Extraction parameters and capillary electrophoresis analysis of limonin glucoside and phlorin in citrus byproducts.

Limonin glucoside (LG) and phlorin were extracted from citrus fruit tissues and assayed by capillary electrophoresis (CE). LG was determined in dried [1.20 +/- 0.10 mg of dry weight (dw)] and wet peel residues (1.16 +/- 0.04 mg of dw), orange juice finisher pulp (0.58 +/- 0.03 mg of dw), dried grapefruit seeds (2.70 +/- 0.15 mg of dw), and 50 degrees Brix molasses (2225 +/- 68 mg/L). Phlorin was purified from orange peel residue and grapefruit albedo, and concentrations were determined in some citrus products. Phlorin and LG were extracted from residues with water/pectinase or with water solutions of methanol and ethanol. Efficient LG extraction from grapefruit seeds (2.40 +/- 0.15 mg/g) was achieved with 50-65% methanol, solvent polarity P' approximately equal to 7-8. Extracts were purified and concentrated by adsorptive resins and HPLC to obtain 95% pure compounds of LG and phlorin. CE analysis did not require extract purification beyond filtration. LG and phlorin migrated as anions in electropherograms containing peaks representing other citrus flavonoids and limonoid glucosides.     

Determination of theaflavins including methylated theaflavins in black tea leaves by solid-phase extraction and HPLC analysis

A quantitative method for four theaflavins and two methylated theaflavin derivatives in black tea leaves was developed by solid-phase extraction and a high-performance liquid chromatographic method with photodiode array detection. The theaflavins in black tea leaves were extracted three times with 40 vol 50% aqueous ethanol (mg dry tea powder/mL) containing 2% ascorbic acid. The ethanol extracts were diluted 4-fold with distilled water. All diluted extracts were directly applied to the solid-phase C18 cartridge column without concentration. The fraction of theaflavins was obtained by 40% ethanol extraction after rinsing with water followed with 15% ethanol extraction. An aliquot of theaflavins after concentration was injected onto an ODS C18 reversed-phase column, and four theaflavins and two methylated theaflavins were sufficiently separated by a linear gradient system using distilled water and acetonitrile with 0.5% acetic acid. This analytical method is sensitive for the determination of a small amount of methylated theaflavins, since various interfering substances produced during the fermentation process were eliminated in advance by solid-phase extraction. Using this analytical method, we also demonstrated that methylated theaflavins were easily produced during the manufacture of black tea.     

Caffeic acid derivatives production by hairy root cultures of Echinacea purpurea

Inoculation of leaf explants of Echinacea purpurea (Moench) with Agrobacterium rhizogenes induced hairy roots with the capacity to produce biologically active caffeic acid derivatives (CADs), especially cichoric acid. The kinetics of growth, the uptake of macronutrients, and the accumulation of CADs were investigated in heterotrophically cultured hairy roots for a 50 day period. A maximum of 12.2 g L(-1) dry biomass was achieved in MS nutrients supplemented with 30 g L(-1) sucrose on day 40. The mathematical relationship between hairy root growth and conductivity was established during the exponential phase in Erlenmeyer flasks. HPLC analyses of methanolic (0.1% phosphoric acid; 70:30, v/v) extracts from hairy roots revealed the presence of important CADs: cichoric acid (19.21 mg g(-1) dry biomass), caftaric acid (3.56 mg g(-1) dry biomass), and chlorogenic acid (0.93 mg g(-1) dry biomass). These results demonstrate that biotechnological production of CADs in hairy roots of E. purpurea is possible. Furthermore, these hairy root cultures offer, for the very first time, an excellent biological model to study the biosynthetic pathway of medicinally important CADs.     

