金银花70％乙醇提取物抗氧有效成分的研究

本文对金银花的70％乙醇提取物进行了分离并对其主要成分进行了抗氧性试验。认为金银花有效成分氯原酸具有一定抗氧性,其抗氧性能优于α-VE,但远不及BHT。提出金银花提取液中可能还有其它更强的抗氧性物质。作者还对氯原酸在其它植物里的存在情况做了一些介绍。     

葵花仁脱油粕中天然抗氧化剂研究

以正丁醇-盐酸、稀氢氧化钠、70%乙醇及稀盐酸分别萃取葵花仁粕中的酚类化合物.从萃取率、萃取剂对蛋白变性程度、萃取后分离蛋白色泽诸方面考虑.选择出了较好之萃取剂是:正丁醇—盐酸.硅胶薄层分离此萃取液,紫外光下显出八条色带.以烘箱法与胡萝卜素乳化法测定各色带抗氧化性.从抗氧性较好之两色带得到两化学物质,结构鉴定为氯原酸与咖啡酸.比较了这两种化合物与BHT的抗氧化性能,知咖啡酸抗氧化性能与BHT接近,比氯原酸好.用醋酸铅直接沉淀出正丁醇-盐酸萃取液中的酚类物质;解析后水解酚类物质,测定水解前后提取物的抗氧化性,知水解后比水解前抗氧性明显增强.     

葵花仁脱油粕中天然抗氧化剂研究

以正丁醇-盐酸、稀氢氧化钠、70％乙醇及稀盐酸为萃取剂,分别萃取葵花仁粕中的酚类化合物,从萃取率,萃取剂对蛋白变性程度、萃取后分离蛋白色译诸方面考虑,选择出了较好的萃取剂是:正丁醇-盐酸。硅胶薄层分离此萃取液,紫外光下显出八条色带。以烘箱法与胡萝卜素乳化法测定各色带抗氧化性。从抗氧性较好的两色带得到两化学物质,结构鉴定为氯原酸和咖啡酸,比较了这两种化合物与BHT的抗氧化性能,知咖啡酸抗氧化性能与BHT接近,比氯原酸好。用醋酸铅直接沉淀出正丁醇—盐酸萃取液中的酚类物质;解析后水解酚类物质,测定水解前后提取物的抗氧化性,知水解后比水解前抗氧性明显增强。     

香辛料的抗氧化特性及其在广式腊肠中的应用

比较了香辛料(肉豆蔻、生姜、丁香、肉桂和竹叶)不同溶剂提取物的抗氧化特性,筛选了抗氧化效果好的香辛料提取物,并考察了香辛料提取物在广式腊肠抗氧化的应用效果。结果表明:在猪油体系中,香辛料乙醇提取物的抗氧化效果明显好于水溶液提取物,且0.1%浓度的丁香乙醇提取物、肉豆蔻乙醇提取物、生姜乙醇提取物的抗氧化能力甚至优于0.005%的BHT;广式腊肠抗氧化应用试验表明:肉豆蔻乙醇提取物能抑制广式腊肠贮藏期间过氧化值的升高,且浓度越大,抑制效果越好;肉豆蔻乙醇提取物可以有效控制酸价,0.1%和0.15%肉豆蔻乙醇提取物的抑制效果与0.01 g/kg BHT相当;肉豆蔻乙醇提取物可抑制广式腊肠TBA值的升高,TBA值甚至低于添加0.1 g/kg BHT的对照组。     

中国沙棘乙醇提取物的体外及对HepG2细胞的抗氧化活性

本文从生化角度全面分析了中国沙棘乙醇提取物的体外抗氧化活性,并在评价细胞毒性的基础上,以Hep G2细胞为模型,利用流式细胞仪评估了提取物的细胞抗氧化能力。结果表明,中国沙棘乙醇提取物对ABTS自由基具有良好的清除效果,当浓度为5 mg/m L时,其清除能力与阳性对照BHT相当;中国沙棘乙醇提取物对NO自由基也有良好的清除效果,但其整体清除能力不及BHT;当浓度为5 mg/m L时,中国沙棘乙醇提取物对亚油酸脂质过氧化表现抑制,但其抑制效果低于BHT;中国沙棘乙醇提取物的总抗氧化能力随浓度的增大而增强,当浓度为5 mg/m L时,其总抗氧化能力与同浓度下的BHT接近。在浓度为0.05~5 mg/m L范围内,中国沙棘乙醇提取物对Hep G2细胞不显示毒性;当处理浓度为0.5、1、5 mg/m L时,中国沙棘乙醇提取物的阳性细胞率与阳性对照相比分别降低了75.22%、72.36%和78.2%。中国沙棘乙醇提取物不仅在体外条件下具有良好的抗氧化活性,而且在Hep G2细胞内表现出良好的抗氧化能力。     

