飞天蜈蚣七中黄酮提取的动力学

根据天然植物中活性成分提取机理和扩散理论,对飞天蜈蚣七中黄酮提取的动力学进行研究。首先在不同提取温度、提取时间下测定提取液中黄酮的浓度,发现随着提取温度的升高、提取时间的增长,黄酮浓度不断增加并最终趋于平衡;然后以Fick第二定律、球形模型为基础建立提取过程中的动力学模型并求得了速率常数、活化能、内扩散系数、相对萃余率等动力学参数。建立的动力学模型可为飞天蜈蚣七黄酮提取的工艺条件优化和深层次研究奠定理论基础。     

飞天蜈蚣七多糖提取动力学研究

根据中草药浸提机制和扩散理论对飞天蜈蚣七多糖浸提的动力学进行初步研究。以Fick第二定律为基础,采用球形模型讨论液料比、提取时间、提取温度与飞天蜈蚣七中多糖浸出量之间的关系,从而建立提取过程中动力学模型,并由此推算出浸提多糖过程中的速率常数、活化能、相对萃余率、有效扩散系数等动力学参数。飞天蜈蚣七中多糖的浸出量随着温度的升高而增加、随着液料比的变化而变化、随着提取时间的增长而逐渐增加并最终趋于平衡;浸提多糖的相对萃余率符合指数模型;有效扩散系数也随着温度升高而增加并受到液料比的影响。研究得到的动力学模型可为飞天蜈蚣七多糖提取的工艺条件优化和深层次研究奠定理论基础。     

皂苷提取分离新技术研究进展

皂苷作为一种天然产物,具有多种生理活性。对皂苷的最新提取分离方法进行了总结,并对各方法的应用情况作了简要说明。     

人参皂苷的提取和精制工艺研究

以西洋参茎叶为原料，索氏提取法提取西洋参茎叶原料中人参皂苷，并采用高氯酸比色法，以人参皂苷标准品Re为对照品，分析西洋参茎和叶中人参皂苷的含量。结果表明，叶中人参皂苷的含量明显高于茎。故以叶为原料，研究不同的提取和精制工艺。结果表明：超声波提取人参皂苷提取率较水煎煮提取大。比较大孔树脂吸附和溶剂萃取两种不同精制工艺，正丁醇溶剂萃取精制得到的人参皂苷含量较大孔树脂吸附大，其人参皂苷提取率较大孔树脂吸附高，再经Al2O3脱色，得到西洋参叶人参皂苷含量均在90％以上。     

酶法提取无患子皂苷的工艺研究

采用酶法提取无患子皂苷,研究了酶的类型对无患子皂苷提取的影响,并通过正交实验优化酶法提取工艺。结果表明,纤维素酶有助于无患子皂苷的提取,酶提法的较优工艺条件为:纤维素酶用量为无患子粉末质量的0.1%,酶提时间2.5 h,酶提温度50℃,pH值4.7。此时,无患子皂苷的提取率达到86.59%,比未加酶处理时提高了19.63%。     

无患子皂苷的提取工艺初步研究

无患子由于其化学成分独特,特别是富含天然肥皂成分,近年来受到人们的广泛关注.近年发现,贵州省分布有大量的野生无患子树木群,但因受到经济和科技水平的限制而缺乏研究.实验采集本地自然生长的无患子为原料,测定其皂苷含量为20.58％,并与栽培种植无患子作对照,研究用水溶液提取、有机溶剂提取无患子的获得粗皂苷产品,结果发现采用...     

超声波提取苦瓜总皂苷的研究

研究了超声波提取苦瓜总皂苷的方法.实验结果表明,其最佳工艺条件为:超声温度50℃,超声功率450 W,超声时间40 min.与水浴振荡法相比,超声提取能减少提取时间,降低提取温度,但并不能显著提高皂苷的提取率.     