Total Phenolics and Antioxidant Activity of Water and Ethanolic Extracts from Distillers Dried Grains with Solubles With or Without Microwave Irradiation

The purpose of this study was to determine the efficacy of extracting phenolic compounds with antioxidant activity from distillers' dried grains with solubles (DDGS) with water, 50% aqueous ethanol, and absolute ethanol, using microwave irradiation or a water bath at various temperatures. DDGS was extracted for 15 min with each solvent while heating at 23, 50, 100, and 150°C by microwave irradiation or in a water bath at 23, 50, and 100°C. Phenolic content of extracts increased with increasing temperature to a maximum of 12.02 mg/g in DDGS extracts that were microwave irradiated in water or with 50% aqueous ethanol at 150°C. Antioxidant activity range was 1.49–6.53 μmol of Trolox equivalents/g of DDGS. Highest antioxidant activities were obtained from 50% aqueous ethanol extracts at all temperatures, and water extracts that were heated at 100 and 150°C. These data indicate that DDGS extracts with high phenolic content and antioxidant activity can be obtained from DDGS, particularly with the use of water or 50% ethanol and high temperature (100 or 150°C). This may be valuable to ethanol manufacturers, livestock producers, and food and nutraceutical companies.     

Antioxidant and antiradical activities in extracts of hazelnut kernel (Corylus avellana L.) and hazelnut green leafy cover

Phenolic compounds in the aqueous systems were extracted, from hazelnut kernel (HK) and hazelnut green leafy cover (HGLC), with 80% (v/v) ethanol (HKe and HGLCe) or 80% (v/v) acetone (HKa and HGLCa). The extracts were examined for their phenolic and condensed tannin contents and phenolic acid profiles (free and esterified fractions) as well as antioxidant and antiradical activities by total antioxidant activity (TAA), antioxidant activity in a beta-carotene-linoleate model system, scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, and reducing power. Significant differences (p < 0.05) in the contents of total phenolics, condensed tannins, and TAA existed among the extracts that were examined. HGLCa extract had the highest content of total phenolics (201 mg of catechin equivalents/g of extract), condensed tannins (542 mg of catechin equivalents/g of extract), and TAA (1.29 mmol of Trolox equivalents/g of extract) followed by HGLCe, HKa, and HKe extracts, respectively. Five phenolic acids (gallic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid) were tentatively identified and quantified, among which gallic acid was the most abundant in both free and esterified forms. The order of antioxidant activity in a beta-carotene-linoleate model system, the scavenging effect on DPPH radical, and the reducing power in all extracts were in the following order: HGLCa > HGLCe > HKa > HKe. These results suggest that both 80% ethanol and acetone are capable of extracting phenolics, but 80% acetone was a more effective solvent for the extraction process. HGLC exhibited stronger antioxidant and antiradical activities than HK itself in both extracts and could potentially be considered as an inexpensive source of natural antioxidants.     

Determination of antioxidant and antimicrobial activities of Rumex crispus L. extracts

The antioxidant activities, reducing powers, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities, amount of total phenolic compounds, and antimicrobial activities of ether, ethanol, and hot water extracts of the leaves and seeds of Rumex crispus L. were studied. The antioxidant activities of extracts increase with increasing amount of extracts (50-150 microg). However, the water extracts of both the leaves and seeds have shown the highest antioxidant activities. Thus, addition of 75 microg of each of the above extracts to the linoleic acid emulsion caused the inhibition of peroxide formation by 96 and 94%, respectively. Although the antioxidant activity of the ethanol extract of seed was lower than the water extract, the difference between these was not statistically significant, P > 0.05. Unlike the other extracts, 75 microg of the ether extract of seeds was unable to show statistically significant antioxidant activity, P > 0.05 (between this extract and control in that there is no extract in the test sample). Among all of the extracts, the highest amount of total phenolic compound was found in the ethanol extract of seeds, whereas the lowest amount was found in the ether extract of seeds. Like phenolic compounds, the highest reducing power and the highest DPPH scavenging activity were found in the ethanol extract of seeds. However, the reducing activity of the ethanol extract of seeds was approximately 40% that of ascorbic acid, whereas in the presence of 400 microg of water and ethanol extracts of seeds scavenging activities were about 85 and 90%, respectively. There were statistically significant correlations between amount of phenolic compounds and reducing power and between amount of phenolic compounds and percent DPPH scavenging activities (r = 0.99, P < 0.01, and r = 0.864, P < 0.05, respectively) and also between reducing powers and percent DPPH scavenging activities (r = 0.892, P < 0.05). The ether extracts of both the leaves and seeds and ethanol extract of leaves had shown antimicrobial activities on Staphylococcus aureus and Bacillus subtilis. However, none of the water extracts showed antimicrobial activity on the studied microorganisms.     

