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1.
The use of supercritical fluid technology as an innovative technology to extract bioactive compounds has grown considerably in recent decades. Particularly, the recovery of antioxidants from different herbs is a matter of continuous research and development. Antioxidants can protect cells against the effects of free radicals and thus, play an important role in heart illness, cancer and other diseases.Rosemary (Rosmarinus officinalis L.) has been recognized as one of the Lamiaceae plant with many important biological activities. Particularly, large antioxidant power has been recognized in rosemary and main substances related with this activity were the phenolic diterpenes such as carnosol, rosmanol, carnosic acid, methyl carnosate, and phenolic acids such as the rosmarinic and caffeic acids. Moreover, carnosic acid and carnosol are recognized as the most abundant antioxidants present in rosemary.In this work, supercritical fluid technology was applied to produce rosemary extracts with different compositions and thus, with different bioactivity properties. Selected extracts, from the variety of samples obtained, were used to study the capability of rosemary supercritical extracts to inhibit the proliferation of human liver carcinoma cells. These extracts showed a dose-dependent effect on inhibiting the proliferation of human hepatoma cells. Moreover, observed citostaticity appeared to be significantly influenced by their different composition, suggesting a relevant role of the technology to produce the extracts and the consequently obtained compositions on the potential antitumoral activity of rosemary.  相似文献   

2.
The objective of this research was to investigate the antioxidative properties of extract from blackcurrant seeds (BCSs) and commercially available rosemary extracts (Stabiloton OS, oil‐soluble and WS, water soluble) in soybean oil (SO). The antioxidant activity of plant extracts was compared with those of α‐tocopherol and butylated hydroxytoluene (BHT). The results of present research reveal differentiation of action of investigated extracts toward primary (peroxide value (PV), conjugated dienes (CDs)) and secondary (measured as anisidine value (AV), hexanal) oxidation products in SO. WS and OS rosemary extracts show high efficiency in delaying primary and secondary oxidative changes. BCSs extract markedly retards oxidation, nevertheless its activity falls down with formation and succeeding deterioration of primary products. Although the use of BCSs, residues of fruit processing, as a source of antioxidants would be reasonable because of economic and environmental reasons, it may be limited by low activity toward secondary oxidation products in certain lipid substrates. Taking primary oxidative changes into consideration, all extracts studied perform better than used standard antioxidants – BHT and α‐tocopherol.  相似文献   

3.
迷迭香早在古希腊时代就用于治疗多种疾病.在化妆品中的应用,已有悠久的历史.据传,十四世纪匈牙利女王伊莉莎白每天白天和晚上都使用由迷迭香配制而成的"匈牙利水"护肤,即使到了70岁高龄仍保持了年青时的美貌.近年来,研究人员对迷迭香的有效性从各个角度进行了研讨.研究涉及抗炎症作用、抗过敏效果、黑色素抑制效果、抗氧化活性、抗菌活性等各个方面.  相似文献   

4.
Eight sage (Salvia officinalis) and twenty-four rosemary (Rosmarinus officinalis) extracts, originating from pilot-plant or commercial sources, had different antioxidative activities as measured by accelerated autoxidation of methyl linoleate. Twenty-seven compounds were characterized in the Labiatae family extracts by high-performance liquid chromatography (HPLC) coupled with mass spectrometry, equipped with an atmospheric pressure chemical ionization interface, and by HPLC coupled with a photodiode array spectrophotometer. Twenty-two compounds were identified, including phenolic acids, carnosol derivatives, and flavonoids. The extracts showed great variation in their HPLC profiles, and no correlation was apparent between their antioxidative efficiency and their composition, in twenty specific phenols. Data indicated that the most effective compounds were carnosol, rosmarinic acid, and carnosic acid, followed by caffeic acid, rosmanol, rosmadial, genkwanin, and cirsimaritin.  相似文献   

5.
Rosemary (Rosemarinus officinalis L.) leaves were extracted with three different solvents, namely hexane, acetone and methanol. A reverse-phase high-performance liquid chromatography system in combination with a mass detector was used to quantitate the content of carnosol, carnosic acid and ursolic acid in the rosemary extracts. All rosemary extracts showed strong inhibitory effects on lipid oxidation and soybean lipoxygenase activity.  相似文献   

6.
7.
The TBA reactivities of several aldehydes, most of them known as ordinary products of lipid autoxidation, have been investigated systematically. Gas liquid chromatography-purified alkanals, 2-alkenals and 2,4-alkadienals were reacted with TBA in water solution. The formation of pigments with maximum absorbance at 450 and 530 nm was measured at optimum time-temperature conditions-different for readings at 450 and 530 nm- and values for absorbance per mole aldehyde were calculated. These values show that on reaction with TBA all studied aldehydes build a yellow 450 nm pigment, while only 2,4-alkadienals and, to a lesser extent, 2-alkenals produce the red 530 nm pigment. Consequently both pigments are measures of aldehydic products of lipid autoxidation: In the case of predominant unsaturated aldehyde formation, determination of the pigment with maximum absorbance at 530 nm is preferable. However, if alkanals are predominant, the determination of the yellow pigment at 450 nm is more apporpriate, as it grants higher sensitivity. The first paper in this series was published inFette, Seifen, Anstrichmittel 72:635 (1970).  相似文献   

