紫草抗氧化成分的提取及其活性研究

分别用石油醚、三氯甲烷和乙醇依次提取紫草成分 ,用OSI仪测定了三种提取物对猪油氧化稳定性的影响 ,发现石油醚提取成分 (LE - pet)和三氯甲烷提取成分 (LE -chl)有明显的抗氧化活性 ,添加到猪油中后 ,w =0 0 2 %时 ,猪油的氧化稳定性比空白样品提高了约 1倍。对LE -pet和LE -chl进行薄层层析分离鉴定 ,得到三种化合物 :β ,β 二甲基丙烯酰紫草醌 (Ⅰ)、乙酰紫草醌 (Ⅱ)和紫草醌 (Ⅲ)。对它们的抗氧化活性进行测试 ,化合物Ⅱ和Ⅲ表现出明显的抗氧化活性 ,当w(Ⅱ)=0 .0 6 %、w(Ⅲ) =0 0 6 %时 ,猪油的氧化稳定性分别提高了 6 0 4和 3 94倍。化合物Ⅰ、Ⅱ、Ⅲ与VE均有较强的协同作用 ,化合物Ⅰ、Ⅱ、Ⅲ的质量分数为 0 .0 2 %与VE 的质量分数为 0 0 2 %共同使用时 ,其抗氧化协同系数 (SE)分别为 81 4(Ⅰ)、5 2 7(Ⅱ)和 132 6 (Ⅲ )     

山楂提取物的体外和体内抗氧化作用

采用ABTS清除2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐自由基、FRAP(铁离子还原/抗氧化能力测定法)和DPPH(清除二苯代苦味肼基自由基)三种体外模型筛选山楂提取物抗氧化活性;用高脂高糖乳剂建立了小鼠髙脂质模型,考察了提取物的体内抗氧化效果。山楂提取物体外ABTS、FRAP和DPPH法清除自由基能力测定结果显示,SC>SD>SB>SE>SA,SC在体内可以明显升高SOD(超氧化物歧化酶)水平(P<0.05)和降低MDA(丙二醛)水平(P<0.001)。研究结果表明,SC体外筛选抗氧化效果最好,与体内作用一致,SC体外抗氧化和体内抗脂质过氧化存在一定的相关性。     

虎杖根不同溶剂提取物的抗氧化活性研究

为探究虎杖根6种不同溶剂提取物的抗氧化活性,利用1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法、2,2-二氮-双(3-乙基苯并噻唑-6-磺酸)铵盐(ABTS)自由基清除法和总还原力检测法对6种不同溶剂虎杖根提取物进行抗氧化能力评价。选用抗氧化活性较强的95%乙醇提取物进行细胞层面内源性抗氧化能力的研究,评价其对抗氧化基因Nrf2、SOD、CAT、HO-1的调控作用。结果表明,相较于其他5种提取物,95%乙醇提取物的抗氧化能力最强且具有最高的多酚含量。95%乙醇提取物可显著增加Nrf2、SOD、CAT、HO-1等抗氧化基因的表达。95%虎杖根乙醇提取物具有较好的抗氧化活性,具有开发成为天然抗氧化剂的潜力。     

杜仲总黄酮对小鼠急性肝损伤的保护作用

研究了杜仲总黄酮对四氯化碳(CCl_4)诱导的急性肝损伤的保护作用。通过腹腔注射CCl_4诱导小鼠急性肝损伤,检测小鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)的含量、肝脏中超氧化物歧化酶(SOD)的活性、谷胱甘肽(GSH)和丙二醛(MDA)的含量,考察杜仲总黄酮的保肝作用。结果表明:杜仲总黄酮能显著降低急性肝损伤小鼠血清中的ALT、AST活性与肝脏中的MDA含量,并能提高肝脏中的SOD与GSH活性。杜仲总黄酮对CCl_4引起的急性肝损伤小鼠具有保护作用,其作用机制可能与抗氧化作用有关。     

