RP-HPLC测定小茴香中槲皮素和山奈酚含量

建立用反相高效液相色谱法同时测定小茴香中槲皮素和山奈酚含量的方法。采用Eclipse XDB-C18色谱柱(4.6 mm×150 mm,5μm);柱温:25℃;流动相:甲醇-0.4%磷酸(50∶50);流速:1mL/min;检测波长:360nm。槲皮素、山奈酚分别在2.19~109.6μg/mL和2.28~114.0μg/mL范围内线性关系良好。槲皮素和山奈酚的平均回收率分别为95.61%,94.41%,RSD分别为2.4%,3.0%。此方法简便、准确、可靠,可作为小茴香中槲皮素和山奈酚的定量分析方法。测定出小茴香总黄酮水解物中槲皮素和山奈酚的含量分别为:槲皮素0.29 mg/g,n=3,RSD=2.60%;山奈酚含量为:0.36mg/g,n=3,RSD=3.25%。     

八角中槲皮素和山柰酚的含量测定

利用反相高效液相色谱法测定八角中两种黄酮的含量。采用Zorbax Eclipse C18色谱柱(4.6mm×150mm,5μm),以甲醇-0.4%磷酸(V/V,50∶50)混合溶液为流动相,在360nm波长处进行测定。结果表明:质量浓度在0.025~0.5mg/mL时,槲皮素和山柰酚峰面积和浓度呈线性关系。槲皮素、山柰酚的平均回收率分别为97.45%,102.51%,RSD分别为2.3%,2.8%。在此条件下测得水解样中槲皮素0.508mg/g(n=3,RSD=2.860%)、山柰酚0.325mg/g(n=3,RSD=1.10%),总黄酮提取物中槲皮素0.110mg/g(n=3,RSD=1.29%)、山柰酚0.031mg/g(n=3,RSD=2.24%)。     

HPLC法同时测定枣叶中5种黄酮的含量

建立了一种枣叶中黄酮类成分定量分析的HPLC方法,并对14个品种的大枣及酸枣叶中这5种黄酮的含量进行了分析。结果得到采用Hypersil BDS C18色谱柱,以乙腈与0.1%甲酸水溶液为流动相梯度洗脱,流速1 m L/min,柱温30℃,检测波长360 nm,实现了槲皮素-3-O-洋槐糖苷、芦丁、槲皮素-3-O-β-D-葡萄糖苷、山奈酚-3-O-芸香糖苷、槲皮素-3-O-α-L-阿拉伯糖-(1→2)-α-L-鼠李糖苷5种黄酮苷的同时检测,最低检出限为1.44~2.59μg/m L,加标回收率在93.8%~105.9%之间。5种黄酮苷的含量测定结果表明不同品种的枣叶中黄酮类成分的组成和含量差异较大,其中芦丁和槲皮素-3-O-洋槐糖苷的含量较高,平均为7.83 mg/g D.W和4.61 mg/g D.W;8个品种枣叶中检测到槲皮素-3-O-α-L-阿拉伯糖-(1→2)-α-L-鼠李糖苷,平均5.32 mg/g D.W;而槲皮素-3-O-β-D-葡萄糖苷和山奈酚-3-O-芸香糖苷的含量较低,分别为0.14 mg/g D.W和0.41 mg/g D.W。     

