ULTRASONIC-ASSISTED PRODUCTION OF ANTIOXIDATIVE POLYSACCHARIDES FROM Crassostrea hongkongensis

The beneficial effects of oyster extract against various disorders and diseases induced by oxidative stress have aroused great interest. In this article, ultrasonic-assisted enzymolysis was employed to produce polysaccharides of Crassostrea hongkongensis (CHP) and their antioxidant activity was investigated. A single-factor experiment and then a four-factor, three-level Box–Behnken design were first used to optimize ultrasonic extraction for polysaccharides. On the basis of ridge analysis, the optimum conditions are obtained as ultrasonic treatment time of 24 min, power of 876 W, temperature of 49°C, and material–solvent ratio of 1:6 (w/v). It is found that ultrasound pretreatment before protease hydrolysis was a great help to improve CHP yield and purity, especially more favorable with flavorzyme, neutrase, alcalase, and pepsin. Furthermore, the polysaccharide fraction, which was obtained by ultrasonic pretreatment and then alcalase hydrolysis at the conditions of 3000 U/g, 55°C, pH 8.0, for 4 hr, exhibited an obvious scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (98.48 ± 0.55% and 99.20 ± 0.12%, respectively) and a lenoleic acid peroxidation inhibition effect (85.48 ± 0.65%) at a concentration of 5.0 mg/mL. These results reveal the potential application of CHP in functional food and nutraceuticals.     

Variation of taxane content in needles of Taxus x media cultivars with different growth characteristics

Needles from 17 different Taxus x media cultivars, belonging to 4 groups showing different growth characteristics, were analyzed using high performance liquid chromatography for their content of 10-deacetylbaccatin III, baccatin III, cephalomannine and paclitaxel (Taxol). The 4 Taxus x media cultivar groups were: 1.) medium to fast growing and upright form; 2.) slow growing and upright form; 3.) fast growing and spreading form; and 4.) slow growing and spreading form. The purpose of this study was to identify yew cultivars of fast growth rate, upright growth and high taxane content in their needles. The highest content of paclitaxel was found in 'Coleana' of group 1 (378 microg/g of the extracted dry weight). Three cultivars in group 1, 'Coleana', 'Stovekenii' and 'Hicksii', make good candidates for taxane extraction because of their high paclitaxel and 10-deacetylbaccatin III content, fast biomass accumulation and upright growing form. They are also good starting materials to develop alternative methods for the production of paclitaxel and its analogous compounds through modern biotechnology approaches.     

Kinetics and Mechanism of Ultrasound-assisted Extraction of Paclitaxel from <Emphasis Type="Italic">Taxus chinensis</Emphasis>

Batch experimental studies were carried out for the ultrasound-assisted extraction of paclitaxel from Taxus chinensis while varying parameters such as ultrasound power, extraction temperature and contact time. The extraction of the majority of the paclitaxel (~99%) was achieved from the biomass by a single extraction at 380W of ultrasound power for a period of 10 min. The kinetics data obtained for the paclitaxel extractions, and the dominant role played by intraparticle diffusion, were found to be in concordance with the pseudo-second-order model, and the intraparticle diffusion model respectively. The effective diffusion coefficient of paclitaxel (4.1882 × 10^-13 ~ 5.7093 × 10^-13 m²/s) and the mass transfer coefficient (4.705 × 10^-8 ~ 14.1160 × 10^-8 m/s) increased when the extraction temperature and ultrasound power were raised.     

响应曲面法优化马尾松中莽草酸的超声提取工艺

以马尾松松针为原料,采用超声波提取法从松针粉中提取莽草酸,通过考察料液比((VH2O∶m松针粉,mL:g)、提取时间、提取温度及超声波功率等因素对松针中总莽草酸含量的影响,并在单因素试验的基础上,选取料液比、提取时间、超声波功率3个变量,进行Box-Behnken中心组合设计优化,获得马尾松松针中莽草酸的最佳提取工艺参数为料液比1∶26,提取时间为46min,超声波功率为359 W,此条件下莽草酸的提取率为1.948%。     

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.     

