Antioxidant Activity and Profile of Phenolic Compounds in Selected Herbal Plants

Plant Foods for Human Nutrition - Herbs are characterized by a high content of biologically active substances that positively affect human health. Phenolic compounds are one of the main bioactive...     

Polyphenolics Profile, Antioxidant and Radical Scavenging Activity of Leaves and Stem of Raphanus sativus L.

Aerial parts (leaves and stem) of Raphanus sativus, which are usually discarded were found to possess potent antioxidant and radical scavenging activity, as measured by standard antioxidant assays. Methanolic and acetone extracts of R. sativus leaves had total polyphenolic content of 86.16 and 78.77 mg/g dry extract, which were comparable to the traditional rich sources such as green tea and black tea. HPLC identification of polyphenolics indicated the presence of catechin, protocatechuic acid, syringic acid, vanillic acid, ferulic acid, sinapic acid, o-coumaric acid, myricetin, and quercetin in leaves and stem. Among the different extraction solvents, methanolic extract of leaves and stem showed potent reductive capacity, significantly inhibited linoleic acid peroxidation and displayed metal chelating activity. Further, they scavenged free radicals effectively with IC₅₀ (half maximal inhibitory concentration) of 31 and 42 μg/ml for DPPH radical, 23 and 52 μg/ml for superoxide radical, 67 and 197 μg/ml for hydrogen peroxide, and 56 and 62 μg/ml for nitric oxide, respectively. Leaves showed most potent antioxidant and radical scavenging activity as compared to stem, which may be accounted for the high polyphenolic content. Leaves and stem of R. sativus, often under-utilized part of this vegetable, thus possessed considerable amount of polyphenolics. Hence, it should be regarded as a potential source of natural antioxidants and could be effectively employed as an ingredient in health or in functional food.     

Phenolic Compounds,Volatiles and Antioxidant Capacity of White Myrtle Berry Liqueurs

The aim of this research was to evaluate the antioxidant capacity and physical-chemical characteristics of commercial white myrtle berry (Myrtus communis L. var. leucocarpa DC) liqueur (WMBL). The total phenolic (TP) content was measured spectrophotometrically, applying a modified Folin-Ciocalteu’s method, and phenolic compounds were identified by high-performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry, and quantified by HPLC coupled with ultraviolet/visible detection. The antioxidant capacities were evaluated by FRAP, CUPRAC, DPPH^?, and ABTS^?+ assays. The volatiles were assessed by gas chromatography and mass spectrometry (GC-MS/FID) after headspace solid-phase microextraction (HS-SPME) and liquid-liquid extraction (LLE). WMBL showed lower TP levels (636.3 ± 39.2 mg GAE/L) than in purple myrtle berry liqueur (PMBL). Nevertheless, WMBL exhibited better antioxidant capacities, potentially due to high concentrations of gallic acid (294.2 ± 14.2 mg/L) and its derivatives (58.3 ± 2.1 mg/L). Other phenolic compounds detected by HPLC-DAD and LC-MS/MS were flavonols like myricetin and its derivatives (myricetin-3-O-galactoside and myricetin-3-O-rhamnoside) with concentrations similar to those found in PMBL. GC-MS/FID analysis revealed 44 compounds (terpenes, higher aliphatic compounds and shikimic acid pathway derivatives). 1,8-Cineole was the most abundant terpene in the liqueur (26.5% (HS-SPME) and 9.6% (LLE)).     

Antioxidant Activity of Phenolics Compounds From Sugar Cane (Saccharum officinarum L.) Juice

Phenolic compounds in sugar cane (Saccharum officinarum L.) juice were identified and quantified by analytical high performance liquid chromatography and photodiode array detection, showing the predominance of flavones (apigenin, luteolin and tricin derivatives), among flavonoids, and of hydroxycinnamic, caffeic and sinapic acids, among phenolic acids, representing a total content of around 160 mg/L. A tricin derivative was present in the highest proportion (>10% of the total). The phenolic extract obtained from sugar cane juice showed a protective effect against in vivo MeHgCl intoxication and potent inhibition of ex vivo lipoperoxidation of rat brain homogenates, indicating a potential use for beneficial health effects and/or therapeutic applications.     

