白肉灵芝化学成分及体外抗氧化活性分析

为研究白肉灵芝的主要化学成分及抗氧化活性,本研究以紫芝、赤芝为参照,采用多种分析方法对白肉灵芝的营养成分、多糖、三萜、总皂苷、灵芝酸A、氨基酸、微量元素进行分析,并考察了不同品种灵芝提取物的1,1-二苯基-2-三硝基苯肼(DPPH)自由基、羟基自由基(·OH)的清除能力.结果表明,白肉灵芝的粗蛋白含量、氨基酸总量分别为...     

黑豆乙醇萃取物中抗氧化成分的分离与鉴定

目的：研究黑豆抗氧化活性成分。方法：采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）法筛选黑豆乙醇提取物抗氧化活性部分,并综合运用硅胶柱色谱、聚酰胺柱色谱、D-101大孔吸附树脂柱色谱、凝胶柱色谱等方法对黑豆乙醇提取物具有较强抗氧化活性部分进行分离纯化,并根据理化性质和波谱数据对化合物进行结构鉴定。结果：采用DPPH法筛选表明黑豆乙醇提取物乙酸乙酯萃取部分和正丁醇萃取部分具有较强抗氧化活性,并从黑豆乙酸乙酯萃取部分、正丁醇萃取物经大孔吸附树脂体积分数30%乙醇洗脱部分中分离鉴定了10 个化合物,其中包括7 个黄酮类化合物：染料木素（1）、大豆素（2）、黄豆黄苷（3）、大豆苷（4）、染料木苷（5）、槲皮素-3-O-葡萄糖苷（6）、3’-甲氧基-表儿茶素-7-O-葡萄糖苷（7）,以及胡萝卜苷（8）,麦芽酚（9）、岩白菜素（10）。结论：化合物6、7、9、10为首次从大豆植物中分离得到,黑豆的抗氧化活性与其含较多酚类化合物有关。     

石榴皮木醋液的化学成分及抗氧化活性

为探索石榴皮资源利用的新途径,以石榴皮为原料经干馏（350～500 ℃）制备了木醋液,并采用气相色谱-质谱联用仪分析其化学成分,通过对1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基和羟自由基清除实验评价其抗氧化活性。结果显示,石榴皮木醋液的总酚、总酮和有机酸含量分别为10.92、7.81 mg/mL和2.53%;共检测出27 种有机化合物,包括酚类、有机酸、醇类、烷烃、醛类及酮类化合物等。石榴皮木醋液对DPPH自由基和羟自由基清除力的VC当量分别为10.22 μg/mg和45.19 μg/mg。结果表明,石榴皮木醋液可作为一种天然抗氧化剂资源,具有一定的开发利用价值。     

3种茉莉花净油化学成分及其抗氧化活性

采用超临界流体萃取法（supercritical fluid extraction,SFE）对云南种植的3个品种茉莉花进行净油提取。通过气相色谱质谱联用技术（gas chromatography-mass spectrometry,GC-MS）研究不同品种茉莉花净油挥发性成分和相对含量的差异,并采用DPPH法和ABTS法评价不同品种茉莉花净油的抗氧化特性。结果表明：3个品种的茉莉花净油萃取得率、外观、香气、化学成分和抗氧化活性均有一定差异,从净油中共鉴定出98种化合物,共有成分有49种;从单瓣茉莉花净油中鉴定出84种化合物,双瓣茉莉花净油中鉴定出56种,多瓣茉莉花净油中鉴定出82种;3个品种净油中相对含量最多的为酯类化合物,不同种类致香物质的数量和相对含量差异明显;3种茉莉花净油都具有较好的自由基清除能力,但抗氧化活性有一定差异,双瓣茉莉净油的抗氧化能力明显高于其他两个品种。     

