Haemolytic properties of some water-soluble para-sulphonato-calix-[n]-arenes.

In this paper, we describe the haemolytic effect of parent para-sulphonato-calix-[n]-arenes and their derivatives bearing one pendant group at the lower rim of calix-arene towards human erythrocytes. A maximum of 30% of haemolysis has been observed for para-sulphonato-calix-[8]-arene for a concentration of 200 mM representing 300 g of calix-arene per liter of human blood, para-sulphonato-calix-[4]-arene and para-sulphonato-calix-[6]-arene show much lower haemolytic effects, 0.5 and 8%, respectively at 200 mM concentration. Coupling of a methoxy-carboxylate function at the phenolic group reduces haemolytic effects in all cases. The presence of an ethoxy-amine function increases the haemolytic behaviour for the calix-[4]-arene and calix-[6]-arene systems, but reduces the effect for the calix-[8]-arene derivatives.