节点文献
玫瑰红景天有效成分分离纯化及结构鉴定
Separation, Purification and Structure Elucidation of Active Compounds from Rhodiola Rosea
【作者】 马朝阳;
【导师】 王洪新;
【作者基本信息】 江南大学 , 食品科学, 2009, 博士
【摘要】 玫瑰红景天在中国和东欧国家是一种有名的传统药用植物,具有去疲劳、增强学习和记忆、兴奋中枢神经系统、提高工作效率、耐缺氧、改善睡眠、预防高原病、抗癌等多种生理功能,目前是一种很受欢迎的药食两用“适应原”植物。本文对该种植物中两种主要的活性成分的提取分离纯化工艺进行了系统的研究,同时对其中的一些植物化学成分进行了分离分析和结构鉴定,建立了不同红景天品种的指纹图谱,为玫瑰红景天资源的深度开发和在医药工业中的应用提供依据。1.在单因素实验的基础上,利用正交组合实验方法研究了三个主要提取因素对两种主要成分(salidroside和rosavin)提取率的影响,得到因素与得率的回归模型及三因素之间相互作用的响应面图。确定两成分提取的最佳工艺条件为:乙醇浓度为70% (v/v),料液比为1:10 (w/v),温度为75℃,提取二次,每次提取时间1h。在最优条件下,两成分的提取率分别为0.80%和0.37%。同时研究了提取过程的动力学和热力学,利用范德霍夫方程计算热力学参数(ΔH0,ΔS0和ΔG0)。研究结果表明两种有效成分的浸出动力学据符合Fick第二定律导出的浸出数学模型,模型拟合得到salidroside和rosavin内扩散传质系数分别为0.75×10-9(m2/s)和0.41×10-9(m2/s);提取是一个吸热熵增过程,同时也是一个自发过程。2.利用静态吸附和动态解吸实验,通过比较不同树脂的吸附-解吸特性和分离选择性选出最适合分离纯化两主要活性成分的非极性树脂HPD-200,两成分在该树脂上的平衡吸附行为符合Langmuir模型。同时研究了HPD-200树脂上吸附动力学和吸附热力学,准一级、准二级反应模型和膜扩散传质模型用来拟合实验数据,结果吸附动力学可以用准二级动力学方程来描述;吸附过程是受膜扩散和内扩散步骤共同控制;吸附为放热、自发过程,升高温度不利于吸附反应的进行。此外,通过动态吸附和解吸实验,确定了最佳分离纯化工艺条件为:吸附:加样浓度为1.89mg/mL(salidroside)和0.24mg/mL (rosavin),加样量6.4 mL(样品溶液)/g(干树脂),柱床高度30cm,温度25℃,流速1BV/h;解吸:温度25℃,流速1BV/h,梯度洗脱的乙醇浓度和体积依次为:5%乙醇(2.5BV)、10%乙醇(2.5BV)、30%乙醇(2.5BV)、40%乙醇(2.5BV)、60%乙醇(2BV)。在最佳条件下,经过两次柱色谱分离,salidroside纯度从粗提物中的5.57%达到91.21%,总回收率48.82%;rosavin纯度从0.69%增加为15.37%,总回收率46.52%。在最佳分离条件下,进行了柱层析放大实验,结果salidroside和rosavin纯度分别为90.36%和16.02%,总回收率分别为44.75%和52.02%。3.对放大分离得到的粗salidroside进行结晶纯化,得到结晶的最佳工艺条件为:结晶溶剂乙醇,结晶溶液的浓度20.5mg/mL(w/v),结晶温度15℃,结晶时间16h。经过一步结晶,可以得到纯度为99.18%的salidroside单体。对放大分离得到的粗rosavin先后经过硅胶柱吸附和ADS-5C反相色谱方法来制备高纯度rosavin单体。确定了两步分离过程的最佳工艺条件。硅胶柱吸附色谱最佳工艺条件为:硅胶粒度200-300目,柱床高度25cm,加样量50 mg(粗rosavin)/g (硅胶),流动相氯仿-甲醇(4:1,v/v),流速l.5 mL/min,洗脱体积3BV。rosavin纯度从16.02%增加到50.17%、回收率为82.46%。ADS-5c反相色谱的最佳佳工艺条件为:加样量16.7 mg(样品)/g (树脂),洗脱剂50%乙醇,洗脱流速2BV/h,纯度最高可以达到98.73%,回收率为43.29%。此外,结合硅胶柱层析和制备反相HPLC方法,对大孔树脂分离salidroside和rosavin得到的其它馏分进行分离纯化,制备得到了19个单体化合物。4.通过UV、ESI-MS、1H-NMR 13C-NMR、DEPT-135和二维谱(1H-1H-COSY、HMQC、HMBC)等现代波谱分析方法,对其中15个单体化合物进行了结构鉴定,15个化合物分别鉴定为对-O-β-吡喃葡萄糖基-苯-2-丁酮, 6’-O-没食子酰-红景天苷,对-O-β-吡喃葡萄糖基-苯丙烯酸,7-甲氧基香豆素,苯乙基-6-O-β-葡萄糖苷,对羟基苯甲酸,红景天苷,肉桂醇-6‘-O-α-吡喃阿拉伯糖基-O-β-吡喃葡萄弹苷,肉桂醇-6’-O-α-吡喃木糖-O-β-吡喃葡萄弹苷,肉桂醇-6’-O-α-呋喃阿拉伯糖基-O-β-吡喃葡萄弹苷,肉桂醇-6-O-β-吡喃葡萄弹苷,对-羟基-苯乙醇,3, 7-二甲基-2, 6-二烯-1, 4-二辛醇,3, 7-二甲基-2, 6-二烯-1, 4-二辛醇-β-吡喃葡萄糖苷。其中,对-O-β-吡喃葡萄糖基-苯-2-丁酮,6’-O-没食子酰-红景天苷,对-O-β-吡喃葡萄糖基-苯丙烯酸、7-甲氧基香豆素为首次从玫瑰红景天分到的化合物。5.通过最佳化提取、分离、分析条件,建立了一种HPLC方法同时测定红景天中六种“适应原”活性成分,色谱条件为:色谱柱Purospher STAR C18;流动相甲醇(A)+ pH 5.6 20mmol/L乙酸铵水溶液(B);梯度程序40分钟内流动相由10A/90B变为100A/0B;流速1mL/min;柱温30℃;检测器二极管阵列(DAD),检测波长分别为276,250 and 205nm。该方法有好的线性,令人满意的精密度和回收率。然后新形成的方法用来分析不同品种不同产地的红景天样品,结果红景天样品中六种有效成分的含量范围分别为salidroside 0.16-11.14 mg/g;tyrosol 0-2.89 mg/g;rosarin 0-1.01 mg/g;rosavin 0-6.78 mg/g;rosin 0-1.51 mg/g;rosiridin 0-7.89 mg/g。六种成分的总量范围为1.3-12.88 mg/g。不同品种和产地的红景天样品所含六种适应源活性成分的种类和含量不同。新形成的方法也用来建立玫瑰红景天、狭叶红景天和高山红景天的HPLC指纹图谱,得到了19个共有峰,利用HPLC-MS方法对19个共有峰的分子量进行确证,其中,根据HPLC-MS提供的特征紫外光谱、分子量信息和一些结构方面的信息,有10个成分被鉴定。对指纹图谱进行相似度、聚类和主成分分析,结果表明同种红景天样品有好的相似性、不同品种间有较大的差异,指纹图谱可以区别不同品种的红景天。
