翅果油树不同部位多糖含量及抗氧化活性比较研究

采用苯酚—硫酸法,测定比较了翅果油树叶片、枝条和种子3个部位的多糖含量;并分别采用邻苯三酚自氧化法和番红花红O—Mn2+—H2O2光度法测定比较了3个部位多糖对超氧离子、羟基自由基的清除活性。结果表明:翅果油树叶片、枝条和种子多糖平均含量依次为69.42,23.15,56.47 mg.g-1;3个部位多糖对羟基自由基、超氧阴离子自由基均有清除作用,其清除超氧离子自由基的活性依次为:Vc>种子>枝条>叶片,清除羟基自由基的活性依次为:叶片>种子>Vc>枝条。该研究结果表明,翅果油树叶片和种子均可作为利用该植物开发天然抗氧化剂的优选部位。     

一品红花色素抗氧化性能的研究

从一品红红色苞片中提取花色素,并用自由基测定试剂盒测试了一品红花色素的体外抗氧化性能,并用碘量法测定了其抑制猪油氧化的效果,用TBARS法测定其对血浆脂蛋白氧化的抑制能力。结果表明:一品红花色素具有较强的清除超氧阴离子(O2.-)和羟自由基(.OH)的能力,清除效果优于同浓度的VC;其对猪油氧化的抑制效果和同浓度的VC相近,而对人血浆脂质过氧化的抑制效果显著高于VC。     

家蝇幼虫提取物清除氧自由基的作用

探讨了家蝇Musca domesticaL.幼虫提取物对氧自由基的清除作用。采用脱氧核糖-铁体系和邻苯三酚自氧化体系分别测定了不同浓度的提取物对羟自由基和超氧阴离子自由基的清除率,同时采用H2O2氧化体系测定了提取物的抗氧化值。结果显示家蝇幼虫提取物对羟自由基和超氧阴离子自由基的IC50分别为1.93 mg/mL和3.26 mg/mL;浓度为0.5%的提取物的抗氧化值为9.01 mg/g,为同浓度维生素C抗氧化值的1.29倍。     

李氏块菌提取物抗氧化活性的研究

对李氏块菌Tuber liyuanum子实体的不同提取物,包括甲醇提取物(ME)、乙醇提取物(EE)、丙酮提取物(AE)、正丁醇提取物(BAE)和乙酸乙酯提取物(EAE),进行清除DPPH自由基、羟基自由基、超氧阴离子自由基、铁离子螯合能力、还原力以及总酚含量的测定和研究,发现ME对DPPH自由基、超氧阴离子自由基清除及还原力活性最高,EC50值分别为23.37mg/m L、11.65mg/m L和24.47mg/m L;EE对羟基自由基清除和铁离子螯合能力活性最高,EC50值分别为7.24mg/m L和小于0.5mg/m L;ME的总酚含量最高(3.08mg GAE/g提取物),其次是EE(1.34mg GAE/g提取物),提取物总酚含量与抗氧化活性呈现出一定的正相关性。     

构树种子油的超声强化提取及其抗氧化性研究

本文采用单因素设计,进行均匀设计实验,用超声波提取法考察了溶剂种类、超声波强度、超声波提取时间、料液比(g/mL)对构树种子油提取率的影响,同时研究了构树种子油清除羟基自由基和超氧阴离子自由基的能力。结果表明,在以丙酮作提取剂,各因素对构树种子油提取效率的影响次序为:超声波强度料液比超声时间;工艺参数为:超声波强度为65%,料液比(g/mL)1∶12,超声提取时间7 min,构树种子油提取率可达30.2%。同时,以构树种子油清除羟基自由基能力和超氧阴离子自由基能力为指标,研究构树种子油的抗氧化能力。通过DPPH法和邻苯三酚自氧化法测定其抗氧化活性,结果发现其对羟基自由基的抑制率高达93.56%,而对超氧阴离子没有明显抑制作用。     