小叶女贞果实花青素组分鉴定及色谱纯化技术

为提高小叶女贞果实的食用、药用价值,该文系统研究了果实中花青素种类构成及提取物的制备技术。试验采用紫外可见光谱法、高效液相色谱-质谱串联法、酸水解制备苷元等技术对小叶女贞果实花青素含量、单体种类进行了测定,并借助提取、萃取、柱层析等技术研究了花青素提取物的分离纯化过程。研究结果如下:测得每100 g小叶女贞果实中含花青素总量为(499±18.42)mg,从中鉴定出2种花青素单体,分别为矢车菊素-3-O-葡萄糖苷和牵牛花色素-3-O-葡萄糖苷,并以后者为主要存在形式;获得了纯天然、简单易行的花青素提取物制备技术,主要包括酸化乙醇提取、乙酸乙脂萃取、Amberlite XAD-7HP大孔树脂层析分离步骤,最终制得的花青素提取物纯度为35%、得率为0.6%。该研究为后期制备高纯度牵牛花素-3-O-葡萄糖苷单体提供了良好原料基础,为深入研究小叶女贞果实花青素功能活性及其在食品、药品领域潜在应用提供了参考。     

Antioxidant and antiproliferative activities of Spirulina and Chlorella water extracts

Liver fibrosis is a chronic liver disease that will further develop to cirrhosis if severe damage continues to form. A potential treatment for liver fibrosis is to inhibit activated hepatic stellate cell (HSC) proliferation and, subsequently, to induce HSC apoptosis. It has been reported that antioxidants are able to inhibit the proliferation of HSCs. In this study, the aqueous extract of spirulina was chosen as the source of antioxidant to investigate the inhibitory effect on the proliferation of HSC. The growth inhibitory effects of aqueous spirulina and chlorella extract on human liver cancer cells, HepG2, were also studied and compared in pairs. Results indicated that the total phenol content of spirulina was almost five times greater than that of chlorella (6.86 +/- 0.58 vs 1.44 +/- 0.04 mg tannic acid equivalent/g of algae powder, respectively). The antioxidant activity of spirulina determined by the ABTS*+ method was higher than chlorella (EC50: 72.44 +/- 0.24 micromol of trolox equivalent/g of spirulina extract vs 56.09 +/- 1.99 micromol of trolox equivalent/g of chlorella extract). Results of DPPH* assay also showed a similar trend as the ABTS*+ assay (EC50: 19.39 +/- 0.65 micromol of ascorbic acid equivalent/g of spirulina extract vs 14.04 +/- 1.06 micromol of ascorbic acid equivalent/g of chlorella extract). The aqueous extracts of these two algae both showed antiproliferative effects on HSC and HepG2, but spirulina was a stronger inhibitor than chlorella. Annexin-V staining showed that aqueous extract of spirulina induced apoptosis of HSC after 12 h of treatment. In addition, the aqueous extract of spirulina triggered a cell cycle arrest of HSC at the G2/M phase.     