天山雪菊不同溶剂提取物的抗氧化活性研究

以天山雪菊为原料,经过超临界二氧化碳萃取后,萃余物又分别采用丙酮、体积分数分别为50%、95%乙醇进行提取,获得不同溶剂提取的4种天山雪菊提取物,比较不同溶剂提取物的抗氧化活性。通过对二苯基苦基苯肼(DPPH)自由基和羟基自由基清除能力的评价,比较各种提取物的抗氧化活性,并对各种提取物中的总多酚和总黄酮的含量进行了分析。结果表明,4种提取物对DPPH自由基均具有较强清除活性,但活性弱于对照品二丁基羟基甲苯(BHT)、水溶性维生素E(Trolox)、α-生育酚和Vc;对羟基自由基的清除能力低于对照品芦丁和BHT。清除DPPH自由基的能力以体积分数为50%乙醇提取物最强,超临界浸膏最弱;清除羟基自由基的活性以体积分数为50%乙醇提取物最强,丙酮提取物最弱。     

杭白菊提取物抗氧化性能的研究

用不同的有机溶剂提取杭白菊（Chrysathemum morifolium Ramat.)中的抗氧化物质,并研究了它们的抗氧化性能。结果表明：各种提取组分都具有一定的抗氧化效果,其中乙醇提取物的抗氧化活性最大,1％乙醇提取物的抗氧化能力强于0．02％BHT。各组分抗氧化性能的强弱顺序为：乙醇提取物＞乙醚提取物＞石油醚提取物＞丙酮提取物,杭白菊提取物中的抗氧化有效成分为黄酮类和多酚类物质。     

罗汉果茎不同溶剂提取物抗氧化活性研究

采用磷钼酸盐法,对罗汉果茎水提取物(WE)、乙醇提取物(EE)、乙酸乙酯提取物(EAE)和氯仿提取物(CE)的抗氧化活性进行了测定,并与BHT、芦丁的抗氧化性进行了比较.结果表明,四种提取物均具有较强的抗氧化性,且比相同浓度的BHT强,但弱于相同浓度的芦丁;抗氧化活性强弱顺序依次为:芦丁＞CE＞EAE＞EE＞WE＞BHT,即随着所用提取溶剂极性的降低,其对应的提取物抗氧化活性随之增强.     

麻疯树籽壳乙醇提取物的抗氧化活性研究

本实验以麻疯树籽壳乙醇提取物中黄酮质量浓度为内标,以维生素C(VC)和2,6-二叔丁基-4-甲基苯酚(BHT)为对照,通过超氧阴离子(O-2·)、1,1-二苯基-2-苦基肼自由基(DPPH·)和亚硝酸盐(NO-2)的清除能力,以及还原力和总抗氧化能力的测定,评价了麻疯树籽壳乙醇提取物的抗氧化活性。实验结果表明,麻疯树籽壳乙醇提取物的O-2·清除率的半数抑制浓度(IC50)为0.502mg/m L,小于VC的0.654mg/m L;其DPPH·与NO-2清除率的IC50分别为0.185、0.494mg/m L,均小于BHT;麻疯树籽壳乙醇提取物中黄酮质量浓度在0.7~1.0mg/m L时,其还原力与同质量浓度VC相当,大于BHT;在测定范围时,其总抗氧化能力随质量浓度增加而增强,且大于同质量浓度的BHT,而小于VC。由此说明,麻疯树籽壳乙醇提取物具有较强的抗氧化活性。     