马尾松松针挥发油化学成分及抗氧化活性研究

采用水蒸气蒸馏法提取马尾松松针挥发油,利用气相色谱-质谱联用(GC-MS)对挥发油进行化学成分分析,并以DPPH自由基、ABTS自由基、超氧阴离子自由基的清除能力以及总还原力为评价指标,研究其抗氧化作用。结果表明,从马尾松松针挥发油中共分离鉴定出了34种化合物,其相对质量分数占挥发油总量的95.76%,主要化合物为石竹烯(15. 85%)、α-杜松醇(12. 12%)、大根香叶烯B(10. 81%)、β-古巴烯(7.94%)、1(10),4-杜松二烯(6.65%)、γ-依兰油烯(6.01%)、蛇麻烯(5.82%)和β-瑟林烯(3.63%)等。马尾松松针挥发油具有较强的抗氧化活性,DPPH自由基、ABTS自由基、超氧阴离子自由基的清除能力以及总还原力随挥发油质量浓度的增加而增强;DPPH自由基、ABTS自由基、超氧阴离子自由基的半数清除率IC_(50)值分别为5.16、5.47、4.34 mg/mL。通过本试验证实,马尾松松针挥发油作为天然抗氧化剂具有较大的开发潜质。     

桂花果实精油化学成分及体外抗氧化活性

采用水蒸气蒸馏法提取桂花果实精油,利用气相色谱-质谱联用技术分析其化学成分,并以面积归一化法测定各成分的相对含量;以维生素C或EDTA为阳性对照,以总还原力、金属离子的螯合作用、ABTS自由基和DPPH自由基的清除作用为指标评价桂花果实精油的体外抗氧化活性。研究结果表明,从桂花果实精油中共鉴定出44个化合物,占精油总量的89.12%,以酯类和酸类为主,分别占挥发油总量的47.28%和15.67%;挥发油主要成分有5-乙烯基-3-吡啶羧酸甲酯、对甲酰基苯甲酸甲酯、棕榈酸、1,21-二十二碳二烯、1,2-环氧十八烷。桂花果实精油具有良好的体外抗氧化活性,其总还原力、金属离子的螯合作用、ABTS自由基和DPPH自由基清除作用的ED50分别为147.63、41.25、33.51、50.94μL,且精油样品量与与各项抗氧化活性指标呈量效关系。     

Combined Effects of Electron-Beam Irradiation and Storage Time on the Chemical and Antioxidant Parameters of Wild Macrolepiota procera Dried Samples

Mushrooms are very perishable foods due to their high susceptibility to moisture loss, changes in color and texture, or microbiological spoilage. Drying is considered as the most appropriate method to prevent these alterations, but it has some limitations, such as shrinkage, enzymatic and non-enzymatic browning reactions, and oxidation of lipids and vitamins. According to previous studies, irradiation might effectively attenuate the undesirable changes caused by drying process, ensuring also higher shelf-life of mushrooms and their decontamination. Electron-beam irradiation presents some technological advantages, since it allows higher dose rates and the possibility to be used in most foods/or thin products in a short period. Herein, the combined effects of electron-beam irradiation (0, 0.5, 1 and 6 kGy) and storage time (0, 6 and 12 months) were evaluated by measuring changes in nutritional parameters, namely, free sugars, tocopherols, fatty acids and antioxidant activity. As indicated by linear discriminant analysis, storage time had a higher effect on all the evaluated parameters, except fatty acids, which suffer significant changes with both factors. Overall, the obtained results indicate that electron-beam irradiation might be considered as a suitable technique, allowing long-lasting conservation periods while reducing changes induced by drying treatment.     

不同品种青砖茶化学成分与抗氧化活性的比较分析

本研究第一次分析比较了赤壁群体种、中茶108、槠叶齐和丹桂品种所制青砖茶在感官品质、化学成分及抗氧化活性方面的差异。采用顶空固相微萃取-气相色谱-质谱仪联用技术,对4个品种青砖茶样品挥发性成分进行了分析鉴定。结果表明,不同品种青砖茶的化学成分含量有明显差异;总抗氧化能力、抑制羟自由基能力和DPPH自由基清除能力以中茶108、槠叶齐和丹桂所制青砖茶较高;相关性分析表明青砖茶茶汤的抗氧化活性主要与茶多酚、儿茶素类化合物总量以及咖啡碱总量具有较大的相关性,其中与表没食子儿茶素没食子酸酯(EGCG)和苹果酸的相关性最强;可溶性糖、反-2-癸烯醛、壬醛与感官评分呈极显著正相关,而没食子酸、3-甲基呋喃、苯乙酮、异佛尔酮等与感官评分呈极显著负相关;不同品种青砖茶的醛类、酮类和醇类化合物具有明显的差异,其中丹桂品种所制青砖茶的品种香明显,与其芳香醛和酮类物质含量较高相关;感官审评结果显示,4个品种所制青砖茶的品质无显著差异。通过对不同品种青砖茶的主要品质化学成分含量、抗氧化活性以及感官品质等分析,为青砖茶品种选育及其应用提供参考依据。     

