不同方法比较黄酮类化合物抗氧化性及其构效关系分析

通过三种化学抗氧化方法（DPPH、FRAP和ORAC法）以及细胞抗氧化方法（CAA法）对芹菜素、山奈酚、木犀草素、槲皮素4种黄酮甙元及它们的糖苷化合物抗氧化活性进行比较研究,结果表明DPPH和FRAP法基本一致,芹菜素、牡荆素和异牡荆素这类C环上无羟基且B环只有一个羟基的黄酮抗氧化性极低;在C环上的羟基相同时,B环有3’,4’-邻二羟基的木犀草素和槲皮素的抗氧化活性显著高于仅含4’-OH的芹菜素和山奈酚;而ORAC法的结果与此相反。化学抗氧化测定结果均表明,当C环羟基被取代形成3-O-连黄酮苷时其抗氧化活性减小;而A环上6、8号位的氢被取代形成C-连黄酮苷时其抗氧化性反而会增加。CAA法结果显示,当C环无羟基时,B环只有一个4-OH的芹菜素及其黄酮苷无细胞抗氧化性,但B环有两个羟基的木犀草素及其糖苷却显示出较强的氧化性。与化学抗氧化性不同,A环上C-连黄酮苷的抗氧化性低于其苷元,而C环O-连糖苷的影响则较为复杂。      

Biological activity and composition of extract from aerial root of Ficus microcarpa L. fil.

Total phenolic content, antioxidant and antibacterial activities of Ficus microcarpa aerial roots were determined on methanol extract and its sub-fractions (hexane, ethyl acetate, n -butanol and water). The ethyl acetate fraction possessed the highest amount of phenolic compounds evaluated by Folin-Ciocalteu reagent method. It also showed the highest antioxidant activity when tested the following methods: DPPH, ABTS⁺ radical-scavenging, superoxide radical scavenging, reducing power and β -carotene linoleic acid bleaching. On the other hand, high phenolics content extracts (ethyl acetate, methanol and n -butanol) showed significantly higher inhibitory activity than low phenolics content extracts (water and hexane) against five tested Gram positive and Gram negative bacteria. Protocatechuic acid, catechol, p -vinylguaiacol, syringol, p -propylphenol, vanillin, p -propylguaiacol, isovanillic acid, 4- n -Propylresorcinol, syringaldehyde and oleanolic acid contained in ethyl acetate fraction were identified by GC-MS and HPLC based on their cochromatography with standard compounds. Protocatechuic acid, catechol and syringol exhibited nearly same antioxidant activity as did by positive control Trolox using the mentioned assays. Results here showed that the ethyl acetate fraction has strong antioxidant and antibacterial activities, which are correlated with its high level of phenolic compounds.     

橙皮苷及铜配合物的抑菌抗氧化活性研究

橙皮苷-Cu(Ⅱ)配合物属于新的物质,用牛津杯法研究了橙皮苷及其配合物对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌的抑菌活性,橙皮苷-Cu(Ⅱ)配合物对3种菌的最低抑菌浓度,以及不用pH值对配合物抑菌效果的影响。另外,还研究了橙皮苷及其配合物对.OH的清除效应。结果发现橙皮苷-Cu(Ⅱ)配合物的抑菌活性强于橙皮苷,而对.OH的清除作用则不如橙皮苷。     

不同分子量分布的美拉德产物的呈味特性及抗氧化抗菌活性研究

通过超滤及葡聚糖凝胶色谱技术结合将美拉德产物按分子量大小分级成三个组分,即小于1000u、1000～5000u和大于5000u,并评价其在清汤中的风味特性、清除DPPH自由基的能力及对金黄色葡萄球菌、李斯特菌、大肠杆菌和沙门氏菌的抑制活性。结果显示,1000～5000u的美拉德产物增强风味的效果最显著,其次是小于1000u的产物,这两种产物对DPPH自由基清除率分别达80%和72%,对四种菌的最低抑制浓度达25～75mg/mL。大于5000u的美拉德产物在较低浓度下清除率达90%,对四种菌的最低抑制浓度为6.25～25mg/mL,且对金黄色葡萄球菌的抑制效果最强,最低抑制浓度达6.25mg/mL。     

