连续逆流提取氢化可的松的实验研究

首先对以乙酸丁酯为萃取剂从发酵液中萃取氢化可的松的液液平衡数据进行了测定,并在此基础上进行了多级逆流模拟试验和单级试验,最后以五级混合澄清槽为萃取设备,进行了连续逆流萃取试验。在选定的实验条件下,氢化可的松的萃取率可以达到98.7%,乙酸丁酯的消耗量相比现行的错流萃取工艺下降了50%。     

用离心萃取器连续逆流提取氢化可的松的研究

采用环隙式离心萃取器进行了提取氢化可的松的研究。用醋酸丁酯从发酵液中萃取氢化可的松 ,其传质过程受扩散因素控制 ,且分配系数随平衡水相浓度的增大而增大。开发了用环隙式离心萃取器连续逆流提取氢化可的松的工艺流程 ,当转速为 340 0～ 380 0r/min ,总流量为 40～ 75mL/min ,V(O ,有机相 )∶V(A ,水相 )为 (0 35～ 0 42 )∶1 0 0时 ,氢化可的松的萃取率为91 0 8%～ 93 16 % ,而厂家现行生产工艺采用的V(O)∶V(A)是 0 7∶1 0 ,氢化可的松的萃取率为90 %。因而 ,新工艺提高了氢化可的松的萃取率 ,降低了萃取剂耗量     

离心萃取器提取氢化可的松的工业试验研究

开发了用环隙式离心萃取器连续逆流提取氢化可的松的工艺流程，用D20和D230环隙式离心萃取器分别进行了台架试验和工业规模试验。台架试验结果表明，当转速为3400－4200r/min，醋酸丁酯与发酵液的流量分别为20mL／min和45mL/min时，氢化可的松粗品收率比工厂现行生产岗位的收率提高1．78％－12．1％，质量达到生产要求。工业试验结果表明，当转速为2000r/min，醋酸丁酯与发酵液的流量分别为1m^3/h和2m^3/h时，氢化可的松粗品收率比工厂现行生产岗位的收率提高2％，且减少了萃取剂耗量，降低了能耗。另外，用环隙式离心萃取器还可从染菌的发酵液中提取到氢化可的松。     

氢化可的松母液错流萃取行为研究

将氢化可的松母液解析为氢化可的松、表氢化可的松和６α－羟基ＲＳ三种组分，模拟了母液的表观分配系数。拟合结果与实验值符合较好，平均相对误差＜５．５％。     

氢化可的松和尼泊金乙酯共存时的分析

本文采用高效液相色谱法同时测定氢氟酸烧伤防治膏内氢化可的松和尼泊金乙酯，而不受其他组份的干扰，回收率氢化可的松、尼泊金乙酯分别为９８．４２％和９９．６２％。     

乙醇对氢化可的松在氯仿-水体系中分配行为的影响

氢化可的松在氯仿－水体系中分配系数的公式指出,用氢化可的松在两相中的溶解度可以预测其分配系数,通过实验分别研究了乙醇的浓度对氢化可的松在氯仿和水中溶解度及在两相中分配系数的影响。实验结果表明,乙醇的 度与氢化可的松在水中的溶解度呈线性关系;与氢化可的松在氯仿中的溶解度呈指数关系;与氢化可的松在氯仿－水体中的分配系数呈抛物线关系。此结果与理论预测存在偏差。这是由于乙醇在氯仿－水体系中分配系数很小,对     

荧光光谱法研究氢化可的松与牛血清白蛋白的结合作用

模拟人体pH值,在不同温度下采用荧光光谱和同步荧光光谱研究了氢化可的松与牛血清白蛋白(BSA)的相互作用及对其同步荧光的影响。结果表明,在pH值7.37的Tris-HCl缓冲溶液中,氢化可的松和BSA彼此扩散和碰撞达到动态平衡导致BSA荧光猝灭,属于动态猝灭机制。计算得到BSA与氢化可的松在25℃和37℃下动态猝灭的猝灭常数分别为1.98105×107 L.mol-1.s-1和2.05933×107 L.mol-1.s-1。根据热力学方程得出氢化可的松与BSA相互作用的参数,ΔH<0、ΔS>0,说明氢化可的松与BSA相互作用以静电引力为主。氢化可的松加入后,BSA同步荧光光谱(Δλ=60nm)的最大发射波长发生红移,表明色氨酸残基所处环境的极性增加。     

氢化可的松在氯仿—水体系中分配系数的预测

氢化可的松在氯仿－水体系中分配系数的预测汤志刚胡熙恩朱永贝睿（清华大学核能技术设计研究院，北京１０２２０１）关键词氢化可的松液－液平衡分配系数Ｍａｒｇｕｌｅｓ方程氯仿１前言Ｗｉｃｈｔｅｒｌｅ和Ｆｏｌｐｒｅｃｈｔｏｖａ［１］曾利用碘在氯仿和水中的溶解度...     