天山北麓产区5个不同红色酿酒葡萄品种非花色苷酚类物质的积累特性

本试验为研究天山北麓产区5个不同红色酿酒葡萄品种非花色苷酚积累特性,选取五家渠产区5个红色酿酒葡萄品种,对其生长发育期黄酮醇和黄烷-3-醇含量及组成进行检测。其中黄酮醇包括:槲皮素、山奈酚和杨酶酮三大类。结果表明:‘赤霞珠’在花后12周时,槲皮素、山奈酚和杨酶酮三类物质都达到最大值0.122 mg/g、0.015 mg/g、0.065 mg/g;‘品丽珠’的槲皮素类物质在花后12周达到最大值0.500 mg/g,山奈酚和杨酶酮类物质在16周时达到最大值0.092 mg/g、0.068 mg/g;‘西拉’的山奈酚在14周时达到最大值0.043mg/g,而杨酶酮在16周时达到最大值0.042mg/g;‘小味尔多’的山奈酚和杨酶酮物质都在16周时达到最大值0.050mg/g、0.035 mg/g;‘马瑟兰’的山奈酚和杨酶酮分别在12和14周时达到最大值0.013 mg/g、0.077 mg/g。通过对5个品种的黄酮醇和黄烷-3-醇物质进行主成分分析,发现‘西拉’的黄烷-3-醇相对含量较高,‘小味尔多’山奈酚相对含量较高,‘赤霞珠’和‘马瑟兰’的槲皮素类物质相对含量较高。试验表明5个品种在该产区的积累特性各不相同,能直观反应各品种在该产区的表现,为日后天山北麓产区葡萄栽培和酿造提供更多帮助。     

HPLC法同时测定白刺果实中8种黄酮成分的含量

建立同时测定白刺果中没食子酸、儿茶素、杨梅素、芦丁、槲皮素、木犀草素、山奈酚和异鼠李素8种黄酮化合物含量的HPLC的方法。采用HYPERSIR C18色谱柱(250 mm×4.6 mm,5μm),柱温35℃,以甲醇-0.1%甲酸水溶液为流动相,进行梯度洗脱,双波长检测(λ1=270 nm,λ2=370 nm),进样量10μL,流速0.8 m L/min。结果:在0~125μg/m L内8种黄酮均有良好的线性关系(R2≥0.999 0),没食子酸、儿茶素、杨梅素、芦丁、槲皮素、木犀草素和山奈酚的平均回收率分别为98.42%,99.19%,90.65%,102.32%,96.51%,98.70%和93.68%,最低检出限依次为0.032,0.052,0.074,0.038,0.059,0.043,0.021和0.036 mg/L。方法精密度RSD≤2.21%(n=6),在此条件下,测得白刺果实中没食子酸、儿茶素、杨梅素、芦丁、槲皮素、木犀草素和山奈酚含量为0.031,0.057,0.064,0.068,0.016和0.038 mg/g。该方法快速简单,重现性好,可为白刺果实质量控制提供定量分析方法。     

油茶黄酮化合物对核桃油氧化稳定性研究

将油茶黄酮化合物添加到核桃油中,通过体外抗氧化实验,探究其对核桃油稳定性的影响。以油茶叶、油茶籽壳为原料,提取黄酮类化合物并通过高效液相色谱法定性定量分析;将黄酮类提取物按照油茶籽壳中杨梅素∶槲皮素∶山奈酚=1.15∶1.00∶1.05,油茶叶中杨梅素∶槲皮素∶山奈酚=2.36∶1.00∶1.60的比例添加到核桃油中,以200 mg/kg的TBHQ、BHA、VE做对照组,测定过氧化值、酸价、总抗氧化能力、还原能力等指标,研究杨梅素、槲皮素、山奈酚不同配比对核桃油氧化稳定性的影响。结果表明：油茶籽壳中杨梅素、槲皮素和山奈酚含量分别为：68.71、59.77、62.71 mg/100 g;油茶叶中杨梅素、槲皮素和山奈酚含量分别为：74.51、31.58、50.58 mg/100 g。对核桃油的抗氧化效果为：TBHQ>杨梅素∶槲皮素∶山奈酚=1.15∶1.00∶1.05>BHA>杨梅素∶槲皮素∶山奈酚=2.36∶1.00∶1.60>VE。油茶中的黄酮化合物作为一种天然抗氧化剂能有效延长核桃油的货架期;油茶籽壳黄酮化合物的抗氧化效果优于BHA、VE;油茶叶黄酮化合物的抗...     