【Abstract】 Rhodiola rosea is a popular plant in traditional medical systems in Eastern Europe and China, with a reputation for eliminating fatigue, improving learning and memory, stimulating the nervous system, enhancing work performance, improving sleep, anti-hypoxia, preventing high altitude sickness and anti-cancer. At present, it is popular as medicine-food plant. In this study, the separation and purification of two major active compounds was investigated in detail. At the same time some monomers were prepared from the extract of R. rosea and their structures were eludicated. On the other hand, a HPLC method was established to determine the six major active compounds of Rhodiola samples from different origins and the established method was used to construct HPLC fingerprints of three species of Rhodiola. The present study can provided help for the deep development of Rhodiola resources and application in pharmaceutical industry.1. Based on the single factor experiments, the effect of three major factors, including temperature,ethanol concentration and solid-liquid ratio, on extraction yield of the two major target compounds from Rhodiola rosea was investigated to optimize the extraction process by central composite design. The regression equation and response surfaee figure from three factor interaction were presented and the obtained optimum extraction conditions were as follows: ethanol concentration 70% (v/v), solid-liquid ratio 1:10 (w/v, g/mL), extraction temperature 75℃, extraction twice 60 minutes for each time. Under the optimum extraction conditions, the yields of rosavin and salidroside can reach 0.80% and 0.37%, respectively. At the same time dynamics and thermodynamics of the extraction were investigated. Thermodynamic parameters, such as standard enthalpy (ΔH0), standard entropy (ΔS0) and standard Gibbs free energy (ΔG0), were evaluated by Van’t Hoff equation. The results showed that dynamic data of extraction were well fitted to mathematical model deduced on the basis of the Fick’s Second Law and diffusion coefficients of salidroside and rosavin were 0.75×10-9 (m2/s) and 0.41×10-9(m2/s), respectively. The salidroside and rosavin extraction was a endothermic, entropy increase and spontaneous processes according to values ofΔH0,ΔS0 andΔG0.2. In static and dynamic experiments, according to adsorption and desorption properties and selectivity of different resins, HPD-200 was selected to separation and purification of the two major active compounds (salidroside and rosavin) and its adsorption isotherm was well fitted to Langmuir equation. Its adsorption kinetics and thermodynamics for the two compounds were also studied. Sorption data were fitted to pseudo-first-order, pseudo-second-order, intra-particle diffusion models, and found that adsorption kinetics can be described according to the pseudo-second-order