微波辅助双水相提取盾叶薯蓣中的皂苷成分

采用微波辅助乙醇/硫酸铵双水相体系,从盾叶薯蓣中提取皂苷成分. 实验结果表明,各种皂苷成分可有效地富集于醇相,盾叶新苷、三角叶皂苷、薯蓣皂苷元-葡萄糖三糖苷、薯蓣皂苷元-葡萄糖二糖苷、延龄草次苷的最大分配系数分别达89, 91, 93, 117和153. 微波辅助双水相提取皂苷成分的最佳药材/乙醇质量比为1:21,最佳相组成为乙醇25%(w),硫酸铵19%(w),该条件下的提取率为,总皂苷95.1%,盾叶新苷99.8%,三角叶皂苷97.4%,薯蓣皂苷元-葡萄糖三糖苷97.3%,薯蓣皂苷元-葡萄糖二糖苷86.6%,延龄草次苷63.2%.     

米曲霉直接转化盾叶薯蓣生产薯蓣皂苷元

利用米曲霉直接转化盾叶薯蓣制备了薯蓣皂苷元,转化中最重要的影响因素是pH、接种量和培养温度. 在pH 6.0的66.7 mmol/L Na2HPO4-KH2PO4缓冲液中,8%接种量、37℃培养84 h后提温至50℃继续转化8 h的条件下,薯蓣皂苷元得率可达17.06 mg/g,是粗酶液转化的6.77倍. 转化过程中甾体的总摩尔数分别是微波辅助提取和酸水解的1.73和1.47倍. 转化产物经质谱和核磁共振鉴定与薯蓣皂苷元同质. 直接微生物转化法优于酶解法.     

马拉硫磷对映体色谱拆分方法的建立

建立了马拉硫磷对映体的高效液相色谱正相体系拆分方法。分别应用了正己烷和石油醚两种流动相,在正己烷流动相体系中采用了乙醇、丙醇、异丙醇、丁醇和异丁醇有机改性剂,石油醚体系则以异丙醇为改性剂,考察,改性剂及其含量对拆分的影响。同时还考察了温度对分离的影响。实验结果显示,室温下正己烷流动相中含5％异丁醇可达最佳分离效果,分离因子为1．22。流动相中醇的含量减少使保留时间延长,分离效果增加。低温有利于对映体的分离。     

硫酸催化黄姜提取液中薯蓣皂苷水解

研究了硫酸催化黄姜提取液中薯蓣皂苷水解的优化。通过正交试验研究了硫酸浓度、水解温度、水解时间等因素对薯蓣皂苷水解的影响。水解温度对薯蓣皂苷元收率的影响最为显著,其次为水解时间和硫酸浓度;黄姜提取液的最佳水解条件为:水解温度为90℃,水解时间为3 h,硫酸浓度为1.0 mol/L。     

近临界水中薯蓣皂苷水解生成薯蓣皂苷元的工艺研究

薯蓣皂苷元是合成甾体激素类药物和甾体避孕药的重要中间体,传统工艺采用盐酸水解法将黄姜中的薯蓣皂苷水解生成薯蓣皂苷元,反应时间4 h,最大收率为1.78%.该工艺反应时间长,耗水量大,对环境污染严重.今研究了无催化剂条件下,近临界水中薯蓣皂苷水解成薯蓣皂苷元的工艺,分别考察了反应温度、反应压力、反应时间等因素对薯蓣皂苷元收率的影响.研究结果表明,近临界水解法工艺简单,反应时间短,对环境友好,在较佳工艺条件下:P=25.0 MPa,T=260℃,t=10 min,薯蓣皂苷元收率为1.46%.     

多元复合酶降解黄姜薯蓣皂苷元的工艺研究

研究了多元复合酶降解黄姜薯蓣皂苷工艺条件对黄姜薯蓣皂苷元收率的影响因素。结果表明：采用碱性果胶 酶+单宁酶+半纤维素酶+β-葡萄糖苷酶4元复合酶的组合形式,在酶用量为黄姜量的 1.5%,pH值为6.5,料液比为 1：4（g：g）,50℃ 下酶解 10 h,以乙醇为萃取剂的条件下进行的降解效果最好,薯蓣皂苷元的收率最高可达 4.34%。相比收率仅为 1.61% 的传统的酸解工艺,应用多元复合酶解工艺最高可使黄姜薯蓣皂苷元的收率提高1.69倍。     

近临界水中薯蓣皂苷的水解反应

在近临界水中研究了薯蓣皂苷水解成薯蓣皂苷元的工艺和反应动力学,分别考察了反应温度、压力、时间等因素对薯蓣皂苷元收率的影响。实验结果表明,近临界水解法的较佳工艺条件为260℃,25 MPa,反应10 min。在此条件下,薯蓣皂苷元收率为1.46%。动力学研究结果表明,薯蓣皂苷在近临界水中水解是一级反应,活化能为76.7 kJ/mol,指前因子k0为5.99×104s-1。     

