绿豆皮中黄酮类化合物的抗氧化活性及其结构分析

本文旨在分析绿豆皮中黄酮类化合物的抗氧化活性及其结构。采用20%、40%、60%、80%乙醇对绿豆皮黄酮粗提物进行梯度洗脱纯化,以总抗氧化能力（total antioxidative capability,T-AOC）、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′-联氨-双-3-乙基苯并噻唑啉-6-磺酸（2, 2′-azinobis-3-ethylbenzothia zoline-6-sulphonic acid,ABTS）自由基清除能力、羟自由基清除能力等为指标,筛选出具有最高抗氧化活性的组分,并对其进行结构鉴定。结果表明,60%洗脱液中绿豆皮黄酮的抗氧化能力最强,其DPPH自由基清除能力为48.03%;ABTS+自由基清除能力为57.53%;羟自由基清除能力为12.02%;T-AOC的抗氧化活性为207.64 U/mL,显著高于其他洗脱液（P<0.05）。绿豆皮中具有最强抗氧化活性的黄酮类化合物分别包括牡荆素(vitexin)、异牡荆素(isovitexin)及圣草酚-6-C-β-D-吡喃葡萄糖苷(eriodictyol-6-C-β-D-glucopyranoside)。     

6种黄酮协同抗氧化作用及构效关系研究

以ABTS~+·清除能力为指标,采用Chou-Talalay中效原理设计试验,研究6种结构不同的小分子黄酮协同抗氧化作用及构效关系。结果表明:6种黄酮化合物对ABTS~+·清除能力依次为:5,6,7-三羟基黄酮6-羟基黄酮3,7-二羟基黄酮5-羟基黄酮3-羟基黄酮7-羟基黄酮抗坏血酸,其中5,6,7-三羟基黄酮、6-羟基黄酮和3,7-二羟基黄酮氧化作用效果显著;在不同浓度下,两种黄酮复配物对ABTS+·清除能力的联合作用指数CI值有较大差异;3,7-二羟基黄酮和其它5种黄酮都有明显的协同作用。充分说明6种黄酮化合物之间的协同抗氧化作用与化合物的羟基位置和数量有关,具有C_(3,7)-二羟基是协同抗氧化作用的主要结构特点。     

红豆皮多酚提取工艺优化及抗氧化活性分析

采用超声辅助提取工艺提取红豆皮中的多酚化合物,选取乙醇体积分数、超声功率、超声时间、液料比进行单因素试验,在此基础上,采用响应面法优化工艺参数。结果表明,红豆皮多酚超声辅助提取最佳工艺参数:乙醇体积分数60%,超声功率360 W,超声时间30 min,液料比30∶1(mL/g),在此条件下的多酚提取量为(145.28±2.21)mg/g。采用高效液相色谱法测定红豆皮多酚中13种单体酚:没食子酸、芦丁、儿茶素、绿原酸、原花青素B2、表儿茶素、阿魏酸、异牡荆素、牡荆素、异鼠李素、金丝桃苷、山奈酚、槲皮素。抗氧化试验结果表明红豆皮多酚的1,1-二苯基-2-三硝基苯肼自由基、超氧阴离子自由基清除能力略低于VC,而2,2′-联氨-双-(3-乙基苯并噻唑啉-6-磺酸)二胺盐自由基(ABTS+·)、羟自由基清除能力高于VC,说明从红豆皮中提取的多酚化合物具有较强的抗氧化活性,是一种极具开发潜力的天然抗氧化剂。     

