Structure–activity relationship study of taxoids for their ability to activate murine macrophages as well as inhibit the growth of macrophage-like cells Original Research Article

A series of new taxoids modified at the C-3′, C-3′N, C-10, C-2 and C-7 positions has been designed, synthesized and evaluated for their potency to induce NO and TNF production by peritoneal murine macrophages (Mφ) from LPS-responsive C3H/HeN and LPS-hyporesponsive C3H/HeJ strains and human blood cells, and for their ability to inhibit the growth of Mφ-like cell lines J774.1 and J7.DEF3. The SAR-study has shown that the nature of the substituents at these positions have critical effect on the induction of TNF and NO production by Mφ. Positions C-3′ and C-10 are the most flexible and an intriguing effect of the length of the substituents at the C-10 position is observed for taxoids bearing a straight chain alkanoyl moiety. An aromatic group at the C-3′N and C-2 positions is required for the activity, while only hydroxyl or acetyl substituents seem to be tolerated at the C-7 position. The natural stereochemistry in the C-13 isoserine side chain of the taxoids is an absolute requirement for macrophage activation. It has also been clearly shown that there is no correlation between the ability of the taxoids to induce TNF/NO production in C3H/HeN Mφ and the cytotoxicity against Mφ-like cells.