Antioxidant properties of various solvent extracts from wild ginseng leaves

Water, methanol and ethanol extracts of freeze-dried leaves of wild ginseng were examined for their antioxidant properties. All leaf extracts were capable of free radicals scavenging activity. Among solvent extracts of wild ginseng leaves, ethanol extract showed the highest DPPH, hydroxyl radical scavenging and ferrous ion chelating activity. Otherwise, the highest superoxide radical scavenging activity was found in water extract followed by ethanol and methanol extracts of wild ginseng leaves. Ethanol extracts contained more phenolics (2333.2 mg/100 g) and flavonoids (1199.1 mg/100 g) than other extracts. These differences in concentrations of key antioxidants among various solvent extracts seemed to be responsible for their differences in antioxidant activities. When various solvent extracts were hydrolysed by acid, two aglycons of flavonoid, quercetin and kaempferol, were detected. According to the results obtained from this study, wild ginseng leaves showed marked antioxidant activities due to their abundant antioxidants.     

Phytochemicals and antioxidant activity of fruits and leaves of paprika (Capsicum Annuum L., var. special) cultivated in Korea

The phytochemical composition of carotenoids, tocopherols, free sugars, organic acids, L-ascorbic acid, capsaicinoids, and flavonoids in green and red paprika (GP and RP), and paprika leaves (PL) cultivated in Korea were analyzed. The ethanolic extracts of GP, RP, and PL were obtained with 80% ethanol, and their antioxidative activities were determined by measuring their ABTS and DPPH radical scavenging activities. RP showed the highest contents of capsanthin (58.33 ± 3.91 mg/100 g dry weight) and L-ascorbic acid (1987.25 ± 19.64 mg/100 g dry weight), and main compounds of PL were lutein, chlorophyll, and γ-tocopherol (96.91 ± 14.58, 2136.71 ± 21.11, and 723.49 ± 54.10 mg/100 g dry weight, respectively). RP showed the strongest antioxidant activity (IC(50) = 55.23 ± 6.77 μg/mL in a 2, 2'-azino-di-[3-ethylbenzthiazoline sulphonate] assay and 150.40 ± 8.07 μg/mL in a 2, 2-diphenyl-2-picrylhydrazyl assay), and the antioxidant activity of PL was higher than β-carotene but lower than RP. The results indicate that the amounts of capsanthin and L-ascorbic acid in RP correlate well with antioxidant activity. PL, which has various phytochemicals such as lutein, chlorophyll, and γ-tocopherol, might be used in nutraceuticals and pharmaceuticals for improving human health.     

响应面法优化超声辅助葛根浸提工艺及浸提液抗氧化活性研究

目的采用响应面法优化超声辅助葛根水浸提的工艺,并比较其浸提液的抗氧化活性。方法采用单因素试验结合响应面法,以葛根总黄酮得率为评价指标,对鲜葛根和干葛根超声辅助水浸提工艺进行优化,并测定比较其浸提液的总黄酮含量和抗氧化活性。结果干葛根浸提最佳工艺为：水料比30:1（mL/g）、超声功率310 W、超声时间38 min;鲜葛根浸提最佳工艺为：水料比4.5:1（mL/g）、超声功率442 W、超声时间39 min;在最佳工艺条件下,干葛根和鲜葛根的葛根总黄酮得率分别为（12.68±0.05）mg/g和（4.36±0.04）mg/g。对于同一种葛根,干葛根提取液总黄酮含量和抗氧化能力均高于鲜葛根（P<0.05）;在同一干或鲜状态下,野葛浸提液的总黄酮含量和抗氧化能力显著大于野生粉葛和栽培粉葛（P<0.01）,野生粉葛浸提液的抗氧化能力与栽培粉葛差异不显著（P>0.05）。     

高粱米不同溶剂提取物的抗氧化活性研究

研究不同极性溶剂对高粱米提取物中活性物质含量及抗氧化活性的影响.结果表明,不同溶剂对高梁米中多酚、黄酮含量及抗氧化活性有明显的影响.80％丙酮提取物中的多酚、黄酮含量最高,分别为6.49 mg GA/g和61.2 mg/100 g,表现出较好的抗氧化能力.其次80％甲醇和80％乙醇提取物也表现出较好的抗氧化能力.与此相反,正己烷提取物中的多酚、黄酮含量最低,分别为1.30 mg GA/g和9.6 mg/100 g,抗氧化能力较差.相关性分析表明,提取物中的多酚、黄酮含量与其抗氧化能力有较高的相关性,说明高梁米不同提取物抗氧化能力的差异主要来源于提取物中抗氧化物质的量的差异.     

