Antioxidant and antimicrobial activities of propolis from several regions of Korea

Biological activities of different propolis extracts in Korea were examined for the evaluation of quality comparison with that from Brazil (BZ). Total polyphenol and flavonoid contents of propolis extracts from Yeosu (YS) and Cheorwon (CW), whose values were higher than BZ, were also shown to be more aboudant. The extracts of YS and CW also showed strong antioxidant activities, using the linoleic acid peroxidation and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. However, the extract from BZ had less active antioxidant activity on linoleic acid peroxidation and DPPH free radical-scavenging activity of less than 70% than other extracts. The DPPH free radical-scavenging activity seems to relate with the antioxidant activity of linoleic acid peroxidation. The propolis with antioxidant activity also had DPPH free radical-scavenging activity. The extracts of YS and CW had effective antimicrobial activities on Staphilococcus aureus, Bacillus subtilis, Salmonella typhimurium and Candida albicans. Strong antioxidant, radical-scavenging and antimicrobial activities of YS and CW seemed to relate with high values, total polyphenol, and flavonoid contents.     

Antioxidant and free radical-scavenging activities of chickpea protein hydrolysate (CPH)

Chickpea protein hydrolysate (CPH) was fractionated by gel filtration on Sephadex G-25. The antioxidant and free radical-scavenging activities of four CPH fractions (Fra.I, Fra.II, Fra.III, and Fra.IV) were measured using reducing power, inhibition of linoleic acid autoxidation, and 1,1-diphenyl-2- pycrylhydrazyl (DPPH)/superoxide/hydroxyl radical-scavenging assay. The antioxidant activity of Fra.IV (81.13%) was closer to that of α-tocopherol (83.66%) but lower than that of BHT (99.71%) in the linoleic acid oxidation system. Amino acid analyses showed that Fra.IV with the strongest antioxidant activity also had the highest total hydrophobic amino acids content (38.94% THAA) and hydrophobicity (125.62 kcal/mol amino acid residue) compared with the other three fractions. The molecular weight distribution of Fra.IV was found to vary from 200 to 3000 Da.     

油菜蜂花粉蛋白的分离提取及其抗氧化活性

以油菜蜂花粉为研究对象,根据溶解性的不同,从中分离出了水溶性蛋白、醇溶性蛋白、碱溶性蛋白及盐溶性蛋白,并对各蛋白组分抗氧化活性进行了研究。结果表明:油菜蜂花粉中主要蛋白为水溶性蛋白,占其干重的7.35%,其次为醇溶性蛋白3.65%,盐溶性蛋白和碱溶性蛋白分别占2.50%和2.24%。4种不同溶解性的油菜蜂花粉蛋白均具有一定的体外抗氧化作用,各蛋白组分的总抗氧化能力以及对DPPH自由基、OH.和O2-.的清除能力呈现较好的量效关系;4种蛋白抗氧化活性由强到弱的顺序依次为水溶性蛋白>醇溶性蛋白>碱溶性蛋白>盐溶性蛋白。因此,油菜蜂花粉蛋白质可作为一种潜在的天然抗氧剂进行深入研究。     

枸杞蜂花粉主要化学成分与抗氧化作用

以枸杞蜂花粉为原料,对其可溶性总糖、游离单糖与双糖、蛋白质、游离氨基酸、总多酚、总黄酮、矿物元素含量进行了分析,并以1,1-二苯基-2-三硝基苯肼自由基清除率、超氧阴离子自由基清除率、2,2-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐自由基清除率、金属离子螯合率为指标对枸杞蜂花粉的抗氧化作用进行了评价。结果表明,枸杞蜂花粉中可溶性糖质量分数为44.8%,果糖、葡萄糖和蔗糖质量分数分别为18.4%、15.2%和3.7%,蛋白质质量分数为25.0%,总多酚和总黄酮含量分别为22.95mg/g（以没食子酸当量计）和21.17mg/g（以芦丁当量计）;枸杞蜂花粉具有显著的抗氧化作用,抗氧化效果顺序为水提醇沉上清物＞水提物＞粗多糖。     

