Antioxidant properties and involved compounds of daylily flowers in relation to maturity

The antioxidant properties of methanol extracts from daylily flowers during maturation were determined with antioxidant assays, including antioxidant activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging and reducing power. Antioxidant compounds, such as phenolic compounds, ascorbic acid and β-carotene were also analysed. Significant variation in antioxidant properties and involved compounds was observed between different maturity stages of daylily flowers. The highest antioxidant activity was observed at stage III (flower opening) accompanying the highest content of ascorbic acid and phenolic compounds, while no significant difference of β-carotene contents was observed among the four maturity stages. Four individual phenolics, such as (+)-catechin, chlorogenic acid, rutin and quercetin were identified and quantified by HPLC. (+)-Catechin was the main phenolic compound identified in daylily flowers, accounting for about 74.11% of total phenolics. Overall, daylily flowers at opening stage possess the highest functional benefit and thus would be the appropriate harvesting stage in view of the nutritional consideration.     

萱草花类黄酮提取、分析及其抗氧化性研究

为了开发利用萱草花资源,在萱草花类黄酮超声辅助提取工艺优化的基础上,利用高效液相色谱法分析了萱草花中类黄酮组分,并对不同品种萱草花的抗氧化性进行了分析。结果表明:萱草花类黄酮超声辅助提取最佳工艺条件为乙醇体积分数75%,超声功率198 W,超声时间23 min,在此条件下萱草花类黄酮提取率为91.15%;萱草花中含有儿茶素、表儿茶素、芦丁、异槲皮素和柚皮素,其中芦丁是萱草花中含量最多的类黄酮;"杜鹃"、"极地之光"和"火凤凰"三个品种的萱草花均具有较好的抗氧化性,以DPPH自由基清除率和·OH清除率为指标其等效V_C当量分别为10.88、24.22、17.55 mg/g(干重)和41.97、38.02、35.38 mg/g(干重)。本研究表明萱草花富含生物活性成分和抗氧化能力。     

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.     

Caffeic acid derivatives,total phenols,antioxidant and antimutagenic activities of Echinacea purpurea flower extracts

This study evaluated the effects of ethanol concentration and extraction temperature on the quality of extracts obtained from freeze-dried Echinacea purpurea flowers. The antioxidant and antimutagenic effects of flower extract were also examined. The optimal extraction conditions for freeze-dried flowers were 50% aqueous ethanol and 65 °C extraction temperature, with extraction yield of 37.4%. The contents of total phenols, caffeic acid derivatives, and cichoric acid in freeze-dried extracts were 473.34 mg chlorogenic acid equivalents/g, 302.20 mg/g and 217.61 mg/g, respectively. The 50% ethanolic flower extract did not show toxicity and mutagenicity toward Salmonella typhimurium TA98 and TA100 with or without S9 mix. The ethanolic extract at 0.25–5 mg/plate exhibits a dose-dependent inhibitory effect against the mutagenicity of 2-aminoanthracene. Thus, freeze-dried E. purpurea flower ethanolic extract exhibits good antioxidant and antimutaginic activities.     

蓝莓花、茎、叶酚类物质含量及抗氧化活性比较

比较蓝莓花、嫩茎、嫩叶及老叶总多酚、总黄酮、原花青素的含量,并研究其抗氧化性能差异。结果表明:嫩叶中总多酚含量最高,为43.77 mg GAE/g(以干质量计,下同),分别是花、嫩茎和老叶的3.45、1.42、1.12倍;老叶中总黄酮、原花青素含量最高,为68.01 mg RE/g、23.29 mg CAE/g,分别是花的2.57倍和4.61倍、嫩茎的1.79倍和1.23倍、嫩叶的1.03倍和1.98倍。抗氧化性能中,老叶的铁还原能力最大,其次是嫩茎和花,嫩叶较差;清除·OH的能力为嫩茎嫩叶花老叶;清除DPPH自由基能力和总抗氧化能力均为嫩茎嫩叶老叶花甲醇提取物,均高于对照品;蓝莓各部分提取物对DPPH自由基的清除能力最强,总抗氧化能力次之,清除·OH能力和铁还原能力较差。     

Proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera)

