木蝴蝶黄酮粗提物体外抗氧化活性研究

用乙醇作为提取溶剂,有效提取木蝴蝶中黄酮类化合物,并体外分析其抗氧化活性。采用DPPH自由基清除活性、Fenton反应和邻苯三酚氧化法,测定该粗提物对不同自由基的清除能力;并用MTT实验法检测该提取物,对过氧化氢诱导的氧化损伤内皮和心肌细胞的保护作用。木蝴蝶中黄酮提取物对O-2·、·OH、DPPH·有较强的清除能力,并具有明显抗过氧化氢氧化损伤和恢复细胞活性的作用。     

弯萼金丝桃总黄酮提取及抗氧化、降糖活性

摘要：为获得弯萼金丝桃总黄酮（TF）最佳提取工艺及抗氧化活性、降糖活性,探究5种提取工艺(超声辅助提取、酸解提取、酶解提取、热水提取、热醇提取) 对TF提取量的影响,通过单因素和响应面实验优化提取工艺。采用高效液相色谱(HPLC)测定并分析7种主要黄酮苷元的分布及含量,并进一步研究TF与体外抗氧化活性（DPPH?清除能力、ABTS自由基清除能力、羟基自由基清除能力、还原能力）的相关性及对α-葡萄糖苷酶的体外降糖能力。结果表明,超声辅助提取TF提取量最高。响应面优化最佳提取工艺为：温度68 ℃,时间23 min、乙醇体积分数24 %、液料比63:1 mL/g,在该条件下,TF提取量为34.85 mg RT/g（以每克弯萼金丝桃中黄酮类化合物相当于芦丁RT质量表示）;高效液相色谱法分别鉴定出TF中7种主要黄酮类化合物,其中TF中含量最高的黄酮化合物为槲皮素-3-O-洋槐糖-7-0-鼠李糖苷、槲皮素,分别为3.897 mg/g、2.874 mg/g;TF质量浓度与DPPH?清除能力、ABTS自由基清除能力、羟基自由基清除能力、还原能力呈显著正相关,对α-葡萄糖苷酶的降糖能力可达到92.6 %。     

石上柏中双黄酮对DPPH自由基的清除作用研究

研究石上柏中双黄酮类化合物的抗氧化活性。采用乙醇回流提取,聚酰胺柱色谱和葡聚糖凝胶柱色谱纯化得到双黄酮类混合物结晶,利用液质联用法鉴定组成。采用DPPH自由基清除法测试其抗氧化活性,以抗坏血酸作为阳性对照。获得的石上柏双黄酮类混合物结晶由穗花杉双黄酮,罗波斯塔双黄酮,7-去甲基银杏双黄酮,罗波斯塔-4'-甲醚,罗汉松双黄酮A组成,在质量浓度52.3μg/mL时,总双黄酮对DPPH自由基的清除率为8.0%,而抗坏血酸为95.5%。石上柏中双黄酮类对DPPH自由基有一定的清除作用,相对于抗坏血酸较弱。     

竹笋壳黄酮类化合物的提取及其抗氧化活性的研究

以竹笋壳为原料,采用乙醇浸提法来提取黄酮类化合物。结果表明,竹笋壳黄酮最佳的提取工艺参数:乙醇浓度为60%,浸提时间为3 h,料液比为1∶25,浸提温度为80℃,此时提取量可达到4.393 mg/g。考察了竹笋壳黄酮类化合物提取液对羟基自由基的清除能力。结果表明,当竹笋壳黄酮类提取物的浓度达到60μg/mL时,其对.OH的清除率达到58.02%,表现出良好的抗氧化活性。     

香樟叶中黄酮类化合物提取方法和抗氧化性的研究

通过各种方法提取香樟叶中的黄酮类化合物,比较不同提取方法的提取效率及提取物中黄酮类化合物的含量,从而得到最佳的提取方法。结果表明,体积分数60%乙醇提取法是较好的提取方法。并采用烘箱贮存法测定了该叶片黄酮提取物在猪油中抗氧化活性。结果表明:香樟叶片黄酮提取物具有明显的抗氧化效果,且抗氧化性随添加量的增加而增强。     

银杏叶中有效成分的提取及其应用

研究了银杏叶中黄酮类抗氧化成分的提取工艺，并对黄酮类物质清除自由基和抗氧化性能进行了探讨。结果表明：用质量分数70％乙醇回流提取银杏叶，65℃时黄酮的质量浓度高达0．0625μg/mL。黄酮类物质有很强的清除自由基能力和抗氧化能力，随着黄酮浓度的增加，溶液的吸光度逐渐减小，即对．OH的清除率逐渐增大，抗氧化能力逐渐增大。且对人体无毒害作用，可考虑代替合成的抗氧化剂。     