红树莓叶片中黄酮类物质提取及抗氧化性的研究

以小浆果果树红树毒叶片为实验材料，利用分光光度法测定其总黄酮含量，并采用烘箱贮存法研究了不同添加量红树毒叶片提取物粗黄酮在猪油中的抗氧化性。结果表明：鲜样中红树毒叶片总黄酮含量是278．73mg／100g，干样中是533．71mg／100g；红树毒叶片提取物粗黄酮对猪油有一定的抗氧化作用，并随添加量的增加而增强；增效剂以(柠檬酸)对红树毒叶片提取物粗黄酮无增效作用，而Vc具有一定的增效作用。抗氧化活性顺序为：0．02％槲皮素＞0．02％PG＞0．02％BHT＞0．4％粗黄酮＞0．05％粗黄酮 0．05％Vc＞0．2％粗黄酮＞0.1％粗黄酮＞0．05％粗黄酮＞0．02％粗黄酮＞0．05％粗黄酮 0．05％CA＞对照。     

青钱柳叶活性成分的抗氧化活性及UPLC-QTOF-MS/MS分析

利用96孔板法测定青钱柳叶不同溶剂(水、70%乙醇、乙酸乙酯和正己烷)提取物中总酚、总黄酮含量及抗氧化活性(DPPH自由基清除能力、还原能力、总抗氧化能力),考察酚类物质含量与抗氧化活性的相关性,并采用超高效液相色谱-四极杆飞行时间串联质谱(ultra performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spetrometry,UPLC-QTOF-MS/MS)分析提取物中主要活性成分。结果表明:不同提取物中总酚、总黄酮含量及抗氧化活性存在显著性差异且70%乙醇溶液提取物表现出最高的总酚(219.01 mg GAE/g)、总黄酮含量(7.23 mg CE/g)及最强的DPPH自由基清除能力(35.46 mg TE/g)和还原能力(1.89 mmol Fe SO_4/g);总酚、总黄酮含量与DPPH自由基清除能力、还原能力之间呈正相关,与总抗氧化能力呈显著负相关,表明多酚类物质是青钱柳中主要的抗氧化剂。UPLC-QTOF-MS/MS分析70%乙醇溶液提取物并初步鉴定出22种化合物,包括2种有机酸、4种酚酸、5种黄酮、8种三萜皂苷类和3种酯类,其中酚酸和黄酮类化合物是主要的抗氧化活性成分,有机酸、三萜皂苷及酯类化合物可能是潜在的抗氧化活性成分。     

绿茶、桑叶和臭黄荆叶细粉水提液抑菌和抗氧化能力

探究绿茶、桑叶和臭黄荆叶3种植物干叶细粉水提液的抑菌和抗氧化能力。采用当量法测定3种原料中黄酮、多酚含量,二倍稀释法测定水提液对大肠杆菌、金黄色葡萄球菌的最小抑菌浓度和最小杀菌浓度,牛津杯法分析原料的抑菌活性。利用分光光度法研究3种水提液及其两两等比混合后的DPPH自由基清除率、羟自由基清除率和Fe²⁺螯合能力。结果表明,绿茶粉中水溶性黄酮、多酚含量最高,分别为62. 22、133. 82 mg/g,桑叶粉次之,臭黄荆叶粉最少。绿茶、桑叶和臭黄荆叶细粉在DPPH自由基清除率、羟自由基清除率和Fe²⁺螯合能力方面无协同作用,但黄酮、多酚含量与其抑菌和抗氧化活性间存在显著的量效关系(P <0. 05)。因此,绿茶、桑叶和臭黄荆叶细粉水提液抑菌和抗氧化能力依次减弱,且三者抗氧化活性没有协同增效作用。     

5种野生浆果的体外抗氧化和抗细胞增殖活性

选取东北大兴安岭地区的特色浆果花楸(Sorbus pohuashanensis H.)、蓝莓(Vaccinium uliginosum L.)、蓝靛果(Lonicera caerulea L.)、沙棘(Hippophae rhamnoides L.)、草莓(Fragaria orientalis Los.)的成熟果实,采用80% 丙酮提取,分别测定多酚、黄酮、花色苷含量,并研究其抗氧化活性和抗细胞增殖活性。结果表明：花楸的多酚和黄酮含量最高;蓝靛果的花色苷含量最高,为(367.5 ± 8.7)g/100g;5 种浆果都具有较好的体外抗氧化活性,花楸显示了最高的抑制癌细胞增殖效应。     