嗜热糖苷酶Fpendo5A转化绞股蓝皂苷XLIX的产物鉴定及分离纯化

目的对嗜热糖苷酶Fpendo5A转化绞股蓝皂苷XLIX的产物进行鉴定及分离纯化。方法应用Fpendo5A酶转化绞股蓝皂苷XLIX,通过高效液相色谱法(HPLC)和快速分离液相色谱-四极杆-飞行时间质谱法(rapid resolution liquid chromatography-quadrupole-time of flight-mass spectrometry/mass spectrometry,RRLC-Q-TOF MS/MS)对转化产物进行鉴定,全制备型高效液相色谱对转化产物进行分离纯化。结果在65℃和p H 6.0条件下,利用Fpendo5A酶转化绞股蓝皂苷XLIX 48 h后,获得单一转化产物,该酶能够水解绞股蓝皂苷XLIX的C20位葡萄糖苷键,生成长梗绞股蓝皂苷Ⅰ。纯化后的转化产物纯度达95.42%,产率为21.6%。结论利用Fpendo5A酶能够成功转化绞股蓝皂苷XLIX,纯化后的绞股蓝皂苷转化产物纯度好,产率高,为今后的药理活性及相关基础研究奠定了基础。     

延龄草苷的合成方法研究

延龄草苷为薯蓣皂苷元-3-O-β-D-吡喃葡萄糖苷,来源于中药延龄草,为甾体皂苷类化合物,具有广泛的生物活性.通过两种方法合成延龄草苷:Koenigs-Knorr法,以溴代糖为糖基供体,以碳酸银作为催化剂,将薯蓣皂苷元与溴代-α-D-四乙酰葡萄糖成苷合成延龄草苷;三氟化硼-乙醚催化法,全乙酰葡萄糖作为糖供体,将薯蓣皂苷元与α-D-五乙酰葡萄糖成苷合成延龄草苷.合成产物和中间体的结构经1H-NMR和13C-NMR法确认.比较两种合成方法:Koenigs-Knorr法路线较长,步骤略为繁琐,收率较高,为74.7％;三氟化硼-乙醚催化法路线较短,反应迅速,成本更低,但收率较低,为34.9％.采用的两种方法均具有操作简单、反应条件温和的优点,可为延龄草苷的广泛应用提供物质保证,并为甾体皂苷类化合物的化学合成提供技术支持.     

伴有水解缩合反应的种子乳液聚合动力学(Ⅰ)模型

伴有水解缩合反应的自由基种子乳液聚合反应是制备有机-无机杂化乳胶粒的一种新方法,水解缩合反应和自由基聚合这两种反应在乳液体系中的动力学耦合过程决定了聚合产物的微结构和应用性质.通过单体的分配系数建立了单体在乳液体系中各相的分配模型,进而建立了考虑单体分配的自由基种子乳液共聚合的动力学模型.针对功能基团在乳液各相中水解缩合反应的特点,结合自由基种子乳液共聚合的动力学模型,建立了伴有水解缩合反应的自由基种子乳液聚合动力学模型.该模型反映了反应过程中的物质传递规律、非均相反应特点、自由基共聚合和水解缩合反应间的耦合关系.     

Novel Gas-assisted Three-liquid-phase Extraction System for Simultaneous Separation and Concentration of Anthraquinones in Herbal Extract

abstract Gas-assisted three-liquid-phase extraction (GATE), which has the advantages of both three-liquid-phase extrac-tion and solvent sublation, is a novel separation technique for separation and con...     

Pathways for the steroidal saponins conversion to diosgenin during acid hydrolysis of Dioscorea zingiberensis C. H. Wright

Diosgenin is an important starting material for the synthesis of steroidal hormone drugs in pharmaceutical industry. Acid hydrolysis of Dioscorea zingiberensis C. H. Wright (DZW) was the key step in the conversion of steroidal saponins to diosgenin in its manufacture factories. The pathways for the conversion of steroidal saponins to diosgenin during acid hydrolysis of DZW were studied experimentally. Three intermediate products and one byproduct were identified. The conversion pathways were from raw steroidal saponins zingiberensis newsaponin (1), deltonin (2), prosapogenin A of dioscin (3) to three intermediate products diosgenin-triglucoside (4), diosgenin-diglucoside (5) and trillin (6), and then to the product diosgenin (7) and byproduct 25-spirosta-3, 5-dienes (8). A maximum diosgenin yield of 2.5% was achieved when reacting in 0.8 M sulfuric acid for 6 h at 120 °C, while the intermediate products were just exhausted. After 6 h, the diosgenin yield decreased, due to the conversion of diosgenin to 25-spirosta-3, 5-dienes (8). The knowledge of the pathways for the conversion of steroidal saponins to diosgenin provide a scientific basis for assessing the performance of acid hydrolysis reaction in diosgenin manufacture factories by monitoring the content of three intermediate products (4-6). It also gives an alternative method for the synthesis of diosgenyl saponins (4-6) from plant material.     

