Free radical scavenging, cytotoxic, and hemolytic activities of an active antioxidant compound ethyl gallate from leaves of Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan

Abstract: In the present study, free radical scavenging, cytotoxic, and hemolytic activities of the polyphenolic compound ethyl gallate isolated from ethanol extract of Acacia nilotica Wild. Ex. Del. leaves were determined. The free radical‐scavenging activities of the ethyl gallate were demonstrated in several in vitro assays in order to evaluate the possible antioxidant mechanism. The results revealed ethyl gallate as hydrogen donor, metal chelator, and free radical scavenger. Ethyl gallate was effective in scavenging 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radicals and the IC₅₀ value was lower than all the positive controls used in this study. Deoxyribose degradation assay revealed that ethyl gallate had more iron‐chelating ability than the direct hydroxyl radical‐scavenging ability. The results of the cytotoxic study revealed that the compound was moderately active and IC₅₀ value was found to be >100 μg/mL for Vero cell lines and 72 μg/mL for Hela cell lines. The compound possessed no hemolytic activity against rat and human erythrocytes revealing its cytotoxic mechanism and nontoxicity. The results from this work will provide an important information for the food and pharmacological industries with respect to the use of the compound as an antioxidant and a health‐related drug. Practical Application: Antioxidant from plant sources is safe to use, as compared to synthetic products. It also can be used as a supplement to alleviate most of the diseases because of its free radical‐scavenging activity.     

Natural preservative ingredient from marine alga Ulva lactuca L.

The contents of total chlorophyll (T-Chl), carotenoids and phenolics compounds were quantified in the biomasses of Ulva lactuca grown either in normal or artificial sea water under indoor conditions. The antioxidant and antibacterial activities of U. lactuca crude organic extracts ( Ulva- COEs) were determined. Thirty-four compounds in Ulva- COEs were characterised by thin layer chromatography and high-performance liquid chromatography. The major compounds were chlorophyll a (Chl a ) (15.60–30.90%) and b (Chl b ) (12.20–14.89%) , 9-cis β-carotene (13.12–14.47%), α-carotene (11.44–11.47%) and all-trans β-carotene (6.16–29.70%, of total carotenoids).The Ulva- COEs exhibited remarkable antioxidant activity, with an IC₅₀ (concentration which causes a 50% of DPPH radical scavenging activity) values ranged from 16.5 and 18.7 μg mL⁻¹, which could be compared with the synthetic antioxidants: α-tocopherol (14.4 μg mL⁻¹), butylated hydroxyanisol (13.1 μg mL⁻¹) and butylated hydroxyltoluene (13.1 μg mL⁻¹). Also, Ulva- COEs exhibited great potential antibacterial activities against six bacterial strains, with minimal inhibitory concentration values ranged from 0.40 to 0.35 mg mL⁻¹.     

Bioactivity and chemical characterization in hydrophilic and lipophilic compounds of Chenopodium ambrosioides L.

The bioactive properties (antioxidant and antitumour activities, and hepatotoxicity) of the infusion and methanolic extracts of Chenopodium ambrosioides L., a plant commonly used in Portuguese folk medicine, were compared. The chemical composition in hydrophilic (sugars, organic acids and phenolic compounds) and lipophilic (fatty acids and tocopherols) fractions were determined. In general, the infusion revealed higher antioxidant activity, while the methanolic extract was the only one showing antitumour effects against colon, cervical and hepatocellular carcinoma cell lines. No toxicity in non-tumour cells was observed either for the infusion or the extract. The studied plant proved to be a good source of natural antioxidants and other bioactive compounds, which may have industrial use. As far as we know, this is the first detailed chemical characterization and bioactivity evaluation of C. ambrosioides methanolic extract and infusion.     

生何首乌体外抗氧化活性及抗菌活性的研究

研究生何首乌不同提取物的体外抗氧化活性及抗菌活性。在体外化学模拟的条件下,采用比色法,测定了何首乌水提物和醇提物对DPPH自由基的还原能力及抗脂质过氧化能力,羟基自由基的清除能力以及总体抗氧化能力。同时测定了何首乌水提物和醇提物的总酚酸和总黄酮的含量。利用滤纸片扩散法测定了何首乌水提物和醇提物对6种微生物的抗菌活性。何首乌醇提物的体外抗氧化活性强于水提物,具有显著的DPPH自由基和羟基自由基清除能力和较强的抗脂质过氧化能力,具有一定的还原能力,其总体抗氧化能力也比较强。何首乌水提取物和醇提取物的总酚酸和总黄酮含量分别126.52、77.25μg/mg和153.04、126.11μg/mg。另外何首乌的醇提物对金黄色葡萄球菌、四联球菌和大肠杆菌显示出较强的抑制活性,水提物对金黄色葡萄球菌和荧光假单胞菌显示出一定的抑菌活性。何首乌具有强的抗氧化活性与一定的抗菌活性。     