The proximate composition of seagrape (Caulerpa lentillifera) from culture ponds in Penghu, Taiwan was analyzed. The phenolic content and the antioxidant activities including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, ferric ion-reducing activity, hydrogen peroxide scavenging activity, and ferrous ion chelating (FIC) activity of the ethanolic extracts of dry seagrape samples using 2 drying methods of freeze drying and thermal drying were compared with the ethanolic extract of Oolong tea as a reference. The contents (dry weight basis) of carbohydrate, crude protein, crude lipid, crude fiber, and ash of seagrape obtained from culture ponds in Taiwan were 64.00%, 9.26%, 1.57%, 2.97%, and 22.20%, respectively. The total phenolic content (1.30 mg gallic acid equivalent [GAE]/g dry weight) of the ethanolic extract of thermally dried seagrape was significantly lower (P < 0.05) than that (2.04 mg GAE/g dry weight) of freeze-dried seagrape, and both were significantly lower than that (13.58 mg GAE/g dry weight) of Oolong tea. At the same phenolic content, the antioxidant activities of freeze-dried seagrape were significantly higher (P < 0.05) than those of thermally dried seagrape. Compared with Oolong tea, seagrape, irrespective of drying method used, generally had strong hydrogen peroxide scavenging activity; but it was weak in DPPH radical scavenging activity, ferric ion-reducing activity, and FIC activity. The antioxidant activity of seagrape and Oolong tea was significantly influenced by their phenolic contents. PRACTICAL APPLICATION: The proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera) in Taiwan were determined in this research to indicate nutritionally of this edible seaweed to human health, and compared these results to previous studies.     

龙眼核的营养成分及其活性物质的抗氧化性能研究

以3 个品种的龙眼核为原料,分析其基本营养成分及其乙醇提取物的抗氧化活性。结果表明：在石硖、储良、大乌圆3 个品种中,石硖中的淀粉、还原糖、总糖和蛋白质含量比储良和大乌圆高;三者的龙眼核乙醇提取物对DPPH·和·OH 有较好的清除作用,且石硖的清除能力略高于储良和大乌圆。但是三者的龙眼核的乙醇提取物对亚硝酸根的清除效果都不明显。     

石榴花游离型和结合型多酚提取物抗氧化活性探究

提取石榴花中游离型和结合型多酚粗提物,探究两种多酚提取物的抗氧化能力。采用Folin-Ciocalteu法测定粗提物总酚含量,利用5种体外抗氧化法测定其抗氧化活性。结果显示:游离型多酚粗提物多酚含量显著高于结合型多酚粗提物（P<0.05）;吸收过氧自由基能力（oxygen radical absorbance capacity,ORAC）和清除过氧自由基能力（peroxyl radical scavenging capacity,PSC）测定中,两种多酚粗提物具有与水溶性维E相似的明显荧光动力学特征与剂量依赖趋势,游离型多酚粗提物抗氧化能力强于结合型多酚粗提物（P<0.05）,水溶性维生素E抗氧化能力显著强于两种多酚粗提物（P<0.05）;游离型多酚粗提物DPPH自由基清除能力（DPPH radical scavenging activity,DRSA）、总氧自由基清除能力（trolox equivalent antioxidant capacity,TEAC）和还原力能力（reducing power,RP）均强于结合型多酚粗提物（P<0.05）,但两种多酚粗提物的抗氧化能力均低于阳性对照维生素C（P<0.05）。研究表明:石榴花游离型和结合型多酚粗提物均具有一定抗氧化活性,且游离型抗氧化能力优于结合型,此研究可为天然抗氧化剂的开发和利用提供一定理论依据。     

不同处理工艺对玫瑰花中抗氧化物质含量及抗氧化活性的影响

目的 研究不同处理工艺对平阴玫瑰中总黄酮、芦丁、总多酚含量及抗氧化活性的影响。方法 对干花直接提取、干花超微粉碎提取以及鲜花冷冻干燥提取3种不同处理工艺的平阴玫瑰进行水提,采用分光光度法测定水提液中总黄酮、总多酚的含量,高效液相色谱法测定水提液中芦丁含量,并对3种不同处理工艺的水提液进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除、羟自由基清除以及超氧阴离子清除能力的研究。结果 3种不同工艺处理的玫瑰花总黄酮含量、芦丁含量、总多酚含量及抗氧化活性均为：鲜花冷冻干燥>干花超微粉碎>干花直接提取。结论 经冷冻干燥处理后的平阴玫瑰抗氧化性物质含量及抗氧化活性均有升高,为玫瑰花抗氧化应用提供依据。     