Dual Functionality of Triticale as a Novel Dietary Source of Prebiotics with Antioxidant Activity in Fermented Dairy Products

The objectives of this study were to: i) define the optimum concentration of triticale bran (TB) that can be incorporated in yogurt, ii) evaluate the prebiotic effects of TB on microbial viability, pH and total titratable acidity (TTA) in yogurt across 28 days of cold storage, and iii) measure the oxygen radical absorbance capacity (ORAC) of water-extractable polysaccharides (WEP) in TB. Lactobacillus bulgaricus and Streptococcus thermophilus were used as starter cultures. Lactobacillus acidophilus and Bifidobacterium lactis were used as probiotics. A concentration of 4% TB in yogurt was determined to be the maximum amount that could be added without causing synersis. By day 7, the number of bacteria greatly increased in yogurt samples containing TB and maintained higher viable bacteria counts at the end of the cold storage period, in comparison to controls (P ≤ 0.05). Confirming this data was the lower pH levels and higher TTA values of TB yogurt samples exhibited throughout 28 days (P ≤ 0.05). Polysaccharide extracts of TB exhibited strong antioxidant activity with an ORAC value of 33.86 ± 2.30 μmol trolox equivalents (TE)/g of bran. Results of this study suggest that TB may serve as a new prebiotic and antioxidant source for functional foods and nutraceutical applications.     

海南桑树青枯病病原菌鉴定及其分子鉴定

桑树青枯病是由青枯雷尔氏菌引起的细菌性病害,热带、亚热带地区发病严重,严重影响蚕桑产业的可持续发展。雷尔氏菌不同种间致病力和宿主各不相同,其防治策略也相应不同,准确地分离鉴定病原菌是青枯病有效防控的先决条件。本研究采集、分离了海南省琼中县桑青枯病发病桑园（‘桂桑优62’）桑树根部、茎部病原菌,并通过致病性、生理小种、生化变种测定,结合16S rDNA、特异性引物、复合PCR检测体系、序列变种等分子鉴定方法初步确定了病原菌的种类和分类地位。结果表明,引发海南省琼中县桑青枯病的病原菌属于青枯雷尔氏菌（Ralstonia solanacearum）、生理小种5（race 5）、生化变种Ⅴ（biovar Ⅴ）,病原菌遗传进化分析结果显示病原菌属演化型Ⅰ（phylotype Ⅰ）即亚洲分支菌株,序列变种12（sequevar 12）。这些结果将为海南桑青枯病的有效防控奠定基础。     

Phenolic Antioxidants and Antioxidant Activity in Pearling Fractions of Oat Groats

To test the feasibility of dry milling oats (Avena sativa L.) to concentrate antioxidant activity and phenolic antioxidants, groats were pearled for 5 to 180 s. These treatments removed <1 to 15% of the weight. The material obtained from short pearling times was mostly bran. Longer pearling times increased the amount of starchy endosperm in the pearlings. Antioxidant activity of 80% ethanol extracts, measured by β-carotene bleaching and by reduction of the free radical, 2,2-diphenyl-1-picrylhydrazyl, was highest in the short-pearling-time fractions and decreased as more endosperm tissue was included. Likewise, there was a decreasing concentration of total phenolics, determined colorimetrically, and of several simple phenolic acids, determined by high performance liquid chromatography, as more material was pearled from the groats. In contrast, concentrations of avenanthramides were not correlated with pearling time, indicating that they were more uniformly distributed in the groats.     

Chemical Composition and Antioxidant Activity of the Main Fruits,Tubers and Legumes Traditionally Consumed in the Andean Regions of Ecuador as a Source of Health-Promoting Compounds

Plant Foods for Human Nutrition - Thirteen fruits, eight legumes and three tubers consumed in the Andean regions of Ecuador were studied to determine their bioactive compounds, organic acids,...     

