大豆异黄酮的AB-8树脂吸附梯度洗脱纯化精制工艺研究

以纯化精制大豆异黄酮为目的,研究了以AB-8大孔树脂为吸附剂,不同浓度梯度有机溶剂A洗脱流程的纯化精制效果.结果表明,以4.5mg大豆异黄酮/mL树脂的上样量,B溶剂→30%A溶剂→70%A溶剂一次上柱洗脱,40%A溶剂→70%A溶剂二次上柱洗脱的工艺流程,可以实现较高纯度大豆异黄酮的获得.     

大豆异黄酮高效液相色谱法测定的研究

通过试验选择了常温、超声波技术、80％甲醇水溶作为大豆异黄酮的前处理条件，所选检测色谱条件为；流动相：MeOH：0．3％H3PO4＝48：52(测定游离型异黄酮所用的流动相条件)；MeOH：0．3％H3PO4＝30：70(测定糖苷型异黄酮所用的流动相条件)；柱温：25℃；流速：0．7mL/min；检测波长：260nm。该研究对于大豆异黄酮的提纯与品质控制提供了有利的技术保证。     

Soybean Isoflavones Ameliorates Lactation Performance in Postpartum Mice by Alleviating Oxidative Stress and Regulating Gut Microflora

Postpartum dysgalactiae syndrome (PPDS) is one of the key issues affecting breastfeeding, usually occurring as breast swelling, a low milk yield, and at length a stop of breast milk secretion. Therefore, there is a need to investigate the effectiveness of Traditional Chinese Medicine (TCM) diet therapy in treating or preventing PPDS. This study aims to analyze the effect of soybean isoflavone (SIF), a natural estrogen found in plants, on postpartum lactation performance in mice and to evaluate its potential as a treatment for PPDS. Adult female BALB/c mice at 8 weeks of age (25 ± 3 g) are randomly divided into four groups fed with different levels of SIF and a normal diet for 14 days. SIF (0, 50, 100, 200 mg kg^-1 BW) is provided via intra-gastric route to the experimental mice. Using a high-throughput sequencing of microbial diversity and mammary gland metabolites, it is found that SIF-treated mice potentially show an improved milk performance via enhanced antioxidant capacity and altered gut microbiota. SIF from plant sources at a high dosage promotes the lactation in normal postpartum mice.     

Engineering of Leuconostoc citreum for Efficient Bioconversion of Soy Isoflavone Glycosides to Their Aglycone Forms

Soy isoflavones are phytochemicals that possess various beneficial physiological properties such as anti-aging, anti-tumor, and antioxidant properties. Since soy isoflavones exist in glycoside forms, their bioavailability requires initial hydrolysis of the sugar moieties bound to them to be efficiently absorbed through the gut epithelium. Instead of conventional chemical hydrolysis using acids or organic solvents, alternative strategies for enhancing the bioavailability of soy isoflavones using biological methods are gaining attention. Here, we engineered Leuconostoc citreum isolated from Korean kimchi for efficient bioconversion of soy isoflavone glycosides into their aglycone forms to enhance their bioavailability. We first constructed an expression module based on the isoflavone hydrolase (IH)-encoding gene of Bifidobacterium lactis, which mediates conversion of isoflavone glycosides to aglycone forms. Using a high copy number plasmid and bicistronic expression design, the IH was successfully synthesized in L. citreum. Additionally, we determined enzymatic activity of the IH using an in vivo β-glucosidase assay and confirmed its highly efficient bioconversion efficiency for various types of isoflavone glycosides. Finally, we successfully demonstrated that the engineered L. citreum could convert isoflavone glycosides present in fermented soymilk into aglycones.     