Antioxidant and antibacterial activity of leaves of Etlingera species (Zingiberaceae) in Peninsular Malaysia

Methanolic extracts from fresh leaves of five Etlingera species were screened for total phenolic content (TPC), antioxidant activity (AOA), and antibacterial activity. Analysis of TPC was done using the Folin–Ciocalteu method. Evaluations of AOA included 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging ability, ferric-reducing antioxidant power (FRAP), ferrous-ion chelating (FIC) ability, and β-carotene bleaching (BCB) activity. Antibacterial activity was screened using the disc-diffusion method. Highest TPC, ascorbic acid equivalent antioxidant capacity (AEAC), and FRAP were found in leaves of E. elatior and E. rubrostriata. Leaves of E. maingayi, with the lowest TPC, AEAC, and FRAP, had the highest FIC ability and BCB activity. Ranking of TPC and AOA of different plant parts of E. elatior was in the order: leaves > inflorescences > rhizomes. Leaves of highland populations of Etlingera species displayed higher values of TPC and AEAC than those of lowland counterparts. Leaves of Etlingera species exhibited antibacterial activity against Gram-positive but not Gram-negative bacteria.     

Effect of cell wall-disruption processes on wall disruption,antioxidant activity and nutrients in tea pollen

Tea pollen is rich in nutritional and bioactive compounds; however, the pollen wall limits their release. In this study, we explored the effects of freeze–thaw processing (FT), a combination of enzymatic hydrolysis and ultrasonication (EHUS) and superfine grinding (SG) on the wall disruption, antioxidant activity, sensory qualities and nutrients in tea pollen. SG-treated pollen had the highest broken-wall ratio (100%), followed by EHUS (79.14%), while FT-treated pollen displayed the lowest ratio (59.86%). Release of nutrient compounds, including polyphenols, flavonoids, carbohydrates, total free amino acids, proteins and theanine, increased after treatment with the three wall-disruption methods compared with untreated samples. Moreover, levels of epigallocatechin gallate (EGCG), epigallocatechin (EGC), catechin gallate (CG) and gallocatechin gallate (GCG) were higher following EHUS or SG than in untreated or FT-treated tea pollen. EGCG was the most potent catechin involved in antioxidant activity of tea pollen, making major contributions to the significant improvement of antioxidant activity in SG- and EHUS-treated groups. Additionally, the overall sensory qualities of tea were lower after treatment with the three wall-disruption methods compared with untreated samples. In summary, SG and EHUS treatment had greater effects on cell wall disruption, nutrient release and antioxidant activity in tea pollen.     

椴树蜜纯度鉴定及其抗氧化活性研究

测定东北地区收集的16批椴树蜜中椴树花粉占总花粉比例;并采用福林酚法测定各批次椴树蜜中的总酚含量;采用DPPH自由基清除法、ABTS+自由基清除法与铁离子还原能力(ferric reducing antioxidant power,FRAP)法测定各批次椴树蜜的总抗氧化能力。结果表明:16批椴树蜜中椴树花粉占总花粉含量分别在7.14%~76.73%之间,椴树花粉含量可用于椴树蜜纯度鉴定,其中7个批次的椴树蜜判定为椴树单花蜜,9个批次椴树蜜为椴树杂花蜜;椴树单花蜜的总酚含量以没食子酸计在174.64μg/g~222.82μg/g,杂花蜜为223.73μg/g~329.18μg/g;DPPH法测得椴树单花蜜的IC50值为(46.61±10.91)g/L~(107.76±34.17)g/L,杂花蜜IC50值为(24.72±6.89)g/L~(76.75±8.09)g/L;测得椴树单花蜜ABTS+自由基清除能力以Trolox计为(0.14±0.07)mmol/kg~(0.43±0.10)mmol/kg,椴树杂花蜜ABTS+自由基清除能力为(0.25±0.01)mmol/kg~(0.56±0.04)mmol/kg;测得椴树单花蜜铁离子还原能力以FeSO4计为(1.96±0.08)mmol/kg~(2.82±0.08)mmol/kg,椴树杂花蜜铁离子还原能力以FeSO4计为(2.08±0.07)mmol/kg~(3.81±0.11)mmol/kg。结果显示,椴树蜜有一定的抗氧化活性,抗氧化活性与总酚含量呈正相关,但与椴树蜜纯度相关性不强。     

