高速逆流色谱法纯化丹酚酸B工艺研究

运用高速逆流色谱法(High-speed counter-current chromatography,HSCCC)分离纯化丹酚酸B。建立了石油醚-乙酸乙酯-甲醇-水-甲酸两相溶剂系统,确定最佳纯化工艺条件为:转速1800 r.min-1,流速1.0 mL.min-1,温度30℃。纯化后的丹酚酸B经HPLC检测,纯度达98.3%。表明高速逆流色谱法分离纯化丹酚酸B具有快速、简便、纯度高等优点,可用于丹酚酸B的制备。     

丹参叶保质干燥工艺的研究

针对丹参叶进行保质干燥,通过单因素和正交试验研究了干燥温度、风速和物料层厚度对丹参叶中丹酚酸B含量的影响。研究表明,通过单因素确定较优的干燥参数为：干燥温度50℃,风速0．6m／s,物料厚度为2层;在单因素实验基础上,通过正交实验确定的最佳保质干燥工艺参数为：A3B2C1,即干燥温度为60℃、干燥风速为0．6m／s、物料厚度为1层。     

基于高效液相色谱法研究铜仁地区丹参中丹酚酸B的含量

目的:基于高效液相色谱法对铜仁地区丹参中的丹酚酸B含量进行探究。方法:采用Hubble C 18色谱柱(200 mm×4.6 mm,5μm),以V(乙腈)∶V(0.1%磷酸溶液)=22∶78为流动相进行洗脱,流速为1.2 m L/min。波长为286 nm;柱温为20℃;,检测波长为270nm,柱温为25℃。结果:通过实验证明其精密度、线性、重复性和稳定性均良好,显示该分析方法可行有效。结论:铜仁各产地丹参中丹酚酸B含量均符合国家标准,铜仁地区环境适应于丹参的生长栽培。     

丹参水溶性提取物丹参酚酸B的制备及应用

探讨丹参水溶性提取物丹参酚酸B的制备及其生物转化应用研究。以丹参酚酸B的出膏率和提取率为评价指标,比较丹参水溶性提取法包括水煎煮回流法、超声提取法、渗漉提取法,采用高效液相色谱（HPLC）法测定。研究发现,常规水煎煮回流法中丹参酚酸B提取率最高可达72.59%,远高于超声提取法的63.72%和渗漉提取法的65.69%(P<0.05)。丹参酚酸B的生物转化应用结果显示,100 g丹参酚酸B可以制备出14.2 g丹参素（纯度≥95%）和35.8 g Prewalskinic acid A（纯度≥91%）,转化效率高。对丹参水溶性提取物丹参酚酸B的制备工艺进行了相关研究,获得了简便、高效、科学的工艺路线,该研究为丹参的进一步开发和实际应用奠定了理论和实践基础。     

大孔树脂吸附分离丹参提取液中丹酚酸B的工艺研究

对国内几种大孔吸附树脂的丹酚酸B吸附性能进行了实验筛选。结果表明。YWD06树脂有较好的吸附和洗脱能力;适宜吸附条件：pH值控制在4-5、流速为2BV/h;以70%乙醇为洗脱剂,pH值=5、流速为3BV/h时,洗脱效果好。     

大孔树脂吸附分离丹参提取液中丹酚酸B的工艺研究

对国内几种大孔吸附树脂的丹酚酸B吸附性能进行了实验筛选。结果表明。YWD06树脂有较好的吸附和洗脱能力;适宜吸附条件:pH控制在4～5、流速为2BV/h;以70%乙醇为洗脱剂,pH=5、流速为3BV/h时,洗脱效果好。     

丹参叶绿茶的保质干燥技术研究

为了发展丹参叶绿茶产品,本文研究了不同干燥方法对丹参叶有效成分的影响。以丹酚酸B和叶绿素含量等指标确定了热风干燥和真空冷冻干燥的最佳工艺参数,并与丹参叶中的有效成分进行比较。最终确定的热风干燥的最佳工艺参数为温度60℃,风速0．6m／s,物料厚度为2层。真空冷冻干燥的最佳工艺参数为采用-25℃进行预冻,保持2h左右的时间,50Pa升华22h左右,20℃解析14h。结果表明真空冷冻干燥是丹参叶绿茶保质干燥的最佳方法,其对丹参叶中的丹酚酸B和叶绿素含量保留率分别为98．76％和82．21％。     

复合式酶法提取丹酚酸B

运用离效液相色谱技术对丹参中丹酚酸B的复合式酶法提取及水煎提法进行了比较分析.复合式酶法提取丹酚酸B的最佳工艺:每克药材加入15 U纤维素酶,在50 ℃下,pH值4.5,提取6 h,药渣加水煎提50 min.复合式酶法提取明显提高了丹参中丹酚酸B的提取率.     

