Antineoplastic activity of azacarbazoles. I. Synthesis and antitumor properties of alpha-carboline and its selected derivatives.

alpha-Carboline and its several derivatives have been synthesized and evaluated for their antitumor activity against L1210 lymphoid leukemia, P388 lymphocytic leukemia and Sarcoma 180. It was found that of these compounds only alpha-carboline and its derivatives substituted in C-4 position with a methyl group or in 6-C position with a methyl group and fluorine or chlorine atoms caused moderate inhibition of the tumor growth of Sarcoma 180. The introduction of bromide, iodide atoms, hydroxy-, amino-groups or some other substituents in C-6 position of alpha-carboline molecule reduced significantly the biological activity of the tested compounds against Sarcoma 180. Additionally, the introduction of an ethyl or ethoxycarbonyl group to the pyrrole ring at N-9 also obliterated antitumor properties of these analogues. None of the tested compounds displayed a significant activity against murine leukemias. In the cytotoxicity test of KB cells all the compounds were inactive.