牛蒡根总黄酮抗氧化活性研究

以牛蒡根为材料,采用常规方法测定牛蒡根总黄酮的DPPH自由基清除能力、羟基自由基清除能力、总抗氧化能力、还原力、金属螯合能力、抗脂质过氧化能力和对DNA氧化损失的保护作用,同时测定了牛蒡根总黄酮的含量。结果表明,牛蒡根总黄酮的自由基清除能力、总抗氧化能力、金属螯合能力和还原力随浓度的增加而增强,且呈剂量依赖性相关,DPPH自由基清除能力的半数抑制浓度（IC50）为15.7mg/mL;对大鼠肝脂质过氧化产生的丙二醛（MDA）有较好的清除效果,IC50为34μg/mL;对K562细胞DNA氧化损伤具有保护作用。由此说明,牛蒡根为一种很好的天然抗氧化剂。     

五味子蜂花粉不同萃取物对小鼠肝脏脂质过氧化及DNA氧化损伤的作用

五味子蜂花粉具有强抗氧化活性,为了探究其抗氧化活性成分分布,本研究采用体积分数75%乙醇溶液对五味子蜂花粉进行浸提,分别用石油醚、乙酸乙酯和正丁醇进行萃取,测定不同萃取物的活性成分和体外抗氧化活性,研究其对小鼠肝脏脂质过氧化的抑制作用和对·OH诱导的pBR322质粒DNA氧化损伤的保护作用。结果表明,五味子蜂花粉不同萃取物抗氧化活性及其对小鼠肝脏脂质过氧化的抑制作用和对DNA氧化损伤的保护作用均存在显著差异（P＜0.05）,其顺序为：正丁醇萃取物＞乙酸乙酯萃取物＞石油醚萃取物。正丁醇萃取物的总酚含量最高,为26.11 g/100 g,总黄酮含量为27.90 g/100 g;有很强的Fe2＋络合能力、还原力和对1,1-二苯基-2-三硝基苯肼自由基的清除能力;0.2 mg/mL正丁醇萃取物对小鼠肝脏脂质过氧化的抑制率可达85%以上。本研究为进一步分离纯化五味子蜂花粉高抗氧化活性酚类物质提供依据,同时为抗氧化功能食品的开发提供参考。     

油菜蜂花粉黄酮醇苷的体内外抗氧化研究

以油菜蜂花粉黄酮醇苷组分为原料,以还原力和DPPH 自由基清除率为指标研究黄酮醇苷在化学模拟体系中的抗氧化活性。结果表明,油菜蜂花粉黄酮醇苷的抗氧化活性不及其苷元成分。以CCl4 制备小鼠脂质过氧化损伤模型,通过体内自由基发生体系进一步研究花粉黄酮醇苷的抗氧化作用,并对可能的作用机制进行探讨。结果显示：油菜蜂花粉黄酮醇苷组分能够显著地降低脂质过氧化小鼠肝匀浆和血清中MDA 含量,提高小鼠SOD 活性和总抗氧化能力(T-AOC),对脂质过氧化损伤有很好的保护作用,原因可能是体内有关酶系可将黄酮醇苷水解使其游离出酚羟基而发挥作用。本研究进一步肯定了油菜蜂花粉黄酮醇苷对机体氧化损伤的保护作用。     