不同极性柳叶蜡梅叶萃取物总酚含量及其抗氧化、抑菌能力研究

采用甲醇回流提取、梯度萃取得到正己烷萃取物、二氯甲烷萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物5个不同极性部分,以多酚含量、还原能力、对1,1-二苯基-2-三硝基苯肼(DPPH)自由基的清除能力及抑制微生物生长为评价指标,研究其体外抗氧化和抑菌活性能力。结果表明:柳叶腊梅叶多酚量较为丰富,乙酸乙酯萃取物含量最多,为(309.5±4.81)mg/g。柳叶腊梅叶萃取物具有较强的抗氧化活性,其还原能力和对DPPH自由基清除能力随其浓度的增加而增强。甲醇、正己烷、二氯甲烷、乙酸乙酯、正丁醇和水萃取物对DPPH自由基清除能力的半数抑制浓度(IC50)值分别为1.24,1.11,0.61,0.48,0.98,1.36 mg/mL。柳叶腊梅叶萃取物对大肠杆菌、金黄葡萄球菌、枯草芽孢杆菌和绿脓杆菌均有抑制作用,二氯甲烷萃取物的抑菌活性最显著,其对4种受试菌的最低抑制浓度为2 mg/mL。故柳叶腊梅叶萃取物具有较好的抗氧化和抑菌特性,为进一步分离提取活性化合物提供依据。     

Comparison of phytochemical profiles,antioxidant and cellular antioxidant activities of seven cultivars of Aloe

A comparative assessment of the phytochemical profiles and antioxidant activities of seven cultivars of Aloe was conducted to evaluate the potential health benefits of Aloe. Aloe arborescens contained the highest levels of phenolic content, total antioxidant capacity by the oxygen radical scavenging capacity assay and cellular antioxidant activity assay. Aloe vera showed the highest levels of flavonoid content and antioxidant capacity by the peroxyl radical scavenging capacity assay. Aloe greenii had the highest CAA value with a PBS wash before adding ABAP. There were no significant differences observed between Aloe arborescens and Aloe greenii. Aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside, catechin, epicatechin, sinapic acid and chlorogenic acid were identified in Aloe samples by the HPLC analysis. Aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside and catechin showed strong relationships with antioxidant activity. Significant levels of aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside and catechin were determined in Aloe greenii, Aloe vera and Aloe saponaria, respectively.     

Comparison of phytochemical profiles,cellular antioxidant and anti-proliferative activities in five varieties of wampee (Clausena lansium) fruits

Wampee (Clausena lansium) fruit is a seasonal food containing high levels of bioactive phytochemicals which may be useful for health benefits. This study compared the phytochemical composition, total and cellular antioxidant activities (CAA) as well as anti-proliferative activities of five different varieties of wampee fruits. The results showed that six phytochemical compounds (vanillic acid, ferulic acid, rutin, syringin, catechin and hesperetin) were found in wampee fruits. Total antioxidant activities varied dramatically in these five varieties when measured with oxygen radical absorbance capacity assay and peroxyl radical scavenging capacity assay. The results also showed that wampee fruit extracts varied enormously in their CAA and exhibited significant anti-proliferative activities against HepG2 human liver cancer cells. These results suggest the potential of wampee fruits as functional foods and industrial application of wampee fruit in the future.     

Short-term toxicity studies of Ficus thonningii Blume (Moraceae) leaf extract in rats

The short‐term toxicity of Ficus thonningii Blume (FT) was studied in Wistar rats following daily oral administration of the leaf extract (250–500 mg kg^?1) for 15 days. Acute toxicity, body weight changes, organ weight, food intake, clinical signs, haematology, gross and tissue histology were monitored. The body weights of treated rats increased progressively, but the changes were not significantly different from control. The relative weights of the essential organs of treated rats were unaffected in both male and female rats. Of the sixteen haematological parameters studied, only the total leukocyte counts and plateletcrit values in male rats fed 500 mg kg^?1 of FT were significantly greater than similar parameters in controls. Histological findings indicated possible testicular, lung and hepatic toxicities. The LD₅₀ of FT was estimated to be >3000 mg kg^?1. The results suggest that short‐term oral application of F. thonningii may not exert severe toxic effects in rats at doses lower than 500 mg kg^?1.     

