超声法提取山里红叶总黄酮及其抗氧化活性研究

采用超声辅助提取法从山里红叶中提取总黄酮。通过Box Behnken实验设计(BBD)结合响应面法(RSM)来优化超声提取的条件。影响山里红叶总黄酮提取效率的4个主要变量为液固比,温度,乙醇浓度和时间,得到的最佳值分别为15,40℃,40%,32 min。在此条件下,总黄酮的产率为15.50 mg·g^-1。体外抗氧化实验表明,山里红叶提取物的DPPH自由基清除能力为0.69 mg·mL^-1(以IC₅₀值表示) ,与传统的浸渍提取和热回流提取方法相比,超声提取的方法具有更好的抗氧化活性。实验结果表明超声提取法适用于提取山里红叶中的总黄酮,并且其提取物具有较好的抗氧化活性。     

Response Surface Methodology-Based Optimized Ultrasonic-Assisted Extraction and Characterization of Selected High-Value Components from Gemlik Olive Fruit

This article presents an optimized ultrasound-assisted ethanolic extraction (UAEE) and characterization of selected high-value components from Gemlik olive fruit (GOF) harvested from Potohar region of Pakistan. Response surface methodology (RSM), involving central composite design (CCD), was applied to optimize the extraction variables i. e., temperature (25–65 °C), extraction time (15–45 min) and aqueous ethanol concentration (60–90 %) for optimal recovery of bioactives extract, total phenolic contents (TPC) and DPPH free radical scavengers. Under the optimized set of conditions such as 43 °C temperature, 32 min extraction time and 80 % aqueous ethanol, the best extract yield (218.82 mg/g), TPC (19.87 mg GAE/g) and DPPH scavenging activity (63.04 %) were recorded. A quadratic polynomial model was found to be reasonably fitted to the observed results for extract yield (p<0.0001 and R²=0.9941), TPC (p<0.0001 and R²=0.9891), and DPPH radical scavenging activity (p<0.0001 and R²=0.9692). Potent phenolic compounds were identified by GC/MS in GOF extract and considerable amount of essential fatty acids were also detected. The current findings support the use of UAEE as an effective green route for optimized recovery of high-value components from GOF and hence its applications can be extended to functional food and nutra-pharmaceutical developments.     

Preparation and antioxidant property of extract and semipurified fractions of Caulerpa racemosa

A microwave-assisted extraction method has been developed for the extraction of phenolic compounds from the green alga, Caulerpa racemosa. An L₁₈(3)⁵ orthogonal experimental array was designed to optimize the extraction conditions. Total phenolic content was determined by Folin–Ciocalteu method. Under the optimized conditions (microwave power, 200?W; ethanol concentration, 60%; extraction time, 40?min; extraction temperature, 50°C; solvent-to-material ratio, 40?mL?g^?1), the maximum total phenolic content reached 67.89?±?3.88?mg 100?g^?1 dried sample. The crude ethanolic extract was further purified by liquid–liquid partition to afford two fractions, of which the ethyl acetate-soluble fraction (EAF) exhibited the strongest antioxidant activity in the hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays and reducing power. EAF was further divided into four subfractions, designated as EAF1 to EAF4, by silica gel vacuum liquid chromatography. The antioxidant capacity of the subfractions was in the following order: EAF1>EAF2>EAF4>EAF3. The results of IR spectral and HPLC analysis, including the research on the correlation between antioxidant capacity and total phenolic content, suggested that phenolic compounds of medium polarity were the major contributors to the antioxidative activity of C. racemosa. The present findings might contribute to a rational basis for the use of phenolic-rich fractions and subfractions as natural antioxidants in different food/pharmaceutical products.     

响应面分析法优化超声波辅助酶法提取南五味子多糖工艺的研究

为了建立超声波辅助酶法提取南五味子多糖的方法,并研究其提取工艺。按照Box-Benhnken中心组合试验设计原理,以多糖得率为响应值,以单因素实验数据为基础,进行响应面分析实验,考察提取pH、提取温度和提取时间对多糖得率的影响。结果显示：最佳提取工艺条件为：提取pH为4.8、提取温度57℃、提取时间66 min、复合酶用量为3.0%,最佳工艺条件下南五味子多糖得率为8.73%±0.25%。研究结果表明,该提取方法可减少多糖提取时间和提取溶剂用量,降低温度,有效提高了多糖的提取得率,可应用于南五味子多糖的制备。研究结果为南五味子多糖的开发应用提供了较好的依据。     

