Patent ID: 7153979

Claim:
A triterpene derivative represented by the following formula (IIa) or a salt thereof: wherein R 16 represents a hydroxyl group, arylmethyloxy, lower alkoxy, excluding methoxy, or lower alkanoyloxy, excluding acetoxy; R 17 represents lower alkenyl, —CH 2 OR 5 wherein R 5 represents a hydrogen atom, arylmethyl, lower alkyl, or lower alkanoyl, formyl, —COOR 6 wherein R 6 represents a hydrogen atom or lower alkyl, —CH 2 OCON(R 9 )R 10 wherein R 9 and R 10 , which may be the same or different, represent a hydrogen atom, lower alkyl, or aryl, —CON(R 7 )R 8 wherein R 7 and R 8 , which may be the same or different, represent a hydrogen atom, lower alkyl, aryl, or lower alkanoyl, —CH 2 N(R 7 )R 8 wherein R 7 and R 8 are as defined above, —C(R 6 ) 2 OH wherein R 6 is as defined above; —COR 6a wherein R 6a represents lower alkyl; —CH═CHR 6 wherein R 6 is as defined above; R 16 and R 17 may combine with each other to form —O—C(R 9 )R 10 —O—CH 2 — wherein R 9 and R 10 are as defined above; R 18 and R 19 , which may be the same or different, represent a hydrogen atom, a hydroxyl group, arylmethyloxy, lower alkyl, —N(R 11 )R 12 wherein R 11 and R 12 , which may be the same or different, represent a hydrogen atom, lower alkyl, or lower alkanoyl, —COOR 6 wherein R 6 is as defined above, —OR 13 wherein R 13 represents lower alkyl, cyclo-lower alkyl, aralkyl, lower alkanoyl, arylcarbonyl, aralkylcarbonyl, lower alkenyl, lower alkenylcarbonyl, or aryl-lower alkenylcarbonyl, —O—(CH 2 ) m —R 22 wherein R 22 represents amino, —NH—COOR 23 wherein R 23 represents arylmethyl or lower alkyl, a hydroxyl group, arylmethyloxy, or —COOR 24 wherein R 24 represents a hydrogen atom, lower alkyl, or arylmethyl, and m is an integer of 1 to 4, —OCOCH(R 25 )(CH 2 ) n —R 22 wherein R 22 is as defined above, R 25 represents a hydrogen atom, lower alkyl, aralkyl, or aryl, and n is an integer of 0 to 3, —OCOCH═CH—COOR 6 wherein R 6 is as defined above, or —OCON(R 29 )R 30 wherein R 29 and R 30 , which may be the same or different, represent a hydrogen atom, lower alkyl, lower alkanoyl, aryl, or aralkyl; or R 18 and R 19 may combine with each other to form oxo, R 20 and R 21 respectively the same meanings as R 18 and R 19 , provided that R 20 and R 21 do not represent a hydrogen atom at the same time; or R 18 and R 20 may combine with each other to form —OCO—[C(R 9 )R 10 ] q —OCO— wherein R 9 and R 10 are as defined above and q is an integer of 0 to 2; and Y represents CH 2 or NH.