Chemistry and Anticancer Activity of Hybrid Molecules and Derivatives based on 5-Fluorouracil

Considering that cancer continues to be an important cause of death worldwide, several conventional anticancer treatments are widely used. However, most of them display low selectivity against malignant cells and induce many adverse side effects. Among these, the use of therapies based on 5-Fluorouracil (5-FU) has been one of the most efficient, with a broad-spectrum. Due to these circumstances, various modifications of 5-FU have been developed to improve drug delivery and reduce side effects. Among the optimization strategies, modifications of 5-FU at N1 or N3 position are made, usually including the incorporation of pharmacologically active compounds with anticancer activity (called hybrid molecule) and functionalization with other groups of compounds (called conjugates). Several studies have been conducted in the search for new alternative therapies against cancer. Many of them have evidenced that hybrid compounds exhibit good anticancer activity, which has emerged as a promising strategy in this field of drug discovery and development. Furthermore, the binding of 5-FU to amino acids, peptides, phospholipids, polymers, among others, improves metabolic stability and absorption. This review highlights the potential of hybrids and derivatives based on 5-FU as a scaffold for the development of antitumor agents. Besides, it also presents a detailed description of the different strategies employed to design and synthesized these compounds, together with their biological activities and structure-activity relationship (SAR) analysis.