Optimization of ultrasound-assisted aqueous two-phase system extraction of polyphenolic compounds from Aronia melanocarpa pomace by response surface methodology

Aronia melanocarpa berries are abundant in polyphenolic compounds. After juice production, the pomace of pressed berries still contains a substantial amount of polyphenolic compounds. For efficient utilization of A. melanocarpa berries and the enhancement of polyphenolic compound yields in Aronia melanocarpa pomace (AMP), total phenolics (TP) and total flavonoids (TF) from AMP were extracted, using ultrasound-assisted aqueous two-phase system (UAE-ATPS) extraction method. First, the influences of ammonium sulfate concentration, ethanol–water ratio, ultrasonic time, and ultrasonic power on TP and TF yields were investigated. On this basis, process variables such as ammonium sulfate concentration (0.30–0.35?g?mL^?1), ethanol–water ratio (0.6–0.8), ultrasonic time (40–60?min), and ultrasonic power (175–225?W) were further optimized by implementing Box–Benhnken design with response surface methodology. The experimental results showed that optimal extraction conditions of TP from AMP were as follows: ammonium sulfate concentration of 0.324?g?mL^?1, ethanol–water ratio of 0.69, ultrasonic time of 52?min, and ultrasonic power of 200?W. Meanwhile, ammonium sulfate concentration of 0.320?g?mL^?1, ethanol–water ratio of 0.71, ultrasonic time of 50?min, and ultrasonic power of 200?W were determined as optimum extraction conditions of TF in AMP. Experimental validation was performed, where TP and TF yields reached 68.15?±?1.04 and 11.67?±?0.63?mg?g^?1, respectively. Close agreement was found between experimental and predicted values. Overall, the present results demonstrated that ultrasound-assisted aqueous two-phase system extraction method was successfully used to extract total phenolics and flavonoids in A. melanocarpa pomace.     

Extraction of total phenolic content from Azadirachta indica or (neem) leaves: Kinetics study

The objective of this work is to put forth the optimization and kinetics of total phenolic compounds extraction from Azadirachta indica leaves in a stirred batch extraction. Various experiential extraction parameters have been studied for maximum extraction of the total phenolic compounds. The maximum yield of total phenolic compounds was found to be 10.80?mg?g^?1 of dried neem powder under the optimized conditions. The extraction kinetics behavior followed first-order kinetics with diffusion coefficient ranged from 1.8?×?10^?12 to 3.2?×?10^?12?m² s^?1 for all sets. Activation energy (E_a) value for the extraction of the total phenolic compounds was found to be 22.87?kJ?mol^?1. The kinetic expression model developed by Spiro and Siddique showed a good agreement with the experimental outcomes. The obtained results can be used to scale up the operations for industrial purposes.     

Optimization of the Cellulase−Ultrasonic Synergistic Extraction Conditions of Polysaccharides from Lenzites betulina

Lenzites betulina has been recognized as a rich source of chemical components, including polysaccharides, sterides and sugar alcohols. In this study, cellulase?ultrasonic synergistic extraction method was applied to extract polysaccharides from L. betulina, and the response surface methodology was used to optimize the extraction conditions. The eight basic factors affecting extraction yield were evaluated by Plackett?Burman design (PBD). Then, the four important factors significantly affecting the yield of polysaccharides from L. betulina, including enzymolysis temperature, enzymolysis time, ultrasound time and ultrasound temperature, were optimized by Box?Behnken design (BBD). Maximum extraction yield of L. betulina polysaccharides was 13.64±0.09 % at a cellulase dosage of 0.8 %, enzymolysis temperature of 60 °C, enzymolysis time of 180 min, pH of 4.5, liquid‐solid ratio of 45 ml/g, ultrasound power of 300 W, ultrasound time of 20 min and ultrasound temperature of 45 °C. Subsequently, the characteristic structure of crude polysaccharides was determined by FT‐IR. Results indicated that cellulase?ultrasonic synergistic treatment is suitable for L. betulina polysaccharides extraction, and it has good prospect for development and utilization.     