胡椒提取物抗氧化性能的研究

研究了 2种不同胡椒提取物在猪油中的抗氧化作用 ,结果表明 ,乙酸乙酯提取物抗氧化性高于乙醇提取物 ;添加量相同时 ,乙酸乙酯提取物可与人工合成抗氧化剂BHT相媲美 ,其添加量越高抗氧化效果越好 ;乙酸乙酯提取物与柠檬酸有较好的协同效应。     

藜蒿中黄酮类物质抗氧化作用的研究

采用Rancimat法对藜蒿提取物的抗氧化作用进行了探讨。研究表明:藜蒿提取物对油脂具有明显的抗氧化作用,且具有剂量效应关系;在乳化体系中提取物的抗氧化效果比在油体系中强;提取物与BHT、PG相比较,提取物浓度达0.10%时的抗氧化活性超过0.02%BHT,而小于0.02%PG;柠檬酸、酒石酸、抗坏血酸对藜蒿提取物表现出较强的协同增效作用。     

Antioxidant activities of red pepper (Capsicum annuum) pericarp and seed extracts

In this study, we examined the antioxidant activities of red pepper (Capsicum annuum, L.) pericarp and red pepper seed extracts. The extracts were evaluated by various antioxidant assays, including 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, [2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid)] (ABTS) radical scavenging, ferrous chelating activity, superoxide dismutase (SOD) activity and reducing power, along with the determination of total phenolic and flavonoid contents. All the extracts showed strong antioxidant activity by the testing methods. The red pepper pericarp extract exhibited strong ferrous chelating activity and high scavenging activity against free radicals, including both the hydroxyl and DPPH radicals, but it exhibited weaker scavenging activity for the superoxide anion radical and for SOD. In contrast, the red pepper seed extract exhibited strong SOD activity and high scavenging activity against the superoxide anion radical, but showed weaker ferrous chelating activity, hydroxyl radical scavenging, and DPPH radical scavenging. We observed that the reducing power level and ABTS radical scavenging activity of the red pepper seed were higher than those of the red pepper pericarp at the highest tested concentration. Most of the test results for the red pepper seed and red pepper pericarp extracts increased markedly with increasing concentration; however, the metal chelating, SOD and ABTS radical scavenging activities did not increase with the concentration. Highest total phenolic and flavonoid contents were obtained from the red pepper pericarp extracts. Overall, the red pepper seed and red pepper pericarp extracts were highly effective for the antioxidant properties assayed, with the exceptions of ferrous chelating activity, hydroxyl radical scavenging and SOD activity.     

Antioxidative activity of extracts from Mengkudu (Morinda citrifolia L.) root,fruit and leaf

This study was conducted to evaluate the antioxidative activity of extracts from different parts of Mengkudu (Morinda citrifolia L.), including leaf, fruit and root. Methanol and ethyl acetate were used as solvents and antioxidative effects measured by a ferric thiocyanate method (FTC) and thiobarbituric acid test (TBA). The methanol extract of Mengkudu root exhibited high antioxidative activity that was not significantly (P<0.05) different from α-tocopherol or butylated hydroxyl toluene (BHT), while the methanol extracts of fruit and leaf showed negligible activities. On the other hand, the ethyl acetate extract of all parts of Mengkudu exhibited significant antioxidative activity, which is comparable to that of both α-tocopherol and BHT. Similar trends of antioxidant activity were observed using either the FTC or TBA methods. Roots showed the highest activity of the parts tested. The results suggest that several compounds contribute to antioxidative activity of different parts of Mengkudu. Activity in the roots may be due to both polar and non-polar compounds but, in the leaf and fruit, only to non-polar compounds.     

火炬树果穗抗氧化物质的提取及其协同效应的研究

用DPPH法测定了不同溶剂对火炬树果穗中抗氧化物质的浸提效果,并以猪油作为底物,采用碘量法研究了火炬树果穗95%乙醇粗提物的抗氧化活性及与其它物质的协同作用。结果表明:不同溶剂火炬树果穗提取物抗氧化性强弱依次为乙醇>乙酸乙酯>正己烷。随着火炬树果穗粗提取物浓度的增加,其抗氧化作用逐渐增强,抗坏血酸、柠檬酸对其具有一定协同作用,但氨基酸对火炬树果穗粗提物无明显协同作用。初步判断火炬果穗粗提物中抗氧化有效成分为酚类物质。     