响应面优化塔拉种子多糖的超声波提取及其抗氧化性研究

为获得塔拉多糖超声波提取的最佳工艺,利用中心组合实验设计原理,采用四因素三水平的响应面分析法,获得多元二次线性回归方程,以多糖提取率为响应值做响应面。并考察塔拉多糖的体外抗氧化活性。结果表明：塔拉多糖的最佳提取工艺条件为,超声辅助提取超声功率363 W,超声温度56℃,超声时间23 min,料液比1：17（g·mL^-1）,塔拉粗多糖的最大提取率（25.56%）与理论推测值（25.71%）相差较小。经纯化后塔拉多糖提取率为17.82%。以VC为阳性对照,对不同纯度的塔拉多糖进行抗氧化性的研究,发现其纯度越高,对ABTS自由基的清除能力越强。     

乌药超声提取工艺的研究

目的:用超声波法提取乌药有效成分,优化提取工艺条件.方法:以醚内醇为考察对象,通过研究超声波条件下影响浸提的几个因素,包括提取次数、超声后浸泡时间、超声时间、超声功率等,并通过单因素试验优化了工艺条件.结果:确定了超声前浸泡时间45 min、超声功率600 w、超声时间13.2 min、液固比10∶1、超声后浸泡时间1...     

Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica

Microwave-assisted extraction was employed for the isolation of polysaccharides from Posidonia oceanica (PPO). The extracting parameters were optimized adopting response surface methodology. The highest polysaccharide yield (2.55 ± 0.09%), which is in concordance with the predicted value (2.76%), was obtained under the following conditions: extraction time 60 s, liquid–solid ratio of 50:1 (mL/g) and power of 800 W. This polysaccharide, with molecular weight of 524 KDa, characterized by gas chromatography–mass spectrometry showed that PPO was mainly composed of galactose, glucose, and arabinose with molar percentages 25.38, 24.37, and 21.64%, respectively. The pharmacological evaluation of PPO using animal models at the dose of 100 mg/kg indicated a significant anti-inflammatory activity with a percentage of inhibition of edema of 54.65% and a significant antinociceptive activity with 78.91% inhibition of writhing for peripheral analgesic activity and an increase in the hot plate reaction time for central analgesic activity.     

响应面法优化红景天总黄酮提取工艺的研究

研究了红景天中总黄酮提取率的影响因素,先经单因素实验初步确定影响因素,再用Box-Behnken响应面法建立影响因素的二次回归模型,通过对二次回归模型求解编码转换得知,液料比40:1(ml/g),酶添加量1.2%,酶解时间4.5 h,酶解温度45℃,pH5,超声时间为12 min,超声功率为250w中的高档,超声次数为3次,在这最优条件下总黄酮提取率为3.99%。     

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.     

超声辅助低共熔溶剂提取沙棘籽粕多酚的工艺优化

以一系列低共熔溶剂为提取剂,采用超声波辅助法从沙棘籽粕中提取多酚。在单因素试验结果基础上,利用Box-Behnken实验设计,运用响应面分析法对影响沙棘籽粕多酚得率的主要因素（超声功率、超声时间、超声温度）进行优化。结果表明,沙棘籽粕多酚最佳提取工艺条件为：以含水量为30%的氯化胆碱-草酸低共熔溶剂为最佳提取剂,液料比为14∶1,超声功率420 W,超声时间56 min,超声温度44℃。在此条件下,多酚得率为3.31±0.008%。对比试验发现：氯化胆碱-草酸低共熔溶剂对沙棘籽粕多酚的得率明显优于传统溶剂;与热回流提取相比,超声提取法具有明显的优势。     