银杏叶提取物中黄酮苷酶法转化苷元的研究

银杏叶提取物中的黄酮类化合物主要以苷形式存在,本文采用酶法水解黄酮苷中的糖基使其转化为苷元,提高抗氧化活性.银杏黄酮苷经过复合酶预处理后,黄酮苷含量仅为0.23%,再用转化酶水解可获得高含量的苷元,产品银杏苷元黄酮含量达59.65%,其中槲皮素占总黄酮苷元的24.87%,山奈酚占30.18%,异鼠李素占4.60%.     

HPLC-UV测定红酒中7种黄酮苷元及其生物活性物

建立了三元梯度的高效液相色谱法(HPLC)测定红酒中的桑色素、槲皮素,山奈酚、异鼠李素、木犀草素、芹菜素等苷元的含量的方法。采用Luna C18(4.6mm×150mm,3μm)色谱柱,预柱(4mm×3.0mm),柱温为50℃,流动相:A相乙腈,B相乙醇,C相为0.2%磷酸水溶液。流速为0.25mL/min,梯度淋洗,检测波长265nm。结果显示:各黄酮苷元在0.7mg/L~32.0mg/L呈线性关系,样品的加标平均回收率为98.2%~101.1%,RSD为1.88%~2.85%,该方法简便、准确,可用于天然产物中黄酮苷元的含量的测定。     

银杏类黄酮O-甲基转移酶活性的高效液相色谱分析

首次明确了银杏叶片类黄酮生物代谢关键酶O-甲基转移酶(flavonoid O-methyltransferase,FOMT)活性的HPLC测定技术与方法。采集扬州大学银杏种质资源圃银杏雄株成熟叶片,提取粗酶液,根据FOMT催化反应生成S-腺苷-L-高半胱氨酸(SAH)的原理,以山奈酚、槲皮素和异鼠李素等3种黄酮苷元为反应底物,采用优化的HPLC体系检测样品中FOMT催化反应生成的SAH峰面积,通过标准曲线求得不同反应底物的FOMT相对活性。FOMT活性反应生成物SAH在1.5～20μg/mL内呈良好的线性关系,RSD为2.1%(n=5),建立了FOMT活性测定优化体系。不同反应底物的FOMT活性表现不同,山奈酚与异鼠李素显著高于槲皮素。FOMT活性HPLC测定方法准确、快速、可靠、灵敏度高。     

新疆野生樱桃李(Prunus cerasifera)叶黄酮类成分研究

此项目研究了新疆野生樱桃李叶乙酸乙酯活性部位中的黄酮类化学成分。采用甲醇浸泡提取野生樱桃李叶,依次采用环己烷、乙酸乙酯和正丁醇萃取其醇提物。乙酸乙酯活性部分采用MCI (Middle Chromatogram Isolated Gel)大孔树脂柱粗分离,后续进一步采用硅胶柱、Sephadex LH-20凝胶柱,ODS (Octadecyl silane)反向硅胶柱和制备HPLC等色谱技术对其进行分离纯化,并根据化合物理化性质和核磁共振波谱(NMR)数据并与相关参考文献比对鉴定化合物结构。从野生樱桃李叶中共分离并鉴定11个黄酮类化合物,分别为:槲皮素-3-O-α-L-呋喃阿拉伯糖苷(1),槲皮素-3-O-β-D-木糖苷(2),槲皮素-3-O-β-D-半乳糖苷(3),槲皮素-3-O-α-L-鼠李糖苷(4),山柰酚-3-O-α-L-呋喃阿拉伯糖苷(5),山柰酚-3-O-β-D-木糖苷(6),山柰酚-3-O-β-D-葡萄糖苷(7),山柰酚-3-O-α-L-鼠李糖苷(8),反式-二氢山柰酚-3-O-α-L-鼠李糖苷(9),顺式-二氢山柰酚-3-O-α-L-鼠李糖苷(10),顺式-二氢山柰酚-3-O-β-D-葡萄糖苷(11)。所有黄酮类成分均为首次从新疆野生樱桃李叶中分离鉴定,槲皮素和山柰酚糖苷是其主要的黄酮类成分。     

