Abstract: A heterocyclic compound of formula (I) or a salt thereof: wherein R1 is an optionally protected amino group or an optionally substituted C1-6 alkyl group; R2 and R3 are each independently a C1-2 alkyl group; X is a hydrogen atom or a halogen atom; Z1 is N or C—R4; Z2 is N or C—R5; Z3 is N or C—R6; Z4 is N or C—R7; R4, R5, R6, and R7 are each independently a hydrogen atom, a halogen atom, an optionally protected amino group, or a C1-6 alkylsulfonyl group; Z is CH or N; and A is a methylene group or a bond, which has an excellent anti-HIV activity and is useful as an anti-HIV agent.

Abstract: An arylamidine derivative represented by a general formula described below or a salt thereof has an excellent antifungal action and high safety, and it is useful as an antifungal agent with good pharmacokinetics and pharmacodynamic properties wherein X represents an unsubstituted or substituted lower alkylene or alkenylene group; G1 represents an oxygen atom, a sulfur atom, or an imino group; G2 represents a carbon atom or a nitrogen atom; Ra represents at least one group selected from the group consisting of a hydrogen atom, a halogen atom, and unsubstituted or substituted alkyl, cycloalkyl and alkoxy groups; R1 represents an unprotected or protected or unsubstituted or substituted amidino group; and R2 represents a substituted amino or substituted cyclic amino group, or the like.

Abstract: An arylamidine derivative represented by a general formula described below or a salt thereof has an excellent antifungal action and high safety, and it is useful as an antifungal agent with good pharmacokinetics and pharmacodynamic properties wherein X represents an unsubstituted or substituted lower alkylene or alkenylene group; G1 represents an oxygen atom, a sulfur atom, or an imino group; G2 represents a carbon atom or a nitrogen atom; Ra represents at least one group selected from the group consisting of a hydrogen atom, a halogen atom, and unsubstituted or substituted alkyl, cycloalkyl and alkoxy groups; R1 represents an unprotected or protected or unsubstituted or substituted amidino group; and R2 represents a substituted amino or substituted cyclic amino group, or the like.