等吸光点紫外分光光度法测定红三叶草中总异黄酮含量的研究

目的应用等吸光点紫外分光光度法测定红三叶草中总异黄酮含量。方法本文以芒柄花黄素(formononetin)和鸡豆黄素(biochanin A)为混合标准品,应用紫外分光光度法在等吸光收点处(253.5nm)测定红三叶草中总异黄酮含量。结果研究表明等吸光点处的总吸光度与总异黄酮含量相关,而与二者的相对比例无关。测定的线性范围为2~8μg/m L,加样回收率为97.3%,相对标准偏差为1.08%。结论与已有的单标准品测试方法相比,以芒柄花黄素(formononetin)和鸡豆黄素(biochanin A)为混合标准品的实验方法更加稳定、准确,并且综合等吸光点紫外分光光度法快速、重复性好的优点,使得此方法适用于红三叶草中异黄酮含量检测,可为一般的红三叶草异黄酮的提取纯化研究和生产厂家提供参考。     

红车轴草提取物中异黄酮成分的分析

目的:以高效液相色谱法对红车轴草中四种主要异黄酮物质(大豆黄素、染料木素、鹰嘴豆芽素B和鹰嘴豆芽素A)的含量进行测定。方法:高效液相色谱法的条件:反相C18柱(250mm×4.6mm),MeOH-CH3CN-H2O(3.7:1.3:5,V:V:V)为流动相,流速1.0ml/min,进样量20μl,柱温为室温,检测波长为260nm。样品前处理方法:称取一定量的红车轴草提取物样品加盐酸甲醇溶液(42:500,V:V)40ml,于85℃水浴中回流水解2h,冷却后用甲醇定容到50ml,匀后用0.45μm滤膜过滤,取滤液。结果:经高效液相色谱法测定,以保留时间定性,以峰面积定量,得出红车轴草(1#)中四种主要异黄酮物质的含量分别为:大豆黄素(0.43%)、染料木素(0.35%)、鹰嘴豆芽素B(4.79%)和鹰嘴豆芽素A(1.32%);而红车轴草(2#)中四种主要异黄酮物质的含量分别为:大豆黄素(0.60%)、染料木素(0.64%)、鹰嘴豆芽素B(9.29%)和鹰嘴豆芽素A(2.63%)。     

红车轴草化学成分研究

目的对红车轴草各部位的化学成分进行系统研究。方法富集总异黄酮,然后采用多种色谱技术、重结晶等方法,对各部位分离、纯化,得化合物单体,通过理化常数和波谱数据分析鉴定化合物单体结构。结果从80%乙醇提取物的乙酸乙酯部位分离鉴定了13个化合物,分别为鹰嘴豆芽素A(1),芒柄花素(2),德鸢尾素(3),(+)-4-羟基-3-甲氧基-8,9-二氧亚甲基紫檀烷(4),玛卡尼(5),鹰嘴豆芽素A-7-O-β-D-吡喃葡糖苷(6)、三叶豆紫檀苷(7),芒柄花苷(8),豆甾醇(9),二氢槲皮素(10),槲皮苷(11),木犀草素(12),大豆素(13)。结论化合物9、10、12系首次从红车轴草植物中分离得到。     

北京地区不同大豆品种异黄酮含量比较研究

异黄酮是大豆生长过程中自然产生的化学物质,被认为可以治疗和预防一些人类依赖激素的疾病.为比较北京地区生态条件下大豆品种间异黄酮含量的差异性,对53个品种种子中3种异黄酮(大豆苷元、染料木素和黄豆黄素)进行测定和分析.结果表明,品种间异黄酮含量存在较大多样性,大豆苷元为39.21～2 363.65 μg/g,染料木素为77.35～1 149.50 μg/g,黄豆黄素为0.0～51.30μg/g,3种异黄酮总量为146.73～2 845.60 μg/g.来自山西和山东品种的异黄酮含量显著高于其他地区的品种.异黄酮总量分别与大豆苷元和染料木素呈极显著正相关,而大豆苷元和染料木素之间没有互作.因此,可以利用高含量大豆苷元或染料木素材料选育高异黄酮品种.     