Antioxidant activity of indigenous edible mushrooms

The current study was undertaken to measure the antioxidant potential from water and methanolic extracts of fruiting bodies of 23 species of mushrooms naturally grown in different geographic locations of India. The antioxidant ability of each species was analyzed for the total antioxidative status, employing multimechanistic antioxidative assays such as inhibition of lipid peroxidation, determination of reducing power, and free radical scavenging ability, in addition to determination of total phenolics and identification of phenolic acids by HPLC analysis, because the phenolics are known to contribute largely to antioxidant potential. The antioxidant potential of these varieties of mushrooms was determined by summing the antioxidative activity (AOA) of each variety by varied antioxidant assays followed by determining the relative percent of AOA defined as the "antioxidant index" (AI). On the basis of the AI, the mushroom species were graded as very high, high, moderate, and low. Termitomyces heimii was identified as the best variety, which showed 100% AI with 37 mg of phenolics/g of sample, 418 units of reducing power ability (RPA)/g, and an IC50 of approximately 1.1 mg (dry weight)/mL, free radical scavenging activity (FRS) in the water extract followed by 11.2 mg of phenolics/g, 275 units of RPA/g, and an IC50 of approximately 2.7 mg (dry weight)/mL of FRS in the methanolic extract. Following T. heimii, Termitomyces mummiformis exhibited an AI of 86% within the "very high" group. Potent inhibitions of lipid peroxidation of approximately 100 and 69% was also observed in T. heimii and T. mummiformis, respectively. Water extracts ranged from 34 to 49% and methanolic extracts varied from 20 to 32% on dry weight of mushroom fruiting body. Total phenolic compounds were higher in the water extracts (2-37 mg/g) than in methanolic extract (0.7-11.2 mg/g). The AOA measured in the water extract was better than that from the methanolic extract. HPLC analysis of phenolic acids in the two mushroom species, namely, T. heimii and T. mummiformis, displaying maximum AOA potential indicated a preponderance of tannic acid, gallic acid, protocatacheuic acid, and gentisic acid. Studies thus provide the precise antioxidant status of 23 indigenous species of mushrooms, which can serve as a useful database for the selection of mushrooms for the function of preparation of mushroom-based nutraceutics.     

Solvent Extraction of Zein from Dry‐Milled Corn

Batch extraction of zein from dry‐milled whole corn with ethanol was optimum with 70% ethanol in water, an extraction time of 30–40 min, and temperature of 50°C. High yields (60% of the zein in corn) and high zein contents in the extracted solids (50%) were obtained at a solvent‐to‐solids ratio of 8 mL of 70% ethanol/g of corn. However, zein concentration in the extract was higher at lower ratios. Multiple extraction of the same corn with fresh ethanol resulted in a yield of 85% after four extractions, whereas multiple extractions of fresh corn with the same ethanol resulted in high (15 g/L) zein concentration in the extract. Optimum conditions for batch extraction of zein were 45°C, with 68% ethanol at a solvent‐to‐solids ratio of 7.8 mL/g for an extraction time of 55 min. Column extractions were also best at 50°C and 70% ethanol; a solvent ratio of 1 mL/g resulted in high zein concentrations in the extract (17 g/L) but yields were low (20%).     

Antioxidant potential of two red seaweeds from the Brazilian coasts

In this work, in vitro antioxidant activity of two Brazilian red seaweeds, Gracilaria birdiae and Gracilaria cornea, was characterized. The total phenolic content, the radical-scavenging activity and the antioxidant activity were determined in two solvent extracts of the algae. Liquid chromatography-mass spectrometry (LC-MS/MS) allowed identification of important antioxidant compounds. The ethanol extract of G. birdiae was found to have the highest value of total phenolic content: 1.13 mg of gallic acid equiv (GAE)/g of extract. The radical-scavenging activity of G. birdiae and G. cornea extracts has been evaluated at different extract concentrations; the IC(50) values of ethanolic extracts of G. cornea and G. birdiae were 0.77 and 0.76 mg mL(-1), respectively, while for methanolic extracts, the IC(50) values of G. cornea and G. birdiae were 0.86 and 0.76 mg mL(-1), respectively. The antioxidant activities of these two seaweeds' extracts as assessed by the β-carotene-linoleic acid assay were equally high, achieving values of β-carotene oxidation inhibition of up to 40%. Finally, in the methanolic extracts, LC-MS/MS allowed identification in both algae of two important antioxidants: apigenin and gallic acid.     

