Novel Nucleolipids of Pyrimidine β‐D‐Ribonucleosides: Combinatorial Synthesis, Spectroscopic Characterization, and Cytostatic/Cytotoxic Activities

Abstract

Four series of nucleolipids with either uridine, 5-methyluridine, 5-fluorouridine, and 6-azauridine as β-D-ribonucleoside component have been prepared in a combinatorial (not parallel!) manner (see Formulae). All compounds have been characterized by elemental analyses, ESI mass spectrometry as well as by (1) H-, and (13) C-NMR, and UV spectroscopy. A selection of eight nucleolipids with different lipophilizing moieties, based on earlier findings, as well as of 5-fluorouridine as control were first tested on their cytotoxic effect towards PMA-differentiated human THP-1 macrophages. Those compounds which did not exhibit a significant inhibitory effect on the survival of the macrophages were next tested on their cytostatic/cytotoxic effect towards the human astrocytoma/oligodendroglioma GOS-3 cells as well as against the rat malignant neuroectodermal BT4Ca cell line. Additionally, induction of apoptosis of the cell lines was evaluated. It turned out that particularly a combined lipophilization of the nucleosides by an 2',3'-O-ethyl levulinate residue plus a farnesyl moiety at N(3) of the pyrimidine moiety of the corresponding nucleolipids leads to an active compound with the highest probability.