白梅花提取物抗氧化及美白功效评价

采用体外评价方法对白梅花提取物进行抗氧化及美白功效研究。通过测定白梅花提取物对超氧阴离子及羟自由基清除的半数抑制浓度(IC₅₀),以及在H₂O₂诱导人皮肤成纤维细胞株(HFF-1细胞)氧化损伤模型中,考察白梅花提取物对细胞形态学、细胞存活率、丙二醛(MDA)含量、活性氧自由基(ROS)含量、超氧化物歧化酶(SOD)活力、谷胱甘肽(GSH)活力、Ⅰ型胶原蛋白(ColⅠ)以及基质金属蛋白酶1(MMP-1)含量的影响,评价其抗氧化功效。采用酪氨酸酶活性抑制实验以及小鼠黑色素瘤细胞株(B16-F10细胞)黑色素含量测定实验评价白梅花提取物的美白功效。结果表明白梅花提取物具有自由基清除作用,且白梅花60%醇提物、白梅花90%醇提物可明显提高HFF-1细胞活力、SOD活力、GSH活力以及ColⅠ含量,下调ROS、MDA及MMP-1含量,并明显降低B16-F10细胞中的黑色素含量,表现出明显的抗氧化及美白功效。     

艾渣不同极性部位的体外抗氧化活性

为考察艾渣不同极性溶剂提取部位的体外抗氧化活性,用紫外分光光度法对以石油醚、氯仿、乙酸乙酯、正丁醇和水为溶剂的5个不同极性部位萃取物中总黄酮含量进行测定,并以抗坏血酸(VC)为阳性对照,采用DPPH、ABTS自由基清除法和Fe~(3+)还原法(FRAP法)测定艾渣不同极性部位的体外抗氧化作用。结果表明,艾渣中黄酮类物质偏中等极性,多富集于乙酸乙酯及氯仿部位。艾渣提取物的不同极性部位均有不同程度的体外抗氧化效果。其中乙酸乙酯部位的DPPH及ABTS自由基清除率最强[IC_(50)值分别为(0.115±0.003) g/L和(0.093±0.003) g/L],正丁醇及氯仿部位的DPPH及ABTS自由基清除率次之。水层还原Fe~(3+)的能力最强,其次为正丁醇与乙酸乙酯部位。石油醚部位在三个抗氧化试验中均表现出较弱的抗氧化性。因此,初步推测抗氧化活性多集中于乙酸乙酯与正丁醇部位,可以将其作为抗氧化剂添加到化妆品中。     

人工栽培肉苁蓉保肝和抗氧化活性研究

采用清除二苯代苦味酰基(DPPH)自由基、清除[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基和铁离子还原/抗氧化能力(FRAP)测定法评价栽培肉苁蓉不同溶剂提取物体外抗氧化能力;腹腔注射四氯化碳复制小鼠急性肝损伤模型,测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性、肝脏指数和肝组织匀浆中丙二醛(MDA)含量及超氧化物歧化酶(SOD)活力值评价栽培肉苁蓉乙醇提取物的保肝作用。栽培肉苁蓉各提取物均显示较好的清除DPPH自由基、ABTS自由基及还原Fe3+-三吡啶三哑嗪(TPTZ)的能力,其中乙醇提取物具有最好的抗氧化活性(3种方法的RACT50值为3 534.32、2 726.39、2 621.68μmol/g),与阳性对照药丁基羟基茴香醚(BHA)相差不大(RACT50值为4 242.31、5 457.65、6 633.04μmol/g),大于丁基羟基甲苯(BHT)(RACT50值为724.59、1 322.27、1 581.68μmol/g);且肝损伤实验显示,乙醇提取物能显著降低小鼠血清中ALT、AST活性以及肝匀浆MDA含量,并能显著提高小鼠肝脏中的SOD值。结果表明,肉苁蓉对四氯化碳致小鼠急性肝损伤具有显著的保护作用,其机制可能与其抗氧化作用有关。     

