Patent ID: 7851503

Claim:
A method of increasing platelets in a human having a disease selected from the group consisting of thrombocytopenia caused by bone marrow transplantation, thrombocytopenia caused by surgery, thrombocytopenia caused by infection, thrombocytopenia caused by gastrointestinal bleeding, aplastic anemia, idiopathic thrombocytopenic purpura, myelodysplastic syndrome, and thrombopoietin deficiency, the method comprising administering an isolated compound or its salt to the human in need thereof in an amount sufficient to increase the platelets in the human in need thereof, wherein the isolated compound or its salt is represented by the formula (1) or its salt, wherein each of R 1 and R 3 is independently a hydrogen atom, SO 3 H, a C 1-6 alkyl group, a C 1-6 alkylcarbonyl group or a C 6-18 arylcarbonyl group, and wherein each of R 2 , R 4 and R a is independently a hydrogen atom, a hydroxyl group or a C 1-6 alkoxy group; wherein the C 1-6 alkyl group, the C 1-6 alkylcarbonyl group and the C 6-18 arylcarbonyl group may be optionally substituted with a halogen atom, a hydroxyl group, a C 2-6 alkenyl group, a C 1-6 alkoxy group, a C 1-6 alkoxycarbonyl group, a C 6-18 aryl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2-furanyl group, a 3-furanyl group, a 2-thienyl group, a 3-thienyl group or NR 9 R 10 , wherein the C 6-18 aryl group, the 2-pyridyl group, the 3-pyridyl group, the 4-pyridyl group, the 2-furanyl group, the 3-furanyl group, the 2-thienyl group and the 3-thienyl group may be optionally substituted with a halogen atom or a C 1-6 alkyl group, wherein each of R 9 and R 10 is independently a hydrogen atom or a C 1-6 alkyl group or R 9 and R 10 mean, together with each other, —(CH 2 ) n X(CH 2 ) m —, wherein the C 1-6 alkyl group may be optionally substituted with a C 6-18 aryl group wherein X is CR 11 R 12 , NR 13 , O or S, wherein each of R 11 and R 12 is independently a hydrogen atom or a C 1-6 alkyl group, wherein R 13 is a hydrogen atom or a C 1-6 alkyl group that may be optionally substituted with a C 6-18 aryl group, wherein n is 1, 2 or 3, and m is 1, 2 or 3, provided that n+m is 3, 4 or 5, wherein the C 1-6 alkyl group may be optionally substituted with a C 6-18 aryl group, wherein R 13 is a hydrogen atom or a C 1-6 alkyl group, and wherein the C 1-6 alkyl group may be optionally substituted with a C 6-18 aryl group.