黑老虎抗氧化冲剂研究

本文利用大孔树脂对黑老虎中提取的多糖类成分进行进一步的分离和纯化,探索最佳的浸提条件及最优化配方工艺,以制备黑老虎抗氧化冲剂。本文也进一步对所制备的黑老虎抗氧化冲剂抗氧化能力开展验证试验,分别考察其对超氧阴离子(O2-·)、DPPH·有机自由基和羟基自由基(·OH)的清除能力。     

黑果腺花楸不同极性物质抗氧化及抗炎镇痛研究

为了高效的提取及分离黑果腺花楸活性物质,以黑果腺花楸为原料,不同极性溶剂作为溶媒(石油醚、乙酸乙酯、正丁醇和水),采用超声波辅助提取法,分别提取到不同极性物质(石油醚相、乙酸乙酯相、正丁醇相和水相)。利用不同的抗氧化模型(铁还原力、清除羟基自由基(OH)·能力、清除ABTS自由基能力、抗肝组织自发性脂质过氧化能力和花生油氧化能力)、炎症模型(小鼠耳廓肿胀和小鼠肉芽肿胀)和镇痛模型(小鼠热板痛阈值和冰醋酸致小鼠扭体次数)来评价黑果腺花楸不同极性物质的活性。结果表明,正丁醇相具有较强的抗氧化能力和消炎镇痛能力。正丁醇可以作为提取黑果腺花楸活性物质及分离抗氧化活性及抗炎镇痛成分的溶剂。     

精甲霜灵和咯菌腈复配对烟草黑胫病菌的联合毒力

在实验室条件下,通过菌丝生长速率法测定了精甲霜灵和咯菌腈复配对烟草黑胫病菌(Phytophtora parasitica var.nicotianae)的联合毒力。结果表明:精甲霜灵和咯菌腈,分别以质量比为5:2、3:2、1:1、2:3和2:5复配的共毒系数CTC分别为149.74、167.80、134.13、142.35和167.20,综合增效作用考虑,3:2和2:5为精甲霜灵与咯菌腈混配的最佳配比。     

贵州烤烟烟叶的化学成分及抗氧化活性研究

【研究目的】研究分离烤烟化学成分单体的清除自由基活性。【方法】以天然产物分离方法,精确鉴定其结构.选取分离的四类化合物(黄酮类、苯丙素类、香豆素类和萜类)中的代表物质进行DPPH清除自由基法评价各化合物的抗氧化能力,以IC₅₀来表示自由基被清除程度与浓度的关系。以抗氧化剂VC为阳性对照,比较不同抗氧化剂对DPPH自由基的清除作用。【结果】芦丁芸香苷是所选活性化合物抗氧化活性中最高但略低于阳性对照VC,东莨菪内酯、紫丁香苷、迷迭香酸、山奈酚-3-O-β-D芸香糖苷抗氧化活性依次递减。[结论]：部分中性致香成分单体具有较好的清除自由基活性,为烟草多用途研究提供了基础。     

黑苦荞麦黄酮的提取及体外抗氧化活性研究

采用超声辅助溶剂浸提法提取黑苦荞麦黄酮,研究黑苦荞麦黄酮的体外抗氧化活性。研究表明,黑苦荞麦黄酮提取的最适条件为:乙醇浓度70%(V/V),液料比50∶1 mL/g,超声功率200 W,超声时间10 min,水浴温度50℃,水浴时间40 min,此时得率为19.31 mg/g干重。黑苦荞麦黄酮具有较好的体外抗氧化能力,对·OH具有很强的清除能力,效果好于V_C;对DPPH、·O^(2-)具有一定的清除效果和还原能力,但是效果均稍差于V_C。     

烟草黑胫病菌对甲霜灵的抗药性风险

为了评估烟草黑胫病菌对甲霜灵的抗药性风险,以对甲霜灵敏感和高抗的烟草黑胫病菌240和191为出发菌株,进行了抗性突变频率测定、抗性诱变、抗性水平测定、遗传稳定性、生长速率、致病性测定和适合度等研究。结果表明,烟草黑胫病菌对甲霜灵敏感的240菌株在含10mg/L甲霜灵的CA平板上的抗性突变频率为7.0×10-5。分别以药剂诱变和紫外诱变获得了抗甲霜灵菌株240-YY和240-ZY。对甲霜灵敏感性不同的烟草黑胫病菌适合度测定结果表明,抗性菌株在潜伏期、侵染率、病情指数和病斑面积等方面均具有较高的适合度水平。研究结果显示,烟草黑胫病菌对甲霜灵具有较大的抗药性风险。     