不同生长期野葛与粉葛的活性成分及体外抗氧化活性研究

对比不同生长期野葛和粉葛的植物化学素及体外抗氧化活性,测定野葛和粉葛的异黄酮含量。采用HPLC方法测定葛根中葛根素、大豆苷、大豆苷元、染料木苷、染料木素、芒柄花黄素、鹰嘴豆芽素、异甘草素等8种异黄酮含量,研究两个品种葛根主要活性物质含量积累动态变化规律,并用DPPH、ABTS和FRAP 3种体外抗氧化方法评价生长期两种葛根的体外抗氧化性,以确定其适宜采收期。结果表明:随着生长期增加,野葛和粉葛中的异黄酮含量均大幅增加,尤其是野葛的总异黄酮含量增加了53%。生长期野葛和粉葛中各异黄酮含量均显著性积累增加(P0.05)。体外抗氧化性研究表明:野葛的体外抗氧化能力均高于粉葛,且随着生长期的增加,体外抗氧化活性随之增强,在12月份异黄酮含量和抗氧化活性达到最高水平。由此确定12月份适宜采收葛根。     

发酵大豆食品中染料木素含量的ELISA测定

染料木素是大豆发酵食品中的主要异黄酮成分。制备了牛血清白蛋白-染料木素免疫抗原和卵白蛋白-染料木素包被抗原,并对它们进行紫外和SDS-聚丙稀酰胺凝胶电泳鉴定。抗染料木素抗体的效价为1:1600。建立竞争ELISA测定发酵大豆制品中染料木素含量方法,染料木素测定浓度范围为6.25～150μg/L;回收率为87%～102%;亲和常数为1.62×108;与大豆甙元、芒柄花素的交叉反应率分别为9.8%、4.57%;与槲皮素、儿茶素、单宁和核黄素等结构类似物无交叉反应。同时将ELISA法与薄层层析法进行比较。     

液质联用测定薯蔓中黄酮类化合物的构成

以我国广泛栽培的徐薯18薯蔓为原料,中试设备水提多糖后的滤渣经醇提、AB-8树脂精制获得薯蔓黄酮(FSPV).利用HPLC-ESI-MS对FSPV进行分析,从获得的质谱分子量信息初步鉴定出了6个主要的黄酮甙元.进一步结合HPLC,通过与标样保留时间对比,确定FSPV中存在:染料木素、木犀草素、槲皮素、刺芒柄花素、芹菜素、山奈酚6种黄酮甙元.其中,首次报道薯蔓中存在染料木素和刺芒柄花素.     

酶水解对大豆异黄酮粗提物中苷元含量的影响

采用β-葡萄糖苷酶水解的方法将大豆异黄酮糖苷转化为苷元,以染料木素和大豆苷元含量为指标,通过单因素试验对水解过程中的不同影响因素进行了考察。以染料木素含量为指标,运用正交试验优化了β-葡萄糖苷酶水解大豆异黄酮的工艺条件为反应温度40℃、水解时间1.5h、水解介质pH4.5、水解底物浓度10mg/mL,在此条件下,水解得到的大豆异黄酮苷元中染料木素的含量可达到22.91%。     

怀槐培养细胞中异黄酮分析及其保肝作用

怀槐愈伤组织具有异黄酮合成能力，HPLC分析表明培养3周的愈伤组织中积累芒柄花黄素、染料木素、大豆甙元等三种主要异黄酮含量分别平均为53．4、12．3、17．4μg/gFW。愈伤组织经乙醇提取和乙酸乙酯萃取可有效去除杂质，萃取出的总异黄酮对小鼠四氯化碳急性肝损伤有显著的保护作用，可以有效降低肝损伤引起的血清GOT、GPT升高，增加血清TP、Alb的含量，效果均好于甘草甜素片。     