Motif‐based search for a novel fructosyl peptide oxidase from genome databases

The measurement of glycated hemoglobin A1c (HbA1c) has important implications for diagnosis of diabetes and assessment of treatment effectiveness. We proposed specific sequence motifs to identify enzymes that oxidize glycated compounds from genome database searches. The gene encoding a putative fructosyl amino acid oxidase was found in the Phaeosphaeria nodorum SN15 genome and successfully expressed in Escherichia coli. The recombinant protein (XP_001798711) was confirmed to be a novel fructosyl peptide oxidase (FPOX) with high specificity for α‐glycated compounds, such as HbA1c model compounds fructosyl‐^αN‐valine (f‐^αVal) and fructosyl‐^αN‐valyl‐histidine (f‐^αVal‐His). Unlike previously reported FPOXs, the P. nodorum FPOX has a K_m value for f‐^αVal‐His (0.185 mM) that is considerably lower than that for f‐^αVal (0.458 mM). Based on amino acid sequence alignment, three dimensional structural modeling, and site‐directed mutagenesis, Gly60 was found to be a determining residue for the activity towards f‐^αVal‐His. A flexible surface loop region was also found to likely play an important role in accepting f‐^αVal‐His. Biotechnol. Bioeng. 2010; 106: 358–366. © 2010 Wiley Periodicals, Inc.     

Suppression of Inflammatory Cytokine Production by ar‐Turmerone Isolated from Curcuma phaeocaulis

Rhizomes of Curcuma phaeocaulis Valeton (Zingiberaceae) have traditionally been used for controlling inflammatory conditions. Numerous studies have aimed to isolate and characterize the bioactive constituents of C. phaeocaulis. It has been reported that its anti‐inflammatory properties are a result of cyclooxygenase‐2 inhibition; however, its effect on the T‐cell function remains to be elucidated. In this study, four known sesquiterpenoids, viz., ar‐turmerone (TM), germacrone (GM), (+)‐(4S,5S)‐germacrone‐4,5‐epoxide (GE), and curzerenone (CZ), were isolated from C. phaeocaulis rhizomes and evaluated for their effects on the CD4⁺ T‐cell function. While GM, GE, and CZ had no effect on the activation of splenic T cells or CD4⁺ T cells, TM suppressed the interferon (IFN)‐γ production, without affecting the interleukin (IL)‐4 expression. TM also decreased the expression of IL‐2 in CD4⁺ T cells, but did not change their cell‐division rates upon stimulation. These results suggest that TM, a major constituent of C. phaeocaulis rhizomes selectively exerts potent anti‐inflammatory effects via suppression of the inflammatory cytokines IFN‐γ and IL‐2.     

Biosurfactants from Bacillus licheniformis: structural analysis and characterization

Summary The surface-active compounds of the strain Bacillus licheniformis were isolated and their structure was elucidated. The high surface-active capacity of the crude extract was basically due to traces of long-chain saturated fatty acids, especially of palmitic and stearic acids, to a mixture of small amounts of hydrocarbons with chain lengths of 20 and 22 carbons, and mainly to appreciable amounts of four slightly different lipopeptides. The lipopeptides were found to be a mixture of four closely related compounds. The lipophilic part consisting of i-, n-C₁₄ or i-, ai-C₁₅ -OH fatty acids was linked to the hydrophilic peptide moiety, which contained seven amino acids (Glu, Asp, Val, three Leu and Ile) by a lactone linkage. Fifteen milligrams per litre of the purified lipopeptide product decreased the surface tension of water from 72 mN m^–1 to 27 mN m^–1, characterizing the product as a powerful surface-active agent that compares favourably to other (bio)surfactants. Antibiotic activity was demonstrated against bacteria and yeasts. Offsprint requests to: O. Käppeli     

Extraction of rapamycin (sirolimus) from Streptomyces rapamycinicus using ultrasound

The study was designed to investigate the use of ultrasound-assisted extraction (UAE) of rapamycin (sirolimus) from bacterial strain of Streptomyces rapamycinicus NRRL 5491. To achieve the maximum extraction yield, various parameters were optimized which include S. rapamycinicus (10?g) of biomass in toluene (50?mL), temperature (20°C), acoustic intensity (35.67?W/cm²), and duty cycle (40%) for 4?min extraction time with probe tip length of 0.5?cm dipped into extraction solvent from the surface. The maximum extraction yield 60.15?±?0.01?mg/L was attained under the mentioned optimum parameters. The use of ultrasound for the extraction of rapamycin shows about twofold increase in the yield as compared to the conventional solid–liquid extraction (29.7?±?0.2?mg/L). The study provides the effective UAE technique to produce potential value-added products.     