Phytosterol and tocopherol components in extracts of corn distiller's dried grain

As the ethanol industry continues to grow, it will become very important to develop value-added markets for its coproducts in order for the industry to remain profitable. Corn distiller's dried grain (DDG) is a major coproduct of ethanol fermentation from corn processed by dry-milling and is primarily sold as livestock feed. The objective of this research was to determine if valuable phytochemicals found in corn oil and corn fiber oil, such as phytosterols and their saturated equivalents, phytostanols, ferulate phytosterol esters (FPE), tocopherols, and tocotrienols, are retained in DDG. Hexane and supercritical carbon dioxide (CO2) extracts of DDG were similar in their concentrations of total phytosterols (15.8-17.3 mg/g of extract), FPE (3.75-3.99 mg/g of extract), and tocols (1.7-1.8 mg/g of extract). Ethanol extracts were slightly lower in concentration of phytosterols (8.9-11.4 mg/g of extract), FPE (1.62-1.98 mg/g of extract), and tocols (0.73-0.76 mg/g of extract).     

Red wine polyphenols alone or in association with ethanol prevent hypertension, cardiac hypertrophy, and production of reactive oxygen species in the insulin-resistant fructose-fed rat

The effects of a red wine polyphenolic extract (RWPE), ethanol, or both combined were evaluated in insulin resistant rats. Rats were fed for 6 weeks with fructose (60%)-enriched food and force-fed with (a) water only (F group), (b) aqueous solution of RWPE (100 mg/kg, FP group), (c) 10% (v/v) mixture of ethanol and water (FE group), or (d) solution containing the same amount of the RWPE and ethanol (FPE group). Animals fed a standard chow (C group) were used for comparison purpose. After 6 weeks, blood pressure was higher in F (130.0 x b1 1.7 mm Hg) than in C animals (109.6 x b1 0.9 mm Hg) and similar to the C group in all other fructose-fed treatment groups. Relative heart weight was higher in F (3.10 x b1 0.05) than in C (2.78 x b1 0.07) and significantly lower in FP (2.92 x b1 0.04) and FPE (2.87 x b1 0.08 mg/g) than in F animals. Left ventricle and aorta productions of reactive oxygen species (O2*-) were higher in F than in C groups and lowered by the RWPE but not by the ethanol treatment. Ethanol but not the RWPE treatment reduced the degree of insulin resistance in the fructose-fed rats. In summary, our study showed that polyphenols are able to prevent cardiac hypertrophy and production of reactive oxygen species in the insulin resistant fructose-fed rat.     

扁蓿豆水浸提液对其种子萌发自毒作用研究

为了明确扁蓿豆是否存在自毒效应，以期为扁蓿豆科学种植提供理论依据。以扁蓿豆种子为受体，采用室内培养皿种子萌发方法，研究了不同质量浓度(0、0.001、0.025、0.050、0.100 g/mL)扁蓿豆(Medicago ruthenica)地上部分和地下部分水浸提液的自毒作用。结果表明，扁蓿豆植株地上部分与根部水浸提液对其种子发芽率、发芽势、发芽指数、胚根长、胚芽长和单株鲜质量具有一定的抑制作用，总体表现为在质量浓度0.100g/mL下抑制作用最强。扁蓿豆地上部分水浸提液处理在0.100 g/mL质量浓度下发芽率较对照蒸馏水显著降低了39.00%(P < 0.05)，种子发芽指数较对照蒸馏水降低了82.00%；根部水浸提液在0.100 g/mL质量浓度下胚根长较对照蒸馏水显著降低了50.00%。各指标的化感效应指数与质量浓度均呈负相关。     

Microbially safe utilization of non-inactivated oats (Avena sativa L.) for production of conjugated linoleic acid

