mm,4 μm）色谱柱;以甲醇：0.4%磷酸=30：70（v/v）为流动相分析染料木苷和黄豆苷;流速为0.7 mL·min^-1;柱温为30℃;检测波长为260 nm。试验结果表明,大豆乳清提取物中的大豆异黄酮含量为72.5%,其组成以染料木苷和黄豆苷为主,二者比例接近1∶1,苷元型大豆异黄酮未检出。染料木苷和黄豆苷的平均回收率分别为98.1%和98.4%,相对标准偏差（RSD）分别为0.7%（n=5）和0.8%(n=5)。该方法快速、准确、重复性好。     

微生物发酵制备大豆异黄酮的研究进展*

综述了微生物发酵制备大豆异黄酮特别是染料木黄酮和大豆苷元所用的菌种、发酵的工艺条件,以及如何从发酵液中提取、分离、纯化大豆异黄酮。     

高效液相色谱(HPLC)技术鉴定中国南方大豆品种异黄酮主要组分

采用高效液相色谱(HPLC)技术检测中国南方六个省份的249份大豆品种异黄酮主要组分含量.结果显示大豆籽粒中可检测出6种主要的异黄酮组分,分别为大豆甙(Daidzin)、甲氧基黄豆甙原(Glycitin)、染料木甙(Genistin)、丙二酰基大豆甙(Malonyldaidzin)、丙二酰基黄豆甙原(Malonylglycitin)和丙二酰基染料木甙(Malonylgenistin).各组分中以丙二酰基(Malonyl)异黄酮组分含量最高(61.2%),且各组分间相关极显著.大豆品种间异黄酮含量变异较大,变异系数达49.6%.来自江苏省的品种海门红黄豆乙异黄酮含量最高(4932.3μg/g),品种宝应等西风含量最低(367.1μg/g).不同省份间异黄酮含量差异极显著,来自浙江省的大豆品种平均含量最高(2717.2μg/g),来自安徽省的平均含量最低(1181.8μg/g).异黄酮含量与生育期呈极显著正相关(r=0.319* * *),与百粒重呈显著正相关(r=0.132*),而与脂肪含量(r=-0.45* * *)和蛋白质含量(r=-0.136)呈负相关.     

大豆异黄酮浸种对盐胁迫大豆幼苗的生理效应

大豆异黄酮( Soybean isoflavones)是在大豆生长过程中形成并在成熟种子和叶片中积累较多的一类具有生物活性的次生代谢物,通常可作为人们日常生活中的一类营养保健品.研究了外源大豆苷或染料木苷溶液(0.01 mg/L)浸种处理对盐胁迫栽培大豆(N23674品种)和滩涂野大豆(BB52种群)及其经逐代耐盐性筛选的杂交后代(4076株系,F5)幼苗叶片伤害率、光合作用、Na+含量和Na+/K+值、活性氧清除酶活性及内源大豆异黄酮含量等生理指标的影响.结果表明:盐胁迫下,两种外源大豆异黄酮浸种处理均可显著抑制叶片相对电解质渗透率和硫代巴比妥酸反应物(TBARS)含量的上升及净光合速率(Pn)的下降,降低Na+含量和Na+/K+值,增强超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,提高内源大豆异黄酮含量,从而表现对盐害的缓解效应,其中对耐盐性较弱的栽培大豆N23674品种效应更明显.这为大豆异黄酮在大豆耐盐育种、化学调控和盐碱地种植利用等提供了理论依据.     

兔肠道大豆异黄酮还原菌株的分离鉴定及其转化特性

【目的】从兔新鲜粪样中分离对大豆异黄酮黄豆苷原和染料木素具有转化作用的特定细菌菌株。【方法】在厌氧工作站内对獭兔新鲜粪样进行梯度稀释后涂板,挑取单菌落与底物黄豆苷原和染料木素分别厌氧混合培养,用高效液相色谱检测底物被转化情况。【结果】分离得到一株对大豆异黄酮黄豆苷原和染料木素均具有转化作用的革兰氏阳性严格厌氧细菌菌株AUH-JLR41(KJ188150)。根据产物的高效液相保留时间、紫外吸收图谱和质谱分析结果,将菌株AUH-JLR41代谢底物黄豆苷原和染料木素生成的产物分别鉴定为二氢黄豆苷原和二氢染料木素。经手性高效液相系统检测,产物二氢黄豆苷原和二氢染料木素均呈现两个等面积物质峰,表明这两个产物的对映体过量率均为0。通过转化动态研究发现,菌株AUH-JLR41分别在底物黄豆苷原和染料木素加入48 h和72 h后将底物全部转化为产物,该菌株能转化底物黄豆苷原和染料木素的最大浓度均为0.6 mmol/L。经BLAST比对,菌株AUH-JLR41的16S r RNA基因序列与斯奈克氏菌属菌株Slackia equolifaciens DZE(EU377663)的相似性高达99.6%。【结论】兔肠道分离的斯奈克氏菌属菌株Slackia sp.AUH-JLR41在厌氧条件下能将大豆异黄酮黄豆苷原和染料木素分别还原为二氢黄豆苷原和二氢染料木素。     

