Structural and antitumor activity study of γ-octamolybdates containing aminoacids and peptides

γ-Type octamolybdates of the formulae, Na4[Mo8O26(alaO)2] · 18H2O (I), Na4[Mo8O26(glyglyO)2] · 15H2O (II) and Na4[Mo8O26(glyglyO)2] · 12H2O (III) have been prepared from sodium molybdate in aqueous solution by adding dl-alanine or glycylglycine. Their crystal structures have been determined by X-ray structure analysis. dl-alanine and glycylglycine coordinate molybdenum atom in γ-octamolybdate [Mo8O26]4− anions via monodentate carboxylate-oxygen atom. The prepared octamolybdates were screened for the possible antiproliferative activity on a panel of five tumor cell lines and on a normal cell line. All tested compounds showed a differential cell-growth inhibition in a dose-dependent manner selectively on hepatocellular carcinoma cell line (HepG2) and breast cancer cell line (MCF-7).