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.     

野葛藤茎的异黄酮化学成分

从野葛Ｐｕｅｒａｒｉａ ｌｏｂａｔａ（Ｗｉｌｌｄ．）Ｏｈｗｉ藤茎中分离得到５个异黄酮类化合物,分别鉴定为：大豆甙元,芒柄花异黄酮,６,７－二甲３‘,４’－次甲二氧基异黄酮,大豆甙和葛根素。     

茉莉酸甲酯和ABA对野葛毛状根中异黄酮含量的影响

10～ 10 0 μmol·L-1茉莉酸甲酯 (MJ)可提高野葛毛状根培养液中葛根素和大豆甙元的水平 ,促进毛状根内总异黄酮含量的增加。而用 0 .5～ 2 .0mg·L-1ABA处理后 ,无论对野葛毛状根还是培养液中葛根素、大豆甙元的含量仅略有提高 ,但对总异黄酮的合成与分泌等则有显著的促进。 10 0 μmol·L-1MJ和 1mg·L-1ABA处理 2 4～ 72h ,可促进毛状根内葛根素和培养液中总异黄酮的水平 ,以处理 4 8h的增加量最大     

野葛花异黄酮化学成分研究

从野葛花中分离得到7个异黄酮类化合物,经理化和光谱鉴定分析为：尼泊尔鸢尾异黄酮（1）、尼泊尔鸢尾异黄酮7-0-β-D-葡萄糖苷（2）、葛花苷（3）、染料木素（4）、刺芒柄花素（5）、大豆甙元（6）和8-C-芹菜糖（1→6）-葡萄糖大豆甙（7）.     

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     

野葛藤茎的异黄酮类化学成分

从野葛Pueraria lobata(Willd.)Ohwi藤茎中分离得到5个异黄酮类化合物,分别鉴定为:大豆甙元(daidzein),芒柄花异黄酮(formononetin),6,7-二甲氧基-3’,4’-次甲二氧基异黄酮(6,7-dimethoxy-3’,4’-methlenedioxyisoflavone),大豆甙(daidzin)和葛根素(puerarin).     

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.     

葛藤与葛根中异黄酮类成分的比较

分析比较了野葛〔Ｐｕｅｒａｒｉａｌｏｂａｔａ（Ｗｉｌｄ．）Ｏｈｗｉ〕的藤（葛藤）和根（葛根）的主要异黄酮类活性成分。从葛藤中首次分离得到３个化合物,经化学方法和光谱鉴定,证实为大豆甙元（Ａ）、大豆甙（Ｂ）和葛根素（Ｃ）。采用双波长薄层扫描法测定葛藤与葛根中上述３种异黄酮化合物的含量,葛藤中大豆甙元、大豆甙和葛根素的含量分别为０．１９５％,３．９３３％和２．４８１％;葛根中则分别为０．０５９％,０．７１４％和４．３１５％。研究结果为葛藤新药源的开发利用提供了科学依据     

大豆异黄酮的分离与纯化

天然大豆异黄酮作为健康食品在防治骨质疏松和癌症方面具有一定功效。由于化合物结构相似,异黄酮甙元特别是高纯度黄豆黄素（glycitein）的获得有一定难度,文献报道大多是通过盐酸水解异黄酮甙的方法获得,而这种方法对环境污染和工厂生产设备腐蚀较大。本文报道了用醇溶剂进行固相提取以及硅胶柱色谱方对含有三种大豆异黄酮甙元的混合物产品进行分离。通过低成本和无环境污染的固相提取方法得到纯度为97％的黄豆黄素和纯度超过95％的大豆黄素（daidzein）;95％纯度的另一种大豆甙元金雀异黄素（genistein）则通过硅胶柱色谱分离得到。应用硅胶柱色谱,一次性分离了一种含有两个异黄酮甙：大豆甙（daidzin）和黄豆甙（glycitin）的产品。     

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。     

大豆籽粒发育过程中异黄酮合成相关酶基因的表达模式与异黄酮积累的相关分析

利用高效液相色谱法和实时定量PCR方法,分别测定了2个异黄酮含量显著差异的大豆品种鲁黑豆2号(LHD2)和南汇早黑豆(NHZ)在子粒发育过程中的异黄酮含量变化以及异黄酮合成相关酶基因的表达模式变化,试图分析异黄酮积累与各基因表达量变化的相关关系。结果表明在大豆子粒发育过程中,异黄酮含量逐渐升高,而不同异黄酮合成相关酶基因的表达趋势不同,CHS7、CHS8、CHR、CHI1A和IFS2的表达趋势与异黄酮积累模式基本一致,而IFS1和CHI1B1的表达趋势与异黄酮积累模式相反。IFR的表达模式在2个大豆品种中存在相反的趋势,在LHD2中与异黄酮组分积累趋势相反,而在NHZ中与异黄酮组分积累趋势相同。结果还表明,同一基因家族中不同基因在子粒发育过程中的表达量也存在差异。查尔酮合酶基因家族中CHS7和CHS8以及查尔酮异构酶基因家族的CHI1A的表达水平相对其他成员较高,异黄酮合酶基因家族中IFS2的表达量显著高于IFS1的表达量,预示这些基因家族在大豆子粒异黄酮积累过程中存在功能分化。此外,各基因表达模式与异黄酮积累的相关分析结果表明,不同基因表达模式与异黄酮积累的相关性在2个品种中也不尽相同。LHD2中CHS7、CHS8和IFS2在子粒发育过程中的表达量变化与不同异黄酮组分呈显著正相关,CHI1B1基因的表达量变化与不同异黄酮组分呈显著负相关。而在NHZ中,IFR在子粒发育过程中的表达量变化与多个异黄酮组分呈显著正相关。这预示了不同大豆品种异黄酮含量差异的潜在遗传基础。各异黄酮合成相关酶基因表达量变化的相关分析表明,在2个品种中,苯丙氨酸水解酶PAL1与4CL,4CL与CHS2以及CHS1与IFS2基因的表达量均呈现显著正相关。表明这些基因可能通过协同作用共同调控异黄酮的合成与积累。这些结果为今后利用基因工程提高大豆异黄酮含量奠定了基础。     