Flavonoid content of commercial capers (Capparis spinosa, C. sicula and C. orientalis) produced in mediterranean countries

 The flavonol content of commercial capers (pickled flower buds of Capparis spinosa L., C. sicula Veill. in Duham. and C. orientalis Veill. in Duham.) produced in different Mediterranean countries (Spain, Italy, Greece, Turkey and Morocco) has been analysed. The content of quercetin 3-rutinoside, kaempferol 3-rutinoside; and kaempferol 3-rhamnosyl-rutinoside as well as the aglycones (quercetin and kaempferol) were evaluated by HPLC coupled with a diode-array detector. The free aglycones were not detected in the original flower buds, indicating that they were produced during the brining process. In addition, brining extracted most of the kaempferol 3-rhamnosyl rutinoside present in the original buds, this being a minor constituent in pickled capers. The average content of flavonoid glycosides in commercial capers was 5.18 mg/g fresh weight. When this value is converted to the corresponding aglycones (quercetin and kaempferol), capers provide an average of 3.86 mg/g fresh weight. A serving of capers (10 g) will provide 65 mg of flavonoid glycosides or the equivalent 40 mg of quercetin as aglycone. Received: 3 March 2000     

微生物转化沙棘黄酮苷生成黄酮苷元的研究

探讨微生物转化沙棘黄酮苷生成黄酮苷元的工艺条件。选取1 株黑曲霉菌株进行试验,考察发酵产物中主要黄酮苷元异鼠李素、槲皮素的含量变化。通过单因素和正交试验分别研究最佳氮源和转化条件,微生物转化后用HPLC 法测定。结果表明：以黄豆粉为氮源可得到最高的黄酮苷元含量;最优发酵条件为发酵温度30℃、装液量体积分数40%、转速180r/min、发酵时间96h,在此条件下,转化得到的异鼠李素为78mg/g,槲皮素为22mg/g。     

天山茶茎黄酮苷元提取工艺优化及其生物活性

为了优化天山茶藨茎5种黄酮苷元（木犀草素、槲皮素、山奈酚、异鼠李素、芹菜素）的酸水解提取工艺,评价其体外抗氧化和α-葡萄糖苷酶抑制活性,本文利用UPLC-MS/MS法测定天山茶藨茎5种黄酮苷元的提取率,通过单因素实验和正交试验优化天山茶藨茎黄酮苷元酸水解提取工艺。利用DPPH、ABTS自由基清除实验测定天山茶藨茎提取物及5种黄酮苷元的抗氧化活性,并测定了其α-葡萄糖苷酶抑制活性。结果表明,5种黄酮苷元的检出限、定量限分别在0.8~1.6、2.9~5.4 μg/L,在3.2~207.0 μg/L范围内具有良好的线性关系（R2≥ 0.9962）,方法的稳定性、精密度和重复性良好（RSD≤4.4%）。确定最佳酸水解提取工艺为:90%甲醇溶液（含5%盐酸）、提取温度:70℃、提取时间:100 min,该条件下,总黄酮苷元提取率为4.06 mg/g,RSD<5%,表明正交试验优化的提取条件稳定可行。天山茶藨茎提取物及5种黄酮苷元均具有一定的α-葡萄糖苷酶抑制活性和抗氧化活性,其中甲醇盐酸提取物与5种黄酮苷元的α-葡萄糖苷酶抑制活性均高于阳性对照阿卡波糖（IC₅₀:53.84±2.41 mg/L）,槲皮素对DPPH自由基的清除活性最好（IC₅₀:（2.94±0.18） mg/L）,木犀草素、山奈酚对ABTS自由基清除活性较好（IC₅₀分别为（5.34±0.10）、（5.55±0.17） mg/L）,它们的抗氧化活性高于阳性对照V_C。本研究建立的UPLC-MS/MS方法灵敏、精确、高效,可以对天山茶藨茎5种黄酮苷元化合物同时进行定量分析。优化的酸水解提取工艺能有效提高天山茶藨茎黄酮苷元的提取率。     

Antioxidant activities and major anthocyanins of Myrobalan plum (Prunus cerasifera Ehrh.)