雪松松针多糖超声波酶法提取及其抗氧化性

为优化雪松松针多糖超声波酶法的提取工艺,并研究多糖结构及其抗氧化性。通过响应面法分析确定最佳提取参数为:3. 0 g松针粉末,液料比20∶1(m L∶g),提取温度80℃,超声功率560 W,超声时间47 min,纤维素酶用量12 FPU/g原料,提取两次,多糖得率高达10. 39%。采用高效液相色谱、红外光谱和核磁共振光谱等对松针多糖进行了结构表征,松针多糖以β-糖苷键为主要连接方式,并由葡萄糖、果糖、阿拉伯糖和半乳糖等单糖组成。体外抗氧化性研究结果表明:松针粗多糖对羟基自由基(·OH)和1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除能力远高于纯化多糖,呈现出良好的量效关系,粗多糖对·OH和DPPH·的半抑制浓度IC50分别为0. 47 g/L和0. 076 g/L。     

Meetings & Symposia

Optimization of the extraction process of phenolics from Bryophyllum pinnatum was carried out using response-surface methodology (RSM). The effect of different variables such as ratio of solvents, plant material/solvent ratio, extraction time, and temperature were investigated. An optimal phenolics yield of 7.952 mg/g gallic acid equivalence (GAE) was achieved at reduced levels of methanol/water ratio (1:1, v/v). During optimization, the product yield was enhanced by ～2-fold at reduced extraction solvent (methanol/water) up to 37%. Validation of the RSM model for extraction of total phenolic content (TPC) was confirmed by high-performance liquid chromatography (HPLC) analysis. The obtained experimental values were in good agreement with the predicted values, thereby indicating the appropriateness of the model generated. Phenolic extracts from B. pinnatum were further examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods for determining the radical scavenging activities. EC₅₀ values of B. pinnatum extracts (BPEs) obtained by these methods were in accordance with the amount of phenolics present in the extract. Significant correlation was found between total phenolic content and antioxidant activities (p < 0.05).     

Continuous lipase-catalyzed esterification of soybean fatty acids under ultrasound irradiation

This work investigates the continuous production of alkyl esters from soybean fatty acid (FA) charges using immobilized Novozym 435 as catalyst. The experiments were performed in a packed-bed bioreactor evaluating the effects of FA charge to alcohol (methanol and ethanol) molar ratio, from 1:1 to 1:6, substrate flow rate in the range of 0.5–2.5 mL/min and output irradiation power up to 154 W, at fixed temperature of 65 °C, on the reaction conversion. Results showed that almost complete conversions to fatty acids ethyl esters were achieved at mild ultrasonic power (61.6 W), FA to ethanol molar ratio of 1:6, operating temperature (65 °C) and remained nearly constant for long-term reactions without negligible enzyme activity losses.     

MODEL DEVELOPMENT AND PROCESS OPTIMIZATION FOR SOLVENT EXTRACTION OF POLYPHENOLS FROM RED GRAPES USING BOX–BEHNKEN DESIGN

The objective of the present study is to find out the optimum extraction conditions for extraction of polyphenols from red grapes using Box–Behnken design. Red grapes polyphenols were extracted using acid–ethanol solvent at various extraction temperature (40–60°C), extraction time (20–100 min) and different solid–liquid ratio (1:5–1:15 g:ml). The effect (main and interactive) of extraction conditions on total anthocyanin, phenolic and flavonoid content were studied using Box–Behnken design (three factors at three levels). The results showed that the contribution of the quadratic model was significant for all the responses. Second-order mathematical regression models were developed and were found to fit well with observed data. Derringer's desirability function methodology was performed to find out the optimal conditions based on both individual and combinations of all responses (extraction temperature: 57°C, time: 61 min, and solid–liquid ratio: 1:8.7 g:ml) were established. At this optimal condition, the anthocyanin yield, total phenolic and flavonoid content were 73.92 mg/100 g, 221.4 mg GAE/100 g, and 79.08 mg CE/100 g, respectively. A desirability value of 0.902 was achieved at this point.     

Optimization of ultrasound-assisted water extraction of flavonoids from Psidium guajava leaves by response surface analysis

Psidium guajava leaves are rich in health-promoting flavonoids compounds. For better utilization of the resource, the ultrasound-assisted aqueous extraction was investigated using Box-Behnken design under response surface methodology. A high coefficient of determination (R²?=?97.8%) indicated good agreement between the experimental and predicted values of flavonoids yield. The optimal extraction parameters to obtain the highest total flavonoids yield were ultrasonic power of 407.41?W, extraction time of 35.15?min, and extraction temperature of 72.69?°C. The average extraction rate of flavonoids could reach 5.12% under the optimum conditions. Besides, HPLC analysis and field emission scanning electron microscopy indicated that the ultrasonic treatment did not change the main component of flavonoids during extraction process and the higher flavonoids content was attributed by the disruption of the cell walls of guava particles. Thus, the extraction method could be applied successfully for large-scale extraction of total flavonoids from guava leaves.     

