Synthesis and HSA binding characterisation of the water soluble 7-succinylpaclitaxel.

A water soluble paclitaxel analogue, the 7-hemisuccinylpaclitaxel, was synthesised and its binding to human serum albumin (HSA) was characterised by difference circular dichroism and optical biosensor methodologies. The carboxylate group was introduced at paclitaxel C-7 position to improve the drug water solubility without significantly changing the biological activity. The paclitaxel analogue showed a relatively low affinity to HSA (3.5x10(4) M(-1)), while no significant interactions were evidenced with selective markers for the most characterised binding sites on the carrier, suggesting a non-selective binding to low affinity binding sites.