Eight new bis(dibenzylstannic heteroaromatic radical carboxylate) oxides {[(PhCH~2)~2SnO~2CR]~2O}~2 (R=2-furanyl, 2-furanvinyl, 2- thiophenyl, 3-pyridyl, 4-pyridyl, 2-pyridyl, 3-indolymethyl, 3- indolypropyl) were synthesized by the reaction of dibenzylstannic oxide with heteroarmotic radical substituted carboxylic acids in 1:1 molar ratio. The compounds were characterized by elemental analysis, MS, IR and NMR (^1H, ^1^1^9Sn). These results revealed that the compounds adopt the dicarboxylate tetraorganodistannoxane structure mode and the four carboxylate ligande were coordinated to Sn in bidentate. The ^1^1^9Sn NMR spectroscopy indicated the presence of two distinct six coordinate tin centers. The compounds were tested in vitro against two human tumour cell lines, MCF-7, a mammary tumour, and WiDr, a colon carcinoma. Some of them showed antitumor activities.

Key words: BENZYL GROUP P, ORGANO TIN COMPOUNDS, OXIDE, HETEROCYCL IC COMPOUNDS, CARBOXYLIC ACID ESTER, BIOLOGICAL ACTIVITY, STRUCTURE CHARACTERISTICS