PROBLEM TO BE SOLVED: To provide a compound and a tumor therapeutic agent which have a high cancer therapeutic effect and hardly cause a side effect such as hypertension. A compound represented by the following chemical structural formula (1) (wherein R represents an alkylene group which may have a branch), a salt thereof, and a solvate thereof. [Selection diagram] Figure 1【課題】がん治療効果が高く、高血圧という副作用が生じ難い化合物及び腫瘍治療剤の提供。【解決手段】下記化学構造式(1)で示される化合物(ただし、式中のRは枝分かれを有してもよいアルキレン基を示す。)及びその塩、並びにそれらの溶媒和物。【選択図】図1