啤酒花废弃枝叶多酚、黄酮含量与抗氧化活性的相关性分析

采用不同极性溶剂对新疆种植的札一和马可波罗啤酒花废弃枝叶的乙醇提取物进行不同极性部位的分 离,以羟自由基、1,1-二苯基-2-三硝基苯肼自由基、β-胡萝卜素-亚油酸及磷钼酸4 个不同的抗氧化活性评价体系 对获得的各提取物的抗氧化活性进行比较性研究,并与提取物中多酚、黄酮含量进行相关性分析。结果表明, 乙醇提取物及各极性部位均具有一定的抗氧化性。其中,乙酸乙酯提取物中的多酚和黄酮的含量均最高,其在主 枝、侧枝和叶子的含量范围分别为5.80～34.20 mg/g和2.00～18.00 mg/g;水相中最低,上述各物质的含量范围仅为 0.73～11.05 mg/g和0.06～5.74 mg/g。相关性分析表明,啤酒花主枝、侧枝和叶子抗氧化活性与其多酚、黄酮含量 具有显著的相关关系（P＜0.05）。     

6 种东北地区红树莓果渣提取物的抗氧化活性差异

以东北地区6 种红树莓果实加工后的果渣提取物为实验材料,研究其总酚、总黄酮、原花青素、花色苷含量和体外抗氧化活性的差异。结果表明：宝石红果渣提取物中总酚、总黄酮和原花青素含量最高,分别为14.18、3.71、15.28 mg/g;哈瑞太兹果渣提取物中花色苷含量最高,为0.68 mg/g;菲尔杜德和野生果果渣提取物的总还原能力与VC接近;除哈瑞太兹外,其他品种红树莓果渣提取物对（1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基和2,2’-二氮-双（3-乙基苯并噻唑-6-磺酸）二铵盐自由基（2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical,ABTS+·）的清除率均大于VC。相关性分析结果表明红树莓果渣提取物的总还原能力与总黄酮、原花青素含量的相关性较大;对DPPH自由基的清除率与原花青素、花色苷含量的相关性较大;而对ABTS＋·的清除率与总酚和总黄酮含量的相关性较大。在6 个红树莓品种中,菲尔杜德和野生果果渣提取物具有较强的抗氧化活性。     

不同品种甘薯叶提取物抗氧化及对α-葡萄糖苷酶抑制活性的研究

本研究旨在通过比较7个品种甘薯叶提取物的抗氧化活性和α-葡萄糖苷酶抑制活性,探讨甘薯叶抗氧化和降血糖的潜力。以甘薯叶为研究对象,测定其总多酚和总黄酮含量,体外实验评价其抗氧化活性(DPPH·清除能力、ABTS+·清除能力、·OH清除能力和还原能力)及对α-葡萄糖苷酶的抑制活性。结果表明7个品种甘薯叶提取物总多酚和总黄酮含量、抗氧化活性以及α-葡萄糖苷酶抑制活性具有明显差异。甘薯叶总多酚含量介于15.02~33.33 mg GAE/g DW,总黄酮含量介于1.06~3.11 mg RE/g DW。徐薯18、济薯18和龙薯9甘薯叶总多酚和总黄酮含量最高,品种间无统计学差异(P>0.05)。龙薯9自由基(DPPH·、ABTS+·、·OH)清除能力最强;济薯18还原能力最强;商薯19抑制α-葡萄糖苷酶活性最强。总多酚和总黄酮含量与抗氧化活性之间具有极显著的正相关性(P<0.01),而与α-葡萄糖苷酶抑制活性之间没有显著的相关性(P>0.05)。本研究表明甘薯叶是潜在抗氧化剂和α-葡萄糖苷酶抑制剂的优质来源,为甘薯种植和生产品种的选择提供理论依据。     

鱼腥草根和叶醇提物抗氧化活性比较研究

对比鱼腥草根和叶的乙醇提取物抗氧化活性。分别采用70%乙醇制备鱼腥草根醇提物、叶醇提物,通过测定还原能力和对羟自由基(·OH)、超氧自由基(O2-·)、亚硝酸盐(NO2-)的清除作用,评价鱼腥草根、叶醇提物体外抗氧化活性,并测定醇提物中多糖、总黄酮和总酚含量。在不同的抗氧化体系中,鱼腥草根、叶醇提物的抗氧化能力有差异,其中叶醇提物的抗氧化活性明显强于根醇提物。多糖、总黄酮、总酚含量测定结果显示,鱼腥草根醇提物中各活性成分的含量均高于叶醇提物。鱼腥草根、叶醇提物均表现出不同程度的抗氧化活性,且抗氧化活性与活性成分含量呈正相关。     