8.
The present investigation revealed the potential benefits of nanofiltration application in herbal extracts processing. Nanofiltrations of modelling solution of caffeic and rosmarinic acid in ethanol and ethanolic rosemary extract were carried out in a laboratory cross-flow system. Duramem™ 200 nanofiltration membrane was selected based on screening experiments. The experimental data and model predictions demonstrated the efficacy of a semi-batch cross-flow diafiltration process for concentration of fresh rosemary extracts. The observed absence of significant loss of antioxidant capacity in the retentate during the process and the degree of extract concentration achieved may allow retentate direct application as preservative and functional ingredient in the foods, cosmetics, neutraceuticals and medicines. The capability of the selected membrane to separate monophenolic acids from higher molecular weight antioxidant compounds in the extracts was also discussed. The dry solids content in the permeate was found sufficiently low as to permit its direct re-use in the extraction process thus bringing additional economical benefits.  相似文献   

9.
10.
Mixed vegetal extracts are interesting target of new products as nutraceuticals, superior ingredients for the design of functional food, singular ingredients for cosmetics, etc. In this work the extraction of a mixture of spinach and rosemary leaves (50 wt.% of each plant) was investigated in terms of its antioxidant activity, and compared with the extraction of the separate species. Phenolic diterpenes of rosemary and carotenoids of spinach were target compounds due their recognized biological activities. Two different extraction techniques were applied, namely pressurized liquid extraction using hexane at two different temperatures (100 and 150 °C) and supercritical fluid extraction with pure carbon dioxide at 40 °C and two different pressures (20 and 30 MPa). For each extraction technique and conditions three different raw materials were employed: spinach leaves, rosemary leaves and the mixture 50:50 of spinach and rosemary leaves.The antioxidant activity of the samples produced was evaluated with the ABTS assay and showed to be enhanced when the species are simultaneously extracted, with antioxidant values around 20% higher than the values corresponding to mixing the extracts obtained by separate. A possible synergic effect between carotenoids and phenolic diterpenes was studied, although no specific synergic activity could be observed. However, the enhanced antioxidant activity could be attributed to a definite increase of the concentration of carnosic acid, which was observed in the samples produced by the simultaneous extraction.  相似文献   

11.
考察了酸析预处理对水性油墨废水CODCr的去除效果,并对酸析沉淀物进行了红外分析。探讨了通过电沉积法制备的未掺杂、掺杂Fe、掺杂Bi、掺杂Fe+Bi 4种钛基二氧化铅电极对酸析后的水性油墨废水的处理效果,对板间距、电解时间、电流密度和pH等工艺条件进行了优化。结果表明:酸析预处理对水性油墨废水具有较好的处理效果;掺杂Fe+Bi钛基二氧化铅电极板的电催化处理效果最好;最优工艺条件:pH为9,电流密度为30 mA/cm2,电解时间为210 min,板间距为1 cm。  相似文献   

12.
Problems associated with continuously planting alfalfa (Medicago saliva L.) or seeding to thicken depleted alfalfa stands may be due to autotoxicity, an intraspecific form of allelopathy. A bioassay approach was utilized to characterize the specificity and chemical nature of phytotoxins in extracts of alfalfa soils as compared to fallow soil or soil where a cereal was the previous crop. In germination chamber experiments, water-soluble substances present in methanol extracts of soil cropped to alfalfa or barley (Hordeum vulgare L.) decreased seedling root length of alfalfa L-720, winter wheat (Triticum aestivum L. Nugaines) and radish (Raphanus sativa L. Crimson Giant). Five days after germination, seedling dry weights of alfalfa and radish in alfalfa soil extracts were lower compared to wheat or red clover (Trifolium pralense L. Kenland). Growth of red clover was not significantly reduced by soil extracts from cropped soil. Extracts of crop residue screened from soil cropped to alfalfa or barley significantly reduced seedling root length; extracts of alfalfa residue caused a greater inhibition of seedling dry weight than extracts of barely residue. A phytotoxic, unidentified substance present in extracts of crop residue screened from alfalfa soil, which inhibited seedling root length of alfalfa, was isolated by thin-layer chromatography (TLC). Residues from a soil cropped continuously to alfalfa for 10 years had the greatest phytotoxic activity.  相似文献   

13.
11种中草药水提物抗氧化活性研究   总被引:1,自引:0,他引:1  
王征帆 《应用化工》2011,(9):1563-1564,1568
罗丹明B在可见光区有强烈的吸收,它与羟基自由基反应生成无色物质,使体系的吸光度降低,中药水提取物可以清除溶液中的.OH,从而使溶液吸光度下降的程度降低,据此原理建立了一种测定中药的抗氧化活性的方法。分别测定了11种中药的抗氧化活性,其中以五倍子的抗氧化活性最强。  相似文献   