model. The intra-particle diffusion model showed a double contribution of the surface and pore diffusivities to the sorption process. The sorption process was a exothermic and spontaneous processes and high temperature was not favorable to adsorption. Dynamic adsorption and desorption tests were carried to optimize the separation process. The optimum separation conditions were as follow: On adsorption, the loading volume was 6.4 mL(sample)/g resin (on dry weight), the concentrations of two comounds in feed solution 1.89mg/mL(salidroside) and 0.24 mg/mL (rosavin), respectively, temperature 25℃,bed height 30 cm, flow rate 1BV/h; on desorption, temperature was 25℃, gradient elution step was firstly 5% and 10%ethanol, respectively, for 2.5 BV, then 30% ethanol for 2.5 BV, and 40% ethanol for 2.5 (BV), finally 60% ethanol for 2BV. After two adsorption and desorption runs, the purity of salidroside and rosavin was increased from 5.57% and 0.69% in Rhodiola rosea crude extract to 91.21% and 15.37% with a overall recovery of 48.82% and 46.52%, respectively. On the base of the conditions optimized above, large-scale preparation of salidroside and rosavin was carried out to allow production of a salidroside-rich fraction with a purity of 90.36% and a overall recovery of 44.75, and a rosavin-rich fraction with a content of 16.02% and a overall recovery of 52.02%.3. Crystallization was performed to purify the salidroside-rich fraction from the large-scale preparation. The optimum crystallization conditions were determined as follows: the salidroside concentration in ethanol solution (w/v) was 20.5mg/mL, temperature 15℃, time 16 h, under which, salidroside crystals with a above 99.18% purity were obtained. The rosavin-rich fraction in large-scale preparation was subsequently subjected to intermediate purification on a silica gel column and a final purification on a ADS-5c resin column . The optimum conditions on the silica gel column were as follows. Silica gel size was 200-300 mesh; packed bed height 25cm; sample amounts 50mg (sample)/g (silica gel); mobile phase chloroform-methanol (4:1, v/v); flow rate 1.5mL/min; elution volume 3BV. After the intermediate purification, the purity of crude rosavin was increased to 50.17 % from 16.02% with a recovery of 82.46%. The optimum conditions on the ADS-5c column were determined as follow. The sample amount was 16.7 mg (sample)/g (dry ADS-5c resin);elution solution 50% ethanol; flow rate 2BV/h. After the final purification, a rosavin monomer with a purity of 98.73% was obtained. In addition, from eluates obtained in the separation process of salidoside and rosavin by macroporous resins, 19 monomers were prepared by silica gel column chromatography and preparative reversed phase high performance liquid phase chromatography after clarification on macroporous resin.4. By UV, HPLC-ESI-MS, 1DNMR (1H-NMR, 13C-NMR, DEPT-135) and 2DNMR (1H-1H-COSY, HMQC and HMBC),15 monomers were elucidated as 4-[4-(β-D- glucopyranosyloxy)phenyl]-2-butanone, [4 - (β-glucopyranosyloxy) phenyl-2-propenoic acid, 2-(4-hydroxyphenyl)ethyl-6-(3,4,5-trihydroxybenzoate)-β-D-glucopyranoside(6’-O-Galloylsalidroside), 7-methoxy-Coumarin, epigallocatechin-3-O-gallate(EGCG),α-phenyl-taloside, 4-hydroxyl-benzoicacid, 3-phenyl-2-propenyl6-O-L-arabinofuranosyl-β-glucopyranoside, 3-phenyl-2-propenyl6-O-L-arabinopyranosyl-β-glucopyranoside, 3-phenyl-2-propenyl 6-O-L- xylopyranosyl-β-glucopyranoside,3-phenyl-2-propenyl-β-glucopyranoside, 2,7-dimethylocta -2,6-diene-1,4-diol (rosiridol), 2,7-dimethylocta-2-6-diene -1,4-diol1-O-β- D-glucopyranoside (rosiridin), 7-methoxycoumarin, p-hydroxyl-phenethylalcohol (tyrosol), of these compounds, 4-[4-(β-D-glucopyranosyloxy)phenyl]-2-butanone,6’-O-galloylsalidroside, 4-[4-(β-glucopyranosyloxy)phenyl]-2-propenoic acid, 7-methoxycoumarin were first identified in Rhodiola rosea.5. By optimizing the extraction, separation and analytical conditions, a sensitive and accurate high performance liquid chromatographic method has been developed for the simultaneous determination of six active compounds in different species of Rhodioa L. The analysis was performed on a Purospher STAR C18 column at 30℃using 20mmol/L aqueous ammonia acetate / methanol gradient system at a flow rate of 1.0mLmin-1 and photodiode array detection (DAD ) at wavelengths 276, 250 and 205 nm, respectively. The method showed good linearity and satisfactory accuracy and recoveries. The newly established HPLC-DAD quantitative method was subsequently utilized to simultaneously determine the quantities of the six active constituents in the samples. The results showed that the contents of the six active compounds ranged from 0.16-11.14 mg/g, 0-2.89 mg/g and 0-1.01 mg/g, 0-6.78 mg/g, 0-1.51 mg/g, 0-7.89 mg/g. The total content of the six active compounds ranged from 1.20-22.88 mg/g and there was a wide variation in content and species of the six active compounds in the samples with different varieties and habitats. Then, the HPLC method was used to conduct fingerprints of three species of Rhodiola. The characteristic analytical fingerprints of them showed 19 common peaks, and molecular weight of 19 peaks were determined by HPLC-ESI-MS method, out of these, according to the characteristic UV spectra, the information of molecular weight and structure provided by ESI–MS, 10 compounds were identified. The resulting fingerprints were examined by similarity analysis, cluster analysis and principal component analysis. The results indicated that there was a good similarity between the same variety of Rhodiola and vice versa, the chromatographic fingerprint can efficiently distinguish Rhodiola from different varieties.
【Key words】 Rhodiola rosea; extraction; macroporous resin; separation and purification; structure eludication; fingerprint;