Antioxidant Activities and Polyphenolic Properties of Raw and Osmotically Dehydrated Dried Mushroom (Agaricus bisporous) Snack Food

Total polyphenolics and free radical scavenging properties of extracts obtained from osmotically dehydrated, and spiced mushroom snack food with raw unprocessed mushrooms were studied. Sensorially acceptable mushroom snack was prepared in the laboratory by osmotically dehydrating Agaricus bisporous in 5% salt solution followed by addition of an adequate combination of spices and vacuum drying. The extracts of raw and dry snack-mushrooms were then evaluated for their scavenging activities against the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical and 2,2-azobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS). The scavenging activity of free extracts of raw and dry snack mushrooms on DPPH radical were 76% and 72%, respectively. The ABTS radical scavenging activity of the free extracts of raw sample expressed as ascorbic acid equivalent antioxidant activity (AEAC) was 2.76 mg ascorbic acid equivalents/100 g and 2.67 mg ascorbic acid equivalents/100 g snack mushroom. Both free and bound polyphenolic contents in mushroom snacks were slightly higher than raw mushrooms whereas total flavonoids levels decreased marginally. No change in antioxidants status of the dry snack product was observed when dry snack stored at ambient temperature for up to 15 days. The results of this study suggested that mushroom snacks prepared using a combination of the above methods was able to retain a significant amount of antioxidants, phenols and flavonoids and mushroom snacks may prove to be an alternative nutritious snack.     

野生和种植藜蒿不同部位提取物的抗氧化活性和酶抑制活性

藜蒿为江西特色食物资源,其嫩茎常被加工成美食,而叶和根被作废弃物直接丢弃。本研究比较了野生藜蒿叶、茎和根及种植藜蒿叶、茎的总酚和总黄酮含量以及提取物的抗氧化、α-葡萄糖苷酶、黄嘌呤氧化酶和乙酰胆碱脂酶活性抑制能力,旨在为藜蒿副产物的高值化利用提供参考。结果表明,野生和种植藜蒿叶分别含有最高的总酚含量(30.12 mg GAE/g DM)和总黄酮含量(0.63 mg QuE/g DM)。野生藜蒿叶提取物的DPPH·清除能力、ABTS^+·清除能力和乙酰胆碱酯酶抑制能力最强,其IC50值分别为0.37,0.39 mg DM/mL和10.06 mg DM/mL。野生藜蒿根提取物的α-葡萄糖苷酶和黄嘌呤氧化酶活性抑制能力最强,其IC50值分别为14.08 mg DM/mL和4.01 mg DM/mL,其次为野生藜蒿叶。相关性分析表明,酚类化合物是藜蒿中最主要的抗氧化活性成分。相比于种植藜蒿和野生藜蒿茎,野生藜蒿叶是天然抗氧剂、α-葡萄糖苷酶抑制剂、黄嘌呤氧化酶抑制剂和乙酰胆碱酯酶抑制剂的更优质的原料来源,具有进一步研究其抗糖尿病、高尿酸血症和老年痴呆症的价值。     

Phenolic composition in different genotypes of Guabiju fruits (Myrcianthes pungens) and their potential as antioxidant and antichemotactic agents

