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。     

99Tcm标记糖肽及其在荷瘤小鼠体内的分布与代谢动力学

Glucose and galactose are conjugated to the N- mercaptoacetyl-Val-Gly-Gly (MAVGG). The glycopeptides and MAVGG are labeled with 99Tcm. The partition coefficients between octanol and water (Pow) are measured. Glycopeptides or MAVGG labeled with 99Tcm areinjected into the mice bearing S180 tumor. 10μL blood samples are withdrawn at different time points and the radioactivities are counted to calculate the effective halflife (T1/2) using a bi-exponential fit. Biodistribution is measured at 3 h postinjection and the percentage of injected dose per gram ( ID%/g ) and tumor to normal tissue ratio (T/NT) were calculated. The assigned structures were confirmed on the basis of IR, NMR and MS. The 99Tcm labeling yield 巨radiochemical purity is greater than 90%. The lgPow of 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG are –1.974, –2.128 and –1.378, respectively. The T1/2αof the three labeled peptides are 24.3, 37.1, 46.3 min and T1/2β are 221.5, 158.4 and 198.4 min, respectively. The tumor uptakes at 3 h postinjection are 1.46, 1.55 and 0.67 for 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG, respectively. Their T/NT for tumor over muscle are 3.74、7.38 and 3.53, respectively. The results demonstrated that after carbohydrate conjugate of peptides, the lipophilicity is decreased , the blood clearance is increased and the tumor uptake is enhanced. Of the two glucopeptides, 99Tcm-Gal-MAVGG shows faster blood clearance, higher tumor uptake and T/NT, which suggests the potential utility of 99Tcm-Gal-MAVGG as a suitable tumor imaging agent.     

Fmoc-N-甲基-L-苯丙氨酸的微波辅助合成

以Fmoc保护的L-苯丙氨酸为起始原料,经恶唑烷酮中间体,在三氟乙酸和无水AlCl3共同催化下,三乙基硅烷还原得到Fmoc保护的N-甲基L-苯丙氨酸,总收率82%。反应过程中,采用微波辐射代替传统的加热方式,缩短了时间,提供了产率,三氟乙酸和无水三氯化铝共同催化体系避免了副产物Fmoc-Tic-OH的生成,该方法优化了生产工艺,缩短了反应时间,节约了原料。     

99Tcm-MAVGG-Glu的肿瘤定位性能

用99Tcm标记了β-N-巯基乙酰基-缬氨酰-甘氨酰-甘氨酰-葡萄糖(MAVGG-Glu),对标记物在荷S180肉瘤在小鼠体内的生物分布与显像进行了研究,并与18F-FDG的生物分布进行对比.结果显示,99Tcm对MAVGG-Glu的标记率大于90％.注射后3h和5h,99Tcm-MAVGG- Glu在肿瘤中的摄取率分...