First Polynuclear Palladium Compounds [(C5H12NO)(PdCl3)]n and [(C10H16NO)2(Pd2Cl6)] with High Antitumor and Radioprotective Activity

Abstract

Polymeric palladium complexes [(C5H12NO)(PdCl3)]n (I) and [(C10H16NO)2(Pd2Cl6)] (II) were synthesized for the first time and studied by X-ray diffraction. Complexes I and II were found to have moderate toxicity (3rd class of toxicity) and high antitumor and radioprotective activities. Treatment of Lewis lung carcinoma (LLC) with I and II induced statistically significant antitumor and antimetastatic effects exceeding those of cisplatin: the use of I and II retarded the growth of LLC by 60.0%, while cisplatin retarded it by 48.0%. The decrease in the LLC metastasis was 75% upon the action of I, 91.0% in the case of II, and 69.0% for cisplatin. It was shown that II has a clear-cut radioprotective action. On single exposure of mice to a dose of 8.2 Gy, their survival rate was 58.0% versus 4.5% for the control. Fractional exposure to increasing doses (2.5, 3, and 3.5 Gy) resulted in 75.0% survival rate versus 33.0% for the control.