姜黄醇提物化学成分及其抗氧化活性分析

目的：研究姜黄（Curcuma longa L.）的化学成分及其抗氧化活性。方法：应用硅胶柱色谱、Sephadex LH-20凝胶柱色谱以及高效液相制备色谱等方法进行分离纯化,根据高分辨质谱、核磁共振谱鉴定化合物的结构;同时采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）法、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)（2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）法和铁氰化钾还原法对分离得到的化合物进行抗氧化活性筛选。结果：从姜黄中分离鉴定了7 个合物,分别为Zingerol（1）、Dihydroferulic acid ethyl ester（2）;乙基-3-(4-羟基-苯基)-丙酸乙酯（3）、Zingerone dimer [4,4’-(6,6’-dihydroxy-5,5’-dimethoxy-[1,1’-biphenyl]-3,3’-diyl) bis(butan-2-one)]（4）、姜酮（5）、4-(3,4-二甲氧基苯基)丁烷-2-酮（6）、香草醛（7）。其中,化合物1～5均具有一定的抗氧化活性,ABTS阳离子自由基清除实验中,化合物1和化合物2的IC50值分别为（3±0.2）μmol/L和（12±1.0）μmol/L,化合物1优于阳性对照VC（VC的IC50值（13±1.1）μmol/L）,化合物2与VC效果相当,还原力实验中,化合物1活性优于VC,浓度低于0.125 μmol/mL时化合物2活性强于VC。结论：化合物4为新的天然产物,化合物1、2、3和6为姜黄属中首次发现,化合物1抗氧化活性较强可能与其脂肪链2位上羟基取代有关,姜黄醇提物中的酚类成分是姜黄抗氧化活性的物质基础之一。     

鹿茸废弃物的化学成分及抗氧化、促创面愈合活性研究

为了更好的发挥鹿茸口服液生产过程中所产生废弃物的再利用价值,本研究对废弃物的化学成分及药理活性进行了研究.采用鹿茸口服液生产工艺(卫生部标准:WS3-B-2232-96),对鹿茸药材进行处理.然后对鹿茸口服液生产过程中产生的两种废弃物,采用水提醇沉的方法进行再提取.运用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱(U...     

香榧叶精油的化学成分、抗氧化及抑菌活性的研究

采用水蒸气蒸馏法提取香榧叶精油,利用气-质联用技术(GC-MS)测定其化学成分及含量,探究其抗氧化及抑菌活性,确定其最低抑菌浓度。结果表明：香榧叶精油中共鉴定出40种化学成分,占总量的99.74%,主要成分为柠檬烯、α-蒎烯、β-蒎烯、香榧酯、β-谷甾醇、月桂烯、δ-杜松烯;具有较强的清除ABTS+自由基、DPPH自由基和羟自由基的能力,且清除能力要强于维生素C;香榧叶精油对黑曲霉菌、蜡样芽胞杆菌、枯草芽孢杆菌、铜绿假单胞菌、大肠杆菌和金黄色葡萄球菌都具有较强的抗菌活性,其最低抑菌浓度分别为：0.2、0.4、0.6、0.6、0.8、0.8 mg/mL。     

Isolation and Structure-Activity Relationship of the Antioxidant Chemical Constituents from the Flowers of Rosa chinensis Jacq