滁菊的功能成分及其体外抗氧化活性

为明确滁菊中抗氧化活性物质的含量及其抗氧化能力,对其进行进一步的开发利用,对滁菊（Chrysanthemum morifolium Ramat）酚类、多糖、类胡萝卜素提取物抗氧化能力及含量进行研究。结果表明：滁菊总酚和黄酮含量较高,分别为53.67 mg/g和70.32 mg/g,高于大洋菊等菊花;多糖和类胡萝卜素含量较低。3 种提取物中,酚类抗氧化能力最强,对1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）和2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）阳离子自由基的清除能力分别为208.79 mmol/g和160.23 mmol/g,对Fe3＋的还原能力达到238.35 mmol/g,高于杭白菊等菊花。采用高效液相色谱法测定了滁菊酚类及类胡萝卜素单体组成,初步鉴定出滁菊含有绿原酸、儿茶素、咖啡酸、阿魏酸、金丝桃苷、槲皮素6 种单体酚,以及叶黄素和β-类胡萝卜素2 种类胡萝卜素单体。酚类物质中绿原酸含量最高,达到813.21 mg/g;金丝桃苷次之,达到408.17 mg/g;类胡萝卜素中叶黄素含量最高,为78.6 mg/g。在不考虑协同作用情况下,酚类物质中绿原酸对Fe3＋还原能力、DPPH及ABTS阳离子自由基清除能力的贡献均最大,类胡萝卜素中叶黄素对DPPH自由基的清除能力贡献最大。     

黄花菜多糖的表征与抗氧化活性分析

黄花菜是我国传统特色蔬菜干制品。为了挖掘黄花菜功能成分,采用硝酸调节水pH至1.8,提取黄花菜多糖,用Sevag法脱除蛋白,对黄花菜多糖基本特性、理化性质和体外抗氧化活性进行了分析。结果表明:脱除蛋白后黄花菜多糖得率为0.72%,多糖含量为34.91%,半乳糖醛酸含量为26.42%。黄花菜多糖含有高酯果胶,甲酯化程度值为96.13%±0.3%。黄花菜多糖中性糖分主要由半乳糖、葡萄糖、木糖组成,其摩尔比为62.50:17.31:11.30。显微观察发现,黄花菜多糖有絮状结构,表面不平整、不连续。傅里叶变换红外光谱（Fourier transform infrared,FTIR）表明,黄花菜多糖中含有较多的酯键。流变学特性分析表明,随着剪切速率增加,黄花菜多糖溶液的表观黏度先快速下降随后维持在较低水平;在各浓度下,其G'均大于G'。黄花菜多糖峰 1分子量较高,Mw为1310.32 kDa;峰 2分子量相对小很多,Mw为83.81 kDa。抗氧化分析表明黄花菜多糖具有较强的2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸自由基（2,2'-Azinobi-(3-ethylbenzthiazoline-6-sulphonate) radical,ABTS+·）清除能力和铁离子还原能力（Ferric reducing antioxidant power,FRAP）。研究结果为深入了解黄花菜多糖理化性质及其生物活性的开发利用提供了依据。     

Antioxidant activity, total phenolics content, anthocyanin, and color stability of isotonic model beverages colored with Andes berry (Rubus glaucus Benth) anthocyanin powder

The stability of anthocyanin (ACN) freeze-dried powders from Andes berry (Rubus glaucus Benth) as affected by storage, addition of maltodextrin as a carrier agent, and illumination was evaluated in isotonic model beverages. The ethanolic ACN extract was freeze dried with and without maltodextrin DE 20. Isotonic model beverages were colored with freeze-dried ACN powder (FDA), freeze-dried ACN powder with maltodextrin (MFDA), and red nr 40. Beverages were stored in the dark and under the effect of illumination. Half life of the ACNs, changes in color, total phenolics content (TPC), and antioxidant activity were analyzed for 71 d. Addition of maltodextrin and absence of light stabilized the color of beverages and improved ACN and TPC stability during storage. The antioxidant activity of the beverages was higher when they were colored with MFDA and highly correlated with ACN content. There was no correlation between antioxidant activity and TPC. It is concluded that addition of maltodextrin DE 20 as a carrier agent during freeze-drying improves the color and stability of nutraceutical antioxidants present in Andes berry extract. This suggests a protective enclosing of ACNs within a maltodextrin matrix with a resulting powder that could serve as a supplement or additive to naturally color and to enhance the antioxidant capacity of isotonic beverages.     