狭瓣鹰爪叶抗氧化作用的研究

分别用乙醇、乙酸乙酯、石油醚和水提取狭瓣鹰爪叶中的抗氧化活性成分,在相同条件下比较它们对猪油的抗氧化效果,过氧化值(POV)采用碘量法测定。结果显示:不同溶剂的狭瓣鹰爪叶提取物均具有一定的抗氧化作用,且随着添加量的增大而增大,其不同溶剂提取物的抗氧化作用的能力强弱顺序依次为乙酸乙酯、水、石油醚、乙醇。     

一种解酒护肝片对小鼠酒精性肝损伤的保护作用的研究

目的:研究解酒护肝片对小鼠急性酒精性肝损伤的保护作用。方法:将小鼠随机分为5组,正常组、模型组、解酒护肝片低剂量组、中剂量组、高剂量组。采用白酒灌胃造模,造模与给药同时进行。6周后测定血清天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、丙二醛(MDA)、甘油三酯(TG)、超氧化物歧化酶(SOD)、还原型谷胱甘肽(GSH)水平。结果:各剂量解酒护肝片能显著降低小鼠血清ALT、AST活性和肝组织MDA、TG含量(P<0.05或P<0.01),提高肝组织SOD和GSH活性,各预防治疗组之间比较提示,以高剂量解酒护肝片作用最为显著。结论:解酒护肝片能有效预防小鼠酒精性肝病。     

臭菜抗氧化活性研究

为了研究臭菜提取物体外抗氧化活性,考察其对DPPH自由基和羟自由基活性的清除能力,并且与多种抗氧化剂进行对照研究。通过实验得出,臭菜提取物清除DPPH自由基活性的能力优于对香豆酸。结果表明,臭菜提取物具有很好的清除DPPH自由基和羟自由基活性的能力,是一种良好的天然抗氧化剂。     

Antioxidant activities of selected oriental herb extracts

Antioxidant activities of methanol extracts of 180 Oriental herbs were studied by determining the peroxide values of linoleic acid during storage at 50°C. Among the herb extracts tested, 44 species showed strong antioxidant activities on the oxidation of linoleic acid. The antioxidative effects of these 44 selected herb extracts were studied further in a methyl linoleate system during storage for 35 d. Among the 44 species tested, 11 species had particularly high antioxidative effects. The effects of type of extraction solvent (methanol, petroleum ether and ethyl acetate) on the antioxidant activities of the 11 species were studied. Antioxidant activities of most herb extracts were greatly dependent on the extraction solvent used; however, some of the extracts showed strong antioxidant activities regardless of the solvents used for the extraction. Among the 11 herbs selected, based on the antioxidant activity of their methanol extracts, two (i.e.,Psoralea corylifolia L. andSorphora angustifolia Sieb. & Zucc.) were selected for further study in lard held at 75°C for 7 d. The methanol extracts ofP. corylifolia L. andS. angustifolia Sieb. & Zucc. greatly decreased the peroxide formation of lard during storage. Treatment with 0.20% methanolic extract ofP. corylifolia L. exhibited significantly stronger antioxidant effect on the oxidation of lard than treatment with 0.02% butylated hydroxyanisole (P<0.05).     

Pereskia aculeata Muller (Cactaceae) Leaves: Chemical Composition and Biological Activities

The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC₅₀ 7.09 mg/mL) and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE)/g). The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY) expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC₅₀ value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression.     

海滩植物厚藤（Ipomoea Pes-caprae）抗氧化活性研究

采用加速溶剂萃取技术(ASE)快速制备厚藤活性提取物,并以DPPH法对厚藤茎叶不同溶剂提取物抗氧化活性进行评价。抗坏血酸抗氧化能力乙酸乙酯提取物抗氧化能力乙醇提取物抗氧化能力甲醇提取物抗氧化能力石油醚提取物抗氧化能力,其IC50值分别为0.203 4、0.836 2、0.868 8、1.867 5、6.628 3 g/L。结果显示,厚藤茎叶提取物具有一定的抗氧化活性,且以乙酸乙酯为提取溶剂时,效果最佳。     

