抗癌药紫杉醇及其衍生物多西他赛药理及毒理性质的密度泛函研究

采用密度泛函理论B3LYP方法在STO-3G基组上对抗癌药紫杉醇和多西紫杉醇分子进行优化并进行理论计算,对它们的分子构型、偶极距、红外光谱(IR)、紫外光谱(UV-Vis)、NBO电荷分布进行了分析。结果表明,紫杉醇和多西紫杉醇发挥其药理和毒理作用的最大可能部位在酰胺基的N原子上。     

HPLC法测定多西他赛及注射液的含量

建立了HPLC法测定多西他赛及注射液含量的新方法。用十八烷基硅烷键合硅胶为填充剂(ZORBAX C18),以0.043 mol/L醋酸铵溶液-乙腈(物质的量之比为45∶55)为流动相;流速1.0mL/min,检测波长为232 nm。注射液中辅料对主药无干扰;线性范围为10~270μg/mL;该方法精密度RSD=0.38%(n=6);回收率为98.5%~101.3%;定量限为2 ng。     

Nanoparticles of Poly(Lactide-Co-Glycolide)-d-a-Tocopheryl Polyethylene Glycol 1000 Succinate Random Copolymer for Cancer Treatment

Cancer is the leading cause of death worldwide. Nanomaterials and nanotechnologies could provide potential solutions. In this research, a novel biodegradable poly(lactide-co-glycolide)-d-a-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) random copolymer was synthesized from lactide, glycolide and d-a-tocopheryl polyethylene glycol 1000 succinate (TPGS) by ring-opening polymerization using stannous octoate as catalyst. The obtained random copolymers were characterized by ¹H NMR, FTIR, GPC and TGA. The docetaxel-loaded nanoparticles made of PLGA-TPGS copolymer were prepared by a modified solvent extraction/evaporation method. The nanoparticles were then characterized by various state-of-the-art techniques. The results revealed that the size of PLGA-TPGS nanoparticles was around 250 nm. The docetaxel-loaded PLGA-TPGS nanoparticles could achieve much faster drug release in comparison with PLGA nanoparticles. In vitro cellular uptakes of such nanoparticles were investigated by CLSM, demonstrating the fluorescence PLGA-TPGS nanoparticles could be internalized by human cervix carcinoma cells (HeLa). The results also indicated that PLGA-TPGS-based nanoparticles were biocompatible, and the docetaxel-loaded PLGA-TPGS nanoparticles had significant cytotoxicity against Hela cells. The cytotoxicity against HeLa cells for PLGA-TPGS nanoparticles was in time- and concentration-dependent manner. In conclusion, PLGA-TPGS random copolymer could be acted as a novel and promising biocompatible polymeric matrix material applicable to nanoparticle-based drug delivery system for cancer chemotherapy.     

蜜胺甲醛树脂-钯催化剂的制备及其催化氢解氯代苯基中间体合成多西紫杉醇及其异构体侧链的研究

制备和表征了蜜胺甲醛树脂钯催化剂，通过光电子能谱、顺磁共振谱和X－射线衍射等测试证明新催化剂与Pd^2 络合，起催化作用的是Pd^0，研究发现催化剂的N／Pd原子在25.6-12.8具有较好的催化效果，而催化氢化温度则在35－40℃之间进行更好。蜜胺甲醛树脂的聚合度越高对钯的附载能力越强，催化剂的催化效果超好。该催化剂在常压和室温条件下将氯代苯基化合物催化氢化为苯基化合物，并有很高的催化活性，通过该方法以较高收率制备了多西紫杉醇和异构体侧链。得到了新化合物均经过^1HNMR、^13CNMR、IR、旋光度和元素分析等给予确证，（3S，4R）－3－羟基－N－[(S)-(1-苯基）乙基]－4－（2′－氯苯基）－2－氮杂环丁酮通过X－单晶衍射确定四元环构型为3S，4R型，并进一步确定了其它化合物的结构。     

Gastrointestinal stability,physicochemical characterization and oral bioavailability of chitosan or its derivative-modified solid lipid nanoparticles loading docetaxel

Abstract

Objective: The purpose of this study was to prepare the positively charged chitosan (CS)- or hydroxypropyl trimethyl ammonium chloride chitosan (HACC)-modified solid lipid nanoparticles (SLNs) loading docetaxel (DTX), and to evaluate their properties in vitro and in vivo.

Methods: The DTX-loaded SLNs (DTX-SLNs) were prepared through an emulsion solvent evaporation method and further modified with CS or HACC (CS-DTX-SLNs or HACC-DTX-SLNs) via noncovalent interactions. The gastrointestinal (GI) stability, dissolution rate, physicochemical properties and cytotoxicities of SLNs were investigated. In addition, the GI mucosa irritation and oral bioavailability of SLNs were also evaluated in rats.

Results: The HACC-DTX-SLNs were highly stable in simulated gastric and intestinal fluids (SGF and SIF). By contrast, the CS-DTX-SLNs were less stable in SIF than in SGF. The drug dissolution remarkably increased when DTX was incorporated into the SLNs, which may be attributed to the change in the crystallinity of DTX and some molecular interactions that occurred between DTX and the carriers. The SLNs showed low toxicity in Caco-2 cells and no GI mucosa irritations were observed in rats. A 2.45-fold increase in the area under the curve of DTX was found in the HACC-DTX-SLN group compared with the DTX group after the modified SLNs were orally administered to rats. However, the oral absorption of DTX-SLN or CS-DTX-SLN group showed no significant difference compared with that of DTX group.