干旱胁迫对苗期大豆异黄酮合成的影响

以不同耐旱性的2个大豆品种(高耐旱JP-6、低耐旱JP-16)为研究材料,采用高效液相色谱和实时荧光定量PCR技术,分析不同时间持续干旱胁迫下,大豆叶片和根系中异黄酮的积累变化及关键酶基因的表达情况.结果表明:大豆根部异黄酮含量显著高于叶部,而异黄酮关键酶基因的表达量则在叶片中更高,耐旱品种JP-6根部的异黄酮积累量更大.随着干旱胁迫持续时间的增加,不同耐旱品种的异黄酮合成与积累变化规律存在显著差异:强耐旱品种JP-6的根和叶中,异黄酮积累量均呈现先下降后升高的趋势;而弱耐旱品种JP-16则相反,异黄酮积累量在不同部位中均呈现先上升后降低的趋势;除JP-6叶中C4H、4CL、IFS2等异黄酮合成上游基因外,其他不同品种、不同部位的关键酶基因表达量均随着干旱胁迫持续时间的增加,呈现先下降后上升的趋势.大豆叶片是异黄酮的主要合成部位,大豆根部也存在少量的异黄酮合成.弱耐旱大豆根部的异黄酮合成和最终积累量均较低,强耐旱品种则较高.根部异黄酮积累量高的大豆品种,其耐旱性更强.     

大豆异黄酮生物合成关键酶及其代谢工程研究进展

异黄酮是一类具有C-6/C-3/C-6骨架的二次代谢产物,具有抗氧化和抗肿瘤活性。异黄酮与黄酮类物质具有相似的苯丙烷生物合成途径。天然的绝大部分异黄酮分布在豆科植物中,目前在大豆中已经发现了超过12个异黄酮(苷)。大豆异黄酮的生物合成主要涉及三个关键的酶查尔酮合酶(CHS)、查尔酮异构酶(CHI)和异黄酮合酶(IFS)。总结了大豆异黄酮的提取分离方法和生物合成途径,着重综述了CHI、CHS、IFS生物学特征和功能及异黄酮的代谢工程研究。     

Developmental and nutritional regulation of isoflavone secretion from soybean roots

Isoflavones play important roles in plant–microbe interactions in rhizospheres. Soybean roots secrete daidzein and genistein to attract rhizobia. Despite the importance of isoflavones in plant–microbe interactions, little is known about the developmental and nutritional regulation of isoflavone secretion from soybean roots. In this study, soybeans were grown in hydroponic culture, and isoflavone contents in tissues, isoflavone secretion from the roots, and the expression of isoflavone conjugates hydrolyzing beta-glucosidase (ICHG) were investigated. Isoflavone contents did not show strong growth-dependent changes, while secretion of daidzein from the roots dramatically changed, with higher secretion during vegetative stages. Coordinately, the expression of ICHG also peaked at vegetative stages. Nitrogen deficiency resulted in 8- and 15-fold increases in secretion of daidzein and genistein, respectively, with no induction of ICHG. Taken together, these results suggest that large amounts of isoflavones were secreted during vegetative stages via the hydrolysis of (malonyl)glucosides with ICHG.     

Isoflavone glucoside stress metabolites of soybean leaves

The isoflavone glucosides daidzin, genistin and ononin, the isoflavones daidzein and formononetin, and glyceollins I-III accumulated in soybean leaves inoculated with phytopathogenic bacteria. Treatment of leaves with sodium iodoacetate or yeast extract also led to isoflavonoid accumulation. Various other stress-inducing treatments were not effective. Bacterially-induced accumulation of isoflavone glucosides and the occurrence of ononin and formononetin in soybean are reported for the first time.     

