Dihydroxybenzene derivatives and antiprotozoal agent comprising same as active ingredient

A pharmaceutical composition comprising:

• as an active ingredient, at least one of a compound represented by Formula (I), an optical isomer thereof, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier
• where,
• R2 represents a C1-7 alkyl group;
• R3 represents —CHO;
• and
• R4 represents a C1-16 alkyl group having one or more substituents on a terminal carbon atom and/or non-terminal carbon atom(s), or a C2-16 alkenyl group having one or more substituents on a terminal carbon atom and/or non-terminal carbon atom(s),
• wherein the one or more substituents of R4 is each any one of —COORa, wherein Ra represents a C1-7 alkyl group;
• —O—CO-Rc, wherein Rc represents a C1-7 alkyl group;
• —O-Rd, wherein Rd represents a C1-7 alkyl group;
• or, —O—CH2—O—CH3, and —O-HET, wherein HET represents a group formed by removing one hydrogen atom on a carbon or nitrogen atom of heterocyclic compounds.

A kit comprising:

• as an active ingredient, at least one of a compound represented by Formula (I), an optical isomer thereof, and a pharmaceutically acceptable salt thereof, and instructions for use
• wherein,
• R2 represents a C1-7 alkyl group;
• R3 represents —CHO;
• and
• R4 represents a C1-16 alkyl group having one or more substituents on a terminal carbon atom and/or non-terminal carbon atom(s), or a C2-16 alkenyl group having one or more substituents on a terminal carbon atom and/or non-terminal carbon atom(s),
• wherein the one or more substituents of R4 is each any one of —COORa, wherein Ra represents a C1-7 alkyl group;
• —O—CO-Rc, wherein Rc represents a C1-7 alkyl group;
• —O-Rd, wherein Rd represents a C1-7 alkyl group;
• or, —O—CH2—O—CH3, and —O-HET, wherein HET represents a group formed by removing one hydrogen atom on a carbon or nitrogen atom of heterocyclic compounds.