光照对大豆幼苗组织中异黄酮含量和分布的影响

利用高效液相色谱（ＨＰＬＣ）测定了不同光照处理的大豆（Ｇｌｙｃｉｎｅｍａｘ（Ｌ．）Ｍｅｒｒｉ．）幼苗不同组织的异黄酮类含量。子叶中最高,叶片和根部相对较少。子叶的异黄酮以大豆甙和染料木甙及其丙二酰基结合体为主,且在光照条件下,异黄酮含量随光照时间的增加而显著升高;相反,黑暗中的异黄酮含量随苗龄的增加呈下降趋势;当子叶由黑暗转为光照处理以后,异黄酮含量同样随光照时间的增加而升高。在叶片和根部异黄酮含量和种类也因光照条件的不同而有很大差异。光照条件下,叶片中以染料木甙及其丙二酰结合体和黄酮芦丁为主,且随时间增加呈上升趋势;黑暗中的黄化叶片,则以大豆甙和丙二酰结合体为主,但随时间的变化不明显。在幼苗根部,黑暗条件下几乎检测不出异黄酮的存在;光照条件下,则可检测到５种异黄酮,其中以大豆甙元及其衍生物占主要部分。实验证实了光照对大豆异黄酮的积累有明显的促进作用     

Race and Racism in America and in Anthropology

Race in North America: Origin and Evolution of a Worldview . Audrey Smedley
Anthropology and Race . Eugenia Shanklin     

Degradation and conversion of somatostatin in normal and diabetic rats in vivo and in vitro

Plasma somatostatin-like immunoreactivity in the portal and jugular veins of streptozotocin diabetic rats was compared with that in normal control rats. In the diabetic group, somatostatin levels in the portal (p less than 0.05) and jugular (p less than 0.01) veins were both elevated compared with those in the control group. Moreover, the degree of elevation was greater in the jugular vein than in the portal vein. To further investigate the role of the liver in the clearance of somatostatin-28 in vivo, 2 micrograms of somatostatin-28 was administered as a bolus into the external jugular vein of intact and functionally hepatectomized rats. The mean half-time of somatostatin-28 was significantly longer in intact diabetic rats than in controls (p less than 0.05). The functional hepatectomy did not cause a significant difference in the half-time in diabetic rats but made it longer in control rats. These results suggest that the longer half-time of somatostatin-28 in diabetic rats in vivo is due to its slower hepatic clearance. The hepatic clearance of somatostatin-28 and somatostatin-14 was further studied in vitro using a recirculating liver perfusion method. The hepatic clearance of 1.2 nM of either somatostatin-28 or somatostatin-14 was significantly lower in diabetic rats than in controls (p less than 0.01). This indicates that elevated plasma somatostatin levels in diabetic rats are caused at least in part by decreased hepatic clearance of somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

MPD and DNA Bending in Crystals and in Solution

Bending of 15 to 24° is observed within crystal structures ofB-DNA duplexes, is strongly sequence-dependent, and exhibits no correlation with the concentration of MPD (2-methyl-2,4-pentanediol) in the crystallizing solution. Two types of bends are observed: facultative bends or flexible hinges at junctions between regions of G·C and A·T base-pairs, and a persistent and almost obligatory bend at the center of the sequence R-G-C-Y. Only A-tracts are characteristically straight and unbent in every crystal structure examined to date. A detailed examination of normal vector plots for individual strands of a double helix provides an explanation, in terms of the stacking properties of guanine and adenine bases. The effect of high MPD concentrations, in both solution and crystal, is to decrease local bending somewhat without removing it altogether. MPD gel retardation experiments provide no basis for choosing among the three models that seek to explain macroscopic curvature of DNA by means of microscopic bending: junction bending, bent A-tracts, or bent general- sequence DNA. Crystallographic data on the straightness of A-tracts, the bendability of non-A sequences, and the identity of inclination angles in A-tract and non-A-tractB-DNA support only the general-sequence bending model. The pre-melting transition observed in A-tract DNA probably represents a relaxation of stiff adenine stacks to a flexible conformation more typical of general-sequence DNA.     

Deoxynivalenol and nivalenol in wheat and by-products in Argentina

The deoxynivalenol and nivalenol contamination in wheat and by-products obtained through milling was analized by Trucksess method slightly modified in the proportion of acetonitrile—water (3:1). Only one sample of wheat showed deoxynivalenol contamination, 1,200μg/kg. No samples obtained in different stages of the milling were contaminated with deoxynivalenol or nivalenol. In the commercial wheat flours the levels found ranged between 400 and 800μg/kg, as follows: 400μ/kg, 5 samples; 800jug/kg, 1 sample.     

Obestatin and ghrelin in obese and in pregnant women

We identified, through qPCR, receptor mRNA for a number of gut peptides in female human omental fat: the incretins, GIP and GLP-1, the orexigenic peptides PYY-Y1 and -Y2 and ghrelin, and the anorexigenic peptide obestatin. Four cohorts of women were examined: lean controls (BMI<23), obese (BMI>41), obese diabetic and term pregnant women. Human fat expressed receptor mRNAs for all six peptides. Pregnant women expressed roughly three times as much orphan GPR-39 receptor, a proposed obestatin receptor, than other women and less than half as much of the ghrelin receptor (GHSR-1a). An immunoblot probed with a GPR-39 selective antibody yielded a single band corresponding to the correct molecular weight (52 kDa) for the proposed obestatin receptor. Fluorescent immunohistochemistry of human fat employing the same antibody indicated the receptor protein was localized to the adipocyte cell membrane. The concentration of obestatin circulating in blood was measured in the same cohort of women and was significantly lower in obese and obese diabetic women compared to control.