Background Screening libraries against a molecular target in vitro are idealized models that cannot reflect the real state in vivo where biomolecules coexist and interact. C-terminal amide tripeptides labelled with Te...Background Screening libraries against a molecular target in vitro are idealized models that cannot reflect the real state in vivo where biomolecules coexist and interact. C-terminal amide tripeptides labelled with Technetium-99m can provide a unique noninvasive approach to trace a large number of compounds in vivo. Methods The C-terminal amide tripeptide libraries were synthesized on Rink Amide-MBHA resin using iterative and pooling protocol. Technetium （V） oxo core [TcO^3＋] was bound to each tripeptide via 4 deprotonated nitrogen atoms to form a library of 8000 ^99mTc tripeptoid complexes. The radiocombinatorial screening （RCS） in vivo was carried out on SD rats and A549 tumour bearing mice. Results Signals of tissue distribution and metabolism of libraries were recorded by counting or imaging and tissue targeting leads identified by both random and directed RCS. Among them, ^99mTc RPA, ^99mTc VIG and ^99mTC RES had specific tissue targeting in kidney, liver and tumour respectively. The percent injected dose per gram tissue of ^99mTc labelled leads in their target tissue was highly structure dependent. Because the nontarget tissue binding and the metabolism of ^99mTc tripeptoid sublibraries were simultaneously monitored successfully by RCS, the interference of background activity was limited to the lowest level. Optimization of renal function agent from the labelled libraries was carried out by directed screening. ^99mTc DSG was finally identified the most promising agent for renal function studies. Conclusions RCS in vivo is a powerful tool for the discovery of tissue targeting drugs. The potential screening bias is probably the major limitation of labelled libraries.展开更多
利用偶发分枝杆菌(Mycobacterium fortuitum)CICC 10279发酵断甾醇侧链进行定向菌株筛选;对选出的具有较高甾醇降解活性的菌株,借助TLC法开展多批次生物降解实验过程研究;并重点对积累9α-羟基雄烯二酮(9α-OH-AD)化合物的菌株稳定性及...利用偶发分枝杆菌(Mycobacterium fortuitum)CICC 10279发酵断甾醇侧链进行定向菌株筛选;对选出的具有较高甾醇降解活性的菌株,借助TLC法开展多批次生物降解实验过程研究;并重点对积累9α-羟基雄烯二酮(9α-OH-AD)化合物的菌株稳定性及转化过程进行考察;在此基础上利用选出的22号菌株分别进行底物为胆固醇和植物甾醇的半微量制备实验.结果显示,分离的样品具有高纯度,HPLC分析为95.7%;TLC、HPLC、MS、1H N M R、13C N M R、i.r.等光谱数据分析结构确证其为9α-OH-A D;半微量制备实验以胆固醇或植物甾醇为底物,9α-OH-A D重量收得率分别可达34.0%和30.8%.本研究可能为高效含卤(氟,氯)皮质激素药物工业生产提供了一种很有用处的中间体.展开更多
基金This work was supported in part by the grants from the National Natural Science Foundation(No.30170280)Foundation of Shanghai Science and Technology Committee(No.02ZB14086 and 03JC14062).
文摘Background Screening libraries against a molecular target in vitro are idealized models that cannot reflect the real state in vivo where biomolecules coexist and interact. C-terminal amide tripeptides labelled with Technetium-99m can provide a unique noninvasive approach to trace a large number of compounds in vivo. Methods The C-terminal amide tripeptide libraries were synthesized on Rink Amide-MBHA resin using iterative and pooling protocol. Technetium （V） oxo core [TcO^3＋] was bound to each tripeptide via 4 deprotonated nitrogen atoms to form a library of 8000 ^99mTc tripeptoid complexes. The radiocombinatorial screening （RCS） in vivo was carried out on SD rats and A549 tumour bearing mice. Results Signals of tissue distribution and metabolism of libraries were recorded by counting or imaging and tissue targeting leads identified by both random and directed RCS. Among them, ^99mTc RPA, ^99mTc VIG and ^99mTC RES had specific tissue targeting in kidney, liver and tumour respectively. The percent injected dose per gram tissue of ^99mTc labelled leads in their target tissue was highly structure dependent. Because the nontarget tissue binding and the metabolism of ^99mTc tripeptoid sublibraries were simultaneously monitored successfully by RCS, the interference of background activity was limited to the lowest level. Optimization of renal function agent from the labelled libraries was carried out by directed screening. ^99mTc DSG was finally identified the most promising agent for renal function studies. Conclusions RCS in vivo is a powerful tool for the discovery of tissue targeting drugs. The potential screening bias is probably the major limitation of labelled libraries.
文摘利用偶发分枝杆菌(Mycobacterium fortuitum)CICC 10279发酵断甾醇侧链进行定向菌株筛选;对选出的具有较高甾醇降解活性的菌株,借助TLC法开展多批次生物降解实验过程研究;并重点对积累9α-羟基雄烯二酮(9α-OH-AD)化合物的菌株稳定性及转化过程进行考察;在此基础上利用选出的22号菌株分别进行底物为胆固醇和植物甾醇的半微量制备实验.结果显示,分离的样品具有高纯度,HPLC分析为95.7%;TLC、HPLC、MS、1H N M R、13C N M R、i.r.等光谱数据分析结构确证其为9α-OH-A D;半微量制备实验以胆固醇或植物甾醇为底物,9α-OH-A D重量收得率分别可达34.0%和30.8%.本研究可能为高效含卤(氟,氯)皮质激素药物工业生产提供了一种很有用处的中间体.