霉菌型豆豉和纳豆中异黄酮含量的比较研究

目的:比较纳豆和豆豉中异黄酮含量的组成变化。方法:利用超声波提取,采用高效液相色谱法测定,色谱柱填料为Hypersil ODS2(4.6 mm×250 mm,5μm),流动相为甲醇(A)-水(B)进行梯度洗脱,检测波长为255 nm。结果:豆豉与纳豆相比较,豆豉中大豆苷、黄豆黄苷、染料木苷、大豆甙元、黄豆黄素、染料木素的含量分别为11,未检出,25,320,65,380μg/g;纳豆中中大豆苷、黄豆黄苷、染料木苷、大豆甙元、黄豆黄素、染料木素的含量分别为330,73,410,12,3.3,28μg/g。结论:豆豉中甙元的含量高,纳豆中糖苷的含量高。     

Red clover (Trifolium pratense L.) isoflavones: determination of concentrations by plant stage,flower colour,plant part and cultivar

BACKGROUND: Red clover (Trifolium pratense L.), a widely used fodder, has recently received considerable interest as a valuable source of isoflavones for many health‐related applications. The aim of this study was to analyse the concentrations of four isoflavones, daidzein, genistein, formononetin and biochanin A, in extracts of leaves, stems, roots and different coloured flowers from red clover by high‐performance liquid chromatography and to determine the antifungal activities of the extracts. RESULTS: Among greenhouse‐grown samples the highest amounts of daidzein and genistein were found in petioles (0.11–0.28 and 0.30–0.54 mg g^?1 respectively), while leaves were rich in formononetin and biochanin A (5.57–9.05 and 10.94–14.59 mg g^?1 respectively). High formononetin concentrations were found in roots, but very little biochanin A. Among field‐grown samples the highest concentrations of daidzein and genistein were detected in stems collected in August (0.24 and 0.55 mg g^?1 respectively), while the highest amounts of formononetin and biochanin A were found in young leaves collected in June (7.47 and 9.69 mg g^?1 respectively). Most of the extracts inhibited the growth of Drechslera teres, while the root extract showed the strongest effect against Microdochium nivale. CONCLUSION: High levels of bioactive compounds found not only in inflorescences but also in roots, leaves and stems suggest that red clover may be an inexpensive and valuable resource for many applications. Copyright © 2007 Society of Chemical Industry     

Suppression of arachidonic acid metabolism and nitric oxide formation by kudzu isoflavones in murine macrophages

Inhibitory effect of kudzu isoflavones on arachidonic acid metabolism and nitric oxide (NO) production in lipopolysaccharide activated RAW 264.7 macrophages were investigated. Isoflavone aglycones, such as daidzein, genistein, biochanin A, and formononetin significantly suppressed arachidonic acid release (50 microM). Biochanin A, which displayed the most active inhibition on arachidonic acid release in HT-29 human colon cancer cells, exhibited its most potent suppression in RAW 264.7 cell (by 86%) without showing cytotoxicity. However, isoflavone glucosides, puerarin and daidzin, showed lower inhibitory activities on the release of arachidonic acid and its metabolites. In NO formation, biochanin A showed marked inhibition, by 62% (50 microM), followed by genistein, daidzein, formononetin, and daidzin, 56, 39, 33, and 8%, respectively. 5,7-Dihydroxyl group in the A-ring of isoflavones could be a key functional group responsible for the strong inhibitory activity of biochanin A and genistein on NO production. These activities may contribute to the antiinflammatory and anticarcinogenic properties of kudzu isoflavones.     

High levels of equol in organic skimmed Finnish cow milk

The isoflavonoids, equol, formononetin, daidzein, genistein, biochanin A, and O-demethylangolensin (O-DMA), were analyzed from commercial cartons of skimmed Finnish milk by HPLC-diode array detector (DAD)-FL. We found 411 +/- 65 ng/mL of equol and traces of formononetin and daidzein in organic skimmed milk whereas conventionally produced milk contained 62 +/- 16 ng/mL of equol and no formononetin or daidzein.     