生何首乌体外抗氧化活性及抗菌活性的研究

研究生何首乌不同提取物的体外抗氧化活性及抗菌活性。在体外化学模拟的条件下,采用比色法,测定了何首乌水提物和醇提物对DPPH自由基的还原能力及抗脂质过氧化能力,羟基自由基的清除能力以及总体抗氧化能力。同时测定了何首乌水提物和醇提物的总酚酸和总黄酮的含量。利用滤纸片扩散法测定了何首乌水提物和醇提物对6种微生物的抗菌活性。何首乌醇提物的体外抗氧化活性强于水提物,具有显著的DPPH自由基和羟基自由基清除能力和较强的抗脂质过氧化能力,具有一定的还原能力,其总体抗氧化能力也比较强。何首乌水提取物和醇提取物的总酚酸和总黄酮含量分别126.52、77.25μg/mg和153.04、126.11μg/mg。另外何首乌的醇提物对金黄色葡萄球菌、四联球菌和大肠杆菌显示出较强的抑制活性,水提物对金黄色葡萄球菌和荧光假单胞菌显示出一定的抑菌活性。何首乌具有强的抗氧化活性与一定的抗菌活性。     

解淀粉芽孢杆菌发酵的3种水豆豉的营养成分、溶栓及抗氧化活性

用产纤溶酶的解淀粉芽孢杆菌CAUNDJ118制备黄豆、黑豆和双青豆3种水豆豉,对其营养成分、溶栓及抗氧化活性进行研究,结果表明:发酵后,3种水豆豉的总酚、总异黄酮类物质含量增加1.7~2.5倍,多肽及氨基酸态氮含量增加3.9~11.6倍。纤溶活性达86.5~102.5 FU/g干重,抗凝血活性IC50为0.27~0.36 mg/mL。DPPH自由基清除能力、ABTS清除能力和FRAP还原能力分别为6.8~15.5μmol TE/g干重,41.4~46.6μmol TE/g干重,8.7~13.6μmol Fe2+相当量/g干重。解淀粉芽孢杆菌CAUNDJ118发酵的3种水豆豉中,黑豆水豆豉具有最高的营养物质含量、溶栓及抗氧化活性,口感良好,豉香浓郁,具备开发成改善心脑血管疾病用功能食品的潜力。     

Contents of phenolics and flavonoids and antioxidant activities in skin, pulp, and seeds of miracle fruit

Miracle Fruit (Synsepalum dulificum) has been studied because of its unique taste modifying properties. This study investigated contents of phenolics, flavonoids, and antioxidant activities in skin, pulp, and seeds of Miracle Fruit. The free phenolic content in skin was almost 3 times of that in pulp and 4 times of that in seeds. Skin contributed 43.96% of free phenolic compounds with 15.91% of freeze-dried solids due to its high phenolic content. As the trend observed for phenolic content, the free flavonoid content in the skin was tremendously higher than that in the seed and pulp. The skin contributed about 52% of total flavonoid with 15.91% of dried solids. On other hand, the differences in the bound phenolic contents were not so distinct among the 3 components. The free antioxidant activities in skin and pulp were comparable, and were significantly higher than that in seeds. Although the antioxidant activities in seeds was considerably lower than that in skin, 49.45% free antioxidant activity, 76.41% bound antioxidant activity, and 58.56% of total antioxidant activity were contributed by seeds due to about 66% of solid of total solids. In general, the results of antioxidant activities using sequential methods were higher than that using direct method. This study suggests that Miracle Fruit is a good source not only for flavor and color, and also antioxidant activity for functional food applications.     

凤仙花提取物的抗氧化活性研究

利用不同溶剂和不同方法对凤仙花红色花瓣进行活性成分提取,采用试剂盒法对其进行抗氧化活性测定,结果显示凤仙花不同提取物均具有抗氧化活性,以凤仙花水提取物的抗氧化活性最强,100g凤仙花水提物的抗氧化能力相当于2.3gVC、0.76g槲皮素和0.02g芦丁的抗氧化能力。     

Antioxidant capacity of extract from edible flowers of Prunus mume in China and its active components