黑枸杞发酵液的抗衰老功效与安全性探究

使用酿酒酵母对黑枸杞进行发酵,获得黑枸杞发酵液。从成分、安全性、抗衰老效果三个方面对其进行检测和评价,为其在化妆品领域的应用提供基础。首先从生化水平对黑枸杞发酵液清除自由基能力进行检测,接着从细胞水平评估黑枸杞发酵液对人成纤维细胞内的胶原蛋白、胶原蛋白酶以及抗氧化酶活性的影响进行检测,最后使用鸡胚尿囊膜和人体斑贴试验对黑枸杞发酵液的眼刺激性和皮肤安全性进行评价。结果表明,黑枸杞发酵液富含多糖和蛋白质,多酚、黄酮和原花青素含量较少。黑枸杞发酵液具有良好的清除DPPH自由基和ABTS+自由基的能力,IC50分别为8.15%和1.08%。此外,5%体积分数的黑枸杞发酵液能够促进胶原蛋白合成,含量为对照组的137.84%(p0.01),同时能够抑制胶原蛋白酶的表达,含量为对照组的70.41%(p0.01)。1%体积分数的黑枸杞发酵液能够极显著提升成纤维细胞内抗氧化酶活性(p0.01),提高总抗氧化能力以及抑制活性氧的生成(p0.01)。鸡胚尿囊膜试验和人体斑贴试验结果显示黑枸杞发酵液具有较高的眼睛安全性和皮肤安全性。     

黑豆皮红色素的不同提取方法对抗氧化性的影响

黑豆皮红色素是从黑豆中提取的花色素苷类色素,该色素为水溶性多酚类物质。它安全无毒同时还具有重要的生物活性可以广泛应用于食品工业、化妆品、以及染色等领域,具有抗氧化、保护人体健康的重要作用。论文对比研究了微波法、超声法以及索氏提取三种不同方法提取黑豆皮红色素的抗氧化性。     

18.7％烯酰·吡唑酯水分散粒剂对烟草黑胫病的防治效果

[目的]探明18.7%烯酰·吡唑酯水分散粒剂对烟草黑胫病的防治效果。[方法]采用菌丝生长速率法和田间药效试验法。[结果]18.7%烯酰·吡唑酯水分散粒剂对烟草黑胫病菌丝生长的抑制效果最好,EC_(50)值为0.09 mg/L。烟草移栽期和团棵期18.7%烯酰·吡唑酯水分散粒剂864.88 g a.i./hm~2处理对烟草黑胫病防治效果达91.43%,极显著高于对照药剂处理,且能较好地促进烟株的良好生长。[结论]18.7%烯酰·吡唑酯水分散粒剂可作为替代药剂,用于烟草黑胫病的大田防控。     

黑果枸杞中多酚类化合物提取及其药理作用的研究

黑果枸杞具有抗氧化、抗衰老的作用,但是发挥作用具体化合物的种类尚不明确。本文通过翻译、整合中国博硕士论文数据库、PubMed、Science Direct、Publications、Springer Link等关于黑果枸杞的研究报告,主要对黑果枸杞中多酚类化合物的种类与结构、提取方法、药理作用研究进行总结。黑果枸杞抗氧化、抗自由基、保护心血管、降血压、抗辐射的药理作用与多酚类物质息息相关。这为临床进一步研究黑果枸杞中的多酚类化合物奠定基础。     

New hybrid materials based on layered double hydroxides and antioxidant compounds. Preparation, characterization and release kinetic studies

New hybrid materials were obtained by intercalation of the antioxidant compounds vanillic acid and gallic acid in layered double hydroxides (LDHs) resulting formulations with controlled release and antioxidant activity. The hybrid materials were prepared by using two methods: coprecipitation and ion exchange. X-ray powder diffraction, infrared spectroscopy and thermogravimetric analysis confirmed that the antioxidant molecules were intercalated into interlayer spaces of LDHs. The release of the antioxidant compounds was investigated in simulated gastrointestinal solution at 37?°C and monitored using a spectrophotometric method. The results prove that these hybrid biocomposites can be classified as controlled release formulations for the antioxidant compounds under study.     