氢化可的松的合成工艺改进

以17α-羟基孕甾-4, 9(11)-二烯-3, 20-二酮-21-醋酸酯为原料,经溴羟化、脱溴及水解等三步反应合成目标化合物氢化可的松。溴代物不经分离并采用氢化三丁基锡代替传统的铬试剂进行脱溴反应,减少了操作步骤及三废排放量,并使反应总收率达到68%。产物结构经~1H NMR、~(13)C NMR及熔点等数据确证。     

光谱法研究β-环糊精与去氢氢化可的松相互作用

运用多种光谱技术研究β-环糊精（β—CD）与去氢氢化可的松（PN）的相互作用。结果表明,β-CD与PN可形成稳定1：1包结物,其包结常数为561L／mol（30℃）。且包结过程中焓变值（△H）和熵变值（△S）分别为-25．32kJ／mol和-0．031kJ／（mol·K）,表明其包结过程是一个焓驱动过程,两者之间的主要作用力是范德华力和氢键作用力。     

Separation of hydrocortisone and epi-hydrocortisone by solvent extraction

Solvent extraction, instead of traditional crystallization, is suggested as a new method for separation of hydrocortisone and its optical isomer, epi-hydrocortisone. The extraction behavior of alcohols, ketones, esters, ethers and chlorinated hydrocarbons was studied experimentally. For the industrial separation process it was found that the best solvents are n-butyl acetate or chloroform. The distribution coefficients of hydrocortisone and epi-hydrocortisone in an n-butyl acetate/water system at 17°C were found to be 9·98 and 2·62, respectively, and 5·57 and 1·93, respectively, in a chloroform/water system at 17°C. When n-butyl acetate or chloroform solution of crude hydrocortisone (the mixture of hydrocortisone, epi-hydrocortisone and other steroid impurities) was scrubbed by deionized water in a nine-stage cross-current at 25°C, the organic phase hydrocortisone purity increased from 78·10% to 98·22% (wt%) for the n-butyl acetate case and from 78·10% to 98·02% (wt%) for the chloroform case. The medicinal standard for hydrocortisone was attained. The effects of alcohol concentration, temperature, salting-out and pH on extraction are also discussed. ©1997 SCI     

Extraction of Hydrocortisone from the Fermentation Liquor with Annular Centrifugal Contactors

Abstract

A continuous countercurrent extraction process for the recovery of hydrocortisone from the fermentation liquor has been developed with annular centrifugal contactors. When the hydrocortisone was extracted from the fermentation liquor with the butyl acetate, the distribution ratio increased with increase of the hydrocortisone concentration in the equilibrium aqueous phase. Both the laboratory tests and the plant tests have been finished with Φ20 mm and Φ230 mm annular centrifugal contactors respectively. In the laboratory tests, when the rotor speed was 3400～4200 r/min, the fermentation liquor flow was 30～50 mL/min and the phase ratio (V_O/V_A) was 0.36～0.50, the percent recovery of hydrocortisone was higher than 92%. In the plant tests, when the rotor speed was 2000 r/min, the fermentation liquor flow was 2000 L/h and the butyl acetate flow was 1000 L/h, the percent recovery of hydrocortisone was about 96.5～98%.     

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...     

Bioconversion of hydrocortisone to prednisolone by immobilized bacterial cells in a two-liquid-phase system

Bioconversion of hydrocortisone to prednisolone by free, immobilized and reused immobilized cells of three bacterial strains (Bacillus sphaericus ATCC 13805, Bacillus sphaericus SRP III and Arthrobacter simplex 6946) in an aqueous and a two-liquid-phase system using different organic solvents was investigated. The experiments were carried out in a 125 cm³ shake flask at 27±2°C, 220 rpm for 96 h. The contents of prednisolone and hydrocortisone in samples taken at 0, 3, 6, 24, 48, 72, 96 and 144 h were determined by HPLC analysis. The immobilized bacterial cells showed higher prednisolone yield than the free form in an aqueous system. In the two-phase systems, the butyl acetate to aqueous media ratio of 1: 30 for all three bacterial strains in immobilized forms gave the highest prednisolone yields, at an incubation time of 144 h, of 87·6, 70·6 and 88·3% respectively. For an n-decane to aqueous ratio of 1: 6, moderate prednisolone yields of 81·8, 47·9 and 71·4% were obtained with shorter incubation times of 72, 96 and 6 h respectively. For cyclohexane and other alcohols, the organisms produced low yields of prednisolone (0–30%). Single reuse of all three immobilized bacterial cells gave a 3–20% lower yield of prednisolone than the non-reused cells. The increase in hydrocortisone concentration decreased the prednisolone production whereas increasing the n-decane to aqueous ratio from 1: 6 to 1: 3 caused no significant change in the productivity. © 1998 Society of Chemical Industry     

Extraction of water-soluble phenols from shale-chemical process water

The extraction of water-soluble phenols from the total phenol water of the Kiviter and Petroter shale-chemical processes with the following extractants was studied: butyl acetate, methyl isobutyl ketone, and a mixture of butyl acetate and isobutyl acetate.     

活性炭固载磷钼钨杂多酸催化合成醋酸正丁酯

采用在80～90℃的水浴中蒸发水分的方法,用活性炭对磷钼钨杂多酸进行了固载。并利用所制备的活性炭固载型杂多酸催化剂,探讨了醋酸正丁酯的合成反应条件。结果表明,加入5ml环已烷作带水剂,采用醇酸的摩尔比为1∶1.1,即加入10ml冰醋酸和14.4ml正丁醇,使用1.0克该固载型催化剂,用分水装置,在回流条件下反应2小时,酯产率可达92.3%。所用的负载型杂多酸催化剂重复使用四次后,产率仍有74.4%。