The objective of this study was to investigate the antioxidant activity, chemical constituents, and structure-activity relationship from the flowers of Rosa chinensis Jacq. The antioxidant activity of the different polar solvent extracts were assayed by a 1,1-diphenyl-2-picrylhydrazyl scavenging experiment. The extract with the strongest 1,1-diphenyl-2-picrylhydrazyl scavenging capacity was further isolated and purified by column chromatography. The structures of the isolated compounds were elucidated on the basis of spectral analysis and physiochemical properties. The antioxidant activity of these compounds was assayed by a 1,1-diphenyl-2-picrylhydrazyl scavenging experiment and ascorbic acid was chosen as the positive control. The ethyl acetate fraction had the strongest 1,1-diphenyl-2-picrylhydrazyl scavenging activity. Ten compounds were obtained, represented as: 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (1), quercetin (2), kaempferol (3), 3,5,7,4′-tetrahydroxy-8-methoxy-flavone (4), isoquercetrin (5), kampferol 3-O-β-D-glucoside (6), tiliroside (7), kampferol 3-O-(6′′-galloyl)-β-D-glucoside (8), kampferol 3-O-(2′′,6′′-digalloyl)-β-D-glucoside (9), quercetin 3-O-(2′′,6′′-digalloyl)-β-D-glucoside (10). The 1,1-diphenyl-2-picrylhydrazyl scavenging capacity for these compounds, in descending order, were as follows: 10 > 9 > 1 ≈ 8 > 5 > ascorbic acid ≈ 2 > 6 > 7 > 3 > 4. Compounds 1, 8, 9, and 10 have the stronger antioxidant activity. Our results suggested the antioxidant activities of these compounds might be influenced by the number and position of hydroxyl groups in their aromatic rings.     

体外模拟胃肠消化过程中四种茶叶活性成分及抗氧化性变化规律

为总结茶叶中的活性成分在人体中的变化规律,选取近年市场上具有代表性的四种茶叶(紫娟、中黄一号、白叶一号和福鼎大白),采用体外模拟胃肠消化的方法,测定其多酚、黄酮、原花青素及抗氧化性变化规律。结果发现,这4种茶叶中福鼎大白的提取液的茶多酚及总黄酮含量最高,紫娟茶叶提取液中原花青素含量最高。福鼎大白茶DPPH自由基清除能力最高,紫娟茶叶ABTS自由基清除能力最好。通过对胃消化阶段(0~2 h)和肠消化阶段(2~4 h)的比较,发现4种茶叶提取液在胃消化阶段多酚含量下降趋势较为明显,原花青素含量下降趋势不明显,福鼎大白、中黄一号、白叶一号黄酮含量呈下降趋势,而紫娟黄酮含量存在一定的上升趋势;在肠消化阶段,福鼎大白、紫娟、中黄一号、白叶一号多酚含量与黄酮含量均呈上升趋势,原花青素含量呈下降趋势。4种茶叶提取液在模拟胃肠消化前后的DPPH自由基清除能力和ABTS自由基清除能力均呈逐渐下降的趋势。     

Chemical and Phytochemical Properties and Antioxidant Activities of Three Pomegranate Cultivars Grown in South Africa

A comparative study of chemical contents and antioxidant activities of three pomegranate cultivars (‘Arakta’, ‘Bhagwa’ and ‘Ruby’) grown in South Africa was conducted. Fresh pomegranate juice (PJ) of each cultivar were assessed for soluble solid contents (SSCs), pH and titratable acidity (TA), while extracted juice samples were evaluated for total phenolic (TP), including total tannins (TT), proanthocyanidins (Pcy), total flavonoids, anthocyanins and gallic acids (GA) using spectrophotometric methods. The antioxidant properties of the juice samples were evaluated against stable 2, 2–diphenyl–1–picryl hydrazyl, as well as in ferric reducing ability of plasma (FRAP) and QuantiChrom? (TAC) antioxidant assays. There were significant differences in the chemical properties of the cultivars. SSC, TA and pH varied between the range of 14.07–15.10 °Brix, 0.22–0.28 g/100 ml and 3.32–3.64, respectively. ‘Bhagwa’ had the highest TP (449.9 mg/100 ml), 1.3-fold and 1.6-fold higher than ‘Arakta’ and ‘Ruby’, respectively. The strongest total antioxidant activity was exhibited by ‘Bhagwa’ with an antioxidant index of 95.7%, followed by ‘Arakta’ (93.2%) and ‘Ruby’ (79.9%). PJ phytochemical properties (TP, TT, Pcy, GA) and antioxidant activity (FRAP and TAC) were significantly correlated (r ²?=?0.509–0.885) with each other.     