不同方法提取荔枝多糖抗氧化活性的比较

从铁离子还原能力、清除DPPH和ABTS+自由基能力三个方面比较了传统热水浸提的荔枝多糖和超声微波酶解协同提取的荔枝多糖的抗氧化活性,并以BHT(2,6-二叔丁基对甲酚)为阳性对照。结果表明,在实验浓度范围内,两种提取方法得到的荔枝多糖均有一定程度的抗氧化活性,且超声微波酶解协同提取的荔枝多糖的总抗氧化力和清除DPPH、ABTS+自由基的能力分别是热水法的2.00、6.40、7.83倍,是阳性对照BHT的24.65%、10.00%、12.49%,(p<0.05)。     

诃子抗氧化作用的研究

用ＤＰＰＨ法、ＴＢＡ法及碘量法研究了不同溶剂诃子精提物的抗氧化活性。结果表明：诃子各溶剂粗提物对ＤＰＰＨ自由基有较强的清除作用,但清除均弱于同浓度的茶多酚,９５％乙醇粗提物对亚油酸氧化的抑制作用强于同浓度的茶多酚;     

Evaluation of antioxidative activity of vegetable extracts in linoleic acid emulsion and phospholipid bilayers

The antioxidative effects of vegetable extracts were evaluated using linoleic acid emulsion and liposomal phospholipid suspension systems. First, the antioxidative activities of water, ethanol and 2% metaphosphoric acid extracts of the vegetables were investigated by measuring the rate of oxygen consumption in the peroxidation of linoleic acid initiated by a radical generator, 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), with a Clark electrode in the absence of metal chelators. Ethanol extracts of moroheiya and perilla exhibited the highest antioxidative activities. Without metal chelators, 12 ethanol extracts and one water extract acted as prooxidants, and this phenomenon could be attributed to the prooxidant action of ascorbic acid in the presence of free transition metal ions. Next, peroxyl radical-scavenging activities of vegetable extracts were examined by adding a metal chelator, diethylenetriaminepentaacetic acid (DTPA), to the linoleic acid emulsion system. The results were compared with their antioxidative activities in phospholipid bilayers by measuring the inhibition of lipid peroxidation in large unilamellar vesicles composed of egg yolk phosphatidylcholine (PC). A good correlation was observed between the antioxidative activities obtained from these two systems. The antioxidative activities in the liposomal phospholipid suspension system correlated with total contents of ascorbic acid and polyphenols in vegetable extracts. © 1999 Society of Chemical Industry     

Antioxidant activity of extracts from Gevuina avellana and Rosa rubiginosa defatted seeds

Chilean hazelnuts (Gevuina avellana Mol) and mosqueta rose (Rosa aff. Rubiginosa L.) meals were extracted with methanol, ethanol, acidified water, acetone, butanol, diethyl ether and ethyl acetate. Ethanol and methanol extracted the highest amount of soluble substances from both seed meals. The highest concentration of total polyphenols was found in the ethanolic extracts, although that of acetone from R. rubiginosa presented similar values. The antioxidant activity of the extracts evaluated by the β-carotene assay and with as hydrogen radical scavenging ability showed that the activity of the butanol and methanol extracts from G. avellana was comparable to those of synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The 2,2,-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging activity of the G. avellana methanol, ethanol and water extracts was 2–3 times lower than those of BHT and BHA, respectively. The activity of R. rubiginosa extracts ranged from that of BHT for the water extracts to 80% inhibition in respect to control achieved with the ethanol extracts.     

杏花花粉中苦杏仁苷的抗氧化性研究

本实验主要从总抗氧化能力、还原力、清除DPPH自由基、清除羟自由基、抑制卵磷脂氧化等方面,对杏花花粉中的乙醇提取物、苦杏仁苷、苦杏仁苷结晶上清物进行了抗氧化性研究。结果表明:杏花花粉中苦杏仁苷的抗氧化能力,除清除羟自由基以外均低于杏花花粉醇提物和苦杏仁苷结晶上清物。故开发杏花花粉产品只需生产到乙醇提取物就可以达到抗氧化和抗癌的双重功效。