【作者】 李俊业；

【导师】 方桂珍；

【作者基本信息】 东北林业大学 ， 林产化学加工工程， 2009， 硕士

【摘要】 慢性肾功能衰竭是一种以临床中毒症状为特征的严重疾病,病因主要是体内积蓄了大量的毒素,因此去除体内过量的毒素是治疗慢性肾衰竭的关键,其中尿素和肌酐是患者体内积聚的两种主要毒素。本研究以微晶纤维素为原料,根据尿素和肌酐的性质,创造性的设计、合成了两种新型治疗慢性肾衰竭的复合靶向吸附剂——苦味酸-纤维素醚和苦味酸-氧化纤维素酯,并将其应用于对尿素和肌酐的吸附。以微晶纤维素（MCC）为原料,经环氧化和醚化反应,制备了苦味酸-纤维素醚（MCC-PA）。采用红外光谱、元素分析、XRD等对其进行结构表征。以含氮量为优化指标,考察了物料比,氢氧化钠（质量分数36%）的用量,反应温度和反应时间对苦味酸-纤维素醚制备的影响。通过单因素实验得出合成条件为:苦味酸（PA）和环氧化纤维素和质量比为5:1,NaOH用量为30mL,反应温度为45℃,反应时间为3h,此时产物的含氮量为2.22%,通过红外光谱可知苦味酸-纤维素醚已经生成,并通过XRD光谱计算出苦味酸-纤维素醚的结晶度为75.7%。在模拟人体生理介质的条件下,测定了苦味酸-纤维素醚对肌酐的吸附性能,绘制了吸附动力学曲线。结果表明,苦味酸-纤维素醚对肌酐的吸附平衡时间为18h,对肌酐的最大吸附容量为2.49mg/g。在吡啶做溶剂兼催化剂条件下,以草酰氯为交联剂,将苦味酸接枝到氧化纤维素C₆位羟基上,得到复合靶向口服吸附剂苦味酸-氧化纤维素酯（DAC-PA）。采用红外光谱、SEM、XRD等对其进行结构表征,以其对肌酐吸附容量为优化指标,考察了草酰氯与苦味酸的摩尔比,第一步反应温度（T1）,第一步反应时间（H2）,氧化纤维素的加入量,第二步反应温度（T2）,第二步反应时间（H2）对苦味酸-氧化纤维素酯制备的影响。通过单因素实验得出合成条件为:草酰氯与苦味酸的摩尔比为1.1:1,T1为40℃,H1为3h,氧化纤维素的加入量为1g,T2为75℃,H2为4h。红外光谱表明苦味酸-氧化纤维素酯已经生成,XRD图谱和SEM扫描表明,产物的结晶结构和表面结构已经发生了变化。在模拟人体生理介质的条件下,测定了苦味酸-氧化纤维素酯对肌酐和尿素的吸附性能,绘制了吸附动力学曲线。结果表明,苦味酸-氧化纤维素酯对肌酐的吸附平衡时间为10h,最大吸附容量为3.5mg/g,对尿素的吸附平衡时间为10h,最大吸附容量为23.7mg/g。通过测定苦味酸-氧化纤维素酯对肌酐的吸附等温曲线,说明在25～50℃和所研究的浓度范围内肌酐在DAC-PA上的吸附等温线符合Freundich方程,苦味酸-氧化纤维素酯对肌酐的吸附为以化学吸附为主的吸热过程。选择对尿素、肌酐具有较好吸附作用的、以酯键连接的3,5-二硝基苯甲酸氧化纤维素酯做稳定性研究。因为其可能的水解产物3,5-二硝基苯甲酸为酸性物质,会刺激胃肠粘膜,在空气中放置一段时间后其对尿素和肌酐的吸附容量可能会发,且水解产物单一,便于检测。在模拟人体生理介质的条件下,分析不同pH值、水解时间以及放置时间对其稳定性的影响。结果表明,4-6h内DCNB在pH=1、pH=2、pH=8的缓冲溶液中,DCNB的水解率分别为0.06%-0.11%、0.01%-0.03%、3.01%-3.50%。室温放置六个月后,37℃时其对肌酐、尿素的饱和吸附容量与新制的DCNB相比基本没有发生变化。3,5—二硝基苯甲酸氧化纤维素酯具有较好的稳定性。更多还原

