Organometallic complexes with biological molecules. XIV. Biological activity of dialkyl and trialkyltin(IV) [Meso-tetra(4-carboxyphenyl)porphinate] derivatives

The effects of several organotin(IV) meso-tetra(4-carboxyphenyl)porphinate] derivatives with the general formula (R2Sn)(2)TPPC and (R3Sn)(4)TPPC (R = Me, Bu, Ph) were tested in vivo on ascidian embryonic development. Embryos at the two-cell stage mere incubated in 1 x 10(-5) or 1 x 10(-7) M solution s of various compounds. The ligand, [meso-tetra(4-carboxyphenyl)porphine] ( H4TPPC) was toxic at 1 x 10(-5) M, because development was blocked at an ea rly gastrula stage, whereas 1 x 10(-7) M H4TPPC allowed the eggs to develop up to the larva stage. The most toxic among the tested compounds was tribu tyltin(IV) [meso-tetra (4-carboxyphenyl)porphinate], (Bu3Sn)(4)TPPC, since the fertilized eggs were unable to divide into two cells, even at a concent ration of 1 x 10(-7) M. To correlate this embryonic arrest with the metabol ic pathway, and especially to understand why cellular organelles first unde rwent chemical damage, 10(-5) and 10(-7) M (Bu3Sn)(4)TPPC-cultured fertiliz ed eggs were tested for DNA, RNA, protein, glucose, lipid and ATP contents, comparing the values obtained with those of control culture fertilized egg contents. The higher concentration (1 x 10(-5) M) reduced the content of a ll the tested compounds, but the lower one (1 x 10(-7) M), even if still un able to allow cleavage, reduced only the lipids and the ATP contents. A hyp othesis concerning initial damage to mitochondrial membrane is proposed. Co pyright (C) 2000 John Wiley & Sons, Ltd.