Antioxidant activity of Smilax excelsa L. leaf extracts

Smilax excelsa L. leaves are used widely in the Black Sea region of Turkey for consumption in the daily diet and in folk medicine for their medicinal properties. In the present study, different antioxidant tests were employed in order to evaluate the antioxidant activities of water, infusion, ethanol and ethyl acetate extracts of S. excelsa leaves. In addition, the results were compared with natural and synthetic antioxidants. The levels of total phenolics, total flavonoids and anthocyanins of the extracts were also determined. The extracts were found to have different levels of antioxidant properties in the test models used. All extracts had good total phenolic and flavonoid contents, inhibited lipid peroxidation, showed radical scavenging and iron-chelating activities. Therefore, the leaves of the plant could be considered as a significant natural antioxidant source.     

Antioxidant phenolic compounds from Smilax sebeana Miq.

Methanol extract and sub-fractions of Smilax sebeana rhizomes and roots were analyzed to evaluate the compounds involved in antioxidant activity. In all separated fractions of the different polarity solvents, ethyl acetate fraction showed the highest antioxidant activity and total phenolic content. This fraction was subjected to the sephadex LH-20 column and preparative HPLC for purification. Six phenolic compounds, chlorogenic acid (1), 4-formylphenol (2), epicatechin (3), cinchonain IIa (4), Ia (5) and Ib (6) were isolated and identified by spectroscopic analyses and further evaluated their potential antioxidant activities by DPPH and superoxide radical scavenging assays. Compared with synthetic antioxidant Trolox, except 4-formylphenol, the other isolated five compounds exhibited excellent antioxidant activities. This is the first report on the chemical constituents of S. sebeana which potentially involved in antioxidant activity. The results suggest that the ethyl acetate extract of S. sebeana might be used as a readily accessible source of natural antioxidant.     

Antioxidant and chelating activity of Jatropha curcas L. protein hydrolysates

BACKGROUND: Antioxidant and chelating activities were determined in protein hydrolysates that were produced by treating a protein isolate of a non‐toxic genotype of Jatropha curcas with the protease preparation alcalase. RESULTS: 50 min protein hydrolysate with a degree of hydrolysis of 31.7% showed highest antioxidant and chelating activity. These activities were also determined in six peptidic fractions that were separated by gel filtration chromatography of the 50 min hydrolysate. The lower‐molecular‐weight peptidic fractions had the highest antioxidant and chelating activities, which correlated with a higher content in antioxidant and chelating amino acids such as tyrosine and histidine. CONCLUSION: Results show that J. curcas represents a good source of bioactive peptides. This may be important for the revalorization of defatted J. curcas flour, a by‐product resulting form oil extraction for biodiesel production. This is especially important in Third World and developing countries such as Mexico. Copyright © 2011 Society of Chemical Industry     

超声波-酶法提取紫甘蓝花青素条件优化及其抗氧化和消化酶抑制活性研究

目的 优化超声波-酶法提取紫甘蓝花青素条件, 研究纯化紫甘蓝花青素提取物体外抗氧化活性、体外消化酶抑制活性。方法 以紫甘蓝粉末为原料, 采用pH示差法测定花青素提取量, 研究料液比、果胶酶添加量、酶解温度和提取时间对提取量的影响, 通过正交试验优化花青素提取条件。采用AB-8大孔树脂纯化紫甘蓝花青素粗提物, 以维生素C为对照, 评价纯化紫甘蓝花青素提取物对DPPH·、ABTS+·、·OH的清除能力, 以阿卡波糖为对照, 研究纯化紫甘蓝花青素提取物体外抑制α-葡萄糖苷酶和α-淀粉酶的能力。结果 紫甘蓝花青素最佳提取工艺是料液比1:40 (g:mL)、果胶酶添加量4 mg/g、酶解温度40℃, 提取时间10 min, 花青素提取量为(5.15±0.03) mg/g; 纯化紫甘蓝花青素提取物对ABTS+·清除能力与维生素C相当, DPPH·和·OH清除能力略低于维生素C; 纯化紫甘蓝花青素提取物对α-葡萄糖苷酶的半抑制浓度(half maximal inhibitory concentration, IC50)为(0.43±0.02) mg/mL, 对α-淀粉酶IC50为(9.17±0.34) mg/mL, 而阿卡波糖对α-葡萄糖苷酶的IC50为(0.02±0.00) μg/mL, 对α-淀粉酶的IC50为(8.83±0.27) μg/mL。结论 超声波-酶法可以有效提取紫甘蓝花青素, 纯化紫甘蓝花青素有优良的抗氧化活性, 具有一定的体外抑制消化酶能力, 研究结论可为紫甘蓝花青素在功能食品中的应用提供基础数据与参考。     

