Abstract: The present invention provides a compound represented by formula (I) or a pharmaceutically acceptable salt thereof as a cationic lipid, and the like.

Abstract: The present invention provides a cationic lipid represented by the formula (I) wherein R1 and R2 each represents alkyl having 8 to 24 carbon atoms or the like; R3 represents a hydrogen atom, alkyl having 1 to 3 carbon atoms, the formula (A) wherein R4 and R5 each represents a hydrogen atom or the like, and n3 represents an integer from 2 to 6, or the formula (B) wherein R6 and R7 each represents a hydrogen atom or the like, and n4 represents an integer from 1 to 6; n1 represents an integer from 0 to 4; and n2 represents an integer from 1 to 4, provided that the case where n1 is 0 and n2 is 1 is excluded, and a composition which contains the cationic lipid and a nucleic acid, or the like.

Abstract: Provided are a cationic lipid which facilitates the introduction of a nucleic acid into, for example, a cell or the like; a composition containing the cationic lipid and a nucleic acid; a method for introducing a nucleic acid into a cell by using a composition containing the cationic lipid and the nucleic acid; and the like. The cationic lipid is, for example, a cationic lipid represented by formula (A): formula (A): (wherein R1 is alkenyl or the like, R2 is alkenyl or the like, R3 and R4 are each alkyl, or are combined together to form alkylene, or R3 and R5 are combined together to form alkylene, R5 is a hydrogen atom or the like, or is combined together with R3 to form alkylene, X1 is alkylene, and X2 is a single bond or alkylene).

Abstract: The present invention provides a compound represented by formula (I) or a pharmaceutically acceptable salt thereof as a cationic lipid, and the like.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.

Abstract: The present invention provides a composition for suppressing the expression of a KRAS gene, comprising a lipid particle containing, as a drug, a double-stranded nucleic acid having an antisense strand having a sequence of bases complementary to the sequence of at least 19 continuous bases of any one KRAS gene's mRNA of sequence Nos. 1 to 3; and a cationic lipid represented by the following formula (I): wherein R1 and R2, which are the same or different, are each linear or branched alkyl, alkenyl or alkynyl having a carbon number of from 12 to 24; L1 and L2, which are the same or different, are each —CO—O— or —O—CO—; a and b, which are the same or different, are each 1 to 3; and R3 is a hydrogen atom, alkyl having a carbon number of from 1 to 6, or alkenyl having a carbon number of from 3 to 6, and the like.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X3 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.

Abstract: The present invention provides a lipid nano-particles, which allow nucleic acids to be easily introduced into cells, comprising a cationic lipid represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X3 is absent or is alkyl, etc, X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and Y1 is absent or anion, L1 is a single bond, etc, R3 is alkyl, etc), and the like.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.

Abstract: The present invention provides a cationic lipid represented by the formula (I) wherein R1 and R2 each represents alkyl having 8 to 24 carbon atoms or the like; R3 represents a hydrogen atom, alkyl having 1 to 3 carbon atoms, the formula (A) wherein R4 and R5 each represents a hydrogen atom or the like, and n3 represents an integer from 2 to 6, or the formula (B) wherein R6 and R7 each represents a hydrogen atom or the like, and n4 represents an integer from 1 to 6; n1 represents an integer from 0 to 4; and n2 represents an integer from 1 to 4, provided that the case where n1 is 0 and n2 is 1 is excluded, and a composition which contains the cationic lipid and a nucleic acid, or the like.

Abstract: The present invention provides a lipid nano-particles, which allow nucleic acids to be easily introduced into cells, comprising a cationic lipid represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X3 is absent or is alkyl, etc, X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and Y1 is absent or anion, L1 is a single bond, etc, R3 is alkyl, etc), and the like.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X3 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.

Abstract: Provided are a cationic lipid which facilitates the introduction of a nucleic acid into, for example, a cell or the like; a composition containing the cationic lipid and a nucleic acid; a method for introducing a nucleic acid into a cell by using a composition containing the cationic lipid and the nucleic acid; and the like. The cationic lipid is, for example, a cationic lipid represented by formula (A): formula (A): (wherein R1 is alkenyl or the like, R2 is alkenyl or the like, R3 and R4 are each alkyl, or are combined together to form alkylene, or R3 and R5 are combined together to form alkylene, R5 is a hydrogen atom or the like, or is combined together with R3 to form alkylene, X1 is alkylene, and X2 is a single bond or alkylene).

Abstract: The present invention provides a cationic lipid and the like. The cationic lipid is for delivering a medicament containing a cationic lipid which facilitates the introduction of a nucleic acid into a cell or the like, and is represented by formula (I).

Abstract: The present invention provides a composition for suppressing the expression of a KRAS gene, comprising a lipid particle containing, as a drug, a double-stranded nucleic acid having an antisense strand having a sequence of bases complementary to the sequence of at least 19 continuous bases of any one KRAS gene's mRNA of sequence Nos. 1 to 3; and a cationic lipid represented by the following formula (I): wherein R1 and R2, which are the same or different, are each linear or branched alkyl, alkenyl or alkynyl having a carbon number of from 12 to 24; L1 and L2, which are the same or different, are each —CO—O— or —O—CO—; a and b, which are the same or different, are each 1 to 3; and R3 is a hydrogen atom, alkyl having a carbon number of from 1 to 6, or alkenyl having a carbon number of from 3 to 6, and the like.

Abstract: The present invention provides a lipid nano-particles, which allow nucleic acids to be easily introduced into cells, comprising a cationic lipid represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X3 is absent or is alkyl, etc, X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and Y1 is absent or anion, L1 is a single bond, etc, R3 is alkyl, etc), and a cationic lipid represented by formula (II) (wherein: R4 and R5 are, the same or different, alkenyl, etc, and X4 and X5 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X6 is absent or is alkyl, etc, Y2 is absent or anion, a and b are, the same or different, 0 to 3, and L4 is a single bond, etc, R6 is alkyl, etc, L2 and L3 are —O—, —CO—O— or —O—CO—), and the like.

Abstract: The present invention provides a composition that comprises a lipidparticle encapsulating a double-stranded nucleic acid molecule, wherein the antisense strand is a polynucleotide of 17 to 30 bases in which a sequence is complementary to the sequence of the 17 contiguous bases of a target gene's mRNA, the sense strand is a polynucleotide of 17 to 30 bases that contains a base sequence complementary to the base sequence of bases 1 to 17 in the 5?-end to 3?-end direction of the antisense strand, and a particular amount of the sugars binding to certain bases of the antisense strand and the sense strand are deoxyribose, or ribose whose hydroxyl group at the 2? position is substituted by a modifying group, and wherein the lipidparticle contains a lipid bilayer membrane whose constituent component is a lipid conjugate, a fatty acid conjugate or an aliphatic hydrocarbon conjugate of a water-soluble substance.

Abstract: The present invention provides a cationic lipid, which allow nucleic acids to be easily introduced into cells, represented by formula (I) (wherein: R1 and R2 are, the same or different, alkenyl, etc, and X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene, and X3 is absent or is alkyl, etc, Y is absent or anion, a and b are, the same or different, 0 to 3, and L3 is a single bond, etc, R3 is alkyl, etc, L1 and L2 are —O—, —CO—O— or —O—CO—), a composition comprising the cationic lipid and a nucleic acid, and a method for introducing a nucleic acid into a cell by using the composition comprising the cationic lipid and the nucleic acid, and the like.