山楂果肉原花青素的体外抗氧化活性和对DNA损伤的保护作用

研究了化学发光法测定山楂果肉原花青素(procyanidins of Hawthorn Sarcocarp 简称HSPC)的体外抗氧化活性及其对DNA损伤的保护作用.运用邻苯三酚-鲁米诺化学发光体系测定了HSPC对超氧阴离子的清除作用,硫酸铜-邻菲啰啉-抗坏血酸-双氧水体系测定了HSPC对羟基自由基的清除作用,双氧水-鲁米诺体系测定了HSPC对体外双氧水的清除作用,采用硫酸铜-邻菲啰啉-抗坏血酸-双氧水-脱氧核糖核酸测定了HSPC对体外DNA损伤的保护作用.结果表明:当HSPC浓度为1 mg/mL时,对超氧阴离子抑制率达87.7%,其半数抑制率浓度IC50值为130.8 μg/mL;100 μg/mL时对羟基自由基抑制率达91.7%,IC50值为61.73 μg/mL;8 μg/mL时对双氧水抑制率达91.6%,IC50值为0.19 μg/mL;40 μg/mL时对体外DNA损伤抑制率达80.7%,IC50值为22.16 μg/mL.表明HSPC具有很好的体外清除活性氧和保护DNA损伤的活性.     

壳寡糖抑菌及抗氧化性的研究

本文通过经典的Fenton反应方法建立体系研究壳寡糖清除羟基自由基能力,邻苯三酚在碱性条件下发生自氧化反应体系研究壳寡糖清除超氧阴离子的能力,以及总抗氧化能力测定。同时以棉花枯萎病菌及烟草赤星病菌为受试菌种,采用生长速率法研究壳寡糖对植物病原真菌的抑制作用。壳寡糖对羟基自由基清除率IC503.78mg/m L,超氧阴离子清除率IC503.3 mg/m L,5g/L壳寡糖对棉花枯萎菌、烟草赤星菌菌丝生长的抑制率达20%和14%。研究结果表明壳寡糖具有较强抗氧化能力,并且有一定抑菌作用的生物活性寡糖,有很广阔的应用前景。     

苹婆种子营养及抗氧化活性

介绍了一种原产华南、种子可食的木本植物——苹婆的生物学特性,并以广西苹婆（Sterculia nobilisSmith）种子为材料,对其营养成分进行了测定。通过测定其多酚提取物的还原力和金属螯合力,以及对1,1-二苯基-2-三硝基苯肼（DPHH）自由基、羟自由基和超氧阴离子自由基的清除能力,探讨了苹婆种子的抗氧化活性。结果显示：苹婆种子营养丰富,含有18种氨基酸,富含酚类物质。其中,淀粉含量60.42 g/100 g FW、蛋白质20.32 g/100 g FW、脂肪2.18 g/100 g FW、氨基酸2.36 g/100 g FW、铁136.86 mg/g FW、维生素C 7225μg/100 g FW;总酚含量为401.84μg/mL没食子酸。苹婆种子多酚提取物有较强的还原力,金属螯合力,以及DPPH自由基、羟自由基和超氧阴离子自由基清除能力,在0～50μg/mL浓度范围,苹婆抗氧化能力与抗坏血酸或乙二胺四乙酸（EDTA）相当。苹婆种子营养全面,具有较强的抗氧化能力,苹婆是很有潜力的功能食品来源植物。     

红果参多糖的提取纯化及抗氧化活性研究

利用超声波辅助水提醇沉法提取并纯化红果参多糖.以抗坏血酸(VC)作参照物,考察了红果参多糖对羟基自由基、超氧阴离子自由基、亚硝基的清除效果及对油脂的抗氧化性能.结果表明:红果参多糖能很好的清除羟基自由基和超氧阴离子自由基,其清除能力与多糖浓度呈正相关性,对油脂的氧化有明显的抑制作用,对亚硝基的清除效果不明显.     