A microbially safe process for the enrichment of conjugated linoleic acid (CLA) in oats was developed. The process consists of hydrolysis of oat lipids by non-inactivated oat flour, followed by propionibacterium-catalyzed isomerization of the resulting free linoleic acid to CLA. The first stage was performed at water activity (a(w)) 0.7, where hydrolysis of triacylglycerols progressed efficiently without growth of the indigenous microflora of flour. Thereafter, the flour was incubated as a 5% (w/v) aqueous, sterilized slurry with Propionibacterium freudenreichii ssp. shermanii. The amount of CLA produced in 20 h was 11.5 mg/g dry matter corresponding to 116 mg/g lipids or 0.57 mg/mL slurry. The oat flour had also the capability to hydrolyze exogenous oils at a(w) 0.7. Sunflower oil, added to increase linoleic acid content in triacylglycerols 2.7-fold, was hydrolyzed rapidly. Isomerization of this oil-supplemented flour as a 5% slurry gave final CLA content of 22.3 mg/g dry matter after 50 h of fermentation, corresponding to 118 mg/g lipids or 1.14 mg/mL slurry. Storage stability of CLA in fermented oat slurries at 4 degrees C was good.     

Simultaneous Determination of Furostanol, Pennogenyl, and Diosgenyl Glycosides in Taiwanese Rhizoma Paridis ( Paris formosana Hayata) by high-performance liquid chromatography with evaporative light scattering detection

A high-performance liquid chromatographic method with an evaporative light scattering detector (HPLC-ELSD) was developed to simultaneously determine 10 steroidal saponins, including 3 furostanol glycosides, 3 pennogenyl glycosides, and 4 diosgenyl glycosides in Taiwanese rhizoma paridis ( Paris formosana Hayata). The condition was a Cosmosil C18 column kept at 35 °C and a step-gradient solvent system consisting of acetonitrile and water (25:75, v/v) in the first 30 min, 45:55 (v/v) from 31 to 45 min, and 50:50 (v/v) from 45 to 65 min, at a flow rate of 1 mL/min. The separation factors (α) and resolutions (Rs) were better than 1, and the limits of detection (LODs) and limits of quantification (LOQs) were 0.01-0.27 and 0.04-0.90 μg, respectively, for these saponins. Moreover, 203 nm UV detection was also used for comparison. The saponins in P. formosana Hayata gathered from various areas of Taiwan were determined by applying the established method.     

Valorization of cauliflower (Brassica oleracea L. var. botrytis) by-products as a source of antioxidant phenolics

The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH(*) and ABTS(*)(+) radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.     

Antioxidant and antiproliferative activities of raspberries

Raspberries are rich in phenolic phytochemicals. To study the health benefits of raspberries, four fresh raspberry varieties (Heritage, Kiwigold, Goldie, and Anne) were evaluated for total antioxidant and antiproliferative activities. The total amount of phenolics and flavonoids for each of the four raspberry varieties was determined. The Heritage raspberry variety had the highest total phenolic content (512.7 +/- 4.7 mg/100 g of raspberry) of the varieties measured followed by Kiwigold (451.1 +/- 4.5 mg/100 g of raspberry), Goldie (427.5 +/- 7.5 mg/100 g of raspberry), and Anne (359.2 +/- 3.4 mg/100 g of raspberry). Similarly, the Heritage raspberry variety contained the highest total flavonoids (103.4 +/- 2.0 mg/100 g of raspberry) of the varieties tested, followed by Kiwigold (87.3 +/- 1.8 mg/100 g of raspberry), Goldie (84.2 +/- 1.8 mg/100 g of raspberry), and Anne (63.5 +/- 0.7 mg/100 g of raspberry). The color of the raspberry juice correlated well to the total phenolic, flavonoid, and anthocyanin contents of the raspberry. Heritage had the highest a/b ratio and the darkest colored juice, and the Anne variety showed the lowest phytochemical content and the palest color. Heritage raspberry variety had the highest total antioxidant activity, followed by Kiwigold and Goldie, and the Anne raspberry variety had the lowest antioxidant activity of the varieties tested. The proliferation of HepG(2) human liver cancer cells was significantly inhibited in a dose-dependent manner after exposure to the raspberry extracts. The extract equivalent to 50 mg of Goldie, Heritage, and Kiwigold fruit inhibited the proliferation of those cells by 89.4 +/- 0.1, 88 +/- 0.2, and 87.6 +/- 1.0%, respectively. Anne had the lowest antiproliferative activity of the varieties measured but still exhibited a significant inhibition of 70.3+/- 1.2% with an extract equivalent to 50 mg of fruit. The antioxidant activity of the raspberry was directly related to the total amount of phenolics and flavonoids found in the raspberry (p < 0.01). No relationship was found between antiproliferative activity and the total amount of phenolics/flavonoids found in the same raspberry (p > 0.05).     