不同产地菊花黄酮化合物抗氧化活性研究

实验从四个不同产地的菊花中提取黄酮化合物,以亚硝酸钠-硝酸铝法对其总黄酮含量进行测定,并以清除羟基自由基、超氧阴离子自由基能力及还原能力三种方式对菊花中黄酮化合物的抗氧化活性进行分析。结果表明,四种菊花中,亳菊黄酮化合物含量最低(11.84%),滁菊最高(14.51%)。四种菊花黄酮化合物且均具有一定的清除羟自由基、清除超氧阴离子及总还原能力,且因菊花来源不同抗氧化活性能力大小不同。     

中药石韦中黄酮类化合物的含量及抗氧化活性研究

目的:对中药石韦中黄酮类化合物进行分离纯化,并对分离纯化后的不同极性的黄酮类成分进行体外抗氧化活性研究。方法:利用超声法提取中药石韦中的黄酮类成分,用乙酸乙酯和正丁醇反复萃取后,将乙酸乙酯萃取液(S_1)用聚酰胺柱分离纯化,分别用体积分数30%、50%、75%乙醇溶液进行洗脱,蒸干后得到3个样品S_2、S_3、S_4(正丁醇萃取液得到的样品记为S_5)。对所得样品进行体外抗氧化活性分析。结果:黄酮类化合物含量:S_4S_1S_5S_3S_2;体外抗氧化活性:S_4S_5S_3S_2。结论:中药石韦中黄酮类化合物有较好的抗氧化活性。其中,75%乙醇洗脱的样品(S_4)黄酮类化合物含量最高,且抗氧化活性最好。说明中药石韦中的黄酮类化合物有较好的抗氧化活性。     

地肤子黄酮类提取物的抗氧化活性研究

研究了地肤子（Kochiascopana）中黄酮类化合物的提取及其抗氧化活性作用。通过对索氏提取方法来提取地肤子中的黄酮类化合物,确立了地肤子黄酮类化合物最佳提取工艺方案。研究结果表明：最佳提取条件是：提取试剂为75％乙醇,固液比为1：10,提取时间4h,提取温度55℃,提取液中黄酮类化合物产率为8．95％。所得到的地肤子黄酮类化合物在一定浓度范围内具有较强的清除自由基和抗氧化能力,这为地肤子黄酮类化合物的开发提供参考。     

土家药筒鞘蛇菰黄酮成分体外抗氧化研究

醇提取土家药筒鞘蛇菰的黄酮成分并测定其体外抗氧化活性。本文以筒鞘蛇菰的粉末为材料,采用超声波辅助醇提法提取黄酮,再以DPPH法去测定黄酮成分的体外抗氧化活性。当筒鞘蛇菰的醇提物黄酮含量为22.7%时,对DPPH自由基的抑制率38.83%。可有效清除DPPH自由基。筒鞘蛇菰的黄酮提取物具有较强的体外抗氧化作用。为以后土家药筒鞘蛇菰的应用提供参考依据和思路。     

紫背天葵黄酮的体内外抗氧化作用

采用体积分数80%的乙醇提取紫背天葵中的总黄酮并测定其含量,将粗提液萃取,经AB-8型大孔吸附树脂纯化,以Vc为对照,测定紫背天葵总黄酮粗提液、纯化液对二苯代苦味酰基自由基(DPPH.)、羟基自由基(.OH)和超氧阴离子自由基(O2-.)的清除能力,并考察紫背天葵黄酮纯化物的体内抗氧化效果。结果表明,紫背天葵中粗黄酮含量为13.928 mg/g,纯化比率为32.79%;紫背天葵总黄酮粗提液、纯化液对3种自由基均有不同程度的清除作用,且清除作用随黄酮质量浓度的升高而增强,纯化液的清除作用强于粗提液;低剂量紫背天葵黄酮纯化物实验组小鼠肝脏和脑组织中超氧化物歧化酶(SOD)活力和肝脏过氧化氢酶(CAT)活力显著高于对照组(p<0.05),而脑中的丙二醛(MDA)含量显著低于正常对照组(p<0.05)。     

Polyphenolic Contents and Antioxidant Potential of Stem Bark Extracts from Jatropha curcas (Linn)

