SYNTHESIS, CHARACTERIZATION AND ANTITUMOR ACTIVITY OF TERNARY COMPLEXES OF ALL-TRANS RETINOIC ACID WITH RARE EARTH METALS

Eight new ternary complexes of all-trans retinoic acid (HRA) with rare earth metals have been synthesized and characterized by elemental analysis, molar conductance, IR, TG-DTA, UV and 1 HNMR. The general formula of the complexes is M(RA) 2 Ac nH 2 O where M = Y, La, Nb, Sm, Eu,Gd, Er,Tm, n = 4-8. Antitumour activity of Sm(RA) 2 Ac 4H 2 O and Y(RA) 2 Ac 8H 2 O was tested with human bladder cancer line EJ cells. The results obtained indicated that the inhibitory rates of the two complexes were significantly greater than that of HRA itself (p < 0.05). Especially, Y(RA) 2 Ac 8H 2 O effects on inducing differentiation, modulating the expressions of P 21 and mutation of P 53 genes in vitro.