不同产地油菜蜂花粉抗氧化活性比较研究

为研究不同产地油菜蜂花粉的抗氧化活性,本实验以青海、湖北、陕西、安徽、新疆、四川、福建7个油菜主产区的油菜蜂花粉为研究对象,测定其乙醇提取物的总酚含量、总黄酮含量、还原力和对DPPH自由基清除率,结果表明,新疆与湖北油菜蜂花粉提取物的抗氧化活性显著高于青海、陕西、福建、四川、安徽(P<0.05),安徽油菜蜂花粉提取物的抗氧化活性显著低于其他产地(P<0.05)。     

Varietal differences among the phenolic profiles and antioxidant properties of four cultivars of spine grape (Vitis davidii Foex) in Chongyi County (China)

Spine grape (Vitis davidii Foex) is an important wild plant species in South China. To provide sufficient experimental evidence for the strong antioxidant activity of spine grapes, four cultivars from Chongyi County, China, including three red varieties (Junzi #1, Junzi #2, and Liantang) and one white variety (Baiyu) were evaluated. The Junzi #1 had the highest phenolic content (total phenolic, flavonoids, flavanols, and anthocyanins) and the strongest antioxidant capacity (DPPH radical-scavenging capacity, cupric-reducing capacity and hydroxyl radical-scavenging activity) among the four varieties. HPLC analysis of spine grapes revealed that the (+)-catechin was the most abundant phenolics and the hydroxycinnamic acids were the major phenolic acids in the four varieties. Hierarchical cluster analysis showed that the Junzi #1 belongs to the group with high phenolic content and strong antioxidant power. The results suggest the Junzi #1 has the best health promoting properties, and the higher utilization value and potential for development.     

银杏花粉黄酮苷的恶味乳杆菌B2生物转化产物及其抗氧化活性评价

目的：研究恶味乳杆菌B2（Lacbacillus perolens B2）生物转化对银杏花粉黄酮组分及其抗氧化活性的影响。方法：分析银杏花粉及其生物转化产物的提取物和各自石油醚相、乙酸乙酯相和正丁醇相萃取物的得率和高效液相色谱图,通过2,2’-连氮基-双-（3-乙基苯并二氢噻唑啉-6-磺酸）、1,1-二苯基-2-三硝基苯肼自由基清除能力评价其体外抗氧化活性,通过对H2O2损伤小鼠巨噬细胞RAW264.7的保护作用评价其细胞抗氧化活性。结果：通过L. perolens B2的生物转化,提取物及各相萃取物得率均有所提高,银杏花粉主要黄酮苷被转化为以山柰酚为代表的黄酮苷元,并富集于乙酸乙酯萃取相。体外抗氧化活性评价显示,通过L. perolens B2的生物转化,提取物和各相萃取物的体外抗氧化能力均得到提高,其中生物转化产物的乙酸乙酯相萃取物的体外抗氧化活性最高。细胞实验显示,供试的银杏花粉及其生物转化产物的提取物和各自的乙酸乙酯相萃取物均可减缓由H2O2损伤导致的RAW264.7细胞凋亡,并且存在剂量依赖关系。生物转化产物的提取物及乙酸乙酯相萃取物对H2O2损伤RAW264.7细胞的保护能力均高于对应的银杏花粉样品,其中生物转化产物的乙酸乙酯相萃取物保护能力最强,当其质量浓度为15 μg/mL时,几乎可以完全保护RAW264.7细胞不受H2O2损伤。结论：通过L. perolens B2的生物转化,银杏花粉主要黄酮苷被转化为以山柰酚为代表的黄酮苷元,提取物及各相萃取物的得率、体外抗氧化活性及对H2O2诱导损伤的RAW264.7细胞的保护作用均显著提高（P＜0.05）,其中生物转化产物的乙酸乙酯相萃取物抗氧化活性最高。     