大豆异黄酮防治前列腺癌的研究进展

大豆异黄酮是广泛分布于豆荚类植物中的黄酮类化合物。流行病学研究表明大豆异黄酮对前列腺癌具有防治作用,该功能与大豆异黄酮能诱导前列腺癌细胞细胞凋亡、抑制生长增殖,增强放疗、化疗的功效,调节DNA损伤修复及DNA甲基化,拮抗雄激素介导的信号通路等有关。本文就近年来大豆异黄酮对前列腺癌的防治作用及机制作一综述。      

高效液相色谱法测定豆粕中大豆异黄酮的含量

采用超声波法提取豆油加工副产品豆粕中的大豆异黄酮,通过高效波相色谱法测定了其含量。在大量摸索性试验的基础上,确定出色谱条件为:色谱柱Waters RP_(18)(5μm,3.9mm×150mm),流动相甲醇:水:磷酸=52:48:0.2,柱温30℃,流速0.7mL/min,检测波长260nm。该测定方法的回收率为99.3％,变异系数小于3％。采用高效液相色谱法测定异黄酮的含量,具有灵敏、准确、重现性好等优点。     

强化大豆异黄酮的营养蛋白粉对去卵巢大鼠骨质疏松的预防作用

目的:探讨强化大豆异黄酮的营养蛋白粉对去卵巢大鼠骨质疏松症的预防作用.方法:运用切除大鼠卵巢的方法建立骨质疏松症模型,50只大鼠随机分为 5 组.假性手术对照组(Sham),去卵巢酪蛋白对照组(Ovx),未强化大豆异黄酮组(O-SI),中剂量大豆异黄酮组(M-SI),高剂量大豆异黄酮组(H-SI).喂养 14 d 后,处死大鼠取血并分离股骨,测定骨密度(BMD)、骨钙、骨磷,并检测实验大鼠血清骨钙素(BGP)含量及血清抗酒石酸酸性磷酸酶(StrACP)和碱性磷酸酶(AKP)活性.结果:强化大豆异黄酮的营养蛋白粉明显增加去卵巢大鼠的骨密度(P<0.01),骨钙(P<0.01),骨磷(P<0.01),并且可明显降低骨钙素含量(P<0.01)、及抗酒石酸酸性磷酸酶活性,增加血清碱性磷酸酶活性(P<0.01).结论:强化大豆异黄酮的营养蛋白粉对绝经后骨质疏松症具有明显的预防作用.     

大豆异黄酮糖苷水解工艺的研究

通过正交试验得到了大豆异黄酮糖苷水解为大豆异黄酮苷元的最佳工艺条件。最佳酸法水解工艺条件为:盐酸浓度3 mol/L,水解温度80℃,水解时间180 min,酸法水解率为81.31%;最佳酶法水解工艺条件为:pH 6.0,酶解温度38℃,酶解时间90 min,加酶量为0.9 mg(50 mg糖苷型大豆异黄酮提取物),酶法水解率为82.54%。酶法水解的效果优于酸法水解的效果。     

酶法水解大豆异黄酮

利用Absidiasp R菌株 ,通过液体发酵 ,得到了一种高活性的大豆异黄酮糖苷水解酶 ,该酶水解糖苷型大豆异黄酮的最适底物浓度为 7 5mg/mL ;最适反应时间为 1 5h ;该酶在温度为 2 0～5 0℃、pH为 4 0～ 7 0范围内相对稳定 ,最适酶解反应温度为 40℃ ,最适pH值为 5 0 ;金属离子对该酶活力的影响不显著 ,其中Co2 +、Zn2 +对该酶有激活作用 ,Ag+、Cu2 +对该酶有抑制作用 ,Fe3+浓度<5 0mmol/L时 ,对该酶有促进作用 ,当离子浓度 >5 0mmol/L时 ,则有抑制作用。利用实验获得的最适酶解条件反应 ,可使染料木苷生成染料木素的转化率达到 1 0 0 %。     

大豆异黄酮作为大豆溯源特征指标的筛选北大核心CSCD

采用高效液相色谱法对黑龙江省不同产地、不同品种大豆中大豆异黄酮含量进行测定,利用不同品种和产地大豆中大豆异黄酮单体含量的不同对大豆异黄酮溯源特征指标进行筛选。结果表明:同一产地不同品种之间大豆异黄酮单体含量总体差异显著(p<0.05),不同产地不同品种之间大豆异黄酮单体含量总体没有显著差异(p>0.05)。因此,可以利用不同品种大豆中大豆异黄酮单体含量作为对大豆异黄酮溯源特征指标实现品种溯源。