高山红景天中有效成分的微波辅助提取

采用微波辅助提取的方法从高山红景天中提取功能性成分红景天苷,研究固液比、微波辐照时间、预浸时间和乙醇浓度四因素对红景天苷提取率的影响.根据回归方程,采用降维方法讨论乙醇浓度对红景天苷提取率的单因子效应,并讨论了乙醇浓度和预浸时间之间的交互作用.结果表明微波功率为130 W,20%(v/v)乙醇作提取溶剂,固液比为1∶29(g/mL),微波辐照时间60 s时,红景天苷的一次提取率达到80%.与传统的乙醇回流法相比,微波1 min提取两次和采用传统乙醇加热回流120 min提取四次的结果相差不大,但传统回流的乙醇消耗量为微波提取的2倍,热耗大.     

苹果渣中原花青素的提取分离条件的优化

采用单因素和正交试验优化了溶剂直接提取及微波辅助提取苹果渣中原花青素的提取条件。结果表明:溶剂直接提取苹果渣中原花青素的最佳提取条件为乙醇体积分数30%,料液比(g/mL)1∶12,浸提温度90℃,提取时间0.5h;微波辅助提取法提取苹果渣中原花青素的最佳提取条件为乙醇体积分数50%,料液比(g/mL)1∶9,微波功率为700W,提取时间3min。与溶剂直接提取法相比,微波辅助提取法能更省时、高效地提取苹果渣中的原花青素。     

微波辅助提取灰树花多糖工艺研究

采用提取时间、微波功率、液料比的单因素试验和正交试验法优化微波辅助提取灰树花多糖条件.结果表明,以净多糖得率为指标,影响微波辅助提取灰树花多糖的主次因素为:提取时间＞微波功率＞液料比,并且提取时间和微波功率的影响达到了极显著水平.灰树花多糖最佳提取工艺条件为:提取时间为10 min,微波功率为80%(全功率为800 W),液料比为25∶1.创立了一种用苯酚-硫酸法测定多糖时排除蛋白质干扰的方法.     

从千层塔中微波协助提取石杉碱甲和石杉碱乙

首先从 8种溶剂中筛选出硫酸作为微波协助提取的浸提溶剂 ,然后用正交试验确立了千层塔生物碱的最佳提取条件。以石杉碱甲和石杉碱乙回收率为指标 ,考察了溶剂倍数、溶剂浓度、微波处理时间等因素。结果表明 ,在室温下微波协助提取的最优条件为 :酸浓度 0.8% (v/v) ,液固比例 2 5∶1 ,微波处理时间 90s。 3次重复实验所得石杉碱甲和石杉碱乙回收率分别是 93.7%和 93.9% ,相对标准偏差分别为 1.79%和 1.5 6% (n =3)。与传统的回流提取工艺相比 ,过程时间从 2h缩短为 90s,回收率提高了 1 0 %以上。     

响应面法优选牡丹果荚中丹皮酚和芍药苷提取工艺的研究

以牡丹果荚为原料,采用响应面分析法对影响微波辅助提取牡丹果荚中芍药苷和丹皮酚的主要因素(料液比、微波功率、微波时间)进行优化。结果表明:微波辅助提取牡丹果荚中的芍药苷及丹皮酚的最佳提取工艺条件为:液料比10∶1、微波功率253 W、微波时间10 min,牡丹果荚芍药苷和丹皮酚的得率分别为2.92、0.91 mg·g-1。与传统提取法相比,微波辅助提取方法不仅提取时间短,原料使用量少,而且提取率高,是一个高效的提取方法。     

桑黄菌丝体粗多糖的提取方法研究

采用正交试验设计,以桑黄菌丝体粗多糖含量为考察指标,用苯酚—硫酸法,分别确定了热水浸提法、微波辅助提取法和超声提取法的最佳工艺。通过极差分析得出:热水浸提法的最优工艺为浸提时间3 h、浸提3次、液料质量比50∶1、浸提温度90℃,粗多糖提取率为2.10%;微波提取法的最优工艺为微波处理15 min、液料质量比50∶1、提取3次,提取率为4.18%;超声提取法的最优工艺为超声30 min、提取2次、液料质量比60∶1、温度60℃、频率60 Hz,提取率为3.02%。微波辅助法与热水浸提法相比,时间缩短,且提取率提高近1倍;与超声提取法相比,时间缩短1/2,但提取率提高40%。因此,微波辅助提取法速度更快、提取效率更高、操作更简便,优于其他2种方法。     

