Compounds of formula II, HI, IV, and V are described. Compounds of formula II are those wherein R1 and R2 are both straight chain alkyl consisting of 1 to 12 carbons, alkenyl or alkynyl of 2 to 12 carbons, both L1 and L2 are 5 to 18 carbons Or a heterocyclic ring with N, X is S and L 3 consists of a bond or a straight chain alkylene consisting of one to six carbons, or N forms a heterocyclic ring, R 3 is a straight-chain or branched alkylene of 1 to 6 carbons, R 4 and R 5 are the same or different and each is hydrogen or a straight-chain of 1 to 6 carbons It consists of compounds consisting of chain or branched alkyl. Compounds of the formulas HI and IV are those in which R1 consists of branched alkyl having from 12 to 20 carbons and R2 is linear alkyl having 5 to 10 carbons or branched alkyl having 12 to 20 carbons L 1 and L 2 each comprise a bond or a straight chain alkyl having 1 to 3 carbon atoms, X is S or O, L 3 is a bond or a lower alkyl, R 3 is a lower alkyl And R 4 and R 5 are the same or different and each consists of a lower alkyl. Compounds of formula V are those in which R1 consists of a straight chain or branched alkyl consisting of 1 to 18 carbons, an alkenyl or alkynyl of 2 to 12 carbons, or cholesteryl, R2 is from 1 to 18 carbons Comprising 606338680 v 1 linear or branched alkyl or alkenyl, when L 1 consists of linear alkyl consisting of 5 to 9 carbons or when R 1 consists of cholesteryl, L 1 is a straight-chain of 3 to 4 carbons Chain alkylene or alkenyl, X @ 1 is--O-(CO)-or-(CO)-O--, X @ 2 is S or O, La is a bond or a straight Chain alkylene, R 3 consists of a linear or branched alkylene having 1 to 6 carbons, R 4 and R 5 are the same or different, Respectively consist of one to six straight or branched alkyl of a carbon, a compound. Compounds of formula II, III, IV, and V may include pharmaceutically acceptable salts thereof.式II、HI、IV、およびVの化合物が記載される。式IIの化合物は、R1およびR2がともに、1~12個の炭素からなる直鎖アルキル、2~12個の炭素からなるアルケニルもしくはアルキニルであり、L1およびL2がともに、5~18個の炭素からなる直鎖アル
