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

Abstract

The effects of several organotin(IV) meso-tetra(4-carboxyphenyl)porphinate] derivatives with the general formula (R2Sn)2TPPC and (R3Sn)4TPPC (R = Me, Bu, Ph) were tested in vivo on ascidian embryonic development. Embryos at the two-cell stage were incubated in 1 × 10−5 or 1 × 10−7 M solutions of various compounds. The ligand, [meso-tetra(4-carboxyphenyl)porphine] (H4TPPC) was toxic at 1 × 10−5 M, because development was blocked at an early gastrula stage, whereas 1 × 10−7 M H4TPPC allowed the eggs to develop up to the larva stage. The most toxic among the tested compounds was tributyltin(IV) [meso-tetra(4-carboxyphenyl)porphinate], (Bu3Sn)4TPPC, since the fertilized eggs were unable to divide into two cells, even at a concentration of 1 × 10−7 M. To correlate this embryonic arrest with the metabolic pathway, and especially to understand why cellular organelles first underwent chemical damage, 10−5 and 10−7 M (Bu3Sn)4TPPC-cultured fertilized 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 × 10−5 M) reduced the content of all the tested compounds, but the lower one (1 × 10−7 M), even if still unable to allow cleavage, reduced only the lipids and the ATP contents. A hypothesis concerning initial damage to mitochondrial membrane is proposed. Copyright © 2000 John Wiley & Sons, Ltd.