| abstract |
A pyrrolocarbazole derivative and a pharmaceutically acceptable salt thereof having the following formula (I): <CHEM> wherein R<1> is lower alkyl or aralkyl; R<2> is hydrogen, substituted or unsubstituted lower alkyl, lower alkenyl, or substituted or unsubstituted aralkyl; R<3>, R<4>, R<5>, R<6> and R<7> may be the same or different, and are hydrogen, halogen, nitro, substituted or unsubstituted lower alkanoyl, NR<9>R<10>, or OR<11>; R<8> is hydrogen or is combined with R<3> to form -CONR<12>-; and when R<1> is benzyl; R<2>, R<3>, R<4>, R<5>, R<6>, R<7> and R<8> are not simultaneously hydrogen. A compound of the present invention stimulates platelet production and is useful for treatment of thrombocytopenia. |