杨梅素及其类似物抗氧化与乙酰胆碱酯酶抑制活性研究

目的:探讨杨梅素、杨梅苷及二氢杨梅素的抗氧化和乙酰胆碱酯酶抑制活性。方法:采用DPPH自由基清除和乙酰胆碱酯酶抑制高通量筛选模型进行研究。结果:杨梅素、杨梅苷和二氢杨梅素清除DPPH自由基的IC50值分别为18.34、28.89、10.70μg/mL,三种化合物的抗氧化活性均强于阳性药芦丁(IC50=31.32μg/mL),其中二氢杨梅素还强于VC(IC50=14.69μg/mL);在质量浓度为0.25mg/mL时,杨梅素、杨梅苷和二氢杨梅素对乙酰胆碱酯酶的抑制率分别为:30.66%±4.05%、38.48%±1.98%、78.81%±2.23%,其中二氢杨梅素对乙酰胆碱酯酶抑制作用较显著,其IC50值为1546±47.05μmol/L。结论:杨梅素、杨梅苷、二氢杨梅素均具有显著的DPPH自由基清除能力,本文首次报道二氢杨梅素具有较好的乙酰胆碱酯酶抑制活性,值得进一步深入研究。     

乳清蛋白水解物抗氧化活性的研究

本实验主要研究了乳清蛋白的碱性蛋白酶水解产物在不同体系中的抗氧化活性。通过测定水解物对卵磷脂脂质氧化体系的硫代巴比妥酸值(TBARS)抑制作用、过氧化值(PV)的抑制作用、亚铁还原能力、金属离子螯合能力、DPPH 自由基清除能力,研究乳清多肽的抗氧化活性。结果表明,底物浓度为5%、蛋白酶量的添加量为2%、水解时间为5h 时乳清蛋白的水解物具有最强的抗氧化能力;碱性蛋白酶制备的乳清蛋白水解物的抗氧化能力与底物浓度、水解时间、溶解度等有关。     

不同干燥方式对油菜蜂花粉色泽、酚酸含量和抗氧化活性的影响

为了探究不同干燥方式对油菜蜂花粉品质的影响,本实验测定自然晾晒、热风、中短波红外、真空冷冻和真空脉动5 种干燥方式处理油菜蜂花粉的干燥特性、色泽、酚酸含量以及抗氧化活性,并分析油菜花粉微观结构和品质变化的内在联系。结果表明,中短波红外干燥速率最快;自然晾晒耗时最长,色泽劣变最严重;真空脉动干燥油菜蜂花粉铁离子还原力最强（（1 961.11±4.42）mmol/g）,比新鲜油菜蜂花粉提高了24.78%,色差值最小（0.98±0.04）。此外,5 种干燥方式均显著提高了油菜蜂花粉的铁离子还原力及绿原酸、香草酸和芥子酸含量（P＜0.05）,而各干燥处理对于对香豆酸含量影响不明显。相关性分析显示,对香豆酸含量与总色差显著负相关（P＜0.05）,与L*值显著正相关（P＜0.05）。聚类分析显示,自然晾晒与其他4 种干燥方式相似度为0;热风干燥与中短波红外干燥相似度高达84.11%。聚类分析与主成分分析很好地体现了5 种干燥方式之间的差异。综合分析不同方式干燥的油菜蜂花粉品质,在低温（45 ℃）干燥条件下,真空脉动干燥能较好地保护油菜蜂花粉的微观结构和色泽,且能显著提高其绿原酸、香草酸、芥子酸含量及铁离子还原力（P＜0.05）,是一种具有良好应用前景的蜂花粉干燥方式。     