Variation on Composition and Bioactivity of Essential Oils of Four Common Curcuma Herbs

Chemical compositions, antioxidative, antimicrobial, anti‐inflammatory, and cytotoxic activities of essential oils extracted from four common Curcuma species (Curcuma longa, Curcuma phaeocaulis, Curcuma wenyujin, and Curcuma kwangsiensis) rhizomes in P. R. China are comparatively studied. In total, 47, 49, 35, and 30 compounds are identified in C. longa, C. phaeocaulis, C. wenyujin, and C. kwangsiensis essential oils by GC/MS, and their richest compounds are ar‐turmerone (21.67%), elemenone (19.41%), curdione (40.23%) and (36.47%), respectively. Moreover, C. kwangsiensis essential oils display the strongest DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical‐scavenging activity (IC₅₀, 3.47 μg/ml), much higher than ascorbic acid (6.50 μg/ml). C. phaeocaulis oils show the best antibacterial activities against Escherichia coli (MIC, 235.54 μg/ml), Pseudomonas aeruginosa (391.31 μg/ml) and Staphylococcus aureus (378.36 μg/ml), while C. wenyujin and C. kwangsiensis oils show optimum activities against Candida albicans (208.61 μg/ml) and Saccharomyces cerevisiae (193.27 μg/ml), respectively. C. phaeocaulis (IC₅₀, 4.63 μg/ml) and C. longa essential oils (73.05 μg/ml) have the best cytotoxicity against LNCaP and HepG2, respectively. C. kwangsiensis oils also exhibit the strongest anti‐inflammatory activities by remarkably down‐regulating expression of COX‐2 and TNF‐α. Therefore, due to their different chemical compositions and bioactivities, traditional Chinese Curcuma herbs should be differentially served as natural additives for food, pharmaceutical, and cosmetic.     

Response surface methodology for the extraction of wedelolactone from Eclipta alba using aqueous two-phase extraction

Abstract

Aqueous two-phase extraction of wedelolactone from Eclipta alba was studied using the polymer-salt system. The system consisted of polyethylene glycol (PEG) as a top phase (polymer) and sodium citrate as a bottom phase (salt). Process parameters such as PEG concentration, PEG molecular weight, salt concentration, and pH have been optimized using response surface methodology (RSM) with the help of central composite design (CCD). The optimized conditions for aqueous two-phase system (ATPS), in the case of one factor at a time approach, were found as PEG 6000, PEG concentration 18% (w/v), salt concentration 16% (w/v), and pH 7; with maximum extraction yield of 6.52?mg/g. While, RSM studies showed maximum extraction yield of 6.73?mg/g with the optimized parameters as PEG 6000, PEG concentration 18% (w/v), salt concentration 17.96% (w/v), and pH 7. ATPS was found to give a 1.3 fold increase in the extraction yield of wedelolactone as compared to other conventional extraction methods.     

Application of response surface methodology to optimise ultrasonic-assisted extraction of four chromones in Radix Saposhnikoviae

Introduction – Radix Saposhnikoviae is one of the most famous Chinese herbal medicines with many pharmacological activities towards inflammatory symptoms and antioxidation. Chromones are considered as one of the effective components. It is important to find a reasonable method to extract the chromones in S. divaricata. Objective – To develop an ultrasonic‐assisted extraction (UAE) to extract chromones in Radix Saposhnikoviae and to optimise extraction conditions. Methodology – Four chromones (prim‐O‐glucosylcimifugin, cimifugin, 5‐O‐methylvisammioside and sec‐O‐glucosylhamaudol) were extracted by the UAE method combined with response surface methodology (RSM). Box–Behnken design (BBD) was applied to evaluate the effects of three independent variables (ethanol concentration, extraction time and extraction temperature) on the chromones yield of Radix Saposhnikoviae. Results – Correlation analysis of the mathematical‐regression model indicated that a quadratic polynomial model could be employed to optimise the extraction of chromones by UAE method. The optimal conditions to obtain the highest chromones yield of Radix Saposhnikoviae were a solvent of 75% ethanol, an extraction time of 48 min and an extraction temperature of 67°C. Conclusion – Under these optimal conditions, the experimental values agreed closely with the predicted values. The analysis of variance indicated a high goodness of model fit and the success of RSM method for optimising chromones extraction in Radix Saposhnikoviae. Copyright © 2011 John Wiley & Sons, Ltd.     

