Sulfonamide derivatives of the general formula (I): ##STR1## wherein preferably R.sup.1 represents a lower alkoxy group, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 may be the same or different from one another and each represent a hydrogen atom, halogen atom or lower alkyl group, A and B may be the same or different from each other and each represent .dbd.N-- or .dbd.CH--, E represents an aromatic 6-membered cyclic group, which may have 1 or 2 nitrogen atoms in the ring, and be substituted with 1 to 3 substituents which may be the same or different from one another with the proviso that a combination of R.sup.1 which is a hydrogen atom, lower alkyl group, nitro group or amino group which may be protected, R.sup.2 and R.sup.3 which are each a hydrogen atom, A and B which are each .dbd.CH-- and E which is a phenyl group which may be substituted with 1 to 3 substituents G which may be the same or different from one another is excluded,or pharmacologically acceptance salts of them, have an excellent antitumo-activity.