中药丹参水溶性成分丹酚酸B醇沉工艺优化研究

目的：优化丹参水溶性成分丹酚酸B的醇沉工艺方法：以溶液中总固体率、丹酚酸B的损失率以及丹酚酸B的含量作为指标,醇沉的体积分数、相对密度、温度、时间为影响因素,优化丹酚酸B的醇沉工艺结果：最佳条件为减压浓缩至相对密度1.05～1.15,边搅拌边加入95%乙醇,调乙醇含量至70%,在10～35℃环境下静置24 h,总固体去除率为27.3%,丹酚酸B的损失率4.96%,丹酚酸B的含量为13.81%。结论：该方法简单可行,可用于醇沉纯化丹参中丹酚酸B。     

丹参酚酸B水提取动力学研究进展

论述了丹参中丹参酚酸B水提取过程的动力学因素,着重分析了提取温度、提取时间、药材粒度等因素对丹参酚酸提取过程的影响,并借助现有模型来进行描述.     

The Thin-Layer Drying Characterstics of White Onion Slices

ABSTRACT

A batch–type experimental dryer with a computer–aided data acquisition system was designed and built for the thin layer drying studies of onion (Allium cew L., cv. Southport White Globe) slices. Twenty seven single–layer drying curves were established for a temperature range of 42.5–90⁰C, an air velocity range of 0.6–1.4 m/s, an air humidity range of 0.0093–0.0442 kg of water/kg of dry air: and a slice thickness range of 0.002–0.005 m. The single–term exponential model adequately described the single–layer drying behaviour of the onion slices. l'he dependence of the drying rate constant on air temperature, absolute humidity, velocity and on slice thickness was best explained by an Arrhenius–type relationship. The drying rate constant in which moisture diffusion and shrinkage effects are lumped was greatly influenced by the sample thickness and drying air temperature, and to a lesser extent, by the air humidity and velocity.     

Evaluation of Wound Healing Activity of Salvianolic Acid B on In Vitro Experimental Model

Despite a wide range of bactericides and antiseptics, the treatment of chronic or complicated wounds is still a major challenge for modern medicine. Topical medications are the most sought-after new agents for use as treatment. The therapeutic concentration of their active substances is easy to achieve with the lowest possible burden on the patient’s body. This study assesses the effect of salvianolic acid B (Sal B) on the proliferation, migration, and production of collagen type III by fibroblasts, which are the most important processes in wound healing. The study was conducted on human gingival fibroblasts obtained from primary cell culture. The results showed that Sal B at a dose of 75 µg/mL increases the cell viability with significant stimulation of the cell migration as demonstrated in the wound healing assay, as well as an increase in the expression of collagen type III, which has great importance in the initial stages of wound scarring. The results obtained in the conducted studies and previous scientific reports on the antibacterial properties and low toxicity of Sal B indicate its high potential in wound healing.     

Effects of Acetic Acid Pretreatment and Hot Air Drying on Resistance of Salmonella on Cabbage Slices

The heat resistance of Salmonella anatum inoculated onto the surface of cabbage slices as affected by acetic acid pretreatment (0.5–1.5% v/v) and hot air drying at 50–60°C was investigated. Approximately 1.5 log₁₀ of Salmonella numbers was reduced after soaking the vegetables in acetic acid solution. The inhibitory effect of acetic acid on the bacteria was more pronounced during drying. The heat resistance of Salmonella on the cabbage surface treated with acetic acid decreased considerably compared with untreated cabbage. Moreover, the vegetable treated with higher acetic acid concentration resulted in a higher degree of acid injury and hence increased the susceptibility to heat during drying. The results revealed that acetic acid pretreatment may be used as an additional processing step to increase the safety margin of dried vegetable products.     

Modeling of degradation kinetics of Salvianolic acid B at different temperatures and pH values

In this work,the effects of degradation time,temperature,and pH value on the degradation of Salvianolic acid B in aqueous solution were determined.Higher pH values,higher extraction temperature,and longer extraction time led to more degradation of Salvianolic acid B.Danshensu concentration increased as Salvianolic acid B degraded.A mechanism model was developed considering the degradation of Salvianolic acid E and lithospermic acid,which were two degradation products of Salvianolic acid B.The reverse reactions of Salvianolic acid B degradation were also considered.Degradation kinetic constants were calibrated.The degradation kinetics of Salvianolic acid B,lithospermic acid,and Danshensu in a Salvia miltiorrhiza extract aqueous solution were predicted using the mechanism model.The predicted concentrations agreed well with the experimental results.This model was developed using degradation data obtained from simple composition systems,but it can be applied in a complex botanical mixture with high prediction accuracy.     

Ascorbic Acid Thermal Degradation during Hot Air Drying of Camu-Camu (Myrciaria dubia [H.B.K.] McVaugh) Slices at Different Air Temperatures

Abstract

Air drying of camu-camu slices was performed in order to estimate the effect of air temperature on the kinetics of ascorbic acid thermal degradation. Moisture variation during the air drying process was monitored gravimetrically by weighing the trays at predetermined time intervals. The experimental points were adjusted by Fick's diffusion model and by the Page empirical model. The effective diffusion coefficient (D_eff) ranged from 8.48 × 10^?10 to 1.34 × 10^?9 m²/s.The ascorbic acid content was evaluated in samples taken during the drying process using Iodine titration, and the results modeled by the Weibull equation. Concerning ascorbic acid retention the best drying condition required air at 50°C. The ascorbic acid retention was 78%, when the moisture content of the product reached 10% (wet basis).     