黄芪多糖超声-微波协同提取研究

本论文采用超声-微波协同提取新工艺,通过单因素实验分别考察提取时间、微波功率、料液比等因素对黄芪多糖提取率及纯度的影响;通过正交实验得出最佳提取工艺参数;通过平行提取实验,与水提法、微波及超声波辅助提取进行比照。得出最佳提取条件为微波功率120 W,提取时间为150 s,料液比1∶25(g/mL)时,黄芪多糖的提取率最高达4.25%,并且证明了超声微波协同提取法的提取效率高于水提法、微波法及超声波法等传统的提取方法。     

苹婆果壳总酚酸提取工艺优化及抗氧化性研究

目的:采用Box-Behnken响应面法优化微波辅助提取苹婆果壳总酚酸的工艺条件,并研究其抗氧化活性.方法:考察微波功率、乙醇体积分数、微波时间、液料比4个因素对苹婆果壳总酚酸提取量的影响.在单因素试验的基础上,采用Box-Behnken响应面试验法对苹婆果壳总酚酸的微波辅助提取工艺条件进行考察,并通过考察苹婆果壳总酚...     

阿魏菇醇提物抗肿瘤功效及三萜类成分的提取

为探究阿魏菇醇溶性物质(PFECs)抗肿瘤功效,优化阿魏菇醇提物三萜类化合物(PFTPs)提取条件,获取最大提取率。采用MTT法检测PFECs对5种肿瘤细胞生长抑制活性;对两种正常细胞无明显抑制作用;采用超声辅助、微波辅助热水浸提法、单因素试验与响应曲面法相结合,对阿魏菇三萜类化合物提取工艺优化。结果显示,PFECs具有显著的抗肿瘤活性;PFTPs提取的最佳工艺参数为:料液比1∶19(g/mL)、提取温度75℃、提取时间22 min(超声40 min后),提取率为4.42%。     

微波辅助提取石榴皮多糖工艺优化及其免疫调节作用研究

优化石榴皮多糖的微波辅助提取工艺并初步探究石榴皮多糖的免疫调节作用。在单因素试验的基础上,以液料比、微波提取时间、微波功率为自变量,石榴皮多糖得率为响应值,利用响应曲面分析方法,确定石榴皮多糖提取工艺的最佳条件为:液料比44∶1 m L/g,微波提取时间10 min,微波功率450 W,在该条件下石榴皮多糖的得率为10.48%。通过MTT法、中性红法、NO释放量测定和黏附试验初步表明石榴皮多糖对RAW264.7巨噬细胞具有一定的免疫调节作用。     

Microwave-assisted extraction of the main phenolic compounds in flaxseed

A microwave-assisted extraction (MAE) method has been applied for the first time to the extraction of the main lignan, secoisolariciresinol diglucoside (SDG), and the two most concentrated hydroxycinnamic acid glucosides in flaxseed. The effects of microwave power, extraction time and alkaline treatment were investigated. It was shown that a 3 min MAE resulted in an SDG content of 16.1+/-0.4 mg/g, a p-coumaric acid glucoside content of 3.7+/-0.2 mg/g and a ferulic acid glucoside content of 4.1+/-0.2 mg/g. These values were compared with those obtained using conventional extraction methods and the results demonstrated that MAE was more effective in terms of both yield and time consumption.     

Hydroxycinnamic acids are ester-linked directly to glucosyl moieties within the lignan macromolecule from flaxseed hulls

In flaxseed hulls, lignans are present in an oligomeric structure. Secoisolariciresinol diglucoside (SDG), ester-linked to hydroxy-methyl-glutaric acid (HMGA), forms the backbone of this lignan macromolecule. The hydroxycinnamic acids p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) are also part of the lignan macromolecule. However, their position and type of linkage are still unknown. The aim of this study was to investigate how CouAG and FeAG are linked within the lignan macromolecule from flaxseed hulls. Fragments of the lignan macromolecule were obtained by partial saponification. After isolation of the fragments by preparative RP-HPLC, several key structures were identified by MS and NMR. Within the lignan macromolecule, CouAG is attached to the C-6 position of a glucosyl moiety of SDG. FeA is linked to the C-2 position of a glucosyl moiety of SDG. FeAG is ester-linked within the lignan macromolecule with its carboxyl group, but it remains unclear whether FeAG links to the C-2 or C-6 position of SDG. Attachment of HMGA to the glucosyl moiety of CouAG or FeAG was not observed. The results clearly show that within the lignan macromolecule, the hydroxycinnamic acids are linked directly via an ester bond to the glucosyl moiety of SDG.     