辣木叶黄酮苷的分离鉴定及抗氧化活性研究

为研究辣木（Moringa Obleifera Lam.）叶片中的黄酮苷成分及其抗氧化活性,利用MCI凝胶柱、羟丙基葡聚糖凝胶（Sephadex LH-20）柱层析、硅胶柱层析（CC）、半制备高效液相色谱等分离手段对石油醚组分进行分离和纯化,利用LC-MS、1H-NMR、13C-NMR等现代波谱技术对分离得到的化合物进行结构鉴定,采用SRB法和DPPH·清除率对分离得到的化合物进行体外抗肿瘤活性筛选和抗氧化活性的测定。结果表明,从辣木叶的石油醚部分分离得到4个化合物,已鉴定为β-谷甾醇（Ⅰ）、胡萝卜苷（Ⅱ）、槲皮素-3-O-β-D-葡萄糖苷（Ⅲ）、山柰酚-3-O-β-D-葡萄糖苷（Ⅳ）。4种化合物均具有抗氧化活性,但化合物Ⅲ的抗氧化活性极显著强于其他三种化合物;体外抗肿瘤活性表明,化合物Ⅰ和化合物Ⅱ对乳腺癌细胞株（MDA-MB-231）有一定的抑制作用。      

The Content of Phenolic Compounds and Radical Scavenging Activity Varies with Carrot Origin and Root Color

The contents of phenolic compounds and radical scavenging activities were assessed in a carrot collection comprising 35 cultivars, landraces and breeding populations. The accessions originated from various world regions and they represented Eastern and Western carrot gene pools. In two-year field trial carrot roots of orange, red, yellow, white and purple color were cultivated, freeze-dried and analyzed for phenolic content by Folin-Ciocalteu assay and UV/Vis assay. Radical scavenging activity in the extracts was determined with a stable DPPH radical. Carrots developing purple roots possessed on average 9 times more phenolics than roots of other colors. Furthermore, they were rich in anthocyanins that caused very high antiradical activity. Red carrots showed higher antioxidant activity than orange, yellow and white carrots and in the season of lower rainfall they accumulated higher amounts of phenolic compounds. Carrots of Asian origin belonging to Eastern gene pool were more often purple or red and richer in phenolics and had higher antiradical activity than those from the Western gene pool with mainly orange roots.     

不同品种荔枝果皮酚类物质组成及其抗氧化活性比较

为比较不同品种荔枝果皮酚类物质含量、组成及其抗氧化活性差异,用80%甲醇分别提取6个品种荔枝果皮中的酚类物质,测定其总酚和总黄酮含量。采用铁离子还原能力（FRAP）和自由基离子清除能力（ABTS）等方法评价其抗氧化活性。通过高效液相色谱（HPLC）鉴定不同的单体酚并分析其在不同品种荔枝果皮之间的差异。结果表明,不同品种荔枝果皮的酚类物质含量为28.69~68.48 mg/g,不同品种荔枝果皮的酚类物质含量和抗氧化能力存在显著的差异（P<0.05）。酚类物质的含量、FRAP和ABTS抗氧化活性能力均以‘荔枝王’为最高,分别为68.48 mg/g_、546.31 μmol/g和511.25 μmol/g。液相色谱结果鉴定出‘糯米糍’中的8种单体酚,而含量相对较高的是A型原花青素三聚体和原花青素A2。研究结果可为荔枝加工废弃物荔枝果皮的开发利用提供理论依据。     

Antioxidant and Antifungal Activity of <Emphasis Type="Italic">Verbena officinalis</Emphasis> L. Leaves

The scavenging activity against DPPH (1,1-diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform, ethyl acetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of different fractions of 50% methanolic extract and some isolated compounds were also investigated. The results suggest that 50% methanolic extract and caffeoyl derivatives could potentially be considered as excellent and readily available sources of natural antifungal and antioxidant compounds.     

Japanese Quince Seeds as a Promising Rich Source of Proteins and Essential Amino Acids

Plant Foods for Human Nutrition - The Japanese quince (Chaenomeles japonica) seeds (JQS) are generated in large amounts as a by-product in considerable quantities during industrial quince fruit...     