金银花叶黄酮体外抗氧化能力及对H2O2诱导RAW264.7巨噬细胞损伤的保护作用

目的：研究金银花叶黄酮的体外抗氧化能力和对H2O2诱导RAW264.7巨噬细胞损伤的保护作用。方法：金 银花叶粉经提取纯化后得到金银花叶黄酮粉,以抗坏血酸为阳性对照,测定金银花叶黄酮的总还原力,对羟自由 基、超氧阴离子自由基及1,1-二苯基-2-三硝基苯肼自由基的清除能力。体外培养RAW264.7巨噬细胞,实验分为空 白组、模型组、对照组和金银花叶黄酮低、中、高剂量组,用H2O2诱导损伤RAW264.7细胞,噻唑蓝法测定细胞存 活率,试剂盒法测定细胞和细胞培养液中丙二醛、谷胱甘肽含量及超氧化物歧化酶、乳酸脱氢酶活力。结果：金银 花叶黄酮的总还原力及对各自由基的清除能力较强,并在足够质量浓度下等同于对照品抗坏血酸。金银花叶黄酮呈 剂量依赖性保护H2O2引起的RAW264.7细胞的损伤,降低细胞及细胞培养液中丙二醛含量,提高超氧化物歧化酶活力 及谷胱甘肽含量,提高细胞内乳酸脱氢酶活力。结论：金银花叶黄酮抗氧化能力较强,可修复H2O2诱导的RAW264.7 巨噬细胞的损伤,其作用可能与调节细胞氧化还原系统、清除自由基、提高细胞内抗氧化酶系的活力有关。     

Flavonoid glycosides in the shoot system of Okinawa Taumu (Colocasia esculenta S.)

Six C-glycosylflavonoids and one O-glycosylflavonoid have been isolated from the shoot system of Taumu (Colocasia esculenta S.). They were identified as schaftoside, isoschaftoside, orientin, isovitexin, isoorientin, vitexin and luteolin 7-O-sophoroside. The presence of catechol moiety in the B-ring of isoorientin, orientin and luteolin 7-O-sophoroside showed strong antioxidant activity with different mechanisms of action in DPPH radical scavenging, β-carotene bleaching and superoxide radical inhibition assays. The amount of dry weight matter extract of water was higher than methanol for both the leaf and the stem parts. Isovitexin was the main compound in water and methanol extracts of the leaf while schaftoside was the main compound of the water extract of the stem. Methanol extract of the leaf showed higher DPPH radical scavenging activity than water extract while the opposite was observed for the stem. The results of this experiment suggest the potential of the leaf of Taumu as a source of dietary antioxidant.     

马兰提取物抗氧化性研究

目的：考查马兰中水提取物和乙醇提取物抗氧化活性。方法：分别以水和乙醇为提取液,探讨马兰中水提取物和乙醇提取物的抗氧化活性,包括还原能力以及清除DPPH自由基、羟自由基、超氧阴离子自由基和H2O2的能力。 结果：提取物主要成分为黄酮类化合物。马兰水提取物的抗氧化活性为：超氧阴离子自由基(IC50 2.2μg/mL)＞H2O2(IC50 2.8μg/mL)＞羟自由基(IC50 5.6μg/mL)＞DPPH自由基(IC50 8.5μg/mL) ＞金属螯合性(IC50 28.0μg/mL)。而马兰乙醇提取物的抗氧化活性为：H2O2(IC50 2.0μg/mL) ＞超氧阴离子自由基(IC50 2.1μg/mL)>羟自由基(IC50 2.5μg/mL)> DPPH自由基(IC50 5.6μg/mL) ＞金属螯合性(IC50 51.2μg/mL)。结论：马兰提取物具有较强的抗氧化活性。     

黄原胶对体外模拟消化过程中4 种竹叶黄酮生物可及性的影响

目的：竹叶碳苷黄酮在胃肠道消化过程中易于降解,导致其生物可及性低,因此,本研究拟探究黄原胶存在时,4 种碳苷黄酮（异荭草苷、荭草苷、异牡荆素、牡荆素）在各模拟消化阶段生物可及性的变化情况。方法：利用体外模拟消化模型结合超高效液相色谱技术,分析在有/无黄原胶存在的条件下,竹叶提取物中4 种碳苷黄酮质量浓度的变化情况。结果：相较于直接消化样品,添加黄原胶的样品可以明显减弱模拟消化过程中碳苷黄酮的降解;口腔、胃、肠道模拟消化对竹叶碳苷黄酮的生物可及性影响存在差异,黄原胶的加入可以明显提高4 种碳苷黄酮,尤其是牡荆素和异牡荆素的生物可及性,模拟肠道消化后,黄原胶保护组的异牡荆素和牡荆素质量浓度分别降低了62%和59%,远低于直接消化组（分别降低84%和80%）。结论：黄原胶可以明显提升体外模拟消化过程中竹叶碳苷黄酮的生物可及性,对于相关功能产品的开发具有良好的应用价值。     

Electron spin resonance spectroscopy studies on the free radical scavenging activity of wine anthocyanins and pyranoanthocyanins