Oregano flavonoids as lipid antioxidants

Oregano (Origanum vulgare L.) leaves were successively extracted with hexane, ethyl ether, ethyl acetate and ethanol. The ethanol extract was reextracted in a separatory funnel with petroleum ether, ethyl ether, ethyl acetate and butanol. The ethyl ether layer was the most effective in stabilizing lard against oxidation, with activity equal to butylated hydroxytoluene. It also showed antioxidant activity when tested on vegetable oils under storage or frying conditions. The main antioxidant factors isolated from the ethyl ether layer consisted of flavonoids. Chromatographic and spectrophotometric analysis demonstrated the presence of the flavone apigenin, the flavanone, eriodictyol and the dihydroflavonols, dihydrokaempferol and dihydroquercetin.     

凤眼草抑菌活性成分的研究

对苦木科臭椿属植物臭椿的果实凤眼草(Ailanthus altissima)的95％乙醇提取液的抑菌活性进行了研究.利用系统溶剂萃取法得到了石油醚提取物、氯仿提取物、乙酸乙酯提取物和正丁醇提取物,重点研究了4种提取物对枯草芽孢杆菌、大肠杆菌和金黄色葡萄球菌的抑菌性和最低抑菌浓度.结果表明,乙酸乙酯提取物和正丁醇提取物均...     

也黄中活性成分的提取及抑菌实验研究

利用4种不同极性溶剂（石油醚、氯仿、乙酸乙酯、正丁醇）浸泡地黄,对地黄不同极性段成分进行提取,得到不同极性段成分的各种浸膏。通过硅胶柱层析对浸膏进行分离浓缩,用纸碟法研究其不同极性段成分的抗菌活性,实验结果表明,氯仿浸膏60％石油醚一40％氯仿洗脱液、20％石油醚一80％氯仿洗脱液,乙酸乙酯浸膏,正丁醇浸膏等对大肠杆菌、金色葡萄球菌、枯草杆菌等有较好的抑菌活性。     

Antioxidant for fats and oils from canary seed: Sterol and triterpene alcohol esters of caffeic acid

Several kinds of seeds used as bird feed were extracted successively with hexane, ether and methanol. In the antioxidant test with extracts, the ether extract from canary seeds showed the highest activity. The antioxidant fraction separated from it by thin layer chromatography showed excellent activity for lard and sardine oil. The effective components were identified by gas chromatography and gas chromatography-mass spectrometry of the hydrolyzed products as the esters of caffeic acid with cycloartenol, gramisterol, sitosterol and campesterol with the minor amounts of 24-methylenecycloartanol, obtusifoliol, brassicasterol and Δ7-stigmastenol.     

Antioxidant behaviour of products resulting from beef sarcoplasmic proteins‐malondialdehyde reaction

The antioxidant properties of the soluble fraction of a Maillard reaction product (MRP) model generated from sarcoplasmic protein/malondialdehyde (MDA) were evaluated. The dry extract colour values showed that it has a pale brown colour appearance, and the carbonyl content of isolated protein increased from 2474 nmol/mg protein to 3904 nmol/mg protein, before and after reaction with MDA, respectively. Reducing power (82.34%) and 1,1‐diphenyl‐2‐picryl hydrazyl radical scavenging (35.20%) were very good, while superoxide anion scavenging showed poor inhibition (324 equivalent SOD units/g). Antioxidant activity in the fused lard system was stronger than in the emulsion system, on all parameters tested, exerting 89% reduction on hydroperoxides, 78% on thiobarbituric acid‐reactive substances (TBARS) and 69% on conjugated dienes (CD) at 80 °C. In the linoleic acid/water emulsion system, the antioxidant activity, measured as peroxide formation inhibition at 37 °C, at the higher concentration assayed was 81%, whereas on CD and on TBARS, it exerted a moderate inhibition (45% and 58%). At 80 °C, the antioxidant activity, for the same concentration, was less effective (37% on CD; 75% on peroxide values, and 40% on TBARS). In conclusion, the sarcoplasmic protein/MDA reaction products showed an excellent antioxidant activity in fused lard and a good performance in the linoleic/water emulsion system.