Fruits of Myrcianthes pungens Berg. Legr. (Myrtaceae), known as guabiju, are widely consumed fresh as well as dried, processed into jam, marmalade, and juices. In this study, chemical composition and antichemotactic and antioxidant activities of fruits from a wild type (GB) and 2 genotypes, PL2 and PL1, of guabiju were investigated. Total anthocyanins for the genotypes ranged from 334 to 531 mg/100 g dry weight (dwt). Total flavonoids and polyphenols ranged from 79.8 to 154 mg/100 g and 2438 to 4613 mg/100 g (dwt), respectively. A reversed phase liquid chromatography method with photodiode array detection was used to determine chemical profiles of the main anthocyanins found in the extracts. An HPLC method for the quantification of flavonoids is proposed, providing a simple procedure with rapid sample preparation. All samples contained 5 identical anthocyanidins, distributed differently, with cyanidin as the main compound. Identified flavonoids were quercitrin, hyperoside, and isoquercitrin; their relative amounts varied among the extracts. The antioxidant activity of guabiju methanolic extract was comparable to that of Trolox, and at a test concentration of 0.25 mg/mL, GB and PL2 activities were higher than those exhibited by Trolox. Total dry extracts of guabiju exhibited greater inhibition of chemotaxis at a concentration of 4 μg/mL, except for GBH (wild-type hydrolyzed extract) which already presented high values at a concentration of 2 μg/mL. These results suggest that the consumption of this fruit, rich in polyphenols, may be beneficial to human health. Practical Application: The paper is the first attempt on the improvement of this native fruit, since it is widely consumed regularly as part of the South American diet. The content of phenolic compounds demonstrates that consumption of guabiju would be beneficial to human health. Differences among samples, originating from open pollination of plants growing on the same site, lead to the conclusion that improvements can be made in the chemical composition and beneficial activity of guabiju fruits by simply selecting genotypes for these characteristics among open-pollinated seedlings.     

大花罗布麻不同部位酚类物质含量及其抗氧化活性比较研究

目的：比较大花罗布麻根、茎、叶、花4 个部位中游离态和结合态酚类物质的含量和抗氧化活性的差异,并分析含量与抗氧化活性之间的相关性。方法：采用Folin-Ciocalteu法、NaNO2-Al(NO3)3法分析罗布麻的根、茎、叶、花4 个部位的游离态和结合态总多酚、总黄酮含量,采用DPPH自由基清除能力、ABTS+·清除能力和铁离子还原能力3 种方法评价其体外抗氧化能力差异。结果：大花罗布麻总酚含量次序为：叶＞根＞花＞茎,各样品间存在显著性差异（P＜0.05）。各部位游离酚、结合酚和总多酚含量分别介于3 560.19～6 273.23、13.45～22.01和3 582.2～6 286.68 mg GAE/100 g干质量,其游离态多酚占总酚含量百分比平均为99.60%;游离态黄酮、结合态黄酮和总黄酮含量分别介于1 080.30～2 488.21、9.69～28.59、1 106.81～2 516.80 mg RE/100 g 干质量,其游离态黄酮占总黄酮含量的百分比平均为98.64%。大花罗布麻叶提取物清除DPPH 自由基、ABTS+·能力和总还原力最强,抗氧化活性与总酚含量之间具有良好的线性关系（r＞0.950 0）。结论：大花罗布麻各部位中含有较丰富的酚类物质,具有较强的抗氧化活性。     

Enhancement of Bioactive Compounds and Antioxidant Activities of Olive (<Emphasis Type="Italic">Olea europaea</Emphasis> L.) Leaf Extract by Instant Controlled Pressure Drop

In this work, the effect of Détente Instantanée Contrôlée (DIC) (French for instant controlled pressure drop) on the total polyphenol, flavonoids, α-tocopherol contents, and antioxidant activities of olive leaves was studied. Olive leaf extracts were pre-treated at one cycle DIC under 0.1 MPa pressure for 11 s and followed by an extraction with 95% ethanol at 55 °C during 3 h. The phenolic compounds, flavonoïds, oleuropein, and α-tocopherol contents were determined, showing 66.63 mg gallic acid equivalent (GAE)/g db, 12 mg catechin equivalent (CE)/g db, 43.9 mg/g db, and 0.15 mg/g db for the untreated leaves against 239.37 mg GAE/g db, 28 mg CE/g db, 70.3 mg/g db, and 0.59 mg/g db for DIC-treated leaves, respectively. Therefore, DIC allows more availability of bioactive compounds contributing to a high antiradical activity (DPPH) compared to a synthetic antioxidant butylated hydroxytoluene (BHT). Both extracts showed a total antioxidant capacity (method of phosphomolybdenum) greater than that of the standard BHT. Likewise, both extracts have a reducing power (FRAP test) significant concentration-dependent. The DIC-treated leaves showed a higher antioxidant capacity compared to that of untreated leaves. Thus, DIC could be an effective treatment to promote the extraction of bioactive molecules of high antioxidant activities from olive leaves.     