Preparation and the antioxidant and antibacterial activities of urushiol powders (YPUOH)

Lacquer sap derived from lacquer trees has been widely used in Asian countries for thousands of years as a natural paint and coating material. These natural lacquers exhibit superior barrier properties against oxygen and water, as well as good durability, chemical resistance, mechanical properties, and antibacterial and antioxidant properties. However, they are limited in commercial application due to their high volatility, low drying rate, and allergic reactions. To overcome these limitations, powder-type urushiols (YPUOH), which are essential to provide convenient handling, were successfully prepared using urushiol and different contents of 3-(trimethoxysilyl) propyl methacrylate (TPM). The prepared YPUOH powders were analyzed by Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), and antibacterial and antioxidant measurements. The as-prepared YPUOH powders exhibited excellent antibacterial activity against E. coli and S. aureus, good antioxidant activity, and high thermal stability.     

葡萄糖与松香胺美拉德反应产物抗氧化性能研究

通过葡萄糖与松香胺的美拉德反应可制备具有抗氧化活性的产物。研究了不同反应条件对美拉德反应产物MRPs的抗氧化性能的影响,并与常用食品抗氧化剂特丁基对苯二酚(TBHQ)进行了对比。研究表明:抗氧化能力最佳的条件是反应时间为4.5 h、温度为65℃、pH值8和葡萄糖与松香胺的物质的量之比为1:1;该条件下的产物MRPs与TBHQ的抗氧化能力接近,有望作为一种新的天然抗氧化剂。     

花椰菜中异硫氰酸酯提取物抗氧化活性研究(英文)

Isothiocyanates(ITCs) extracts were prepared from fresh broccoli.Their antioxidant properties were evaluated by using the in vitro bioassays,including superoxide anion radical( 2 O·-) ,hydroxyl radical(HO·-) and 2,2-diphenyl-1-picrylhydracyl(DPPH·) radical-scavenging methods,lipid peroxidation assay,and reducing power assay.The ITCs extracts exhibited significant dose-dependent antioxidant activities(P0.01) .Its antioxidant-stability was affected by temperature and storage condition,although it was more stable than vitamin C(Vc) .GC-MS iden-tified sulforaphane in the ITCs extracts.The antioxidant activity of sulforaphane was approximately one tenth to one fifth of that of Vc.Sulforaphane was experimented to be one of dominating contributors to antioxidant capacity of ITCs extracts.However,there was no direct antioxidant activity found for benzyl isothiocyanate(BITC) in vitro. Therefore,it could be concluded that the general group(-N=C=S) was not the essential part for the antioxidant activity of sulforaphane.It is suggested that the ITCs extracts from broccoli can be developed into a promising food additive for healthy food.     

The Effect of Using Micro-Clustered Water as a Polymer Medium

The aim of the study was to investigate the changes within the physicochemical properties of gelatin, carrageenan, and sodium alginate hydrosols prepared on the basis of micro-clustered (MC) water. The rheological parameters, contact angle and antioxidant activity of hydrosols were investigated. Moreover, the pH, oxidation–reduction potential (ORP) and electrical conductivity (EC) were measured. The hydrosols with MC water were characterized by a lower pH, decreased viscosity, a lower contact angle, and only slightly lower antioxidant activity than control samples. The results showed that hydrosol’s properties are significantly changed by MC water, which can lead to enhancement of its applicability but requires further investigation.     

Sulfated and Oxygenated Imidazoline Derivatives: Synthesis,Antioxidant Activity and Light-Mediated Antibacterial Activity

Imidazoline derivatives with different exocyclic substituents were simply prepared from common starting materials. The procedures were carried out in an eco-friendly manner. The antioxidant activity of these derivatives was explored by different experimental assays, such as ABTS^.+ and DPPH^. scavenging assay, as well as reducing power assay. The structural differences are discussed in terms of the results. Sulfur analogs showed higher antioxidant activity than their oxygenated counterparts. The same tendency was observed in microbiological studies, in which the same imidazoline compounds were assayed for light-mediated activity against of Staphylococcus aureus and Escherichia coli strains. A light-enhanced activity was observed for almost all the sulfated imidazolines after exposure to UV-A (400-320 nm) light.     