We assessed the polyphenolic contents and antioxidant potential of the aqueous, ethanol and methanol stem bark extracts of Jatropha curcas. The total phenol, flavonoids, flavonols and proanthocyanidin contents of the extracts were evaluated to determine their effect on the antioxidant property of this plant, using standard phytochemical methods. The antioxidant and free radical scavenging activity of ethanol, methanol and aqueous extracts of the plant were also assessed against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing, nitric oxide (NO), superoxide anion, (O(2) (-)) and hydrogen peroxide (H(2)O(2)) using spectroscopic methods and results were compared with that of butylated hydroxyl toluene (BHT) and ascorbic acid as standards. The concentrations of different classes of phenolic compounds were higher in methanol and ethanol extracts compared to aqueous extracts. There was correlation between total phenol, total flavonoids, total flavonol and total proanthocyanidins (r = 0.996, 0.978, 0.908, and 0.985) respectively. There was correlations between the amount of phenolic compounds and percentage inhibition of DPPH radicals scavenging activity of the extract (r = 0.98). Findings from the present study indicated that J. curcas is a potential source of natural antioxidants and may be a good candidate for pharmaceutical plant based products.     

大孔吸附树脂分离纯化猪毛菜总黄酮及其抗氧化活性

采用不同大孔吸附树脂分离纯化猪毛菜总黄酮,并对纯化后的总黄酮进行体外抗氧化活性测试。通过考察影响树脂静态和动态吸附与洗脱的主要因素,确定猪毛菜总黄酮分离纯化优化工艺条件。静态吸附实验表明,AB-8树脂分离纯化效果较好,并且吸附符合Langmuir和Freundlich方程。动态吸附和解吸的最佳工艺条件为:上样液质量浓度1.25 g/L、p H=4.5、上样流速2 m L/min、上样量2.5 BV(BV指树脂柱内装载树脂的体积)、洗脱剂为体积分数80%的乙醇溶液、洗脱流速1.0 m L/min,洗脱剂用量4 BV。所得洗脱液中黄酮质量分数从纯化前10.20%增加到纯化后51.89%,回收率为84.43%。体外实验表明,纯化后的黄酮可以清除羟自由基和超氧阴离子自由基,并有较好的还原力。纯化后的黄酮可以作为一种潜在的天然抗氧化剂。     

Antioxidant Properties of the Edible Basidiomycete Armillaria mellea in Submerged Cultures

Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from dried mycelia (MEM) and mycelia-free broth (MEB) and hot water extracts from dried mycelia (HWEM) by A. mellea submerged cultures show good antioxidant properties as evidenced by low EC(50) values (<10 mg/mL). Total flavonoid is mainly found in hot water extracts; however, total phenol is rich in methanol and hot water extracts from mycelia. Ascorbic acid and total phenol contents are well correlated with the reducing power and the scavenging effect on superoxide anions. Total flavonoid content is dependent on the antioxidant activity and the chelating effect on ferrous ions. Total antioxidant component contents are closely related to the antioxidant activity and the scavenging superoxide anion ability. Results confirm that extracts with good antioxidant properties from fermenting products by A. mellea are potential good substitutes for synthetic antioxidants and can be applied to antioxidant-related functional food and pharmaceutical industries.     

Flavonoids as stabilizers of fish oil: An alternative to synthetic antioxidants

The antioxidant activities against fish oil oxidation of six commercially available flavonoids and of five flavonoids purified from two Chilean native plants were compared to those ofdl-α-tocopherol and of two synthetic antioxidants, butylated hydroxytoluene and butylated hydroxyanisole. Among the commercial flavonoids, catechin, morin and quercetin showed a higher activity when fish oil oxidation (either spontaneous or Fe²⁺-induced) was assessed from the formation of peroxides or thiobarbituric acid-reactive substances. Among the native flavonoids, the 5,3′,4′-trihydroxy-7-methoxy flavanone (designated as Pt-2) showed the highest antioxidant activity. Mixtures of quercetin or of Pt-2 withdl-α-tocopherol produced better inhibitory effects when compared to that of each substance assayed by itself. Also, when Pt-2 and quercetin were assayed in combination (0.3 g/kg oil and 0.7 g/kg oil, respectively), a synergistic antioxidant effect was observed. Results indicate that several flavonoids could be used as natural antioxidants as a means to replace those synthetic antioxidants, the use of which has been questioned.     