三种天然来源黄酮物质抗氧化活性和抑制胰脂肪酶活性的研究

以葛根黄酮、沙棘叶黄酮和山楂叶黄酮为研究对象,在不同体系中评价了总抗氧化能力、DPPH自由基清除活性、ABTS自由基清除活性及还原能力,同时评价了抑制胰脂肪酶活性的能力。结果表明:在不同体系中三种黄酮物质都呈现较强抗氧化活性,其中山楂叶黄酮总抗氧化能力最强,沙棘叶黄酮清除DPPH自由基(IC50 0.057±0.004)mg/m L和清除ABTS(IC50 0.096±0.014)mg/m L自由基活性最强,山楂叶黄酮与葛根黄酮呈现较强的还原能力,三种黄酮物质都呈现一定的抑制胰脂肪酶活性,沙棘叶黄酮活性最强。该研究为天然植物资源的综合利用提供了理论的支撑。     

大果榕果实乙醇提取物抗氧化活性及对α-葡萄糖苷酶和乙酰胆碱酯酶抑制活性

研究大果榕果实的多酚含量及其抗氧化活性、α-葡萄糖苷酶和乙酰胆碱酯酶抑制活性,为其进一步开发利用奠定基础。以采自海南保亭七仙岭的大果榕果实为实验材料,用体积分数65%的乙醇提取大果榕果实多酚,采用Folin-酚法测定总酚含量。对获得的大果榕果实多酚进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS)自由基、羟自由基(·OH)清除率以及α-葡萄糖苷酶抑制活性和乙酰胆碱酯酶抑制活性测定。结果表明:大果榕果实多酚含量较高,达1.92 mg/g(以干质量计),其对DPPH自由基、ABTS+·和·OH均具有显著的清除活性,且呈质量浓度依赖性,IC50值分别为141.25、91.20、45.71μg/m L;大果榕果实多酚对α-葡萄糖苷酶抑制活性强于阳性对照阿卡波糖,且呈现明显的质量浓度依赖性,IC50值为102.33μg/m L;同时大果榕果实多酚对乙酰胆碱酯酶也具有一定的抑制活性,IC50值为4.9 mg/m L。研究结果表明大果榕果实多酚具有良好的抗氧化性、α-葡萄糖苷酶抑制活性和一定的乙酰胆碱酯酶抑制活性。     

Gel-forming Ability and Radical-scavenging Activity of Soy Protein Hydrolysate Treated with Transglutaminase

ABSTRACT: Gel-forming ability and 1,1-diphenyl-2-picrydrazyl (DPPH) radical-scavenging activity of the peptic hydrolysate from soy protein isolate (SPI) were investigated. The gel-forming ability of mixtures consisted of SPI and its hydrolysate decreased as the percentage of hydrolysate increased. The inferior gel-forming ability of the hydrolysate was shown to be related to both the low surface hydrophobicity of the hydrolysate and the drop in sulfhydryl exchange reactions during gelation. Although antioxidants in the SPI-hydrolysate mixture (SHM) could be helpful in enhancing the radical-scavenging activity of the peptide-based gel, they suppressed the oxidization of sulfhydryls in sulfhydryl group/disulfide bond interaction. As a result of this, antioxidants present reduced the gel-forming ability of the SHM. The addition of transglutaminase (TGase) improved the gel-forming ability of SHM. A mixture of 70% SPI and 30% hydrolysate in the presence of TGase resulted in a gel with good gelling property and high radical-scavenging activity.     

山杏果肉可溶性膳食纤维的抗氧化活性与红外光谱分析

对2种不同制备方法制得的山杏果肉可溶性膳食纤维(SDF)的抗氧化活性进行了比较。文中通过对DPPH自由基清除能力,总还原能力,在邻二氮菲-Fe2+体系中清除羟基自由基能力,邻苯三酚自氧化法中清除超氧阴离子能力等的测定,评价了二者的抗氧化活性,并对其进行了红外光谱对比分析。结果表明:2种不同方法制备的山杏果肉可溶性膳食纤维(SDF)均具有一定的抗氧化活性,且复合酶酶解法制备的SDF较微生物法发酵液酶解法制备的抗氧化效果更好,由于水解程度不同导致二者在红外光谱吸收方面略有差别,吸收强度差别明显。