| abstract |
What is described is a compound of formula I n n n n n n n n n n consisting of a compound in which R 1 is a branched chain alkyl consisting of 10 to 31 carbons; R 2 is a linear alkyl, alkenyl, or alkynyl consisting of 2 to 20 carbons; L 1 and L 2 are the same or different, each a linear alkylene of 1 to 20 carbons or a linear alkenylene of 2 to 20 carbons; X 1 is S or O; R 3 is a linear or branched alkylene consisting of 1 to 6 carbons; and R 4 and R 5 are the same or different, each a hydrogen or a linear or branched alkyl consisting of 1 to 6 carbons; or a pharmaceutically acceptable salt thereof. |