知母总皂苷元的提取工艺研究

知母总皂苷元由知母经提取和水解而得,通过单因素实验和正交实验,研究提取知母皂苷元的工艺条件。结果表明,在料液比为1∶4,每次提取的时间为40min的条件下,知母总皂苷的最佳提取工艺是:粉碎原料过45目筛,用浓度75%乙醇溶液在80℃下回流提取3次;知母总皂苷的最佳水解工艺为:加入总皂苷提取液体积2倍量的1.5mol/L盐酸,在120℃条件下水解2h。     

人参皂苷的提取和精制工艺研究

以西洋参茎叶为原料,索氏提取法提取西洋参茎叶原料中人参皂苷,并采用高氯酸比色法,以人参皂苷标准品Re为对照品,分析西洋参茎和叶中人参皂苷的含量。结果表明,叶中人参皂苷的含量明显高于茎。故以叶为原料,研究不同的提取和精制工艺。结果表明:超声波提取人参皂苷提取率较水煎煮提取大。比较大孔树脂吸附和溶剂萃取两种不同精制工艺,正丁醇溶剂萃取精制得到的人参皂苷含量较大孔树脂吸附大,其人参皂苷提取率较大孔树脂吸附高,再经A l2O3脱色,得到西洋参叶人参皂苷含量均在90%以上。     

苦瓜中提取苦瓜皂苷的工艺研究

研究了苦瓜皂苷的提取工艺,以粗苦瓜可皂苷收率为考察指标,以提取温度、提取次数、回流时间、乙醇浓度、料液比为考察因素,通过单因素实验确定了最佳提取条件:乙醇浓度80%,提取次数2次,温度60℃,回流时间1.5 h,料液比1:15。并经放大十倍的重现性试验,结果皂苷提取率3.20%。     

剑麻皂苷的萃取与絮凝工艺优化研究

以剑麻膏为原料,考察了表面活性剂的种类及浓度、料液比、超声功率、萃取时间、萃取次数和浸泡时间对剑麻皂苷萃取的影响。确定较佳萃取条件为:十二烷基硫酸钠浓度0.025 8 mol/L,料液比1∶10(g∶mL),超声功率120 W,萃取时间40 min,萃取次数3次,浸泡时间4 h。同时考察了絮凝剂的种类及添加量、絮凝温度和复合絮凝剂对剑麻皂苷富集的影响。确定较佳絮凝条件为:100 mL剑麻皂苷萃取液中先加20 mL 1%聚合氯化铝,再加2 mL 0.1%阳离子聚丙烯酰胺的复合絮凝剂,絮凝温度50℃。对在较佳的萃取和絮凝条件下所得絮凝物进行水解,结果显示,该工艺得到的剑麻皂素的质量比传统工艺提高了15.5%,每生产1 g剑麻皂素酸用量减少了81.2%,COD排放量减少了96.5%。     

茶皂素提取工艺及其应用研究进展

介绍了从茶籽饼提取茶皂素的生产工艺以及茶皂素的化学组成和理化性质,并重点综述了其表面活性、生物活性、药理活性及其在化妆品、洗涤剂和纺织工业等领域的研究和应用;就目前的生产和使用情况提出了一些看法和需要解决的问题。     

越橘花色苷不同提取工艺研究

对国产红豆越橘中花色苷的提取工艺进行了研究,得到了最佳提取工艺,即pH值为2的酸性水液提取,超滤法纯化。     

乙醇-氨水浸提法提取油茶饼粕中茶皂素的工艺研究

研究乙醇-氨水浸提法从油茶饼粕中提取茶皂素的提取工艺。以乙醇为提取剂,分别考察提取次数、氨水量、乙醇浓度、料液比、提取温度、提取时间对茶皂素得率的影响,再经正交试验L16(45)得到茶皂素最佳提取工艺为:提取温度78℃,脱脂茶枯质量与溶剂体积的比值(料液比)为1∶10(g/mL),提取时间55 m in,乙醇水溶液的体积分数为70%,氨水的体积分数为0.1%,其茶皂素得率达到22.41%。     