Proteins and trypsin inhibitor activity of guar (Cyamopsis tetragonoloba L. Taub) seed

Proteins soluble in tris-acetate buffer (pH9.0) were fractionated by DEAE-cellulose, DEAE-Sephadex A-50 and Sephadex G-200 column chromatography. The purified proteins which contained 5–6% carbohydrate, had molecular weights of 125 900 and 22 390 amu. The high molecular weight fraction was homogeneous by polyacrylamide gel electrophoresis. Proteins extracted in phosphate buffer (0.1M , pH7.6) when subjected to Sephadex G-200 gel chromatography were resolved into three fractions, all of which showed considerable trypsin inhibitor activity. Germination for 3 days reduced the trypsin inhibitor activity of the seed by about 30%.     

Molecular Characterization and Identification of Bioactive Peptides Producing Lactobacillus sps. Based on 16S rRNA Gene Sequencing

In the present study, 3 bacterial cultures were isolated from faecal samples of human infant. The biochemical traits showed similarity with Lactobacillus sps and 16S rRNA sequence analyses, confirmed as Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus rhamnosus. The cultures were screened for their proteolytic activity and good ability to release peptides from milk proteins was found. Hence, these bacteria were used as a proteolytic starter culture for the fermentation of skim milk and whey for the liberation of small peptides. Bioactive nature of the peptides released from whey and skim milk was tested, and results demonstrated that peptides obtained after fermentation of whey and skim milk by Lactobacillus strains showed antimicrobial activity against all the pathogens causing food borne infections in humans. These peptides also indicated antioxidant as well as ACE (angiotensin-converting enzymes) inhibitory activity.     

檀香叶提取物抗氧化及抗菌活性初步研究

研究檀香(Sandalwood)叶不同溶剂提取物的抗氧化及抗菌活性,为檀香叶资源开发利用提供依据。采用4种不同溶剂提取檀香叶中抗氧化、抗菌活性成分;采用清除DPPH自由基方法测定抗氧化活性,采用平板打孔法测定抗菌活性。结果表明:檀香叶80%乙醇、水、乙酸乙酯提取物可以清除DPPH自由基;80%乙醇提取物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌有抗菌作用,但对霉菌、啤酒酵母没有抑菌作用。乙醇提取物经不同温度、不同光照时间处理后,其抗氧化、抗菌活性较稳定。乙醇提取物经不同pH处理后,抗氧化物质在pH6～8范围内稳定,抗菌物质在pH3～7范围内稳定,碱性条件下不稳定。檀香叶乙醇提取物化学成分标识结果表明:檀香叶乙醇提取物中含有多糖、鞣质、黄酮类、酚类物、有机酸以及氨基酸、多肽、蛋白质等成分。结论:80%乙醇、水、乙酸乙酯提取物具有抗氧化活性,其中,80%乙醇提取物抗氧化活性最好。只有80%乙醇提取物具有抗菌活性。     

Radical scavenging activity and phenolic compounds in persimmon (Diospyros kaki L. cv. Mopan)

ABSTRACT:  The Mopan persimmon ( Diospyros kaki L. cv. Mopan) is the major cultivar of astringent persimmon in northern China. This study investigates the radical scavenging activity against ABTS and DPPH radical, and the content of total and individual phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) with apple, grape, and tomato as controls. The radical scavenging activities against ABTS and DPPH radicals of the Mopan persimmon are 23.575 and 22.597 μm trolox eq/g f.w., respectively. These findings suggest that the Mopan persimmon's antioxidant activity is significantly ( P < 0.05) stronger than that of reference materials. The Mopan persimmon showed the highest content of total phenolics among the 4 materials tested. Significant correlations ( R ²= 0.993, P < 0.05, ABTS radical; R ²= 0.980, P < 0.05, DPPH radical) are found between the total phenolics and the radical scavenging activities. The total content of these 6 kinds of phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) is significantly correlated ( R ²= 0.831, P < 0.05, ABTS radical; R ²= 0.745, P < 0.05, DPPH radical) with the individual radical scavenging activity of the 4 materials, although the total content of the 6 phenolics accounts for no more than 20% of the total phenolics in the Mopan persimmon. Gallic acid exhibits the strongest antioxidant activity in all 6 kinds of phenolics and its content is the largest in the Mopan persimmon, presumably being responsible for its much higher antioxidant activity as compared to apple, grape, and tomato.     

