Anti-Cancer Activity of some Organomercury (II) Complexes: Establishment of Structure-Activity Relationships

Organometallic derivatives of mercury(II) having the composition, p-MeC₆H₄HgL¹ (I), p-MeC₆H₄HgL² (II), p-MeOC₆H₄HgL² (III), p-NO₂C₆H₄HgL³ (IV), p-MeOC₆H₄L⁴ (V) and p-NO₂C₆H₄HgL⁴ (VI) [L¹=deprotonated 6-mercaptopurine, L²=deprotonated 6-thioguanine, HL³=deprotonated 5-fluorouracil, L⁴=phenyldithiocarbazate unit] were synthesized and characterized. Their composition and has been confirmed by elemental analysis, while their purity has been gauged by TLC. Conductance measurements reveal the non-electrolyte nature of the complexes. The bidentate bonding modes of the coordinating groups and the stoichiometry of the complexes has been ascertained by spectral studies. From thermogravimetric analysis the relative lability of the complexes has been determined. The complexes have been tested against L 1210 leukemia cells. The disparity in anti-cancer activity has been correlated with the structure of the analogues. The 5-fluorouracil complex (IV) has the lowest inhibitory concentration and the highest kinetic lability.