Lipid oxidation inhibitory effects and phenolic composition of aqueous extracts from medicinal plants of colombian amazonia

Diverse plants of ethnobotanic interest in Amazonia are commonly used in traditional medicine. We determined the antioxidant potential against lipid peroxidation, the antimicrobial activity, and the polyphenol composition of several Amazonian plants (Brownea rosademonte, Piper glandulosissimum, Piper krukoffii, Piper putumayoense, Solanum grandiflorum, and Vismia baccifera). Extracts from the plant leaf, bark, and stem were prepared as aqueous infusions, as used in folk medicine, and added to rat liver microsomes exposed to iron. The polyphenolic composition was detected by reverse-phase HPLC coupled to diode-array detector and MS/MS analysis. The antimicrobial activity was tested by the spot-on-a-lawn method against several indicator microorganisms. All the extracts inhibited lipid oxidation, except the P. glandulosissimum stem. The plant extracts exhibiting high antioxidant potential (V. baccifera and B. rosademonte) contained high levels of flavanols (particularly, catechin and epicatechin). By contrast, S. grandiflorum leaf, which exhibited very low antioxidant activity, was rich in hydroxycinnamic acids. None of the extracts showed antimicrobial activity. This study demonstrates for the first time the presence of bioactive polyphenolic compounds in several Amazonian plants, and highlights the importance of flavanols as major phenolic contributors to antioxidant activity.     

Effect of Drying Methods on Odorous Compounds and Antioxidative Activity of Gelatin Hydrolysate Produced by Protease from B. amyloliquefaciens H11

Gelatin hydrolysates with antioxidative activity produced by protease from Bacillus amyloliquefaciens H11 with different hydrolysis times were prepared. Alpha-amino group content and antioxidative activities increased with increasing hydrolysis time (p < 0.05). When gelatin hydrolysate prepared with hydrolysis time of 3 h (GH-3H) was subjected to freeze drying and spray drying, the powder obtained from spray drying showed a decrease in antioxidant activity as measured by DPPH and ABTS radical scavenging activities, ferric-reducing antioxidant power, and metal chelating activity. Spray-dried gelatin hydrolysate (GH-3H-SD) showed higher whiteness with lower fishy odor and off-odor associated with fermentation. This was concomitant with the decreases in several odorous compounds in the sample, except for nonanal, which was higher in comparison with the powder obtained by freeze drying. Thus, spray drying could be an effective drying method to improve color and reduce undesirable odor of gelatin hydrolysate.     

用综合热分析仪对SiCp/Cu复合材料抗氧化性能的研究

采用ZRY-2P型综合热分析仪,对浮动凹模双向压制方法和复压烧结工艺制备的五种SiCp/Cu复合材料进行高温氧化性测试,结果表明：30～1000℃的氧化条件下,SiCp/Cu复合材料比纯Cu具有更好的抗氧化性能。其中20%SiCp/Cu复合材料的抗氧化性最佳,这与加热称重法测定结果相同;利用热分析仪得出拟合曲线的方法与经典的加热称重法相比,样品用量少、测速快、测定方便,得到曲线直观明了,比手绘的精确度高,具有实际应用价值。     

Antioxidant activity and free radical‐scavenging capacity of ethanolic extracts of thyme,oregano, and marjoram

Phenolic compounds were extracted from thyme (Thymus vulgaris L.), oregano (Origanum vulgare L.) and marjoram (Origanum majorana L.) with 95% ethanol. A number of antioxidant and radical‐scavenging capacity tests were performed on the prepared extracts using colorimetric assays and model system studies. Specifically, these included determining the content of total phenolics, antioxidant efficacy in a linoleic acid‐ferric thiocyanate model system, reducing power, scavenging effect on 2,2'‐diphenyl‐1‐picrylhydrazyl radical, and hydroxyl radical‐scavenging activity by electron paramagnetic resonance spectroscopy. Moreover, the efficacies of the prepared herb extracts were investigated in a real‐life food product: the stabilization of butter against oxidation.