Anthocyanins are a group of natural occurring pigments responsible for the red-blue color of grapes and many fruits and vegetables. Anthocyanins and derived pigments are of double interest, one technological, as they can be used as natural colorants, and another one due to their implication on human health through their antioxidant activity. Although there are numerous studies regarding the antioxidant activity of grape extracts as well as red wine, the free radical scavenging activity of purified anthocyanins and pyranoanthocyanins is largely unknown. In the present study, the hydroxyl and superoxide anion scavenging activities of anthocyanins and their pyruvic acid adducts were systematically investigated by electron spin resonance spectroscopy and spin trapping. The 3-glucosides of delphinidin, cyanidin, petunidin, pelargonidin and malvidin, and the pyruvic adduct of the 3-glucoside of delphinidin exhibited a potent superoxide anion radical scavenging and, to a lesser extent hydroxyl anion radical scavenging activity. The pyranoanthocyanins of cyanidin, petunidin, malvidin and pelargonidin showed a high capacity to scavenge superoxide anion radicals but did not scavenge hydroxyl radicals. Current data indicate that formation of anthocyanin adducts with pyruvic acid, which may occur during wine ageing or fruit juice processing, decreases the hydroxyl and superoxide anion scavenging and thus could decrease the antioxidant potential of these compounds.     

中华真地鳖酶解短肽的抗氧化作用

目的：研究中华真地鳖酶解短肽的体内外抗氧化作用。方法：测定中华真地鳖酶解短肽体外对?OH、O2－?和DPPH自由基的清除作用;并将中华真地鳖酶解短肽灌胃,颈背部皮下注射D-半乳糖致衰老模型小鼠,以小鼠血浆和肝脏中丙二醛(MDA)含量、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(T-SOD)及清除?OH活性为指标,研究其体内抗氧化活性。结果：中华真地鳖酶解短肽对?OH、O2－?和DPPH自由基有较强的清除作用,其IC50分别为0.40、8.73、1.32mg/mL;并且与模型组相比,中华真地鳖酶解短肽能显著降低模型小鼠血浆和肝脏中MDA含量(P＜0.01),显著提高其CAT活力(P＜0.05)、GSH-Px活力(P＜0.01)及清除?OH(P＜0.05)能力,显著提高小鼠肝脏T-SOD活力(P＜0.05)。结论：中华真地鳖酶解短肽有较强的体内外抗氧化作用。     

Antioxidants of therapeutic relevance in COPD from the neotropical blueberry Anthopterus wardii

Four flavone C-glycosides, isoorientin (1), orientin (2), vitexin (3), and isovitexin (4), were isolated from the neotropical blueberry of Anthopterus wardii, a so-called “superfruit”, using antioxidant activity-guided fractionation. A dose-response relationship of compounds 1-4 was determined for their anti-inflammatory activity against interleukin-8 (IL-8) and for the inhibition of matrix metalloproteinase-1 (MMP-1) expression, an inflammatory marker for chronic obstructive pulmonary disease. The four flavone C-glycosides exhibited inhibitory activity against IL-8 production and MMP-1 expression, with compounds 1, 3, and 4 having the most potent inhibitory activities in both assays at 100 μg/ml. The structures of compounds 1-4 were determined by spectroscopic methods. These flavone C-glycosides are reported for the first time in the Anthopterus genus.     

Inhibitory effect of mung bean extract and its constituents vitexin and isovitexin on the formation of advanced glycation endproducts

The anti-glycation activity of four kinds of beans including mung bean, black bean, soybean and cowpea were evaluated. Aqueous alcohol extract of mung bean exhibited the strongest inhibitory activity against the formation of fluorescent advanced glycation endproducts (AGEs) in a bovine serum albumin (BSA)-glucose model, and the inhibitory activities of extracts of the four beans were found to be highly correlated with their total phenolic contents (R² = 0.95). Subsequent HPLC analysis of mung bean extract revealed two major phenolics which were purified and identified as vitexin and isovitexin by spectral methods. In the anti-glycation assays, both vitexin and isovitexin showed significant inhibitory activities against the formation of AGEs induced by glucose or methylglyoxal with efficacies of over 85% at 100 μM. In another assay, vitexin and isovitexin failed to directly trap reactive carbonyl species, such as methylglyoxal, suggesting that their anti-glycation activities may mainly be due to their free radical scavenging capacity.     