The flavonoid herbacetin diglucoside as a constituent of the lignan macromolecule from flaxseed hulls

Lignans in flaxseed are known to be part of a macromolecule in which they are connected through the linker-molecule hydroxy-methyl-glutaric acid (HMGA). In this study, the lignan macromolecule was extracted from flaxseed hulls and degraded to its monomeric constituents by complete saponification. Besides secoisolariciresinol diglucoside (SDG), the phenolic compounds p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) were isolated, which was expected based on indications from the literature. Also the flavonoid herbacetin diglucoside (HDG) was found. The presence of HDG was confirmed by NMR following preparative RP-HPLC purification. Also the presence of the three other constituents (CouAG, FeAG and SDG) was confirmed by NMR. To prove that HDG is a substructure of the lignan macromolecule, the macromolecule was fragmented by partial saponification. A fragment consisting of HDG and HMGA was indicated. This fragment was isolated by preparative RP-HPLC and its identity was confirmed by NMR. It is concluded that the flavonoid HDG is a substructure of the lignan macromolecule from flaxseed hulls and that it is incorporated in the macromolecule via the same linker-molecule as SDG.     

Regulation of zinc transporters by dietary flaxseed lignan in human breast cancer xenografts

Zinc is essential for cell growth. Previous studies have shown that zinc concentration in breast cancer tissues is higher than that in normal breast tissues. Zinc cannot passively diffuse across cell membranes and specific zinc transporter proteins are required. Two gene families have been identified involved in zinc homeostasis. ZnT transporters reduce intracellular zinc while ZIP transporters increase intracellular zinc. In this study, three human zinc transporter members: ZnT-1, ZIP2 and LIV-1 were chosen. We aimed to determine the effect of flaxseed lignan on the growth of ER-negative breast cancer cells in a nude mice model and observe the effect of flaxseed lignan on the regulation of the three zinc transporter in mRNA level. Nude mice were xenografted with human breast cancer cell line MDA-MB-231 and 6 weeks later were fed either the basal diet (BD) or BD supplemented with 10% FS and SDG for 5 weeks. The SDG levels were equivalent to the amounts in the 10% FS. RT-PCR was performed. Compared with the BD group, the tumor growth rate was significantly lower (P < 0. 05) in the FS and SDG group. ZnT-1 mRNA level in mammary tumor was increased in SDG group and decreased in FS group, but no significant difference was found. Extremely low amplification of ZIP2 from mRNA was detected, with no difference between the treatment groups. LIV-1 mRNA expression of SDG group increases compared with BD group. In FS group, it significantly increases nearly 9 times than that in BD group (P < 0. 005).     

The chain length of lignan macromolecule from flaxseed hulls is determined by the incorporation of coumaric acid glucosides and ferulic acid glucosides

Lignan macromolecule from flaxseed hulls is composed of secoisolariciresinol diglucoside (SDG) and herbacetin diglucoside (HDG) moieties ester-linked by 3-hydroxy-3-methylglutaric acid (HMGA), and of p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) moieties ester-linked directly to SDG. The linker molecule HMGA was found to account for 11% (w/w) of the lignan macromolecule. Based on the extinction coefficients and RP-HPLC data, it was determined that SDG contributes for 62.0% (w/w) to the lignan macromolecule, while CouAG, FeAG, and HDG contribute for 12.2, 9.0, and 5.7% (w/w), respectively.Analysis of fractions of lignan macromolecule showed that the higher the molecular mass, the higher the proportion of SDG was. An inverse relation between the molecular mass and the proportion (%) CouAG + FeAG was found. Together with the structural information of oligomers of lignan macromolecule obtained after partial saponification, it is hypothesized that the amount of CouAG + FeAG present during biosynthesis determines the chain length of lignan macromolecule.Furthermore, the chain length was estimated from a model describing lignan macromolecule based on structural and compositional data. The average chain length of the lignan macromolceule was calculated to be three SDG moieties with CouAG or FeAG at each of the terminal positions, with a variation between one and seven SDG moieties.     

Feeding flaxseed oil but not secoisolariciresinol diglucoside results in higher bone mass in healthy rats and rats with kidney disease

Flaxseed's oil and lignan, secoisolariciresinol diglucoside (SDG), are implicated in attainment of health and treatment of renal injury and osteoporosis. To test for these benefits, weanling Han:SPRD-cy rats (n=171) with or without kidney disease were randomized to diets made with either corn oil or flaxseed oil and with or without SDG for 12 weeks. In females, weight was lower with the SDG diet. In males fed flaxseed oil, lean mass was higher and fat % was lower. In both sexes, fat % was lower in diseased rats. Bone mineral content (BMC) and density were higher in rats fed flaxseed oil and lower in diseased rats, additionally; BMC was lower in SDG-supplemented females. The benefit of flaxseed oil on body composition is sex specific but the effect on bone mass is not. Lastly, reduced weight due to early rat kidney disease is not due to loss of lean body mass.     