Aquatic photochemistry of isoflavone phytoestrogens: degradation kinetics and pathways

Isoflavones are plant-derived chemicals that are potential endocrine disruptors. Although some recent studies have detected isoflavones in natural waters, little is known about their aquatic fates. The photochemical behaviors of the isoflavones daidzein, formononetin, biochanin A, genistein, and equol were studied under simulated solar light and natural sunlight. All of these phytoestrogens were found to be photolabile under certain conditions. Daidzein and formononetin degraded primarily by direct photolysis. Their expected near-surface summer half-lives in pH 7 water at 47° latitude are expected to be 10 and 4.6 h, respectively. Biochanin A, genistein, and equol degraded relatively slowly by direct photolysis at environmentally realistic pH values, though they showed significant degradation rate enhancements in the presence of natural organic matter (NOM). The indirect photolysis rates for these compounds scaled with NOM concentration, and NOM from microbial origin was found to be a more potent photosensitizer than NOM from terrestrial sources. Mechanistic studies were performed to determine the indirect photolysis pathways responsible for the rate enhancements. Results of these studies implicate reaction with both singlet oxygen and excited state triplet NOM. Environmental half-lives for biochanin A, genistein, and equol are expected to vary on the basis of pH as well as NOM source and concentration.     

Comparison of nutritional components (isoflavone,protein, oil,and fatty acid) and antioxidant properties at the growth stage of different parts of soybean [<Emphasis Type="Italic">Glycine max</Emphasis> (L.) Merrill]

This is the first study to investigate antioxidant capacities of isoflavones prepared using microwave-assisted hydrolysis method from different parts (seeds, leaves, leafstalks, pods, stems and roots) of soybean at growth stages. In addition, the fluctuations in the isoflavone, protein, fatty acid, and oil contents in R6-R8 (R6: beginning; R7: beginning maturity; R8: full maturity) seeds were confirmed. The R7 seeds exhibited the most predominant contents of isoflavones (1218.1±7.3 μg/g) in the following order: daidzein (48%)>genistein (35%)>glycitein (17%). The second highest isoflavone content was found in the leaves (1052.1±10.4 μg/g), followed by R8 seeds>roots>R6 seeds>leafstalks> pods; the stems exhibited the lowest isoflavone content (57.2±1.7 μg/g). Interestingly, daidzein showed the highest individual isoflavone content with remarkable variations (57.2-766.8 μg/g), representing 46-100% of the total isoflavone content. R8 exhibited higher protein, fatty acid, and oil contents than R6 or R7. Moreover, the antioxidant capacities against two radicals in different parts of soybean plant showed considerable differences depending upon the isoflavone content. Our results suggested that soybean leaves and seeds might be useful materials for functional foods.     

Distribution of isoflavones and coumestrol in neglected tropical and subtropical legumes

BACKGROUND: Isoflavones and coumestrol from dietary legumes are plant constituents showing multiple beneficial effects on humans. Owing to their ability to bind with mammalian estrogenic receptors and thereby intervention in several kinds of hormone‐related cancers, they have received much attention. Soybean (Glycine max) is currently the major source of isoflavonoids in human diet. However, dozens of tropical and subtropical leguminous species remain unexplored for their isoflavonoids content. RESULTS: We have analyzed 55 extracts from 41 tropical and subtropical legume species used either in human or animal diet by high‐performance liquid chromatography for the content of soy isoflavones, biochanin A, daidzein, daidzin, formononetin, genistein, genistin, sissotrin, ononin and the coumestan coumestrol. Genistein and biochanin A were the most abundant compounds. The highest content of genistein was found in aerial parts of Andira macrothyrsa, seeds of Pachyrhizus tuberosus and aerial parts of Calopogonium mucunoides (598, 250 and 184 µg g^?1, respectively) and biochanin A in aerial parts of Cratylia argentea, C. mucunoides and flowers of A. macrothyrsa (76, 53 and 40 µg g^?1, respectively). CONCLUSION: None of the samples tested was richer overall source of soy isoflavones and coumestrol than soybean; nevertheless several species (C. mucunoides or A. macrothyrsa) may serve as a promising source of individual compounds. © 2012 Society of Chemical Industry     

