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1.
Plant derived flavonoids have not been well explored in tissue engineering applications due to difficulties in efficient formulations with biomaterials for controlled presentation. Here, the authors report that surface coating of epigallocatechin gallate (EGCG) on polymeric substrates including poly (L‐lactic acid) (PLLA) nanofibers can be performed via oxidative polymerization of EGCG in the presence of cations, enabling regulation of biological functions of multiple cell types implicated in bone regeneration. EGCG coating on the PLLA nanofiber promotes osteogenic differentiation of adipose‐derived stem cells (ADSCs) and is potent to suppress adipogenesis of ADSCs while significantly reduces osteoclastic maturation of murine macrophages. Moreover, EGCG coating serves as a protective layer for ADSCs against oxidative stress caused by hydrogen peroxide. Finally, the in vivo implantation of EGCG‐coated nanofibers into a mouse calvarial defect model significantly promotes the bone regeneration (61.52 ± 28.10%) as compared to defect (17.48 ± 11.07%). Collectively, the results suggest that EGCG coating is a simple bioinspired surface modification of polymeric biomaterials and importantly can thus serve as a promising interface for tuning activities of multiple cell types associated with bone fracture healing.  相似文献   
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氧化还原酶催化合成芳香聚合物的研究进展   总被引:2,自引:0,他引:2  
主要概括了近年来以典型的氧化还原酶包括辣根过氧化物酶,大豆过氧化物酶和漆酶等催化合成苯酚,双酚,蒽醌类聚合物,苯胺类聚合物,聚苯醚等聚芳香族功能高分子材料的研究进展,并对多酶法与化学酶法的酶促合成作了介绍。  相似文献   
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树脂对茶多酚与咖啡因的吸附分离   总被引:7,自引:1,他引:7  
从低档绿茶末的水提取液中,利用离子交换,吸附树脂成功地分离出茶多酚与咖啡因,并详细考察了其交换与吸附性能。与其它方法相比,该树脂法具有产品收率高,成本低廉等特点。  相似文献   
5.
Alsophila spinulosa is a tree-like fern, and many evidences suggested that plant polyphenols had the potential therapeutic for Alzheimer s disease (AD). Herein, polyphenols (ASP) was isolated from A. spinulosa leaves and its major constituent were isoorientin and vitexin. ASP displayed excellent antioxidant activity and obvious anti-lipid peroxidation capacity in vitro. ASP improved the survival rate of C. elegans under high temperature by enhancing the antioxidant enzymes activities and decreasing the lipid peroxidation level. Moreover, ASP alleviated β-amyloid (Aβ) induced paralysis and reduced Aβ deposition, decreased reactive oxygen species (ROS) accumulation and improved the level of skn-1 mRNA. In addition, ASP decreased the levels of pdk-1 and akt-1 mRNA in P13K/AKT signaling pathway. In conclusion, ASP may be a potential ingredient for the alleviation of AD.  相似文献   
6.
A new and simple LC-MS method for analysis of flavonoids from Sambucus ebulus berry extracts was developed and validated. Successfully were quantitated seven polyphenols: epicatechin, epigallocatechin gallate, rutin, resveratrol, myricetin, quercetin, and kaempferol.

Two detectors, working in parallel, were used: photodiode-array and single quadrupole mass-detector. The mass detection was used for identification and quantification of the analytes, while the diode-array detector was as confirmation tool. The following m/z were tracked: 457.15 (epigallocatechin gallate); 289.06 (epicatechin); 609.13 (rutin); 227.05 (resveratrol); 317.0 (myricetin); 301.02 (quercetin); 285.02 (kaempferol). For optimization the chromatographic separation three wavelengths 205?nm, 305?nm, 272?nm were monitored. The method was capable to detect in one run compounds with no UV or fluorescence chromophore and with very similar structures, such as plant polyphenols. The linearity was from 0.05?mg/L to 50?mg/L (R2 0.9962–0.9987). The recoveries for all tested analytes were between 81.6% and 104.7%.

The method was applied for analysis of crude extract of Sambucus ebulus ripe fruits. Three major polyphenols – epicatechin (0.84?mg/100gFW), quercetin (0.15?mg/100gFW) and kaempferol (0.05?mg/100gFW) were identified and quantified.

