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。     

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     

大豆种子发育过程中异黄酮的积累

3个大豆品种种子中的异黄酮含量随着种子的发育进程而逐渐提高,尤其在种子成熟的最后1周内,异黄酮含量迅速增加,且与发育天数是显著正相关,与水分含量呈极显著负相关。在种子积累的不同异黄酮组分中,以雨二酰基结合体的含量最多,达总量的65％左右,而游离态积累的较少。     

双歧杆菌发酵对豆芽汁中大豆异黄酮含量及组分影响的研究

目的探讨双歧杆菌发酵对豆芽汁中大豆异黄酮含量及组分影响.方法采用HPLC法检测波长260 nm,测定豆芽汁中金省异黄素、大豆黄素的含量.结果表明通过发酵处理后,豆浆中总大豆异黄酮浓度没有明显的变化(P＞0.05);大豆异黄酮甙元的浓度较未经过发酵处理的豆浆组明显增加(P＜0.05);而大豆异黄酮糖甙的浓度却明显降低(P＜0.05).结论豆浆中的大豆异黄酮糖甙在双歧杆菌的β葡萄糖苷酶作用下水解为异黄酮甙元,异常酮甙元的浓度显著增加.     

西南大豆种质资源的化学评价及其与田间霉变抗性的相关性研究

以西南地区不同来源的15个大豆种质资源为研究对象,研究大豆主要化学成分与其田间霉变抗性间的相关性。采用高效液相色谱法测定大豆中12种异黄酮含量,气质联用法测定大豆中19种脂肪酸含量,分光光度法测定大豆皂苷、可溶性多糖、蛋白含量,并进行聚类及相关性分析。结果表明,15个大豆种质资源依据化学成分含量被分为5个类别,C103等材料的品质性状优良,具有较好的田间霉变抗性,可作为优质大豆种质资源进一步开发利用。棕榈酸、反亚油酸和芥酸等脂肪酸组分含量高的大豆材料其霉变程度更高,A环C-6位甲氧基化的GL型异黄酮(黄豆黄素、黄豆黄苷、乙酰黄豆黄苷、丙二酰黄豆黄苷)及异黄酮苷元含量高的大豆具有更大的抗霉变潜力。     

大豆微核心种质蛋白质及脂肪含量的遗传变异

大豆是人类最重要的植物蛋白和油脂来源。提高大豆蛋白质及脂肪含量一直是大豆品质育种的重要研究方向。采用NIR检测方法,对77份大豆微核心种质进行蛋白质及脂肪含量分析,探讨微核心种质蛋白质及脂肪含量的遗传变异特性及其与主要农艺性状的相关性,为种质利用及品质育种提供依据。结果表明,蛋白质含量和脂肪含量在品种间和生态区间均存在极显著的差异,变异丰富;蛋白质含量和脂肪含量的变异幅度为40.68%~50.03%和13.81%~21.51%,平均含量为45.95%和17.42%,变异系数为4.42%和7.96%;不同生态区品种蛋白质含量为南方品种>黄淮海品种>北方品种>国外品种,脂肪含量则相反。蛋白质含量与脂肪含量呈极显著负相关(r=-0.825**),与单株粒数和单株荚数呈极显著和显著负相关(r=-0.205**,r=-0.156*),与底荚高度呈极显著正相关(r=0.240**)。主成分分析显示,4个主成分可解释82.25%信息,分别为产量构成因子、品质因子、株型因子和粒重因子。     

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。     

中国北方地区大豆主栽品种五种成分检测与分析

对中国北方黑龙江省、吉林省、内蒙古3省50种大豆主栽品种进行检测分析,分别测定了蛋白质、脂肪、植酸、总异黄酮和胰蛋白酶抑制剂的含量。通过分析不同省份大豆品种各项指标平均含量得出：黑龙江省大豆蛋白质、植酸、总黄酮平均含量最高,脂肪氧化酶含量最低;吉林省大豆脂肪平均含量最高,蛋白质、总黄酮含量最低;内蒙古大豆脂肪氧化酶平均含量最高,脂肪、植酸含量最低。对不同省份之间大豆品种各项指标平均含量进行差异性分析得出：各省份脂肪、脂肪氧化酶平均含量差异显著或极显著,蛋白质、植酸含量差异显著或不显著,总黄酮含量差异不显著。各省大豆品种之间相关性分析结果表明：蛋白含量、脂肪含量、总黄酮含量和脂肪氧化酶含量之间两两呈负相关关系,植酸含量与蛋白质含量、总黄酮含量呈正相关关系,与脂肪含量、脂肪氧化酶含量呈负相关关系。     

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。     

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）。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.