Total phenolic content, total antioxidant activity of Myrobalan plum (Prunus cerasifera Ehrh.) and anthocyanin content in peel were analyzed in this article. In addition, ultra-performance liquid chromatography with photodiode array detection and electrospray ionization tandem mass spectrometry were used to determine anthocyanin composition of this fruit. The range of total phenolic content of the tested samples was 1.34 to 6.11 g/kg fresh weight (FW), and anthocyanin content in fruit peel of Myrobalan plum was from 1.93 to 19.86 g/kg peel. Ferric reducing antioxidant power values varied from 11.20 to 44.83 μmol Trolox equivalent/g FW. Four main kinds of anthocyanins in purple Myrobalan plum were detected while 6 kinds in red ones. PRACTICAL APPLICATION: The article showed the anthocyanin composition, phenolic content, and antioxidant activities of wild Myrobalan plum. The purple Myrobalan plum could be developed as a resource of fruit drinks because of its high antioxidant activity and the peel could be used as the resource to extract natural pigments.     

Determination of flavonoids by LC/MS and anti-inflammatory activity in Moringa oleifera

Moringa oleifera is an important multipurpose tropical tree under-recognized for its nutritional and medicinal properties. Leaves of moringa collected from sub-Sahara Africa were analyzed for phenolic components by HPLC–UV–MS. Twelve flavonoids were identified, including quercetin and kaempferol glucosides and glucoside malonates as major constituents. To facilitate quantitative analysis, acid hydrolysis during extraction of moringa samples was employed to convert the conjugates into their respective flavonoid aglycones, allowing accurate quantitation of total flavonoids as aglycones. Validation of the method demonstrated recoveries ranging from 92.6% to 107.5% for the two analytes. Using this method, total flavonoids from moringa collected from Ghana, Senegal and Zambia were determined and their content ranged from 0.18% to 1.64% (g/dry weight) across the respective environment or country of production and by variety. Moringa was found to exhibit anti-inflammatory activity of constituents-rich varieties. As flavonoid malonates are among the major constituents in the original plant material, a study examining thermal stability of flavonoid malonyl derivatives showed that these compounds were not thermally stable and easily cleaved to yield their respective flavonoid glycosides.     

Flavonoids and phenolic acids from Labisia pumila (Kacip Fatimah)

Both total phenolic content (TPC) and total flavonoid content (TFC) of Labisia pumila extracts were determined spectrophotometrically. L. pumila leaves extracted in 60% methanol (MeOH) were fractionated on C18 cartridge and the antioxidant property of each fraction was determined by measuring free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The 40% MeOH fraction exhibited the highest scavenging activity. Nine flavonols (quercetin, myricetin and kaempferol), two flavanols (catechin and epigallocatechin) and nine phenolic acids were identified from this active fraction by UPLC–ESI-MS/MS, and confirmed by comparison with the mass spectra of standard aglycones, theoretical fragments generated from MS Fragmenter software, and literature values.     

Composition of flavonoids in fresh herbs and calculation of flavonoid intake by use of herbs in traditional Danish dishes