The proposed method could be successfully used for routine analysis of epigallocatechin gallate, epicatechin, rutin, resveratrol, myricetin, quercetin, and kaempferol in Sambucus ebulus extracts.  相似文献   

7.
Microsorum scolopendia (MS), which grows on the Chilean island of Rapa Nui, is a medicinal fern used to treat several diseases. Despite being widely used, this fern has not been deeply investigated. The aim of this study was to perform a characterization of the polyphenolic and flavonoid identity, radical scavenging, antimicrobial, and anti-inflammatory properties of MS rhizome and leaf extracts (RAE and HAE). The compound identity was analyzed through the reversed-phase high-performance liquid chromatography (RP-HPLC) method coupled with mass spectrometry. The radical scavenging and anti-inflammatory activities were evaluated for DPPH, ORAC, ROS formation, and COX inhibition activity assay. The antimicrobial properties were evaluated using an infection model on Human Dermal Fibroblast adult (HDFa) cell lines incubated with Staphylococcus aureus and Staphylococcus epidermidis. The most abundant compounds were phenolic acids between 46% to 57% in rhizome and leaf extracts, respectively; followed by flavonoids such as protocatechic acid 4-O-glucoside, cirsimaritin, and isoxanthohumol, among others. MS extract inhibited and disaggregated the biofilm bacterial formed and showed an anti-inflammatory selective property against COX-2 enzyme. RAE generated a 64% reduction of ROS formation in the presence of S. aureus and 87.35% less ROS in the presence of S. epidermidis on HDFa cells. MS has great therapeutic potential and possesses several biological properties that should be evaluated.  相似文献   
8.
This study aimed to evaluate the impact of widely grown fruits (wild roses, elderberries, sea buckthorns, rowans, chokeberries, and hawthorns) as a functional ingredient in wheat-flour cookie formulation on antioxidative properties with a simultaneous reduction of the carcinogen-like compound acrylamide. The organoleptic features of the cookies were assessed by a panel of consumers. The following parameters were measured: chemical composition, total polyphenols, polyphenolic profile, antioxidant activity, and acrylamide content. The overall ratings of the tested cookies with the addition of chokeberries, hawthorns, sea buckthorns, and elderberries were more than satisfactory, while wild rose and rowan cookies were the most widely accepted and best rated by the panelists. The antioxidant activity of the tested cookies was 1.1–15.22 μmol trolox·g−1 dm and 2.46–26.12 μmol Fe (II)·g−1 dm as measured by the ABTS and FRAP methods, respectively. All the fruit-enriched cookies had significantly higher antioxidative properties (p < 0.05) in comparison to the control cookies, but among the fruit-enriched cookies, there were differences in the quality and quantity of particular polyphenols. The acrylamide content was significantly decreased by 59% (hawthorn), 71% (rowan), 87% (wild rose), 89% (sea buckthorn), 91% (elderberry), and 94% (chokeberry) compared with the control cookies (p < 0.05). Cookies enriched with wild-grown fruits could constitute a promising novel snack food.  相似文献   
9.
Moringa oleifera is an ancient remedy plant, known as the miraculous plant due to its many prominent uses and significant health benefits. It is a nutrient-rich plant, with exceptional bioactive compounds, such as polyphenols that possess several medicinal properties. Many significant studies have been carried out to evaluate the ethnomedicinal and pharmacological properties of M. oleifera in various applications. Therefore, this comprehensive review compiles and summarizes important findings from recent studies on the potential properties of different parts of M. oleifera. The pharmacological properties of M. oleifera have been studied for various potential biological properties, such as cardio-protective, anti-oxidative, antiviral, antibacterial, anti-diabetic and anti-carcinogenic effects. Therefore, the potential of this plant is even more anticipated. This review also highlights the safety and toxicity effects of M. oleifera treatment at various doses, including in vitro, in vivo and clinical trials from human studies.  相似文献   
10.
Brunfelsia grandiflora is an ancient plant widely used for its promising medicinal properties, although little explored scientifically. Despite being a rich source of phenolic compounds responsible in part for the proven anti-inflammatory activity, its characterization has not been carried out to date. The present work deals with the exhaustive identification and quantification of its phenolic fraction, along with its antioxidant activity. Decoction resulting from the bark as fine powder was filtered and lyophilized, and polyphenols were extracted from the resulting product by aqueous-organic solvents. Seventy-nine polyphenols were identified using LC-MSn. Hydroxycinnamates was the most abundant group of compounds (up to 66.8%), followed by hydroxycoumarins (15.5%), lignans (6.1%), flavonols (5.7%), phenolic simples (3.1), gallates (2.3%), flavanols (0.3%), and flavanones (0.2%). About 64% of the characterized phenols were in their glycosylated forms. The quantification of these phytochemicals by LC-QToF showed that this medicinal plant contained 2014.71 mg of phenolic compounds in 100 g dry matter, which evidences a great antioxidant potency determined by ABTS and DPPH assays. Therefore, Brunfelsia grandiflora represents an important source of polyphenols which supports its therapeutic properties scientifically proven.  相似文献   
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