| 摘要 |
Compounds of the formula <IMAGE> (I) in which one of the symbols R1 and R2 represents an alkyl radical that has 3 or 4 carbon atoms and is unsaturated in the 2,3-position, and the other represents such a radical or lower alkyl, R3 and R4 each represents, independently of the other, hydrogen or methyl, and A represents a radical of the formula <IMAGE> in which Z1, or each of Z2 and Z3 independently of the other, represents hydrogen or lower alkyl, or Z2 and Z3 together represent lower alkylene, and salts of such compounds in which Z1, or Z3 and optionally also Z2, represent(s) hydrogen, exhibit tumor-inhibiting activities. |