Many herbs are known as excellent sources of natural antioxidants, and consumption of fresh herbs in the diet may therefore contribute to the daily antioxidant intake. The present study was performed in order to quantify flavonoids in commonly eaten fresh herbs. Fifteen fresh herbs (basil, chives, coriander, cress, dill, lemon balm, lovage, oregano, parsley, rosemary, sage, spearmint, tarragon, thyme, and watercress) were analysed by HPLC and mass spectrometry. Five major flavonoid aglycones were detected and quantified by HPLC after acid hydrolysis: apigenin, isorhamnetin, kaempferol, luteolin, and quercetin. The highest levels of flavonoids were found in parsley (510–630 mg apigenin /100 g), lovage (170 mg quercetin/100g), mint (18–100 mg apigenin/100 g), and dill (48–110 mg quercetin/100 g). Mass spectrometric detection, using atmospheric pressure chemical ionisation (APCI), was used to verify the presence of flavonoids in the hydrolysed extracts of herbs. Some traditional Danish dishes contain herbs, particularly parsley, dill, cress and chives, and the contribution to the flavonoid intake by consumption of these dishes was calculated.     

Flavonoids as biochemical markers of the plant origin of bee pollen

The flavonoid compounds present in almond (Prunus amygdalus, Rosaceae), Jara (Cistus sp Cistaceae), Echium sp (Boraginaceae) and Chrysanthemum sp (Compositae) bee pollens have been studied by TLC, 2D PC and HPLC techniques. These bee pollens show characteristic flavonoid patterns which allow their use as biochemical markers of their plant origin. In addition, the flavonoid patterns of natural almond and ?Jara’? pollens have been shown to be identical to those of the corresponding bee pollens confirming their use as chemical markers. The flavonoid aglycones obtained by acid hydrolysis of pollen flavonoids are also useful for identification purposes. Almond bee pollen contains 8-methoxykaempferol, kaempferol and quercetin 3-glycosides, ?Jara’? bee pollen produces quercetin and isorhamnetin 3-glycosides and trace amounts of myricetin and kaempferol 3-glycosides, Echium bee pollen contains mostly kaempferol 3-glycosides and traces of quercetin 3-glycosides, and Chrysanthemum contains kaempferol, apigenin, and quercetin 3-glycosides. The major compound in almond pollen, namely 8-methoxykaempferol 3-glycoside, was not detected in the related apple, pear, cherry and plum pollens.     

Antioxidant properties of various solvent extracts from wild ginseng leaves

Water, methanol and ethanol extracts of freeze-dried leaves of wild ginseng were examined for their antioxidant properties. All leaf extracts were capable of free radicals scavenging activity. Among solvent extracts of wild ginseng leaves, ethanol extract showed the highest DPPH, hydroxyl radical scavenging and ferrous ion chelating activity. Otherwise, the highest superoxide radical scavenging activity was found in water extract followed by ethanol and methanol extracts of wild ginseng leaves. Ethanol extracts contained more phenolics (2333.2 mg/100 g) and flavonoids (1199.1 mg/100 g) than other extracts. These differences in concentrations of key antioxidants among various solvent extracts seemed to be responsible for their differences in antioxidant activities. When various solvent extracts were hydrolysed by acid, two aglycons of flavonoid, quercetin and kaempferol, were detected. According to the results obtained from this study, wild ginseng leaves showed marked antioxidant activities due to their abundant antioxidants.     

苦荞麸皮黄酮提取物及有效成分的抑菌活性

研究苦荞麸皮总黄酮粗品及精品对病原菌的抑制作用,并初步分析其黄酮类成分,评价不同黄酮单体的抑菌活性。通过平板打孔法及二倍稀释法检测苦荞麸皮总黄酮粗品及精品及其4种黄酮单体的抗菌活性,使用高效液相色谱法定性定量检测苦荞麸皮总黄酮粗品及精品的黄酮成分。结果表明,苦荞麸皮黄酮精品对金黄色葡萄球菌、藤黄微球菌、肠球菌、大肠杆菌、志贺氏杆菌、沙门氏菌的抑制效果优于粗品。苦荞麸皮黄酮主要黄酮成分为芦丁、山奈酚-3-O-芸香糖苷、槲皮素和山奈酚,精品的总黄酮含量是粗品总黄酮含量的2.84倍。4种黄酮单体的抑菌能力具有一定的构效关系,其中槲皮素对所有供试菌均表现出较好的抑菌活性。