坛紫菜多酚提取工艺及体外抗氧化与抑菌活性研究

以四水坛紫菜为原料,优化超声波辅助提取坛紫菜多酚工艺,评价其体外抗氧化和抑菌活性。采用单因素考察液料比、超声时间和乙醇浓度对坛紫菜多酚含量的影响,并利用响应面分析法优化提取工艺。结果表明:坛紫菜多酚提取最佳工艺条件为液料比351(mL/g)、超声时间43min、乙醇浓度66%,该条件下坛紫菜多酚含量为(6.85±0.13)mg GAE/g;体外抗氧化试验表明,坛紫菜多酚对DPPH自由基和ABTS自由基清除率的IC50值分别为(36.54±0.75),(16.07±0.32)μg/mL,ORAC值为(1 005.1±11.8)μmol TE/g;体外抑菌试验表明,坛紫菜多酚对大肠杆菌、金黄色葡萄球菌、枯草芽胞杆菌和藤黄八叠球菌的最小抑菌浓度分别为1,1,1,2mg/mL。     

枫香叶正丁醇提取物抑菌效果及其抗氧化活性研究

采用打孔法测定抑菌圈大小和试管连续稀释法测定最小抑菌浓度(MIC),研究了枫香叶正丁醇提取物抑菌效果,并测定其对DPPH自由基、超氧阴离子自由基和羟自由基的清除活性。结果表明:枫香叶正丁醇提取物对7种实验菌均有抑制作用,不同浓度间、不同菌种间存在极显著(p<0.01)差异;且对细菌的抑制作用强于真菌,对革兰氏阴性菌的抑菌效果比革兰氏阳性菌好;对大肠杆菌、枯草杆菌、金黄色葡萄球菌、四联球菌、黄曲霉、黑曲霉、青霉的MIC分别为3.1、12.5、12.5、6.25、12.5、25、12.5mg/m L。枫香叶正丁醇提取物具有较强的的抗氧化活性,可作为功能性食品资源开发利用。      

小叶薜荔茎叶提取物的抗氧化活性研究

用95%乙醇对小叶薜荔茎叶进行浸提,浸膏分别用石油醚、乙酸乙酯、氯仿、正丁醇和水进行萃取,最后用大孔吸附树脂进行梯度洗脱,得到11种粗提物。采用Folin-Ciocalteu比色法、ORAC（氧自由基吸收能力）分析法和DPPH（1,1-二苯基-2-三硝基苯肼）法对粗提物进行总酚含量和抗氧化能力评价。同时测定了粗体物的羟基自由基的清除能力。结果表明,小叶薜荔茎叶粗提物的总酚含量在14.1%～68.6%之间,同时粗提物具有较强的抗氧化能力,它们的ORAC值在1.01×103～1.82×104μmolTE/g之间。粗提物的总酚含量与抗氧化能力之间具有明显的相关性。      

Antioxidant, antimicrobial, and anticancer activity of 3 Umbilicaria species

Abstract: The aim of this study is to investigate in vitro antioxidant, antimicrobial, and anticancer activity of the acetone extracts of the lichens Umbilicaria crustulosa, U. cylindrica, and U. polyphylla. Antioxidant activity was evaluated by 5 separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds, and determination of total flavonoid content. Of the lichens tested, U. polyphylla had largest free radical scavenging activity (72.79% inhibition at a concentration of 1 mg/mL), which was similar as standard antioxidants in the same concentration. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. Total content of phenol and flavonoid in extracts was determined as pyrocatechol equivalent, and as rutin equivalent, respectively. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was extract of U. polyphylla with minimum inhibitory concentration values ranging from 1.56 to 12.5 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀ values ranging from 28.45 to 97.82 μg/mL. The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggests that lichens may be used as possible natural antioxidant, antimicrobial, and anticancer agents.     