Combined microwave-assisted extraction and high-speed counter-current chromatography for separation and purification of xanthones from Garcinia mangostana

A microwave-assisted extraction (MAE) method is presented for the extraction of xanthones, α-mangostin and γ-mangostin from Garcinia mangostana. The MAE conditions including extraction temperature, liquid/solid ratio, extraction time and concentration of ethanol were optimized with an orthogonal test, and 5 g sample was extracted with the optimized conditions. The crude extraction of MAE was successfully isolated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (0.8:0.8:1:0.6, v/v) in one-step separation. The separation yielded 75 mg of α-mangostin at 98.5% purity, and 16 mg of γ-mangostin at 98.1% purity from 360 mg crude extract of G. mangostana in less than 7h. The purity of the two xanthones was determined by HPLC. Their structures were further identified by ESI-MS, (1)H NMR and (13)C NMR.     

Antioxidant activity of the flaxseed lignan secoisolariciresinol diglycoside and its mammalian lignan metabolites enterodiol and enterolactone

The antioxidant activities of the flaxseed lignan secoisolariciresinol diglycoside (SDG) and its mammalian lignan metabolites, enterodiol (ED) and enterolactone (EL), were evaluated in both lipid and aqueous in vitro model systems. All three lignans significantly (p 0.05) inhibited the linoleic acid peroxidation at both 10 and 100 M over a 24-48 h of incubation at 40°C. In a deoxyribose assay, which evaluates the non site-specific and site-specific Fenton reactant-induced ·OH scavenging activity, SDG demonstrated the weakest activity compared to ED and EL at both 10 and 100 M; the greatest ·OH scavenging for ED and EL was observed at 100 M in both assays. The incubation of pBR322 plasmid DNA with Fenton reagents together with SDG, ED or EL showed that the inhibition of DNA scissions was concentration dependent. The greatest non site-specific activity of lignans was at 100 M, thus, confirming the results of the deoxyribose test. In contrast, the protective effect of SDG and EL in the site-specific assay was lost and that of ED was minimal. Therefore, the results indicate a structure-activity difference among the three lignans with respect to specific antioxidant efficacy. All three lignans did not exhibit reducing activity compared to ascorbic acid, therefore, did not possess indirect prooxidant activity related to potential changes in redox state of transition metals. The efficacy of SDG and particularly the mammalian lignans ED and EL to act as antioxidants in lipid and aqueous in vitro model systems, at relatively low concentrations (i.e. 100 M), potentially achievable in vivo, is an evidence of a potential anticarcinogenic mechanism of flaxseed lignan SDG and its mammalian metabolites ED and EL.     

Microwave-assisted extraction of glycyrrhizic acid from licorice root

In the present study, a microwave-assisted extraction (MAE) technique has been developed for the extraction of glycyrrhizic acid (GA) from licorice root. Various experimental conditions, such as extraction time, different ethanol and ammonia concentration, liquid/solid ratios, pre-leaching time before MAE and material size for the MAE procedure were investigated to optimize the efficiency of the extraction. Under appropriate MAE conditions, such as extraction times of 4-5min, ethanol concentrations of 50-60% (v/v), ammonia concentrations of 1-2% (v/v) and liquid/solid ratios of 10:1(ml/g), the recovery of GA from licorice root with MAE was equivalent with conventional extraction methods. Those methods include extraction at room temperature (ERT), the traditional Soxhlet extraction, heat reflux extraction and ultrasonic extraction. Due to the considerable savings in time and solvent, MAE was more effective than the conventional methods. This novel method is suitable for fast extraction of GA from licorice root.     

Accelerated solvent extraction of monacolin K from red yeast rice and purification by high-speed counter-current chromatography

Monacolin K from red yeast rice was extracted by accelerated solvent extraction (ASE). The effects of various extraction parameters including extraction temperature, static extraction time and cycle index on yield were investigated using a DIONEX ASE 300 system to select the optimal conditions by an orthogonal test design L₉ (3)³. The optimum extraction conditions were determined as follows: extraction temperature 120 °C, static extraction time 7 min, and cycle index 3. Under the optimal conditions, the yield of ASE extract and monacolin K was 5.35% and 9.26 mg/g of dry red yeast rice, respectively. A separation and purification method of monacolin K was then established using high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (8:2:5:5, v/v/v/v). From 300 mg of crude extract, 51.2 mg of monacolin K was obtained with the purity of 98.7%. The chemical structure of isolated compound was identified by UV, ESI-MS and ¹H NMR.