PURPOSE: To obtain a new compound useful for prophylatic or curing treatment of cancers such as leukemia, tumor, or metabolic disease of normal genomes, autoimmune diseases such as multiple rheumatic arthritis and systemic lupur erythematosus.

CONSTITUTION: This compound denoted by the formula I, e.g. 2,9-dimethoxy-6,13- dioxo-pyradino [1,2-a:4,5-a'] diindole, etc., is obtained by allowing two molecules of 2-indole carboxylic acid, whose 5-position is optionally substituted or not substituted by group R and R', to condense in the presence of a condensing agent such as bicyclohexylcarbodiimide. In the formula I, R and R' are each H, hydroxy, 1-5C alkyl, halogen, 1-5C alkoxy, 1-3C acyloxy.