Extraction,development and validation of HPLC-UV method for rapid and sensitive determination of colchicine from Colchicum autumnale L. Bulbs

Colchicum autumnale L. also known as the autumn crocus, contains colchicine alkaloid having antifungal properties. The tuber of this plant is rich in terms of colchicine. In this research an ultrasound-assisted extraction (UAE) method was optimized for the extraction of colchicine from Colchicum autumnale L. bulbs before high-performance liquid chromatography with UV detection (HPLC-UV). Optimization of various extraction parameters was performed using response surface methodology (RSM) to evaluate the maximum colchicine yield from Colchicum autumnale L. bulbs. The Box-Behnken design (BBD) and RSM were used to investigate the effect of three key parameters (extraction time (20–60?min), extraction temperature (40–80?°C) and ultrasound power (500–700?W) on extraction efficiency. The variance analysis suggested that the dependent response variable of yield of colchicine may be expressed by a quadratic polynomial model. The optimal theoretical extraction conditions were found to be an ultrasonication power of 602.4?W, an extraction time of 42?min and a temperature of 64?°C. Under these conditions, the optimum foreseen yield was 0.237%. The experimental colchicine yield obtained by following the optimized conditions was found to be 0.238%. These values are very well compatible with each other.     

Phytochemical Compounds of Euphorbia bivonae Extract and Their Cytotoxicity Effects on the Lethality of Brine Shrimp Artemia salina and Embryonic Kidney (HEK293) Cells

In this research article, we investigated the effect of Euphorbia bivonae extract compounds on the lethality of brine shrimp Artemia salina and on embryonic cell lines (HEK293) proliferation. Our GC/MS analysis revealed that the E. bivonae ethanolic extract contained essentially sitosterol, euphol, and lupeol. The 24-h LC50 was determined using the probit analysis method (LC50=357.11 mg l⁻¹). Depending on this cytotoxicity test result, E. bivona extract induced a significant increase in Superoxide Dismutase (SOD), Catalase (CAT), Glutathione-Peroxidase (GPx) activities, and lipid peroxidation (LPO) in A. salina larvae. In addition, the cytotoxicity effect of this extract had proved against the HEK293 cell lines in vitro. We suggest that the three compounds of E. bivonae extract (sitosterol, euphol, and lupeol) are the most responsible for this cytotoxicity. The possible application of this extract as an alternative natural antiproliferative is considered.     

Extraction and Antioxidant Activities of Magnolia kwangsiensis Figlar & Noot. Leaf Polyphenols

Microwave‐assisted extraction was employed to extract polyphenols from the leaf of Magnolia kwangsiensis Figlar & Noot . The yield of polyphenols was 2.44±0.02 % under the optimal conditions of RSM: acetone concentration of 70 %, ratio of solvent to material of 21 mL?g^?1 and extraction time of 16 min. The antioxidant activities were evaluated in terms of total antioxidant ability, reducing power, DPPH ^? and ^? OH scavenging activity. Results showed the polyphenols presented potential antioxidant activities, especially the stronger scavenging activity on ^? OH. In term of ^? OH scavenging activity, the IC₅₀ value of NKA‐9 purification was 0.335 mg mL^?1, equivalent to 35.23 % of V_C. The IC₅₀ values of crude extract and ethyl acetate extract were 0.580 and 0.828 mg mL^?1, equivalent to 60.99 % and 87.07 % of V_C. Results indicated that M. kwangsiensis leaf polyphenols present potential antioxidant activities that make it beneficial for human health by preventing or reducing oxidative damage.     

Enhancement of total phenolic and flavonoids extraction from <Emphasis Type="Italic">Rosmarinus officinalis</Emphasis> L using electromagnetic induction heating (EMIH) process

Electromagnetic induction heating (EMIH) assisted extraction of phenolic compounds from Rosmarinus officinalis L, and the antioxidant and antimicrobial activities of the plant extract were examined in this study. The extraction yield acquired with this process was found to be 25.1?±?2%, with maximum amounts of phenolic compounds: 127.87?±?2.1 mg Gallic acid equivalents per g dry weight and total flavonoids contents 14.48?±?1.5 mg quercetin equivalents per g dry weight, under optimum extraction conditions (extraction time 2 h, ratio of raw material to liquid 1:2 and 0% of NaCl). The antioxidant activity was assessed by the 1,1-diphenyl-2-picrylhydrazyl (DPPH); 2, 2′-azinobis (3-ethylbenzothiazoline-6- sulfonic acid) radical cation (ABTS⁺) and ferric reducing power (FRAP) methods. The results indicate the extract derived through EMIH showed a strong antioxidant ability (89.25%; EC₅₀ of 0.0148 µg/mL). Besides, the antimicrobial bioassay demonstrated that the extract possessed a good antimicrobial activity against all tested fungi and bacteria.