树枝状聚赖氨酸的合成及表征

Synthesis and Characterization of Poly-L-Lysine Dendrimers

以己二胺为核,L-2,6-二叔丁氧羰基赖氨酸.二环己胺盐(Boc-L-Lys(Boc)-OH.DCHA)为原料,在均相反应条件下采用发散法设计合成了t-Boc保护的树枝状聚赖氨酸,然后用三氟乙酸切割保护基团获得高纯度的树枝状聚赖氨酸。利用核磁共振(1H-NMR、13C-NMR)和基质辅助激光解析串联飞行时间质谱(MALDI-TOF MS)等手段对所得产物结构进行了表征。分析结果表明,采用1-羟基苯丙三氮唑(HOBT)和苯并三氮唑-N,N,N’,N’-四甲基脲六氟磷酸盐(HBTU)作为缩合剂,在25℃缩合24 h、三氟乙酸溶液(TFA∶DCM=95∶5)室温切割1.5 h,合成了一至四代结构规整的树枝状聚赖氨酸,产率介于60%～80%之间。

Using a hexamethylene diamine as initiator core,Nα,Nε-di-t-BOC-L-lysine dicyclohexylammonium salt（Boc-L-Lys（Boc）-OH·DCHA）as raw material,t-Boc-protected poly-L-lysine dendrimers were designed and divergently synthesized by solution phase peptide chemistry,then t-Boc groups were removed by trifluoroacetic acid（TFA）.Poly-L-lysine dendrimers were obtained in high purity.The structures of the products were further characterized by 1H-NMR spectroscopy,13C-NMR spectroscopy,electrospray ionization mass spectrometry（ESI-MS） and matrix-assisted laser desorption time of flight mass spectrometry（MALDI-TOF MS）.The results represent the consistency for products with the target poly-L-lysine dendrimers.Monodispersed dendritic poly-L-lysine dendrimers of first and fourth generations were obtained in high yield（60%～80%）.Due to many advantages of poly-L-lysine dendrimers relative to linear polypeptides,their applications are considered to be prospective in biochemistry,molecular biology,and chemistry biology field.