不同品种桑葚叶总酚含量及其抗氧化活性比较

为了研究不同品种桑葚叶的总酚含量差异及应用价值,以收集引种的40个品种桑葚叶为研究对象,采用超声波辅助提取桑葚叶中酚类物质,以总酚提取率为指标,利用单因素试验和正交试验考察各因素对超声辅助提取桑葚叶总酚提取率的影响;采用DPPH自由基清除能力评价不同品种桑葚叶提取物的抗氧化能力,同时对不同品种桑葚叶中总酚含量及其抗氧化...     

Bioactive Compounds,Antioxidant and Binding Activities and Spear Yield of Asparagus officinalis L.

The aim of this investigation was to find a proper harvesting period and establishing fern number, which effects the spear yield, bioactive compounds and antioxidant activities of Asparagus officinalis L. Spears were harvested at 2, 4, and 6 weeks after sprouting. Control for comparison was used without harvest. Spears and total yield increased with prolonged spear harvest period. In harvest of 6 weeks long optimum spear yield was the highest and fern numbers were 5?~?8. Bioactive compounds (polyphenols, flavonoids, flavanols, tannins and ascorbic acid) and the levels of antioxidant activities by ferric-reducing/antioxidant power (FRAP) and cupric reducing antioxidant capacity (CUPRAC) assays in asparagus ethanol extracts significantly differed in the investigated samples and were the highest at 6 weeks harvest period (P?<?0.05). The first and the second segments from the tip significantly increased with the increase of catalase (CAT). It was interesting to investigate in vitro how human serum albumin (HSA) interacts with polyphenols extracted from investigated vegetables. Therefore the functional properties of asparagus were studied by the interaction of polyphenol ethanol extracts with HSA, using 3D- FL. In conclusion, antioxidant status (bioactive compounds, binding and antioxidant activities) improved with the harvesting period and the first segment from spear tip. Appropriate harvesting is effective for higher asparagus yield and its bioactivity.     

Effect of Drying on the Phenolic Content and Antioxidant Activity of Red Grape Pomace

Winemaking by-products are considered to be a rich source of bioactive compounds. Grape pomace is susceptible to microbial degradation due to the degree of residual moisture, so the drying of this pomace for conservation is considered to be an essential first step. Previous studies concerning the way in which drying affects winery by-products have produced contradictory results. In this study, a new methodology for drying grape pomace in a climatic chamber has been evaluated. Five red grape pomace varieties were dried in a climatic chamber at 40 °C and 10% relative humidity and the phenolic content and antioxidant activity of the dried and wet pomace samples were compared. The results indicate that this drying process is both feasible and beneficial because significant increases in the extractability of phenolic compounds and antioxidant activity were achieved.     

Jellyfish from Fisheries By-Catches as a Sustainable Source of High-Value Compounds with Biotechnological Applications

The world’s population growth and consequent increased demand for food, energy and materials together with the decrease of some natural resources have highlighted the compelling need to use sustainably existing resources and find alternative sources to satisfy the needs of growing and longer-aging populations. In this review, we explore the potential use of a specific fisheries by-catch, jellyfish, as a sustainable source of high-value compounds. Jellyfish are often caught up with fish into fishing gear and nets, then sorted and discarded. Conversely, we suggest that this by-catch may be used to obtain food, nutraceutical products, collagen, toxins and fluorescent compounds to be used for biomedical applications and mucus for biomaterials. These applications are based on studies which indicate the feasibility of using jellyfish for biotechnology. Because jellyfish exhibit seasonal fluctuations in abundance, jellyfish by-catches likely follow the same pattern. Therefore, this resource may not be constantly available throughout the year, so the exploitation of the variable abundances needs to be optimized. Despite the lack of data about jellyfish by-catches, the high value of their compounds and their wide range of applications suggest that jellyfish by-catches are a resource which is discarded at present, but needs to be re-evaluated for exploitation within the context of a circular economy in the era of zero waste.     

Functional Teas from the Stems of Penthorum chinense Pursh.: Phenolic Constituents,Antioxidant and Hepatoprotective Activity

Plant Foods for Human Nutrition - Penthorum chinense Pursh (PCP), a medicinal and edible plant, is traditionally used for liver protection and treatment of liver diseases. In this study, we...