4种珍稀食用菌水提物的抗氧化活性研究

用DPPH自由基清除法、羟基自由基清除法和超氧阴离子自由基清除法对4种珍稀食用菌灵芝、云芝、茶树菇、松茸的水提物进行抗氧化活性评价,为更好评价其抗氧化活性,以维生素C作为阳性对照。实验结果显示：4种食用菌水提物具有不同程度的抗氧化活性。云芝对DPPH自由基的清除能力最强,其IC₅₀值为1.46 mg/mL,维生素C清除DPPH自由基的IC₅₀为0.046 mg/mL;茶树菇对清除羟基自由基的清除能力最强,其IC₅₀值为1.41 mg/mL,云芝和松茸也有较强清除羟自由基能力,其IC₅₀值分别为1.56、1.57 mg/mL,三者的清除能力均明显优于阳性对照样品,维生素C清除羟自由基的IC₅₀为2.41 mg/mL;灵芝和云芝有较强清除超氧阴离子自由基能力,其IC₅₀值分别为124.48、138.28 mg/mL。     

棘豆蠕孢菌多糖抗氧化活性研究

以总还原力、羟自由基(.OH)抑制活性、超氧阴离子自由基O 2的清除率、亚硝酸根离子(NO2-)的清除率为评价指标,探明内生真菌棘豆蠕孢菌(Embellisia oxytropis Q.Wang,Nagao&Kakish)次级代谢产物多糖的抗氧化作用。结果表明:棘豆蠕孢菌多糖的抗氧化活性随着多糖浓度的增加而增大,呈量效关系,其中胞内多糖对自由基和亚硝酸根离子具有较好的清除作用,清除率高达80%以上,与维生素C对照组接近。     

咖啡和绿茶的抗氧化活性研究

茶和咖啡是全世界消费最多的饮料。该工作利用电子自旋共振(ESR)技术和ABTS〔2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid)〕等方法,研究和比较了3种绿茶(龙井、碧螺春和毛峰)和3种咖啡的抗氧化活性,以及对ABTS 、DPPH、超氧阴离子、羟基自由基、单线态氧的清除作用和对脂质过氧化的抑制作用。利用高压液相色谱(HPLC)分析了绿茶中的抗氧化成分之一EGCG((-)-epigallocatechin gallate)和咖啡中的抗氧化成分之一绿原酸(chlorogenic acid5,CQA)的含量。结果发现,如果按每克剂量比较,对于清除ABTS 的能力而言,茶和咖啡水提取液对ABTS 清除能力各有千秋,咖啡水提取液的比龙井、毛峰水提取液的高,但与碧螺春无显著差异,咖啡B比咖啡A和C强;按每杯茶(3g/200mL)和咖啡(2.4g/200mL)对ABTS 的清除能力进行比较,咖啡的比龙井和毛峰的高但比碧螺春低,咖啡B比咖啡A和C强。对超氧阴离子、羟基和DPPH自由基及单线态氧的清除作用和对脂质过氧化的抑制作用的研究表明,如果按每克剂量比较,茶和咖啡水提取液没有明显区别;按每杯量进行比较时,茶水提取液比咖啡水提取液对自由基的清除能力稍强。HPLC结果表明,EGCG含量在毛峰中最高,5CQA含量在咖啡B中最高。该研究结果表明茶和咖啡中均含有丰富的抗氧化成分,并都具有较强的抗氧化活性和清除自由基能力。     

Antioxidant and antitumor activities of the polysaccharide from seed cake of Camellia oleifera Abel

To explore biomedical potential of the polysaccharide from seed cake of Camellia oleifera Abel, we investigated antioxidant and antitumor capacities of the polymer. The results showed that the polysaccharide is capable of scavenging both superoxide anion and hydroxyl radicals in vitro. The highest scavenging rate of superoxide anion and hydroxyl radicals is 85% and 76%, respectively. Using the model animal, Caenorhabditis elegans, we further show that the polysaccharide can increase antioxidant enzyme activity, decrease lipid peroxidation level, and reduce paraquat-induced oxidative damage at a polysaccharide concentration more than 50mg/l. We also revealed that the polysaccharide has some ferric chelating ability and strong in vivo antitumor activity. The antitumor rate against Sarcoma180 solid tumor grown in BALB/C mice reached 85.6% at the highest dose of 40×20mg/kgdays.     