Trehalose-Induced Changes in Seed Oil Composition and Antioxidant Potential of Maize Grown Under Drought Stress

The present investigation was conducted to determine if foliar-applied trehalose (an osmoprotectant) could ameliorate the adverse effects of water shortage on maize seed oil composition and oil antioxidant potential. Drought stress significantly reduced the seed oil but increased oleic acid and linolenic acid contents of the oil with a concomitant decrease in linoleic acid content, which resulted in an increased oil oleic/linoleic ratio in both maize cultivars. Water stress also increased the seed oil α- γ- δ- and total tocopherols and flavonoids of both maize cultivars, however, oil phenolic content and oil antioxidant activity decreased. Exogenously applied trehalose positively influenced seed composition of both maize cultivars under non-stress and water stress conditions. Exogenous application of trehalose further increased the oil oleic and linolenic acid contents with a subsequent decrease in linoleic acid. Furthermore, exogenous application of trehalose increased the oil antioxidant activity in terms of oil DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity with an increase in oil tocopherols, total flavonoids and total phenolics contents.     

油橄榄叶中多酚和黄酮的含量分析

以儿茶素为标准品,采用Folin试剂分光光度法建立油橄榄叶中多酚的分析方法;以芦丁标准品为对照,建立油橄榄叶中黄酮的分析方法,研究不同树龄和干燥方式对油橄榄叶中黄酮和多酚含量的影响。结果表明:3年生油橄榄叶中黄酮和多酚的含量明显高于20年以上树龄的油橄榄叶。高温或阳光能降低黄酮和多酚的含量,采用大孔树脂精制油橄榄叶提取物,可获得多酚含量在80%以上的油橄榄叶提取物。     

草果不同极性萃取物总黄酮、总多酚含量与其抗氧化活性的相关性

以草果为原料,通过50%乙醇、水、乙酸乙酯、丙酮、正丁醇、甲醇和石油醚不同极性溶剂萃取活性物质,探讨萃取物中总黄酮和总多酚含量与总还原能力及对DPPH自由基清除率、ABTS⁺自由基清除率、OH^-自由基清除率、NO^-₂清除能力的相关性。结果表明:50%乙醇萃取物总黄酮和总多酚含量均最高,各萃取物均有抗氧化能力,且呈明显的量效关系,其中50%乙醇萃取物总还原能力、清除ABTS⁺和DPPH能力最强,石油醚萃取物清除OH^-和NO^-₂能力最强。相关性分析表明,草果萃取物中总黄酮含量与ABTS⁺清除能力呈极显著相关,与DPPH清除能力呈显著相关,总多酚含量与ABTS⁺和DPPH的清除能力呈极显著相关,可为草果作为天然抗氧化剂提供理论依据。     

Lipid characterization and antioxidant status of the seeds and meals of Camelina sativa and flax

Four different antioxidant activity assays including 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and oxygen radical absorption capacity (ORAC), and thiobarbituric acid reactive substances were performed on the methanolic and ethyl acetate extracts of Camelina seeds (CS), flaxseeds (FS), Camelina meal low fat (CMLF, 9.9% fat), Camelina meal high fat (CMHF, 24.6% fat), and flaxseed meal (FSM, 2.7% fat). In addition, the fatty acid profile, and phenolic, tocopherol, flavonoid, and glucosinolate contents of CS, FS, CMLF, CMHF, and FSM were studied. The major fatty acid was α‐linolenic acid (C18:3 n‐3) which was 33.2, 29.4, 30.2, 60.1, and 39.3% in CS, CMLF, CMHF, FS, and FSM, respectively. The methanolic extract of CMLF showed the highest values of ABTS, DPPH and FRAP and the highest content of phenolic compounds, flavonoids, and glucosinolates. The methanolic and ethylacetate extracts of CMHF showed the highest values for ORAC and α‐ and γ‐tocopherols. The ethylacetate extracts of seeds and meals of Camelina sativa and flax showed lower values for antioxidant activity, phenolic compounds, and flavonoids than the methanolic extracts. In general, Camelina and FS meals showed higher antioxidant activities, and phenolic and flavonoid contents than their respective seeds. Practical applications: Camelina sativa seeds (CS) and flaxseeds (FS) are rich sources of omega 3 oils. Their by‐products after oil extraction are an attractive source of proteins, lipids, fiber, and natural bioactive compounds such as antioxidants. These by‐products may be used to improve nutritional value and prevent lipid oxidation in feed or food systems.     

Phytochemical Screening and Polyphenolic Antioxidant Activity of Aqueous Crude Leaf Extract of Helichrysum pedunculatum

We evaluated the in vitro antioxidant property and phytochemical constituents of the aqueous crude leaf extract of Helichrysum pedunculatum. The scavenging activity on superoxide anions, DPPH, H₂O₂, NO and ABTS; and the reducing power were determined, as well as the flavonoid, proanthocyanidin and phenolic contents of the extract. The extract exhibited scavenging activity towards all radicals tested due to the presence of relatively high total phenol and flavonoids contents. Our findings suggest that H. pedunculatum is endowed with antioxidant phytochemicals and could serve as a base for future drugs.