Antioxidant capacity and cytotoxicity of essential oil and methanol extract of Aniba canelilla (H.B.K.) Mez

The leaves and fine stems, bark, and trunk wood oils of Aniba canelilla showed yields ranging from 0.2 to 1.3%. The main volatile constituent identified in the oils was 1-nitro -2-phenylethane (70.2-92.1%), as expected. The mean of DPPH radical scavenging activity (EC 50) of the oils (198.17 +/- 1.95 microg mL(-1)) was low in comparison with that of wood methanol extracts (4.41 +/- 0.12 microg mL(-1)), the value of which was equivalent to that of Trolox (4.67 +/- 0.35 microg mL(-1)), used as antioxidant standard. The mean amount of total phenolics (TP) (710.53 +/- 23.16 mg of GAE/g) and this value calculated as Trolox equivalent antioxidant capacity (TEAC) (899.50 +/- 6.50 mg of TE/g) of the wood methanol extracts confirmed the high antioxidant activity of the species. On the other hand, in the brine shrimp bioassay the values of lethal concentration (LC50) for the oils (21.61 +/- 1.21 microg mL(-1)) and 1-nitro-2-phenylethane (20.37 +/- 0.99 microg mL(-1)) were lower than that of the wood methanol extracts (91.38 +/- 7.20 microg mL(-1)), showing significant biological activities.     

芥菜浸提液对豇豆连作土壤性质及幼苗生理指标的影响

为探究芥菜浸提液对豇豆种子发芽和连作下豇豆早期幼苗生长影响的生理机制,在盆栽条件下,研究不同浓度(0、10、20、40 g·L^-1)的芥菜浸提液对豇豆种子萌发及5年连作条件下豇豆幼苗生长指标、根系形态指标、叶片保护酶活性和土壤性质的影响。结果表明,高浓度(40 g·L^-1)芥菜浸提液对种子萌发和胚根生长有强烈的抑制作用,其中发芽率、活力指数、胚根长度和数量分别显著降低85.70%、82.66%、36.15%和46.54%;而低浓度(10 g·L^-1)芥菜浸提液对种子胚根生长有显著的促进作用,其中胚根长度和数量分别显著提高44.84%和80.82%。豇豆连作土壤浇灌芥菜水浸提液可不同程度地增加豇豆幼苗株高、茎粗、干质量、鲜质量和壮苗指数,在低浓度处理下豇豆生长指标分别显著增加60.33%、12.24%、85.87%、77.31%和50.82%;此外,豇豆幼苗根长度、根系表面积、根体积、根尖数等根系指标也均有不同程度地增加,其中以低浓度浸提液处理下的豇豆幼苗综合指标最好。芥菜浸提液处理还能促进幼苗叶片过氧化氢(H₂O₂)含量升高、以及抗氧化酶活性的提升,其中H₂O₂含量,过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和脱氢抗坏血酸还原酶(DHAR)活性均随着芥菜浸提液浓度的增加而降低,过氧化物酶(POD)活性则相反,而谷胱甘肽还原酶(GR)活性未表现出明显的规律;芥菜浸提液还可以提高土壤pH值,降低土壤电导率,以及提高土壤酶活性,其中蔗糖酶和酸性磷酸酶活性随着芥菜浸提液浓度的增加而升高。综上所述,不同浓度芥菜浸提液对豇豆种子萌发起着低促高抑的作用,芥菜与豇豆之间存在明显的化感作用;芥菜浸提液可通过提高豇豆幼苗的抗氧化酶活性和改善豇豆根系环境,促进豇豆幼苗生长,缓解连作障碍对豇豆幼苗的危害,从而提高豇豆幼苗的抗逆能力。本研究结果为缓解豇豆连作障碍提供了新的途径。