A 4,6-hexadecadiene-2,4-dicarboxylic acid derivative represented by the following general formula (1) or a pharmaceutically acceptable salt thereof, each of which has an anti-tumor activity, and the like, are provided. [wherein, R1 represents hydroxy, —OR3 (wherein R3 represents optionally substituted lower alkyl or an optionally substituted aliphatic heterocyclic group), or —NR4R5 (wherein R4 and R5 may be the same or different, and each represents a hydrogen atom or optionally substituted lower alkyl) and R2 represents hydroxy or —OR6 (wherein R6 represents optionally substituted lower alkyl or optionally substituted aralkyl)].