Linear and Nonlinear Drying Behavior in Tuberous Crop Slices

Understanding drying physics is a complex task because interactions between phases and variations in thermal properties change over time. In this investigation we used two models to simulate the drying of potatoes slices. Drying kinetics were modeled by both the drying characteristic curve (DCC) method and by a mechanistic approach implemented in COMSOL Multiphysics. The DCC was developed on the basis of experimental data and a referential drying rate, which for potatoes is the maximum evaporation rate during the process. The surface thermal evolution was considered to estimate the drying rate curve and the drying stages. The phenomenological model considers both the transport of free water and water vapor by applying a mechanistic approach. In order to simulate free water transport we took into account the capillary diffusivity term, and to simulate water vapor evacuation we considered the desorption isotherm. Two drying conditions were analyzed, 1.0 and 2.2 m/s of air flow with 60°C and 30% relative humidity (RH). The mechanistic model solves the primary unknown's moisture content, temperature, and dry air density. Both models were compared against experimental data. The simulation correctly describes the drying kinetics for the trial at 2.2 m/s and fails to simulate the phenomena at 1.0 m/s. Two different drying behaviors influenced by air flow speed were identified by following the evolution of surface temperature and mass flux. The dependence of mass flux on the difference in temperature (T_air?T_surface) shows that the area of exchange is a very important parameter to be considered in simulations, because both linear and nonlinear behaviors are manifested.     

Modeling Microwave Vacuum Drying Kinetics and Moisture Diffusivity of Carrot Slices

Carrot slices of 3.5 mm thickness were dried in a laboratory microwave vacuum dryer at five different microwave power density levels of 2, 4.66, 7.33, 10, and 12.66 W/g and at three vacuum chamber pressure levels of 6.66, 19.98, and 33.3 kPa to 4–6% d.b. moisture content. Inside the dryer the sample holding plate was rotated with the speed of 4 rpm for uniform microwaves application. The drying rates were increased with the increase in microwave power density at all pressure levels and the Page model was found to be the most suitable model to predict the drying behavior of carrot slices at all process conditions. The Page model drying rate constant (k, min^?1) showed high correlation with microwave power density at constant pressure by a power law equation and showed a logarithmic relationship with the microwave power density and pressure. Similar to the drying rate constant, the average moisture diffusivity at constant pressure was found to be function of microwave power density by power law equation as well as was also dependent on the power density and pressure by a logarithmic relationship.     

乙醇/硫酸铵双水相体系从丹参粗提液中分离丹酚酸B

采用中心复合设计的响应曲面法优化了乙醇/硫酸铵双水相体系从丹参粗提液中分离丹酚酸B的工艺参数,并对放大效果进行了对比研究。结果表明,在确定pH2.0和30℃的条件下,当硫酸铵和乙醇质量分数分别为20%和29%时,丹酚酸B的分配系数最大为58.7,回收率为97.3%。上相加乙醇脱除硫酸铵,减压浓缩、干燥,丹酚酸B的纯度为57.4%。与小试相比,放大40倍后,分配系数(59.3)、回收率(98.2%)和纯度（58.6%）均无显著差异（p<0.05）。500g丹参,经煮提,双水相萃取,脱硫酸铵,氯仿脱脂,乙酸乙脂萃取,可得26.1g浸膏,丹酚酸B的纯度为78.1%,总回收率为87.0%。因此,双水相萃取可以作为从丹参粗提液中规模分离丹酚酸B的有效手段。     

Modeling Microwave Vacuum Drying Kinetics and Moisture Diffusivity of Carrot Slices

Carrot slices of 3.5 mm thickness were dried in a laboratory microwave vacuum dryer at five different microwave power density levels of 2, 4.66, 7.33, 10, and 12.66 W/g and at three vacuum chamber pressure levels of 6.66, 19.98, and 33.3 kPa to 4-6% d.b. moisture content. Inside the dryer the sample holding plate was rotated with the speed of 4 rpm for uniform microwaves application. The drying rates were increased with the increase in microwave power density at all pressure levels and the Page model was found to be the most suitable model to predict the drying behavior of carrot slices at all process conditions. The Page model drying rate constant (k, min^-1) showed high correlation with microwave power density at constant pressure by a power law equation and showed a logarithmic relationship with the microwave power density and pressure. Similar to the drying rate constant, the average moisture diffusivity at constant pressure was found to be function of microwave power density by power law equation as well as was also dependent on the power density and pressure by a logarithmic relationship.     

磷钨酸催化合成苹果酯B

介绍以磷钨酸为催化剂,乙酰乙酸乙酯和１,２－丙二醇为原料合成苹果酯Ｂ,并经折光率,化学性质,红外光谱,核磁共振氢谱和碳谱确证其结构。