| abstract |
(57) Abstract: A novel fused tetracyclic heterocyclic derivative having an excellent antitumor activity and a method for producing the same are provided. SOLUTION: General formula (I) [In the formula, A ring and B ring are the same or different and each represents a monocyclic aromatic ring which may have a substituent, and X represents a bond, an oxygen atom, a sulfur atom or -CH = CH-. , Y represents a group represented by the formula-e-f (wherein e represents a lower alkylene group, and f represents an amino group optionally substituted with a lower alkyl group). Alternatively, a pharmaceutically acceptable salt thereof. [Effect] It has excellent antitumor activity. |