超高压处理对蛹虫草汁纤维素酶活性的影响

为了明确超高压加工技术对纤维素酶活性的影响,分别研究了压力、保压时间、温度、乙醇体积分数、加压次数和pH值等对蛹虫草汁中纤维素酶的羧甲基纤维素酶活性(CMC)和滤纸酶活(FPA)的影响。结果表明,纤维素酶的最适压力、保压时间、温度、乙醇体积分数、pH值和加压次数分别为:400MPa、10min、35℃、30%,pH4.0~7.0,加压1次,在最适条件下,CMC酶活比处理前分别提高了82.07%、52.41%、87.22%、54.48%、67.52%和66.67%;FPA酶活比处理前分别提高了97.37%、61.4%、69.4%、61.4%、1.31%和33.91%。因此,利用超高压处理能有效提高蛹虫草汁中的纤维素酶活性。     

姜黄提取物的抗氧化及抗菌活性研究

以猪油的过氧化物值为指标,抗氧化能力由强到弱依次为姜黄素类化合物〉姜黄素〉挥发油。挥发油的抗菌能力比较强,对大肠杆菌、枯草芽孢杆菌、青霉、酵母菌均有抑制作用;姜黄素类化合物只对青霉有抑制作用;姜黄素对四种菌均无抑制作用。     

Antioxidant and antimicrobial activity of Satureja montana L. extracts

BACKGROUND: This study aimed to evaluate the antioxidant and antimicrobial activity of extracts (aqueous, ethanolic and essential oil) from Satureja montana and to characterise the chemical composition of its essential oil. RESULTS: Satureja montana L. essential oil had relatively high antimicrobial activities against the seven species of bacteria tested. In contrast, aqueous extracts did not reveal antibacterial activity, and the ethanol extract was not effective against Salmonella typhimurium. The major volatile constituents of the essential oil were carvacrol (306 g L^?1), thymol (141 g L^?1), and carvacrol methyl ether (63 g L^?1). The strongest antioxidant capacity was obtained with the hot water extracts of S. montana, whereas the plant essential oil revealed the highest phenolic content. CONCLUSION: The findings indicate that the bioactive extracts of S. montana have strong potential for use as natural antimicrobials and antioxidants in the preservation of processed food. Copyright © 2011 Society of Chemical Industry     

Bioactivity evaluations of ingredients extracted from the flowers of Citrus aurantium L. var. amara Engl

Citrus aurantium L. var. amara Engl, a member of genus Citrus (Rutaceae), widespread in China, is used as folk medicine for the treatment of helping digest, phlegm, enteritidis, stomachic and other deceases. In the present research, silica gel column, Sephadex LH-20, mass spectrometer (MS) and nuclear magnetic resonance (NMR) were used to separate and identify the chemical compounds from the flowers of C. aurantium var. amara, and several bioactivity assays were used to evaluate their antioxidant, anti-inflammatory, anti-virus and antitumour activities. Two major compounds, 5-hydroxy-6,7,3′,4′-tetramethoxyflavone (HTF) and limonexic acid (LA), were isolated and identified from C. aurantium var. amara for the first time. The results of the bioactivity assays showed that HTF and LA displayed significant antioxidant activities and showed significant inhibition effects on the B16 cell lines at a concentration range from 6.25 to 50 μg/ml, and on the SMCC-7721 cell lines from 12.5 to 200 μg/ml. The antitumour effect, anti-inflammatory activity and the inhibiting expression of HBsAg and HBeAg of 2.2.15 cells displayed the tendency in a concentration-dependent manner. These two compounds from C. aurantium var. amara could potentially be used as a promising natural agent in the pharmaceutical industries.     

不同酸性条件对保加利亚乳杆茵存活性影响

探讨了pH值4.0～6.2范围内，酸度对保加利亚乳杆菌存活性影响，同时还探讨了不同酸味剂和盐酸对保加利亚乳杆菌存活性的影响。结果在保存培养基pH值为4.0时保加利亚乳杆菌存活率最高；乙酸、柠檬酸和乳酸等酸味剂调pH值4.0的胡萝卜汁保存保加利亚乳杆菌，结果对菌的存活均有影响，但乙酸影响较小；pH2.0～4.0的盐酸对存活都有影响，酸度越大存活率越低。