Triterpene derivatives and pharmaceuticals for treating hepatic disorders

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein
• R1 represents a hydroxyl group;
• R2 represents —CH2OR5 wherein R5 represents a hydrogen atom, C1-6 alkyl, aralkyl which may be optionally substituted, or C1-6 alkylcarbonyl;
• R3 represents a hydrogen atom;
• and
• R4 represents C1-6 alkyl,
• hydroxy C1-6 alkyl,
• formyl,
• —COOR11 wherein R11 represents a hydrogen atom or C1-6 alkyl, or
• —OR12 wherein R12 represents C1-6 alkyl, aralkyl which may be optionally substituted, arylcarbonyl which may be optionally substituted, C2-6 alkenyl, C2-6 alkenylcarbonyl, or arylalkenylcarbonyl which may be optionally substituted.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein
• R1 represents aralkyloxy which may be optionally substituted,
• R2 represents —CH2OR5, wherein R5 represents a hydrogen atom, C1-6 alkyl, or C1-6 alkylcarbonyl, and
• R3 and R4 represent a hydrogen atom.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein
• R1 represents a hydroxyl group,
• R2 represents —CH2OR5, wherein R5 represents C1-6 alkyl or C1-6 alkylcarbonyl, and
• R3 and R4 represent a hydrogen atom.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein
• R1 represents a hydroxyl group, C1-6 alkoxy, or C1-6 alkylcarbonyloxy,
• R2 represents —CH2OR5, wherein R5 represents aralkyl which may be optionally substituted, and
• R3 and R4 represent a hydrogen atom.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein
• R1 represents C1-6 alkoxy or C1-6 alkylcarbonyloxy,
• R2 represents —CH2OH
• and
• R3 and R4 represent a hydrogen atom.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein in the formula (II),
• R1 represents a hydroxyl group,
• R2 represents —COO—C1-6 alkyl,
• R3 represents a hydrogen atom and
• R4 represents a hydroxyl group.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein in the formula (II),
• R1 represents C1-6 alkoxy,
• R2 represents —CH2OH,
• R3 represents a hydrogen atom and
• R4 represents a hydroxyl group.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein in the formula (II),
• R1 represents aralkyloxy,
• R2 represents formyl, carboxyl, —COO—C1-6 alkyl or —CH2OR5, wherein R5 represents a hydrogen atom, C1-6 alkyl or C1-6 alkylcarbonyl,
• R3 represents a hydrogen atom and
• R4 represents aralkyloxy.

A triterpene derivative represented by the formula (II) or a pharmaceutically acceptable salt thereof:

• wherein in the formula (II),
• R1 represents a hydroxyl group or C1-6 alkoxy,
• R2 represents aralkyloxymethyl,
• R3 represents a hydrogen atom and
• R4 represents aralkyloxy.

A method for treating a hepatic disorder excluding autoimmune hepatitis, comprising the step of administering to a mammal, including a human, a triterpene derivative represented by the formula (I) or a pharmaceutically acceptable salt thereof:

• wherein
• R1 represents a hydroxyl group,
• C1-6 alkoxy,
• C1-6 alkylcarbonyloxy, or
• aralkyloxy which may be optionally substituted;
• R2 represents C1-6 alkyl,
• —CH2OR5 wherein R5 represents a hydrogen atom, C1-6 alkyl, aralkyl which may be optionally substituted, or C1-6 alkylcarbonyl,
• formyl,
• —COOR6 wherein R6 represents a hydrogen atom or C1-6 alkyl), or
• —CH2N(R7)R8 wherein R7 and R8, which may be the same or different, represent a hydrogen atom or C1-6 alkyl;
• or
• R1 and R2 may combine with each other to form —O—CR9(R10)—OCH2— wherein R9 and R10, which may be the same or different, represent a hydrogen atom, C1-6 alkyl, or aryl which may be optionally substituted;
• R3 and R4, which may be the same or different, represent
• a hydrogen atom,
• a hydroxyl group,
• C1-6 alkyl,
• hydroxy C1-6 alkyl,
• formyl,
• —COOR11 wherein R11 represents a hydrogen atom or C1-6 alkyl, or
• —OR12 wherein R12 represents C1-6 alkyl, aralkyl which may be optionally substituted, optionally substituted C1-6 alkylcarbonyl, arylcarbonyl, C2-6 alkenyl, C2-6 alkenylcarbonyl, or arylalkenylcarbonyl which may be optionally substituted;
• or
• R3 and R4 combine with each other to form a methylene group =O;
• — — — represents a single or double bond, provided that, when — — — represents a double bond, R4 is absent.