The present invention provides a cationic lipid which is able to be used for nucleic acid delivery to the cytoplasm. A cationic lipid according to the present invention is, for example, a compound represented by formula (1) or a pharmaceutically acceptable salt thereof, wherein L
1
and L
2
independently represent an alkylene group having 3 to 10 carbon atoms; R
1
and R
2
independently represent an alkyl group having 4 to 24 carbon atoms or an alkenyl group having 4 to 24 carbon atoms; R
3
represents an alkyl group having 1 to 3 carbon atoms; and X
1
represents a single bond or CO—O—.
本发明提供了一种阳离子脂质,可用于将核酸传递至细胞质。根据本发明的一种阳离子脂质,例如,是由式(1)表示的化合物或其药学上可接受的盐,其中L1和
L2分别表示具有3至10个碳原子的烷基基团;R1和R2分别表示具有4至24个碳原子的烷基基团或具有4至24个碳原子的烯基基团;R3表示具有1至3个碳原子的烷基基团;X1表示单键或CO—O—。