Studies on the kinetics of cobalt(III) complexes with various charge and chirality crossing human erythrocyte membrane

The kinetics that four complexes with various charge and chirality crossed human erythrocyte membrane was studied, and their rate constants(k) of first-order kinetics were determined. The experimental results showed that the [Co(C2O4)(3)](3-) has an obviously higher rate of cross-membrane than [Co(en)(3)](3+), [Co(en)(2)(C2O4)](+) and [Co(en)(C2O4)(2)](-), and the k values of the latter three kinds of complexes increased gradually with the decreasing of their positive charge, their mechanism of transmembrane transport are simple passive diffusion. The rate of transmembrane transport of [Co(C2O4)(3)](3-) was obviously inhibited by DIDS, an anion channel inhibitor, the inhibition rate is 51.95%, its mechanism of transmembrane transport has been considered involving anion channel transport and passive diffusion. The uptake rate of L-[Co(C2O4)(3)](3-) is larger than that of D-[Co(C2O4)(3)](3-) by human erythrocytes, this exhibited that there was chiral selectivity when erythrocytes took up the optical isomers.