This invention provides for a compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein R
1
-R
4
, L and X are defined herein. The compounds of formula (I) and pharmaceutically acceptable salts thereof are cationic lipids useful in the delivery of biologically active agents to cells and tissues.
这项发明提供了式(I)的化合物或其药学上可接受的盐,其中R1-R4,L和X的定义如下。式(I)的化合物及其药学上可接受的盐是阳离子脂质,可用于将
生物活性剂递送到细胞和组织中。