Scavenging effect of schizandrins on active oxygen radicals

The reactive oxygen radicals produced from human polymorphonuclear leukocytes (PMN) stimulated with PMA (phorbol myristate acetate), hydroxyl radicals generated by a Fenton reaction, and superoxide anion radicals produced by irradiating solutions of riboflavin in the presence of EDTA have been taken as the models for production of oxygen radicals. With the use of the electron spin resonance spin trapping method, the scavenging effects of schizandrol A (solA) (5 x 10(-4) M) and schizandrin B (sinB) (5 x 10(-4) M) have been studied and compared with the effects of vitamin E (5 x 10(-4) M) and vitamin C (5 x 10(-4) M). It has been found that in cell system the scavenging effects of sinB and solA, as judged by ESR spin trappings, on hydrpxyl radicals (.OH) are greater than vitamin E and vitamin C and the scavenging effects on superoxide anion (O2) are greater than vitamin E but lower than vitamin C. With respect to the Fenton reaction, sinB has the strogest scavenging effect on .OH (77%) and solA has strong scavenging effect on .OH (63%), both of them larger than that of vitamin E (35%) and vitamin C (56%). In the riboflavin/EDTA system, the scavenging effect of sinB (46%) is smaller than that of vitamin C (96%) but larger than that of vitamin E (23%); the scavenging effect of solA is not obvious (14%). With the use of spin probe oximetry, the oxygen consumption during the respiratory burst of stimulated PMN has been measured when exposed to schizandrins. The experiment results demonstrated that they do not affect the activity of production of active oxygen radicals in the respiratory burst of PMN stimulated with PMA.     

高效抗氧化大型真菌的筛选

为获得高效抗氧化菌株,采用直接提取方式从20个大型真菌菌株菌丝体培养液中提取抗氧化活性物质,采用邻苯三酚自氧化法、水杨酸法、DPPH法测定各菌株菌丝体培养粗提液对超氧阴离子自由基(O2)、羟基自由基.(OH)及1,1-二苯代苦味酰基自由基(DPPH-)的清除作用。结果表明:各菌株菌丝体培养粗提液对(O2)、.OH及DPPH-均有一定的清除作用,其中菌株NG菌丝体培养粗提液对OH-的清除效果最好,清除率为75.56%;菌株02菌丝体培养粗提液对(O2-)的清除效果最好,清除率为37.51%;菌株EG菌丝体培养粗提液对DPPH-清除效果最好,清除率为66.91%。     

Antioxidant activity of extract from Polygonum aviculare L

Free radicals induce numerous diseases by lipid peroxidation, protein peroxidation, and DNA damage. It has been reported that numerous plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum aviculare L. (Polygonaceae) has antioxidant activity is unknown. In this study, dried Polygonum aviculare L. was extracted by ethanol, and the extract was lyophilized. The antioxidant activities of extract powder were examined by free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays. The results show that the IC50 value of Polygonum aviculare L. extract is 50 microg/ml in free radical scavenging assays, 0.8 microg/ml in superoxide radical scavenging assays, and 15 microg/ml in lipid peroxidation assays, respectively. Furthermore, Polygonum aviculare L. extract has DNA protective effect in hydroxyl radical-induced DNA strand scission assays. The total phenolics and flavonoid content of extract is 677.4 +/- 62.7 microg/g and 112.7 +/- 13 microg/g. The results indicate that Polygonum aviculare L. extract clearly has antioxidant effects.     