南方红豆杉毛状根诱导体系的建立及毛状根中 紫杉醇的分离纯化研究

目的:研究发根农杆菌对南方红豆杉转化的转化体系和毛状根中紫杉醇的提取纯化工艺;方法:采用发根农杆菌对南方红豆杉不同外植体进行诱导,并对影响毛状根转化的因素进行分析。采用超临界CO2流体萃取法、硅胶柱色谱法以及高效液相法对毛状根中的紫杉醇进行分离提纯;结果:成功构建了南方红豆杉毛状根诱导体系。其中农杆菌的种类、外植体类型、预培养和共培养时间、培养基中激素浓度均影响毛状根的转化率。毛状根经高压纸电泳检测显示表达冠瘿碱。毛状根中紫杉醇经超临界CO2法提取及硅胶柱色谱法分离提纯,采用高效液相法分析显示其纯度可达到98%。结论:发根农杆菌诱导南方红豆杉产生的毛状根中可产生紫杉醇,可作为紫杉醇的主要来源。     

Identification and production of a novel natural pigment, cordycepoid A, from Cordyceps bifusispora

A novel yellow pigment, cordycepoid A, was isolated and identified from the entomogenous fungi Cordyceps bifusispora. Cordycepoid A exhibited no significant toxicity against Chinese hamster ovary (CHO) cells and mice, and showed high stability against food addictives, metal ions and heat. A liquid/solid double-phase cultural process for the production of the pigment was optimized as follows: 3 days aged liquid seed, 7.5 % inoculums, incubation temperature at 25 °C, 10 days of solid culture, and the last 5 days exposed to 200 Lx scattered light. The liquid seed medium and the solid culture medium were also optimized. Ethanol was selected as extracting solvent for its scale-up production. The optimal extracting conditions were determined as liquid/solid ratio at 20:1, extracting temperature at 40 °C, ultrasonic power at 400 W, and extracting time of 40 min.     

Separation of taxanes from <Emphasis Type="Italic">Taxus canadensis</Emphasis> using dynamic pressurized liquid extraction

An extraction technique, dynamic pressurized liquid extraction (DPLE), was proposed to extract the taxanes; including 10-DAB III, Baccatin III, 9-DHB III and paclitaxel, from powdered Taxus canadensis needles. A dual-solvent approach was adopted in which the impurities were firstly removed by extraction with hexane, and the taxanes were subsequently extracted with an appropriate solvent. The performance of chloroform, dichloromethane, and mixtures of methanol/dichloromethane was compared for use as the taxane-extracting solvent, and it was found that solvents containing a higher proportion of methanol had higher extraction capabilities. The effect of temperature on DPLE extraction of the taxanes was also studied, and it was found that higher extraction efficiencies could be realized with increasing temperature up to a threshold of 90°C. Based on a progressive conversion model, a kinetic equation for the extraction process was proposed. This model successfully confirmed that smaller needle powder particle sizes would result in higher extraction rates, which is consistent with the data obtained by experimentation.     

核桃楸树皮中胡桃醌提取方法及其工艺研究

对核桃楸树皮中胡桃醌的提取方法及相关影响因素进行探讨。以胡桃醌含量为指标,分别考察冷浸法、超声波提取法、回流提取法对提取率的影响,以及液料比、超声时间对提取率的影响,并对提取方法(A)、液料比(B)和提取时间(C)三因素设计正交试验。结果表明,影响胡桃醌提取率的主次因素为A> B> C,即提取方法> 液料比> 提取时间,最佳提取工艺为A₂B₃C₁,即使用超声法,在液料比为12:1时,提取20 min。