【Abstract】 Chronic renal failure(CRF)is severe disease which is characterized by clinical symptom of poisoning,depositing large numbers of toxins in organism is the main cause of CRF,therefore Removal of the excess toxins is the key problem for the treatment of CRF.Urea and creatinine are two of the major toxins to the patient who suffered from chronic renal failure.In this study,according to the properties of urea and creatinine,two new oral adsorbent named ether of microcrystalline cellulose-based picric acid(MCC-PA) and ester of dialdehyde cellulose-based picric acid(DAC-PA)were prepared and their adsorption for creatinine and urea were studied.The new ether of microcrystalline cellulose-based picric acid(MCC-PA)was prepared from microcrystalline cellulose by the reaction of epoxidation and etherification.The structure of MCC-PA was analyzed by FTIR,element analyzer,XRD,etc.Influences of reaction conditions such as the ratio of epoxy cellulose and picric acid(PA),volume of NaOH(36%,by weight),reaction time and reaction temperature were investigated with nitrogen content as optimization index.The results showed that the synthetical conditions was that the ratio of epoxy cellulose and Picric acid was 5 to 1 by weight,the volume of NaoH(36%,by weight) was 30 mL,reaction temperature was 45℃and reaction time was 3 hours with the nitrogen content of 2.22%by single-factor experiment.The FTIR showed that MCC-PA have been synthesized,and the XRD showed that the degree of crystallinity of MCC-PA is 75.7%.The adsorption property of MCC-PA for creatinine were studied under simulated biological conditions and The kinetic curve was drawn.The results showed that adsorption equilibrium reached after 18 hours and the maximal adsorption capacity for creatinine was 2.49mg/g.The multi-effect oral adsorbent DAC-PA was prepared by esterification of DAC and picric acid with oxalyl chloride as substance for crosslinking reaction and pyridine as solvent and catalyst.The product was characterized by FTIR,XRD,SEM.investigated The effects of molar ratio of the materials,reaction temperature in the first step(T1),reaction time in the first step(H1),amount of dialdehyde cellulose,reaction temperature in the second step(T2) and reaction time in the second step(H2)were investigated with adsorbtion capacity of DAC-PA for creatinie as optimization index.The results showed that a high adsorption capacity for creatinine of 3.5mg/g was obtained when the molar ratio of oxalyl chloride to picric acid was 1.1 to 1,T1 was 3 hours,H1 was 40℃,the amount of dialdehyde cellulose was 1g,T2 was 75℃,H2 was 4h.The FTIR showed that MCC-PA have been synthesized,XRD and SEM showed that both crystal structure and surface structure of DAC-PA had been changed.The adsorption property of MCC-PA for creatinine and urea were studied under simulated biological conditions and the kinetic curve was drawn.The results showed that adsorption equilibrium for creatinine reached after 10 hours and the maximal adsorption capacity for creatinine was 3.5mg/g while the adsorption equilibrium for urea reached after 10 hours and the maximal adsorption capacity for urea was 23.7mg/g.Equilibrium data of creatinine fitted well with Freundich equation within temperature range from 20℃to 50℃and investigative concentration range.The adsorption of creatinine on MCC-PA was a chemically endothermic process.Dialdehyde cellulose 3,5-dinitrobenzoate which contained ester bond and had good adsorption for urea and creatinine was selected for study of Stability,Because 3,5-Dinitrobenzoic acid which is the hydrolysate of DCNB is an acidic substance,and dissociative 3,5-Dinitrobenzoic acid might stimulates gastrointestinal mucous membrane,adsorption capacity of DCNB for urea and creatinine might change when it is exposured in the air for a period of time,moreover hydrolysis product of DCNB is single and convenient to detect.The stability properties of DCNB were studied under simulated body conditions in the paper.The influence of pH,hydrolysis time and time exposured in the air to stability of DCNB was studied.The results showed that between 4 to 6 hours,the hydrolysis rate of DCNB is 0.06% 0.11%,0.01%～0.03%and 3.01%～3.50%in the buffer solution of pH=1,pH=2 and pH=8 respectively.When the DCNB was exposured in the air for six month,The Saturated adsorption capacity of DCNB for urea and creatinine didn’t change obviously compared with new-made DCNB.In conclusion,the DCNB had a good stability property.更多还原