Three-liquid-phase salting-out extraction of effective components from waste liquor of processing sea cucumber

A three-liquid-phase (TLP) salting-out extraction system composed of n-hexane/ethanol/sodium carbonate/water was investigated to extract oils, saponins, proteins and polysaccharides simultaneously from waste liquor of processing sea cucumber. The effects of the ratio of ethanol to sodium carbonate, n-hexane concentration and extraction time were investigated. The results showed that 86.7% of oils were distributed in the top n-hexane phase, 82.9% of saponins in the middle ethanol phase, 93.2% of proteins and 92.9% of polysaccharides in the interface between the middle and the bottom salt phase when the system composed of 28% (w/w) n-hexane/11.52% (w/w) ethanol/8.64% (w/w) sodium carbonate was used at 37 °C for 0.5 h. When the system was progressively enlarged from 30 g to 25 kg, the yield of polysaccharides, proteins, oils and saponins was decreased only by 1.0%, 2.8%, 1.0% and 2.6%, respectively. The recycle of salt and solvents in three-liquid-phase system was also studied, and the results showed that the recovery of n-hexane, ethanol and salt were 81.4%, 80.8% and 72.0%, respectively. Recycling materials for the extraction, the yield for proteins and oils decreased by 2.0% and 5.4%, respectively, comparing with the pure system.     

液液液三相萃取装置:操作参数对传质效率的影响(英文)

A new mixer-settler-mixer three chamber integrated extractor is proposed in this work for liquid-liquid-liquid three phase countercurrent and continuous extraction.Experiments revealed the influences of the structural design of the three-liquid-phase extractor and some key operational parameters on three-phase partition of two phenolic isomers,p-nitrophenol(p-NP) and o-nitrophenol(o-NP).The model three-liquid-phase extraction system used here is nonane(organic top-phase)-polyethylene glycol(PEG 2000)(polymer middle-phase)-(NH4)2SO4 aqueous solution(aqueous bottom-phase).It is indicated that agitating speed and retention time in three-phase mixer are key parameters to extraction fraction of nitrophenol.Dispersion band behavior is related to agitating in-tensity,and its occurrence does not affect the extraction fraction of target compounds.The present work highlights the possibility of a feasible approach of scaling up of the proposed three-phase extraction apparatus for future in-dustrial-aimed applications.     

Combined Ozone and Ultrasound for the Removal of 1,4-Dioxane from Drinking Water

Ozone, ultrasound, and ozone/ultrasound processes were evaluated for the removal of 1,4-dioxane from tap water using a continuous flow reactor with on-line aqueous ozone measurement. The addition of ultrasound to ozone was found to significantly boost removal. The removal of 1,4-dioxane by ozone/ultrasound process exceeded the sum of the removals from ozone alone and ultrasound alone. Ultrasound alone showed less than 20% removal of 1,4-dioxane. The effects of reactor pressurization and bicarbonate as a hydroxyl radical scavenger were also studied. It was observed that at constant aqueous ozone concentration, additional pressure in the reactor tended to mute the 1,4-dioxane removal boost noted in the ozone/ultrasound process, while additional pressure did not affect 1,4-dioxane removal via ozone alone. The removal of 1,4-dioxane was found to be dependent on the consumption of aqueous ozone, and the consumption of ozone was found to be increased by either the addition of ultrasound or by increasing pH. Rate constants were calculated for various ozone concentrations for the ozone and ozone/ultrasound processes and the systems were fitted to a Chick–Watson model.     

Partition Behavior of Penicillin in Three-liquid-phase Extraction System

Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system, which is composed of butyl acetate (BA), polyethylene glycol (PEG), ammonia sulfate [(NH4)2SO4] and water (H2O). The main components in the top, middle and bottom phases are butyl acetate, polyethylene glycol aqueous solution and ammonia sulfate aqueous solution, respectively. Some parameters such as partition coefficients Di/j and mass fractions Ei of penicillins G and V were determined at the room temperature, respectively. Experimental efforts have been made to investigate the partition behavior of penicillin in the three-liquid-phase extraction system, including initial concentrations of phase-forming components [PEG and (NH4)2SO4], PEG molecular weight, pH, initial concentration of penicillin. The results indicated that penicillins G and V have the similar partition behavior. They preferentially distribute into the middle phase with the increase of initial concentration of phase-forming components and into the top phase with the decrease of pH, while partition coefficient Dm/b is hardly affected by pH value. The variation of PEG molecular weight has little effect on mass fractions of penicillin. The increase of initial concentration of penicillins G and V could lead to the increase of Dt/b, Dm/b and the decrease of Dt/m, while their mass fractions in all phases were almost independent on their initial concentrations.     

液-液萃取及新型液-液-液三相萃取机理研究进展

根据新型液-液-液三相体系的特点,对传统两相溶剂萃取、双水相萃取机理研究进展进行了综述,提出应用Lewis酸碱理论对两种萃取体系的萃取机理分别进行归类,评述了新型液-液-液三相体系研究进展并对其研究方向进行了展望。