3种新型查尔酮衍生物的合成及抗氧化活性

以查尔酮为起始原料,经缩合反应得到双查尔酮类、查尔酮结构的黄酮醇类、查尔酮结构的黄酮类3 种共8 个查尔酮类衍生物化合物。分别用红外光谱、核磁共振波谱法、质谱法和元素分析法对化合物的结构进行确证。比较了查尔酮类衍生物化合物清除超氧阴离子自由基、羟自由基和1,1-二苯基-2-三硝基苯肼自由基的活性及相对还原能力,并将效果较好的化合物应用于油脂中,对其抗氧化性能进行研究。结果表明：当样品质量浓度为0.5 mg/mL时,多数查尔酮类衍生物化合物具有显著的自由基清除活性,其中双查尔酮类化合物2对油脂抗氧化作用较强,优于VC对照组。     

大球盖菇多糖清除自由基活性和对D-半乳糖氧化损伤小鼠的抗氧化作用

目的：探讨大球盖菇多糖(SRP)体外自由基清除活性和对D- 半乳糖所致氧化损伤小鼠的抗氧化作用。方法：SRP 体外抗氧化活性用自由基清除能力、红细胞溶血作用、肝匀浆MDA 生成作用和抑制线粒体肿胀的方法来测定;在动物实验中,通过连续60d 颈背部皮下注射D- 半乳糖建立氧化损伤动物模型,在造模的同时给予低、中、高剂量(100、200、400mg/kg·d) SRP,并定期测定血液SOD 活性和MDA 含量,动物被处死后测定血液和肝脏的抗氧化指标。结果：SRP 在体外清除超氧自由基IC50 为132.5μg/ml,在583.1μg/ml 浓度时对羟自由基清除率为47.44%,在832μg/ml 时对红细胞氧化溶血抑制率为23.8%,在500μg/ml 时抑制线粒体肿胀程度与对照组相同,在537μg/ml 时在自氧化和诱导氧化条件下,抑制肝匀浆MDA 的生成分别为38.0% 和40.9%;在动物实验中,SRP 对小鼠体重变化无显著影响,能使降低的血红蛋白(Hb)含量和肝指数恢复到正常水平给予SRP(200mg/kg)在20、45、60d 时能提高血液SOD 活性,在45、60d 时能降低血液MDA 含量,与模型组比差异有显著性;在小鼠血清抗氧化指标中,模型组MDA 含量升高,谷胱甘肽过氧化物酶(GPx)和总抗氧化能力(TAOC)水平降低,与对照组比差异有显著性,给予SRP 后MDA 含量显著降低,GPx 活性和TAOC 显著提高。与模型组比,SRP 组的肝抗氧化酶(总SOD、MnSOD、CuZnSOD 及GPx)活性及TAOC 显著提高,MDA 含量显著下降,差异有显著性。结论：SRP 能有效地清除自由基,对D- 半乳糖所致氧化损伤小鼠血液和肝脏有显著的改善作用,说明SRP 体内和体外具有很好的抗氧化作用。     

石斛多糖体外抗氧化活性的研究

本实验利用对邻苯三酚自氧化体系产生的超氧阴离子自由基(O2·)的清除作用、Fenton反应检测对羟基自由基(·OH)的清除作用以及对烷基自由基引发的亚油酸氧化体系的抑制作用,对霍山石斛和铁皮石斛多糖抗氧化活性能进行了研究。结果表明,两种多糖对超氧阴离子自由基和羟基自由基具有不同程度的清除作用,同时对烷基自由基引发的亚油酸氧化体系也有显著的抑制作用。研究还发现霍山石斛多糖的抗氧化能力显著强于铁皮石斛多糖。     

云南种植的三种颜色玛咖体外抗氧化活性分析?