透骨草不同极性成分抗氧化活性研究

研究透骨草不同极性成分的抗氧化活性,探讨作为天然食用抗氧化剂开发的可行性。采用ABTS、DPPH自由基及还原性反应体系,利用分光光度法测定透骨草的总提物、乙酸乙酯层、正丁醇层及水层提取物在不同浓度下的抗氧化能力。透骨草的不同极性成分对DPPH、ABTS+自由基均具有较强的清除能力及还原能力,其中正丁醇层提取物的抗氧化能力最强。还原性测定中,在浓度为3.2mg/mL时,正丁醇层提取物的吸光度值为2.537,表明正丁醇层提取物的还原能力强,抗氧化作用好。DPPH法测定中,正丁醇层提取物对DPPH自由基的最大清除率为97.37%。ABTS法测定中,正丁醇层提取物对ABTS+自由基的最大清除率为99.56%,与同浓度Vc的清除率接近。结论:透骨草具有较好的抗氧化能力,可进一步研究开发成天然食用抗氧化剂。     

Antioxidant Potential of Spices and Their Active Constituents

Excessive free radical generation overbalancing the rate of their removal leads to oxidative stress. Oxidative stress has been implicated in the etiology of cardiovascular disease, inflammatory diseases, cancer, and other chronic diseases. Antioxidants are compounds that hinder the oxidative processes and thereby delay or suppress oxidative stress. There is a growing interest in natural antioxidants found in plants. Herbs and spices are most important targets to search for natural antioxidants from the point of view of safety. A wide variety of phenolic compounds present in spices that are extensively used as food adjuncts possess potent antioxidant, anti-inflammatory, antimutagenic, and cancer preventive activities. This paper reviews a host of spice compounds as exogenous antioxidants that are experimentally evidenced to control cellular oxidative stress, both in vitro and in vivo, and their beneficial role in preventing or ameliorating oxidative-stress-mediated diseases, from atherosclerosis to diabetes to cataract to cancer. The antioxidative effects of turmeric/curcumin, clove/eugenol, red pepper/capsaicin, black pepper/piperine, ginger/gingerol, garlic, onion, and fenugreek, which have been extensively studied and evidenced as potential antioxidants, are specifically reviewed in this treatise.     

新疆阿勒泰百里香挥发油化学成分GC-MS分析及抗氧化活性测定

利用水蒸汽蒸馏法提取了新疆阿勒泰百里香挥发油,测得含量为0.31%。并采用气相色谱- 质谱联用技术对拟百里香的挥发性成分进行了分离鉴定,分离出82 种成分,共确认了其中72 种。采用峰面积归一化法确定了各成分的相对含量。同时测定了挥发油的金属螯合性、还原力和抗氧化能力,结果表明阿勒泰百里香挥发油、BHT 和百里香酚均无金属螯合性,挥发油还原能力高于百里香酚和BHT,并且抗氧化活性较好。     

干腌驴肉火腿加工过程中理化特性的动态变化

为了探究驴肉火腿加工过程中的品质变化及风味的形成规律,对加工过程中7个工艺点(原料期、腌制初期、腌制中期、腌制末期、发酵初期、发酵末期、成熟期)驴肉火腿的理化特性和氧化变质规律进行了研究,以期找到驴肉火腿最佳发酵时间。结果表明,在加工过程中,驴肉火腿pH比较稳定且处于微酸性环境中(6.2~6.6),各工艺点差异不显著(p>0.05);水分含量由72%先显著(p<0.05)下降后趋于平稳在35%,NaCl含量显著(p<0.05)上升在成熟期达到12.39%;TBA值先显著(p<0.05)上升至最大值0.385 mg/kg后缓慢下降最后趋于平稳在0.34 mg/kg且火腿未出现腐败现象,POV显著上升(p<0.05)成熟期达到5.26 meq/kg在国家标准范围内;TVB-N含量呈现稳定上升趋势,在成熟期含量达到85.76mg/100g且能表现出浓郁的特有香味;灰分含量先显著上升(p<0.05)后趋于平稳(p<0.05)。综上所述,驴肉火腿加工过程中理化和氧化特性的变化影响了火腿品质和最终风味的形成且发酵6个月时火腿风味最佳。