| abstract |
New camptothecin derivatives of the general formula (1), preparations thereof and antitumor agents comprising the same, (see formula 1) wherein R1 represents a hydrogen atom or a C1-C6 alkyl group, R2 represents a hydrogen or a C1-C6 alkoxy group, R3 represents a hydrogen or halogen atom or a C1-C6 alkyl, C1-C6 alkoxy, hydroxyl, C2-C6 acyloxy or methoxyethoxymethoxy group, R4 represents a hydrogen or halogen atom, and R5 represents a C1-C6 alkyl, C3-C6 unsaturated alkyl, alkylthioalkyl, alkoxyalkyl, pyridyl or substituted phenyl group, with the proviso that all of the R2, R3 and R4 substituents should not be a hydrogen atom. |