采用铁离子还原能力(FRAP)、Fenton 反应体系、DPPH 法及邻苯三酚自氧化体系评价种植于云南的玛咖乙醇提取物体外抗氧化能力。结果表明：在云南种植的3 种颜色玛咖乙醇提取物均表现出抗氧化活性,且呈现一定的量效关系,但在4 种抗氧化体系中的结果有所不同;紫色玛咖的总还原能力最强,黄色次之,白色最弱,3200m 海拔地区种植的玛咖高于其他相对低海拔地区的玛咖;紫色和黄色玛咖的清除DPPH 自由基能力高于白色,3200m 海拔地区种植的玛咖高于其他相对低海拔地区的玛咖;3 种颜色玛咖对羟自由基的清除能力明显,各样品的清除率在加入量为200μL 时均达到90% 以上,3000m 海拔地区种植的黄色玛咖最强;3 种颜色玛咖对超氧阴离子自由基的清除能力在实验范围内均较弱。     

干燥方式对金银花多酚组分及其抗氧化活性的影响

研究传统热风干燥、自然阴干以及真空干燥、真空冷冻干燥等不同干燥方式对金银花多酚类物质含量及抗氧化活性的影响。采用Folin-酚比色法及高效液相色谱（high performance liquid chromatography,HPLC）法分别检测4 种干燥方式下的金银花总酚及多酚类组分含量,并比较其清除1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、羟自由基（•OH）和2,2’-二氮-双（3-乙基苯并噻唑-6-磺酸）铵盐（2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonate acid) diammonium salt,ABTS）自由基的能力。结果表明：4 种干燥方式对金银花总酚含量及多酚类组分均有一定影响,其中真空冷冻干燥处理时金银花总酚及多酚类组分损失最小;不同干燥方式对金银花的抗氧化能力影响显著（P＜0.05）,真空冷冻干燥样品清除DPPH自由基、•OH和ABTS＋•的半抑制浓度（IC50）分别为5.43、17.64、44.32 μg/mL;而自然阴干、真空干燥和热风干燥处理的样品清除DPPH自由基、•OH及ABTS＋•的IC50高于真空冷冻干燥金银花相应的IC50。相关性分析显示,金银花酚酸类组分与其抗氧化活性显著相关（P＜0.05）。因此,真空冷冻干燥能较好地保留金银花多酚类物质,且具有较强的抗氧化活性,适宜用于金银花的干燥。     

Effects of Germination on the Nutritional Properties,Phenolic Profiles,and Antioxidant Activities of Buckwheat

Germination is considered to be an effective process for improving the nutritional quality and functionality of cereals. In this study, changes of nutritional ingredients, antinutritional components, chemical composition, and antioxidant activities of buckwheat seeds over 72 h of germination were investigated, and the reasons for these changes are discussed. With the prolonged germination time, the contents of crude protein, reducing sugar, total phenolics, total flavonoids, and condensed tannins increased significantly, while the levels of crude fat, phytic acid, and the activity of trypsin inhibitor decreased. Phenolic compounds, such as rutin, vitexin, isovitexin, orientin, isoorientin, chlorogenic acid, trans‐3‐hydroxycinnamic acid, and p‐hydroxybenzoic acid increased significantly during the germination process, which may be due to the activation of phenylalanine ammonialyase. The improvement of flavonoids led to significant enhancement of the antioxidant activities of germinated buckwheat. Germinated buckwheat had better nutritional value and antioxidant activities than ungerminated buckwheat, and it represented an excellent natural source of flavonoids and phenolic compounds, especially rutin and C‐glycosylflavones. Therefore, germinated buckwheat could be used as a promising functional food for health promotion.     

食用委陵菜黄酮的抗氧化性及清除自由基能力研究

从总体抗氧化能力、对Fe2+诱发卵黄脂蛋白PUFA过氧化体系的抑制能力、清除羟基自由基能力、清除超氧阴离子自由基能力、清除DPPH自由基能力五个方面评价了四种委陵菜中黄酮类化合物的活性,并与其他的合成抗氧化剂VC和PG进行了比较。实验结果表明,在一定浓度范围内,四种委陵菜中黄酮类化合物在上述前四个方面的性能有着固定的顺序:三叶(福建)>三叶(河北)>西南(河北)>西南(福建),但在清除DPPH自由基方面,其强弱顺序为:西南(福建)>三叶(河北)>西南(河北)>三叶(福建),且与VC和PG相比,清除DPPH自由基的能力相差无几。     

天然调味香料众香子精油的抗氧化性能及清除自由基能力研究

文章研究了众香子精油的总体抗氧化能力、清除超氧阴离子自由基能力、清除羟基自由基能力,并与合成抗氧化剂没食子酸丙酯(PG)进行了比较。实验结果表明,在一定浓度范围内,众香子精油清除超氧阴离子自由基的能力和清除羟基自由基的能力均强于PG。从而说明众香子精油具有良好的抗氧化效果。