超临界CO2萃取大黄总蒽醌工艺研究

对大黄游离蒽醌的超临界萃取工艺进行了优化,确定最优萃取工艺条件为:静萃取时间60 m in,动萃取时间30 m in,夹带剂乙醇相对大黄用量3 mL/g,萃取温度45℃,萃取压力45 MPa。然后分别采用无机酸和生物酶对大黄结合蒽醌进行水解,以提取总蒽醌。结果表明:当盐酸浓度为5 mol/L,淀粉酶质量浓度为2 g/L,纤维素酶质量浓度为1 g/L时,大黄结合蒽醌的糖苷键达到最优水解,此时总蒽醌质量分数分别为2.46%、2.33%和2.23%。     

Kinetics of oil extraction from corn germ

This paper describes the effect of temperature and moisture content on the kinetics of oil extraction from corn germ flakes prepared by a dry degermination process. The experiments were carried out according to the factorial design 3². The moisture content in the extracted material was varied in the range 8%–12%, whereas the extraction temperature varied in the range 52.5°C–57.5°C. From the method of response surfaces, a functional dependence was established between the extraction rate, the moisture content in the material and the temperature of extraction. On the basis of this dependence, it was concluded that moisture content had a crucial effect on the rate of oil extraction. A decrease in moisture from 12% to 8% yielded a doubling of the extraction rate. On the other hand, temperature variations in the given range had no practical effect on the course of the extraction. Kinetics of oil extraction was determined according to the method developed in the Leningrad Institute of Oils and Fats (VNIIZh-method), modified to the extent described in the paper.     

The effect of extraction techniques on yield,extraction kinetics,and antioxidant activity of aqueous-methanolic extracts from nettle (Urtica dioica L.) leaves

Five extraction techniques, maceration, reflux, Soxhlet, Tillepape, and ultrasonic extraction, were used to obtain the extractive matter from nettle leaves. The antioxidant activity of extracts was assessed by DPPH, FRAP, and H₂O₂ test, while the total phenolic and total flavonoid content was determined according to the Folin–Ciocalteu and aluminium chloride methods, respectively. Model Ponomarev and a non-stationary diffusion model through the plant material were used for modelling extraction process. The extract obtained by Soxhlet extraction, containing higher amounts of extractive matter as well as phenolic and flavonoid compounds, showed better antioxidant activity than those obtained by other extraction techniques.     

Separation and Purification of Three High-Purity Isoflavonoids from Belamcanda chinensis (L.) DC. by Supercritical Fluid Extraction and High-Speed Counter-Current Chromatography

Supercritical fluid extraction (SFE) was used to extract three isoflavonoids including irigenin, irisfloretin and dichtomitin from Belamcanda chinensis (L.) DC. The parameters including pressure, temperature, sample particle size, and flow rate of CO₂ were optimized with an orthogonal test. Under the optimized conditions of 15 MPa, 55°C, a sample particle size of 20–40 mesh and CO₂ flow rate of 40 L h^?1. The process was then scaled up by 10 times using a preparative SFE system. The yield of the crude extract from SFE was 4.1%, which contained irigenin, irisfloretin, and dichtomitin 0.71%, 0.49%, and 0.05%, respectively. To compare the extraction methods, Soxhlet Extraction (SE) was performed. The results indicated that SFE was better than SE. Irigenin, irisfloretin, and dichtomitin in the SFE extract were then separated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (2:4:3:3, v/v). From 5.0 g of dry crude extract, 27.8 mg irigenin, 16.4 mg irisfloretin, and 2.1 mg dichtomitin were obtained at purities of 97.1%, 96.4%, and 98.0%, respectively, as determined by HPLC-PDA. These results well indicate that SFE and HSCCC are very powerful techniques for the extraction and purification of irigenin, irisfloretin, and dichtomitin from B. chinensis.