Conclusions: The positively charged HACC-DTX-SLNs with a stable particle size could provide the enhanced oral bioavailability of DTX in rats.     

四步纯化法合成多西紫杉醇的工艺研究

以苯甲醛为起始原料，将原12步反应的合成路线经过简化处理通过三步纯化关健中间体和最后纯化目标化合物得到了多西紫衫醇；该方法条件温和、操作简便、收率高，是一条适合工业化生产的廉价反应路线，为多西紫杉醇的全面降价提供了可能，也为更多患者对它的使用开了方便之门。     

Sulfobutylether-β-cyclodextrin/chitosan nanoparticles enhance the oral permeability and bioavailability of docetaxel

The aim of this research is to develop novel chitosan nanoparticles including cyclodextrins complexes for docetaxel (DTX), evaluate the performance of nanoparticles which could enhance the oral permeability and bioavailability of DTX in vitro and in vivo. DTX/sulfobutylether-β-cyclodextrin inclusion complexes were made and it was the main ingredient to prepare the DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles due to their promising physicochemical properties. DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles were prepared by the ionic gelation of chitosan with tripolyphosphate in the presence of cyclodextrins. Results indicated that DTX/sulfobutylether-β-cyclodextrin inclusion complexes and docetaxel/sulfobutylether-β-cyclodextrin/chitosan nanoparticles both had good performances in the studies of release and the rat small intestinal absorption in vitro. DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles showed preferable capability in improving the small intestinal absorption and inhibiting the efflux of DTX. In pharmacokinetics study, the DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles increased the AUC_0→t and decreased the clearance significantly, and the oral relative bioavailability of the DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles was as high as 1447.53% compared to the pure DTX formulation. The DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles prepared in this study have a good prospect for oral administration as an alternative of current DTX formulations.     

泰索帝对Lewis肺癌放疗增敏作用的实验研究

研究了泰索帝（docetaxel）对荷Lewis肺癌C57BL小鼠的放疗增敏作用。给荷Lewis肺癌C57BL小鼠腹腔注射不同剂量的泰索帝12h或48h后进行10Gy局部照射，结果表明，经过泰索帝放疗增敏治疗后肿瘤生长相对速率明显减慢，4个放疗增敏组q值在1.21-1.38之间。研究还显示泰索帝的放疗增敏作用机制是通过将大量增殖期细胞阻滞的G2和M期以及诱导细胞凋亡。本实验提示秦索帝作为放疗增敏剂应用于肺癌的治疗，既发挥了化疗作用，又具有放疗增敏作用，是很有开发潜力的抗肿瘤药物。     

Oral Delivery of DMAB-Modified Docetaxel-Loaded PLGA-TPGS Nanoparticles for Cancer Chemotherapy

Three types of nanoparticle formulation from biodegradable PLGA-TPGS random copolymer were developed in this research for oral administration of anticancer drugs, which include DMAB-modified PLGA nanoparticles, unmodified PLGA-TPGS nanoparticles and DMAB-modified PLGA-TPGS nanoparticles. Firstly, the PLGA-TPGS random copolymer was synthesized and characterized. DMAB was used to increase retention time at the cell surface, thus increasing the chances of particle uptake and improving oral drug bioavailability. Nanoparticles were found to be of spherical shape with an average particle diameter of around 250 nm. The surface charge of PLGA-TPGS nanoparticles was changed to positive after DMAB modification. The results also showed that the DMAB-modified PLGA-TPGS nanoparticles have significantly higher level of the cellular uptake than that of DMAB-modified PLGA nanoparticles and unmodified PLGA-TPGS nanoparticles. In vitro, cytotoxicity experiment showed advantages of the DMAB-modified PLGA-TPGS nanoparticle formulation over commercial Taxotere^® in terms of cytotoxicity against MCF-7 cells. In conclusion, oral chemotherapy by DMAB-modified PLGA-TPGS nanoparticle formulation is an attractive and promising treatment option for patients.     

经不对称氨羟基化反应合成多西紫杉醇及其衍生物的新方法研究

首次用取代肉桂酸酯和叔丁氧基碳酰胺为原料，经改进的Sharphless不对称氨羟基化反应一步得到了多西紫杉醇及其衍生物的侧链，并最终得到了多西紫杉醇和新型抗癌化合物3，4-亚甲二氧基取代多西紫杉醇，该方法是目前合成多西紫杉醇及其衍生物的最简化和较高收率的路线。研究发现Sharphless不对称氨羟基化反应中手性配体、催化剂的用量和比例对原料的转化率、产物的产率等都有影响，当催化剂K2OsO2(OH)4、手性配体(DHQ)2PHAL的摩尔分数分别为原料的4％和5％时更倾向于生成多西紫杉醇衍生物侧链。所有新化合物及其结构均经过^1HNMR、^13CNMR、IR、MS、旋光度和元素分析等给予确证。3，4-OCH2O取代多西紫杉醇的初步药理活性显示具有较好的抗癌活性。