Phenols,Flavonoids, and Antioxidant and Antibacterial Activity of Leaves and Stem Bark of Morus Species

Leaves and stem bark composition from Morus species (M. alba var. alba, M. alba var. rosa and M. rubra) was evaluated for its antioxidant and antimicrobial activities in order to enhance its therapeutic uses. Total phenolics and flavonoids contents were estimated in hydromethanolic and aqueous extracts. Results showed highest content in M. rubra leaves aqueous extract (1129 mg gallic acid equivalent/100 g dry weight and 816 mg gallic acid equivalent/100 g dry weight, respectively). Using 2,2-diphenyl-1-picrylhydrazyl assay, the highest antioxidant activity was obtained in aqueous stem barks extracts. M. alba var. alba has an IC₅₀ of 2.84 mg/ml and the IC₅₀ value of M. rubra was the highest (4.78 mg/ml). ABTS^.+ (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) method and reducing power assay were used to confirm the results from the 2,2-diphenyl-1-picrylhydrazyl test. All extracts expressed considerable free radical-scavenging properties. Hydromethanolic and aqueous extracts were tested against Staphylococcus aureus, Enterococcus feacalis, Staphylococcus epidermis, Escherichia coli, and Salmonella Typhimurium bacteria. Hydromethanolic stem bark extracts have the highest antimicrobial activities, and it may be a good antimicrobial agent for human gastrointestinal infections. This plant could be used as an additive to foods and also as a possible source to obtain new and effective herbal medicines to treat infections of multi-drug resistant strains of microorganisms.     

绞股蓝中6 种多酚化合物的HPLC检测及其醇提液的抗氧化活性

采用高效液相色谱法分析野生（5 叶、7 叶和9 叶3 种生态类型）和人工种植（7 叶）绞股蓝的叶及茎中6 种多酚化合物的含量,并测定样品醇提液的总多酚含量及抗氧化活性。结果表明：色谱条件为色谱柱poroshell 120 PFP（4.6 mm×100 mm,2.7 μm）,流动相1%甲酸（A）和乙腈（B）,检测波长254 nm和350 nm,在此条件下绞股蓝样品中6 种多酚单体可在35 min内得到较好分离,且重复性好（相对标准偏差（relative standard deviation,RSD）≤4.6%）、精密度高（RSD≤2.68%）、稳定性好（RSD≤2.45%）、加标回收结果准确可靠（平均回收率84%～99%,RSD≤4.02%）。6 种多酚单体在不同的绞股蓝样品中含量差异较大,但均呈现出芦丁含量最高,对羟基苯甲酸含量最低。绞股蓝样品醇提液中总多酚及抗氧化活性在不同样品间差异较大,在野生绞股蓝（7 叶）叶中最高（分别为75、39.65、70.48 mg/g）,在其茎中最低（分别为2.81、2.1、3.7 mg/g）。总体而言,绞股蓝的叶中总多酚含量高于茎中,醇提液的抗氧化活性也强于茎。     

木贼醇提物不同萃取部位总酚酸、黄酮含量测定及抗氧化活性研究

目的:对木贼的乙醇提取物不同萃取部位进行总酚酸、黄酮含量测定及抗氧化活性比较,以探知木贼抗氧化活性物质基础。方法:木贼经70%乙醇超声提取浓缩后,采用有机溶剂萃取法依次得到石油醚、乙酸乙酯、正丁醇、水相4个部位萃取物;利用紫外-分光光度法比较各萃取部位总黄酮、酚酸含量差异;以抗坏血酸为阳性对照,比较不同萃取部位还原能力、羟自由基(·OH)、1,1-二苯基-2-三硝基苯肼(DPPH·)、2,2'-联氮-双(3-乙基苯并噻唑-6-磺酸)二铵盐(ABTS+·)清除率的差异,评价各部位抗氧化能力强弱。结果:木贼各萃取物总黄酮含量在5.70~61.55 mg/g 范围内,总酚酸含量在4.07~19.10 mg/g 范围内,乙酸乙酯萃取物总黄酮与酚酸含量明显高于其他萃取物,其还原能力、羟自由基、DPPH·、ABTS+·清除率也明显高于正丁醇、石油醚和水相萃取物,乙酸乙酯萃取物对羟自由基、ABTS+·、DPPH·清除能力IC₅₀值分别为:(0.321±0.0026)、(0.213±0.0010)和(0.169±0.0014) mg/mL。结论:经各相溶剂萃取后木贼有效成分得到初步分离,乙酸乙酯相萃取部位总黄酮和酚酸相对含量及抗氧化活性明显强于总提物和其他萃取部位,且其抗氧化能力呈量效关系。实验发现木贼中黄酮和酚酸类成分与其抗氧化能力密切相关。