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排序方式: 共有320条查询结果,搜索用时 15 毫秒
1.
Antioxidant activity of grape extracts in a lecithin liposome system 总被引:15,自引:0,他引:15
Ock-Sook Yi Anne S. Meyer Edwin N. Frankel 《Journal of the American Oil Chemists' Society》1997,74(10):1301-1307
Extracts of 14 different grapes were tested for their antioxidant activities in a copper-catalyzed lecithin liposome oxidation
assay and analyzed for their phenolic components by high-performance liquid chromatography (HPLC). The total phenolic contents
of the grape extracts varied from 176 to 1236 mg gallic acid equivalents (GAE)/L. Extracts of red wine grape varieties contained
higher concentrations of phenolics than other varieties. When compared at the same 20 μM GAE basis, the grape extracts inhibited
formation of conjugated diene hydroperoxides by 25.1 to 67.9%, and hexanal formation by 49.3 to 97.8%. Extracts of red table
grape varieties Red Globe and Emperor and white wine grape varieties Chardonnay and Sauvignon Blanc gave the highest antioxidant
activities. The relative percentage inhibition of conjugated dienes and hexanal correlated with total phenols (r=0.86 and 0.89). HPLC analyses showed that anthocyanins were the most abundant phenolic compounds in extracts of red grapes,
and flavonols were most abundant in extracts of white grapes. 相似文献
2.
以薄膜水化法制备的阴离子脂质体的平均粒径为(180±2.3)nm.Zeta电位为-33.9mV.分别以脂质体中钙黄绿素的泄露量和紫外分光光度法测定蛋白含量,以表征羟丙基书-环糊精(HP-β-CD)对脂质体和真核微生物蓝色犁头霉(Absidiacoerulea)细胞通透性的影响.结果表明:在HP-f1.CD作用下,两者的通透性变化趋势一致.分析比较HP-β-CD作用下的甾体化合物17a,21-二羟基孕甾-4-烯-3,20-二酮(RS)在脂质体和菌体细胞中的通量变化的相关性,表明脂质体与细胞通量变化的拟合度达到97.9%,相关性显著(P〈0.05).由此说明,本研究建立的脂质体制备方法以及获得的脂质体能够模拟真核细胞,应用于真核微生物的生物学研究. 相似文献
3.
LIANG Zhihong ZHAO Yong DENG Xia HE Gang NIE Rongrong CHEN Zhiqing 《武汉理工大学学报(材料科学英文版)》2005,20(B12):60-62
The bio- inspired strategy of triggered release of Ca^2+ , Pi, F from prosomal compartments was used to induce rapid formation of FHA for potential dental use : Calcium and inorganic phosphate salts were separately loaded into temperature-sensitive liposome composed of 90% DPPC and 10% DMPC. When heated from the room temperature to 35- 37 ℃ , the entrapped calcium, inorganic phosphate and fl~rin released from the liposome,A mixture of Ca- Pi and F-loaded liposome formed apatite. The mineral was indicated by a rapid drop in suspension PH from 7.4 approximately 6. This was illustrated by applying a liposome suspension warmed human dentin and enamel surface which resulted in deposition of apatite onto the tissue substrates. 相似文献
4.
Vincenzo De Leo Anna Maria Maurelli Livia Giotta Valeria Daniello Sante Di Gioia Massimo Conese Chiara Ingrosso Fulvio Ciriaco Lucia Catucci 《International journal of molecular sciences》2023,24(1)
Curcumin (Cur) is a hydrophobic polyphenol from the rhizome of Curcuma spp., while hydroxytyrosol (HT) is a water-soluble polyphenol from Olea europaea. Both show outstanding antioxidant properties but suffer from scarce bioavailability and low stability in biological fluids. In this work, the co-encapsulation of Cur and HT into liposomes was realized, and the liposomal formulation was improved using polymers to increase their survival in the gastrointestinal tract. Liposomes with different compositions were formulated: Type 1, composed of phospholipids and cholesterol; Type 2, also with a PEG coating; and Type 3 providing an additional shell of Eudragit® S100, a gastro-resistant polymer. Samples were characterized in terms of size, morphology, ζ-potential, encapsulation efficiency, and loading capacity. All samples were subjected to a simulated in vitro digestion and their stability was investigated. The Eudragit®S100 coating demonstrated prevention of early releases of HT in the mouth and gastric phases, while the PEG shell reduced bile salts and pancreatin effects during the intestinal digestion. In vitro antioxidant activity showed a cumulative effect for Cur and HT loaded in vesicles. Finally, liposomes with HT concentrations up to 40 μM and Cur up to 4.7 μM, alone or in combination, did not show cytotoxicity against Caco-2 cells. 相似文献
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This study was designed to evaluate the prolonged antimicrobial stability of nisin-loaded liposome (LipoN) nanoparticles against Listeria monocytogenes and Staphylococcus aureus. The sizes of bare liposomes and LipoN were uniformly distributed between 114 and 125 nm. The nanoparticles were homogeneously dispersed in water with less than 0.2 of polydispersity index. The zeta potential value of LipoN was +17.1 mV due to the positive charged nisin, attaining 70% of loading efficiency. The minimum inhibitory concentration of LipoN against L. monocytogenes and S. aureus was 320 international unit/mL. The LipoN significantly enhanced the antimicrobial stability in brain heart infusion agar compared to free nisin. The numbers of L. monocytogenes and S. aureus exposed to LipoN were effectively reduced by more than 6 log colony-forming unit/mL after 48 and 72 h of incubation, respectively. These results provide useful information for the development of antimicrobial delivery system to improve food safety. 相似文献
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响应曲面法优化石榴皮多酚脂质体的制备及质量评价 总被引:1,自引:0,他引:1
以包封率作为评价指标,采用响应曲面法(RSM)研究逆向蒸发法制备石榴皮多酚脂质体工艺及制备过程中卵磷脂与胆固醇的质量比(SPC/CH)、有机相与水相体积比(O/A)、缓冲液pH及其交互作用对包封率的影响,利用软件优化出最佳的工艺配方,并对其理化性质进行评价。结果表明,制备石榴皮多酚脂质体的最佳工艺为:卵磷脂与胆固醇的质量比(SPC/CH)为3.08、有机相与水相体积比(O/A)为4、缓冲液pH为6.17,在此条件下制备的石榴皮多酚脂质体包封率理论值为55.08%,实际值为54.87%。有效粒径为(91.13±2.5)nm,Zeta电位为-55.7mV,体外释放程度缓慢,缓释率延长32h,缓释效果明显,稳定性方面,在4℃条件下储存稳定性良好,60d之内,包封率共下降13.72%。逆向蒸发法制备脂质体工艺简单可行,包封率高,粒度均匀,稳定性好,可用于石榴皮多酚脂质体的制备。 相似文献