Occurrence and mass balance of isoflavones on an experimental grassland field

Isoflavones and coumestrol (COU) are estrogenic compounds that are naturally produced by plants (e.g., red clover, soybeans). Although these compounds have been extensively studied in food and feed, only little is known about their environmental fate. Therefore, we investigated the occurrence of isoflavones (formononetin, daidzein, equol, biochanin A, and genistein) and COU over 3.5 years in red clover, manure, and soil of a grassland field with and without manure application, as well as their emission via drainage water. Isoflavones were regularly quantified in plant (≤ 15 × 10(6) ng/g(dry weight (dw))), manure (≤ 230 × 10(3) ng/g(dw)), soil (≤ 3.4 × 10(3) ng/g(dw)), and drainage water samples (≤ 3.6 × 10(3) ng/L). In contrast, COU was observed only in manure and soil. Cumulative isoflavone loads emitted via drainage water were around 0.2 × 10(-3) kg/ha/y, which is very little compared to the amounts present in red clover (105-220 kg/ha/y), manure (0.5-1.0 kg/ha/y), and soil (0.1-5.1 kg/ha/y). Under good agricultural practice, no additional emission of isoflavones into drainage water was observed after manure application. With calculated 17β-estradiol equivalents up to 0.46 ng/L in drainage water, isoflavones can constitute a dominant and ecotoxicological relevant portion of the total estrogenicity in small rural river catchments.     

Determination of phytoestrogens in dietary supplements by LC-MS/MS.

Labelling data quantifying the exact content of individual phytoestrogen analytes in dietary supplements are generally poor. As these products are commonly used in the management of menopause symptoms, any clinical benefits would be dependent on the exact dosage of isoflavones received. Well-established extraction procedures and updated isotope dilution mass spectrometry liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) have been used to accurately quantify the concentrations of ten common isoflavones in 35 dietary supplement samples on sale in the UK, Canada and Italy. Concentration-specific ionization suppression is described for biochanin A and formononetin. All supplements contained phytoestrogens. The soya isoflavones (genistein, daidzein, glycitein) were present in all products and the majority also contained the red clover isoflavones (biochanin A, formononetin) and some the Kudzu isoflavones (daidzein, puerarin). The content of total isoflavones per dose ranged from <1 to 53 mg. Trace amounts of coumestrol were found in six products. Other less common analytes, the prenylnaringenins (6-prenylnaringenin, 8-prenylnaringenin, 6,8-diprenylnaringenin) were not found in any of the products. Only 14 of 35 supplements were found to deliver more than or equal to 40 mg day(-1) of aglycone isoflavones, a consensus dose value recognized as delivering therapeutic benefit. Eleven did not match label claims. Six delivered less than 10 mg day (-1) of isoflavones. There has been little improvement in the overall quality of industry labelling in the five years since this was last investigated. Consequently, the public, retailers and healthcare professionals should consider using standardized isoflavone supplements, which are supported by analytical measurements.     

Determination of phytoestrogens in dietary supplements by LC-MS/MS

Labelling data quantifying the exact content of individual phytoestrogen analytes in dietary supplements are generally poor. As these products are commonly used in the management of menopause symptoms, any clinical benefits would be dependent on the exact dosage of isoflavones received. Well-established extraction procedures and updated isotope dilution mass spectrometry liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) have been used to accurately quantify the concentrations of ten common isoflavones in 35 dietary supplement samples on sale in the UK, Canada and Italy. Concentration-specific ionization suppression is described for biochanin A and formononetin. All supplements contained phytoestrogens. The soya isoflavones (genistein, daidzein, glycitein) were present in all products and the majority also contained the red clover isoflavones (biochanin A, formononetin) and some the Kudzu isoflavones (daidzein, puerarin). The content of total isoflavones per dose ranged from <1 to 53 mg. Trace amounts of coumestrol were found in six products. Other less common analytes, the prenylnaringenins (6-prenylnaringenin, 8-prenylnaringenin, 6,8-diprenylnaringenin) were not found in any of the products. Only 14 of 35 supplements were found to deliver more than or equal to 40 mg day(-1) of aglycone isoflavones, a consensus dose value recognized as delivering therapeutic benefit. Eleven did not match label claims. Six delivered less than 10 mg day (-1) of isoflavones. There has been little improvement in the overall quality of industry labelling in the five years since this was last investigated. Consequently, the public, retailers and healthcare professionals should consider using standardized isoflavone supplements, which are supported by analytical measurements.