Prunus mume flowers are used as traditional edible and medicinal materials in China. In this study, phenolic compounds and antioxidant activity of ethanolic extract from flowers of P. mume in China were investigated for the first time. The total phenol content was estimated as gallic acid equivalents by the Folin-Ciocalteu reagent method. The antioxidant activity was measured by DPPH, ABTS⁺, and OH free radicals scavenging and ferric-reducing antioxidant power (FRAP). Three chlorogenic acid isomers, namely, 3-O-caffeoylquinic, 4-O-caffeoylquinic and 5-O-caffeoylquinic acids, were isolated and purified by preparative HPLC from the ethanolic extract and identified by UV, MS and NMR. The contents of these isolated compounds were quantified by HPLC. Results showed that 5-O-caffeoylquinic acid was of the highest level in these three isomers. The ethanolic extract demonstrated activity to some degree in all the antioxidant assays. In all tested assays, all of the isolated chlorogenic acid isomers exhibited strong antioxidant activities, which were almost the same. The results showed that chlorogenic acid isomers are the key phenolic compounds which are responsible for antioxidant activity of the ethanolic extract from Chinese P. mume flowers.     

大花罗布麻不同部位酚类物质含量及其抗氧化活性比较研究

目的：比较大花罗布麻根、茎、叶、花4 个部位中游离态和结合态酚类物质的含量和抗氧化活性的差异,并分析含量与抗氧化活性之间的相关性。方法：采用Folin-Ciocalteu法、NaNO2-Al(NO3)3法分析罗布麻的根、茎、叶、花4 个部位的游离态和结合态总多酚、总黄酮含量,采用DPPH自由基清除能力、ABTS+·清除能力和铁离子还原能力3 种方法评价其体外抗氧化能力差异。结果：大花罗布麻总酚含量次序为：叶＞根＞花＞茎,各样品间存在显著性差异（P＜0.05）。各部位游离酚、结合酚和总多酚含量分别介于3 560.19～6 273.23、13.45～22.01和3 582.2～6 286.68 mg GAE/100 g干质量,其游离态多酚占总酚含量百分比平均为99.60%;游离态黄酮、结合态黄酮和总黄酮含量分别介于1 080.30～2 488.21、9.69～28.59、1 106.81～2 516.80 mg RE/100 g 干质量,其游离态黄酮占总黄酮含量的百分比平均为98.64%。大花罗布麻叶提取物清除DPPH 自由基、ABTS+·能力和总还原力最强,抗氧化活性与总酚含量之间具有良好的线性关系（r＞0.950 0）。结论：大花罗布麻各部位中含有较丰富的酚类物质,具有较强的抗氧化活性。     

檀香叶提取物抗氧化及抗菌活性初步研究

研究檀香(Sandalwood)叶不同溶剂提取物的抗氧化及抗菌活性,为檀香叶资源开发利用提供依据。采用4种不同溶剂提取檀香叶中抗氧化、抗菌活性成分;采用清除DPPH自由基方法测定抗氧化活性,采用平板打孔法测定抗菌活性。结果表明:檀香叶80%乙醇、水、乙酸乙酯提取物可以清除DPPH自由基;80%乙醇提取物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌有抗菌作用,但对霉菌、啤酒酵母没有抑菌作用。乙醇提取物经不同温度、不同光照时间处理后,其抗氧化、抗菌活性较稳定。乙醇提取物经不同pH处理后,抗氧化物质在pH6～8范围内稳定,抗菌物质在pH3～7范围内稳定,碱性条件下不稳定。檀香叶乙醇提取物化学成分标识结果表明:檀香叶乙醇提取物中含有多糖、鞣质、黄酮类、酚类物、有机酸以及氨基酸、多肽、蛋白质等成分。结论:80%乙醇、水、乙酸乙酯提取物具有抗氧化活性,其中,80%乙醇提取物抗氧化活性最好。只有80%乙醇提取物具有抗菌活性。     

桑叶总黄酮提取纯化工艺及抗氧化性研究

本文通过单因素实验和响应面分析优化得到超声辅助提取桑叶总黄酮最佳工艺,并通过过氧化氢清除试验测定了桑叶总黄酮的抗氧化活性。结果表明,最佳提取工艺参数是:乙醇浓度80%,料液比1:30 g/mL,超声时间75 min,超声温度40 ℃,得率达2.7%。桑叶总黄酮的含量经过AB-8大孔树脂处理后由12.3%提高至33.8%。抗氧化实验结果表明,桑叶总黄酮的抗氧化能力大于抗坏血酸,是一种潜在的天然抗氧化剂。