14.
The objective of this paper was to formulate high performance water-based paints by an esterified epoxy resin, synthesized by reacting epoxy resin with pyromellitic dianhydride (PMDA) and pigmented with non-toxic phosphate using varying pigment-volume concentrations (PVCs). The influence of pigment concentrations on some physico-chemical properties was evaluated and assessed for the optimized PVC coating formulation. The structural and thermal stability of the epoxy ester vehicle was also evaluated through FT-IR and thermogravimetric analysis (TGA). Film properties of the coatings were studied and it was found that the coating composition at lower PVCs exhibited better film property over higher PVCs.  相似文献   

15.
针对甲基丙烯醛氧化酯化浆态床反应过程中颗粒催化剂易破碎、活性组分易流失等缺点,采用浸渍法在电沉积到泡沫镍合金表面的氧化铝-氧化镁涂层上负载活性组分,制备了PdxPby/Al2O3-MgO/泡沫镍合金整体式催化剂。研究分析了铝溶胶含量、Al2O3含量、沉积电压和沉积时间等条件对涂层负载的影响,并对载体和催化剂进行了BET、XRD、SEM、ICP和TEM表征和气-液-固固定床反应性能评价。结果表明,当铝溶胶的体积含量为35%~40%,Al2O3含量为25~30 g·L-1,沉积电压为10~12 V,沉积时间为8~12 min,搅拌速度为200~250 r·min-1时可得到稳定的涂层。在温度为80℃、压力为0.3 MPa、醇醛摩尔比为8:1、液相物料进口流量为0.5 ml·min-1、氧气进口流量为35 ml·min-1、反应时间为2 h条件下,整体式催化剂上甲基丙烯醛转化率最高为76.1%,甲基丙烯酸甲酯选择性为81.2%。研究结果可为甲基丙烯醛氧化酯化制甲基丙烯酸甲酯的生产工艺优化提供科学数据。  相似文献   

16.
Wool dyed with acid dyes has low wash fastness because of the weak, secondary forces between the fibre and the dye molecule. The amount of covalently fixed dye increases when aftertreating the dyed wool samples with carbodiimides. Several water-soluble carbodiimide derivatives proved to be effective for this purpose. They were synthesised by our method involving the use of: N-propyl-N′-(3-trimethyl-ammoniumpropyl)-carbodiimide-iodide, N-cyclohexyl-N′-(3-trimethylammonium-propyl)-carbodiimide-iodide, and N-cyclohexyl-N′-(2-morpholinoethyl)-carbodiimide-methyl-p-toluene-sulphonate. No damage occurred in the fibre structure during the treatment. The effect of both the carbodiimides and the dyes (Sandolan Fast Blue P-L, Egacyd Yellow T) is discussed.  相似文献   

17.
18.
A simplified method for the evaluation of antioxidants   总被引:2,自引:0,他引:2  
A procedure is described for rapid evaluation of antioxidants. Dilute aqueous emulsions of an antioxidant, carotene and lipid were prepared in spectrometer tubes. The oxidative destruction of carotene in the emulsion was observed directly with a colorimeter. The antioxidants were then evaluated according to their effect on the rate of carotene decolorization.  相似文献   

19.
A chemiluminescence multi-sample apparatus and method are described for determining polymer stability by measuring the intensity of the light emitted during thermal oxidation. Depending on the nature of a material analyzed the experiments are performed either under O2 atmosphere at a constant temperature or under N2 atmosphere at a constant heating rate. In the former case applicable to polypropylene (PP) and acrylonitrile-butadiene-styrene copolymers (ABS), parameters such as induction time and oxidation rate can be evaluated. In the latter case applicable to nylon and polyethylene terephthalate (PET), the extent of oxidation in a certain temperature region can be evaluated by measuring the area under the intensity of light—temperature curve. Along with providing a great deal of knowledge on thermal oxidative stability, the chemiluminescence approach gives the additional information concerning polymer quality. The appearance of the low-temperature pulses on the chemiluminescence curve observed before the onset of autocatalytic oxidation is associated with the history and processing of the sample and with the natural aging of the polymer.  相似文献   

20.
Antioxidative activities of evening primrose seed meal extracts in sunflower and rapeseed oils were compared with that of commercially used antioxidants, namely butylated hydroxytoluene (BHT), ascorbylpalmitate as well as Grindox‐118. The study was carried out under Schaal oven conditions at 60 °C and the weight gain was followed up by p‐anisidine value measurement following the oxidation. An Oxidograph apparatus monitored the oxidation of oils at 110 °C. Among the examined extracts, the ethyl acetate extract (0.2%), containing only 87 mg/g of total phenolics, exhibited a stronger antioxidant activity than BHT (0.01%) and effectively stabilised both oils. A strong antioxidative effect was also noted for the ethanol‐ethyl acetate extract (168 mg/g of total phenolics). The study showed that addition of ethyl acetate and ethanol‐ethyl acetate extracts could extend the sunflower and rapeseed oils shelf‐life by protecting oils from further decomposition that naturally occurs during thermal treatments.  相似文献   

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