Antioxidant, antimicrobial and anticancer activities of three Parmelia species

BACKGROUND: Lichens are symbiotic organisms consisting of algae and fungi. They are used for human and animal nutrition and in the production of colours, perfumes and alcohol. Lichens have also been used in traditional medicine to treat diseases such as jaundice, pulmonary, stomach and cranial diseases. In this study the acetone extracts of three lichens, Parmelia caperata, Parmelia sulcata and Parmelia saxatilis, were tested for their antioxidant, antimicrobial and anticancer potential. RESULTS: Of the lichens tested, P. saxatilis had the highest free radical‐scavenging activity (55.3% inhibition). Moreover, all tested extracts showed effective reducing power and superoxide anion radical scavenging. Strong relationships between total phenolic and flavonoid contents and antioxidant effects of the tested extracts were observed. The extract of P. sulcata was most active in terms of antimicrobial ability, with minimum inhibitory concentration values ranging from 0.78 to 12.5 mg L^?1. All extracts were found to have strong anticancer activity, with IC₅₀ values ranging from 9.55 to 22.95 µg mL^?1. CONCLUSION: The present study showed that the tested lichen extracts exhibited strong antioxidant, antimicrobial and anticancer effects. This suggests that lichens may be used as possible natural antioxidant, antimicrobial and anticancer agents. Copyright © 2012 Society of Chemical Industry     

绿芦笋不同部位营养成分及活性评价研究

对绿芦笋不同部位的营养成分及其抗氧化活性进行测定分析。结果表明,绿芦笋四个部位的营养成分和抗氧化活性存在显著差异(p<0.05);绿芦笋叶和嫩尖中含有较高含量的蛋白质、粗脂肪,叶和嫩茎中含有较高含量的总糖和还原糖;四个部位均含有多种矿物质元素,其中K、Ca、Mg、Fe等元素含量较高;四个部位均含有16种氨基酸,包括8种必需氨基酸,其中天冬氨酸、谷氨酸、赖氨酸、亮氨酸含量较高;对活性物质分析得出新鲜绿芦笋叶中皂苷、黄酮含量最高,分别为1.33g/100g鲜重、0.48g/100g鲜重;四个部位水提物和醇提物均有一定的抗氧化能力,其中绿芦笋叶抗氧化能力显著高于其他三个部位(p<0.05)。绿芦笋营养价值较高,有很好的开发前景。      

菱茎多酚的提取工艺及其抗氧化、抑菌活性研究

目的:研究菱茎多酚的超声波辅助提取工艺及其体外抗氧化、抑菌活性。方法:以菱茎为材料,采用正交实验对菱茎多酚的提取工艺进行优化;通过测定菱茎多酚的DPPH、ABTS自由基清除力及还原力来评价其体外抗氧化活性;采用滤纸片扩散法测定菱茎多酚对6种腐败微生物的抑菌活性。结果:菱茎多酚的最佳提取工艺条件为乙醇浓度60%、pH1、提取温度70 ℃、提取时间35 min、料液比1：35 (g/mL),此工艺条件下多酚的提取得率为67.31 mg GAE/g DW;菱茎多酚对DPPH、ABTS自由基清除力和对Fe³⁺还原力(FRAP)的IC₅₀值分别为228.34、220.57、152.00 μg/mL;对金黄色葡萄球菌、蜡样芽孢杆菌、大肠杆菌、腐败希瓦氏菌、青霉和酿酒酵母的最小抑菌浓度(MIC)分别为6.25、3.13、0.20、0.39、1.56、0.78 mg/mL。结论:菱茎多酚具有良好的抗氧化和抑菌活性,可作为潜在抗氧化剂和抑菌剂的来源进一步开发利用。     

豆腐柴提取物不同极性部位的总酚、总黄酮含量及体外抗氧化活性

目的:研究豆腐柴提取物不同极性部位的体外抗氧化活性。方法:用甲醇提取豆腐柴减压浓缩后得豆腐柴提取物,依次用石油醚、三氯甲烷、乙酸乙酯、正丁醇萃取,得包括水相的五个不同极性部位,测定各极性部位的总多酚、总黄酮含量,比较各极性部位清除DPPH、ABTS、FRAP自由基的能力。结果:豆腐柴提取物的不同极性部位中乙酸乙酯相的总酚、总黄酮含量最高(总酚含量（635.935±6.529）mg GAE·g^-1,总黄酮含量（953.018±21.774）mg QE·g^-1),各极性部位均提示有一定的抗氧化活性,且自由基清除力在一定范围呈显著的剂量效应关系,乙酸乙酯相与石油醚相、水相的抗氧化能力差异性较大（p<0.01）。结论:豆腐柴提取物各极性部位都具有一定的抗氧化活性,可能与总酚、总黄酮含量有关,乙酸乙酯相抗氧化活性强于VC,可重点对该极性部位进一步分离纯化。