Abstract: To provide a novel colitis ameliorating agent. A colitis ameliorating agent comprising a trans-astaxanthin derivative of formula (I), geometric isomers thereof, a mixture of the geometric isomers, an optical isomer thereof, or a salt thereof; (wherein m1, m2, n1, and n2 are each the same or different and mean an integer of 1 to 6).

Abstract: The object of the present invention is to find a carotenoid compound that is excellent in water solubility. A carotenoid derivative having a formula (I): wherein X represents a carbonyl group or a methylene group, one of R1 and R2 represents (a) or (b) and the other represents (a), (b), (c) or a hydrogen atom: (a): —CO-A-B-D wherein A represents an alkylene group an alkenylene group, etc., B represents a formula of —S(O)n— or a formula of —NR4CONR5— and D represents a hydrogen atom, a carboxy group, etc., (b): —CO-E-F wherein E represents an alkylene group or a formula of —NR3— wherein R3 represents (a1) a hydrogen atom, (b1) an alkyl group etc., and F represents a sulfo group and (c): —CO-G wherein G represents a hydrogen atom, an alkyl group, etc., a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable ester or amide thereof.