药用真菌灵芝液体培养过程中的抗氧化活性研究

灵芝Ganoderma lingzhi是一种重要的药用真菌,已被《中国药典》正式收录。本研究主要以菌丝体干重、多糖含量、多酚含量、黄酮含量、抗坏血酸（ascorbic acid,AA）含量、总抗氧化能力（total antioxidant capacity,T-AOC）、超氧化物歧化酶（superoxide dismutase,SOD）活性、羟自由基清除能力、超氧阴离子清除能力、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、2,2′-连氮-双(3-乙基苯并噻唑-6-磺酸)[2,2′-azino-bis(3- ethylbenzthiazoline-6-sulphonic acid),ABTS]自由基清除能力、铁离子还原能力（ferric reducing antioxidant power,FRAP）和亚铁离子螯合能力为测定指标,对灵芝液体培养过程中的抗氧化活性进行了评价。结果显示,该菌具有较高的抗氧化活性,体现在液体培养过程中生长代谢旺盛,可分泌大量多糖、多酚、黄酮、AA等物质和SOD等酶类,对羟自由基、超氧阴离子、DPPH自由基及ABTS自由基等的清除效果显著,且具有较强的铁离子还原能力和亚铁离子螯合作用,这也说明该菌的抗氧化活性与其自身的生长状况、次级代谢产物分泌及还原能力等密切相关。此外,一定的环境胁迫压力也可以激发该菌启动自身的抗氧化系统以保护机体免受氧化损伤。     

“黑美人”土豆色素体外抗氧化性研究

采用普鲁士蓝法、DPPH清除体系、H2O2/Fe2+/水杨酸检测体系、亚硝基清除体系、卵黄脂蛋白不饱和脂肪酸(PUFA)过氧化体系、邻苯三酚自氧化法研究了黑美人土豆色素的体外抗氧化活性,并同VC进行了比较。结果表明,黑美人土豆色素对几种自由基均有不同的清除作用,其中黑美人土豆色素的还原力、抗脂质过氧化能力、清除羟基自由基、亚硝基、超氧阴离子自由基(O2-.)和DPPH自由基的能力均高于VC。该结果显示,黑美人土豆色素是一种较好的天然自由基清除剂,可以作为绿色食品用于人们的日常饮食,有较大的开发利用潜能。     

芦丁等天然产物清除活性氧自由基O_(?)~-和·OH的ESR研究

本文用促癌剂PMA(phorbol myristate acetate)刺激人多形核白细胞(PMN)呼吸暴发产生的活性氧自由基,Fenton反应产生的羟自由基·OH,光照核黄素和黄嘌呤/黄嘌呤氧化酶体系中产生的超氧阴离子自由基O(?)为模型,用自旋捕集方法研究天然产物芦丁,槲皮素,异槲皮苷和汉防已甲素对活性氧自由基(?)和·OH的清除作用.除汉防已甲素外,其它药物都能很明显地清除PMN呼吸暴发过程中产生的活性氧自由基.芦丁和异槲皮苷对(?)的清除率分别高达78.1%和79.9%,远远大于维生素E(12.7%)的作用.除汉防已甲素外,其它三种药物对·OH的清除作用也大于维生素E.四种天然产物对O(?)和·OH的清除作用都小于维生素C.     

Antioxidant activity in vitro of two aromatic compounds from Caesalpinia sappan L

Two antioxidant compounds were isolated from C. sappan L by multiple steps of column chromatography and thin layer chromatography in succession with superoxide scavenging assay as activity monitor. Structures of the two compounds were determined by spectroscopic methods as 1',4'-dihydro-spiro[benzofuran-3(2H),3'-[3H-2]benzopyran]-1',6',6',7'-tetrol (compound 1) and 3-[[4,5-dihydroxy-2(hydroxymethyl) phenyl]-methyl]-2,3-dihydro-3,6-benzofurandiol (compound 2). Characterization of antioxidant properties of these two compounds was done by determining the inhibitory effect on xanthine oxidase activity as well as scavenging effect on superoxide anion and hydroxyl radicals. Our results indicated that compounds 1 and 2 inhibited xanthine oxidase activity and scavenged superoxide anion and hydroxyl radicals. Compounds 1 and 2 possessed similar radical scavenging activities as ascorbic acid, and they were more effective than other well-known antioxidants such as alpha-tocopherol, beta-carotene, and BHT. As inhibitors of free radical formation, compounds 1 and 2 were more effective than all the other antioxidants tested. In conclusion, compounds 1 and 2 can be regarded as primary antioxidants with radical-scavenging and chain-breaking activities as well as secondary antioxidants with inhibitory effect on radical generation.