水提取法分离大豆异黄酮苷和苷元

本文建立了一种仅用水作为溶剂分离大豆异黄酮苷和苷元的方法。采用水加热提取的方法分离大豆异黄酮苷和苷元,分别对所用溶剂,提取温度,提取时间和物料比进行优化。实验上清液干燥后的固形物中大豆异黄酮苷含量为32．24％,苷元含量仅为3．05％,沉淀中大豆异黄酮苷元含量为72．03％,苷含量仅为4．28％。该方法经济,简单,绿色无毒,适合工业生产。     

食用真菌发酵豆浆过程中对豆浆中几种生物活性物质的影响

本实验以灵芝、金耳以及冬虫夏草作为发酵菌种,选用豆浆为基本原料配制培养基,在发酵过程中定时取样并测定其中几种生物活性物质的含量,分析各生物活性物质在发酵过程中的变化。研究结果表明,三种食用真菌发酵豆浆的发酵液中总游离型大豆异黄酮含量在发酵过程中均缓慢上升并分别在发酵72 h、24 h和36 h达到最高,与发酵初期相比分别增加了31.81μg/m L、19.05μg/m L和15.71μg/m L;三种食用真菌发酵液中蛋白质含量随着发酵时间的推移而降低的同时氨基酸含量均有增加,且发酵液中的肽主要是分子量范围在300 Da~1 500 Da之间的具有较高生物活性的小分子肽,发酵液中的必需氨基酸含量以及占总氨基酸含量的比值均有增加。本实验探究了食用真菌发酵豆浆过程中生物活性物质的变化,为日后的富集游离型大豆异黄酮、多肽以及氨基酸等生物活性物质实验提供依据,并为工业化生产提供实践基础。     

Endogenous isoflavones are essential for the establishment of symbiosis between soybean and Bradyrhizobium japonicum

Legume iso/flavonoids have been implicated in the nodulation process, but questions remain as to their specific role(s), and no unequivocal evidence exists showing that these compounds are essential for nodulation. Two hypotheses suggest that the primary role of iso/flavonoids is their ability to induce rhizobial nod gene expression and/or their ability to modulate internal root auxin concentrations. The present work provides direct, genetic evidence that isoflavones are essential for nodulation of soybean roots because of their ability to induce the nodulation genes of Bradyrhizobium japonicum. Expression of isoflavone synthase (IFS), a key enzyme in the biosynthesis of isoflavones, is specifically induced by B. japonicum. When IFS was silenced using RNA interference in soybean hairy root composite plants, these plants had severely reduced nodulation. Surprisingly, pre-treatment of B. japonicum or exogenous application to the root system of either of the major soybean isoflavones, daidzein or genistein, failed to restore normal nodulation. Silencing of chalcone reductase led to very low levels of daidzein and increased levels of genistein, but did not affect nodulation, suggesting that the endogenous production of genistein was sufficient to support nodulation. Consistent with a role for isoflavones as endogenous regulators of auxin transport in soybean roots, silencing of IFS resulted in altered auxin-inducible gene expression and auxin transport. However, use of a genistein-hypersensitive B. japonicum strain or purified B. japonicum Nod signals rescued normal nodulation in IFS-silenced roots, indicating that the ability of isoflavones to modulate auxin transport is not essential to nodulation.     

Novel major quantitative trait loci regulating the content of isoflavone in soybean seeds

Despite their medicinal, pharmaceutical, and nutritional importance of isoflavones, the genetic basis controlling the amounts of isoflavones in soybean seeds is still not well understood. The main obstacle is the great variability in the content of isoflavone in seeds harvested from different environments. In this study, quantitative trait loci (QTL) for the content of different isoflavones including daidzein, genistein, and glycitein were investigated in a population of recombinant inbred lines derived from the cross of “Hwangkeum” (Glycine max) by “IT182932” (Glycine soja). Seeds analyzed were harvested in three different experimental environments. QTL analyses for isoflavone content were conducted by composite interval mapping across a genomewide genetic map. Two major QTL were mapped to soybean chromosomes 5 and 8, which were designated QDZGT1 and QDZGT2, respectively. Both loci have not been previously reported in other isoflavone sources. The results from this study will be useful in cloning genes that can control the contents of isoflavones in soybean and for the development of soybean lines containing a high or low isoflavone content.     

Soyfoods and soybean products: from traditional use to modern applications

Soybean products (soyfoods), reported as potential functional foods, are implicated in several health-enhancing properties, such as easing the symptoms of postmenopausal women, reducing the risk of osteoporosis, preventing cardiovascular disease, and antimutagenic effects. Isoflavone, for example, is one of the most important compounds abundantly found in soybean, mainly accounting for the health-enhancing properties as mentioned earlier. However, most biological activities of isoflavones are mainly attributed to their aglycone forms. It has also been demonstrated that isoflavone aglycones are absorbed faster and in greater amount than their glycosides in human intestines. Fortunately, deglycosylation of isoflavones can be achieved during fermentation process by several strains such as lactic acid bacteria, basidiomycetes, filamentous fungus, and Bacillus subtilis with their β-glucosidase activity. This article presents an overview of soybean's chemistry, application, state-of-the-art advances in soybean fermentation processing and products as well as their applications in food and pharmaceutical industries. Different compounds, such as isoflavone, dietary fibers, and proteins which exhibit significant bioactivities, are summarized. The roles of different microorganisms in bioconversion and enhancement of bioactivities of fermented soybean are also discussed.