Metal Complexes with Hydroxyflavones: A Study of Anticancer and Antimicrobial Activities

Abstract

Metal chelation to bioactive small molecules is a well-established strategy to enhance thebiological activity of the resulting complexes. Among the widely explored structural motifs,the combination of prominent metal centers with naturally inspired derivatives has attractedconsiderable attention. One such promising platform is the flavone scaffold, derivedfrom flavonoids and studied since ancient times. Flavones are plant-derived compoundsknown for their diverse biological activities and health benefits. They exhibit significantstructural variability, primarily through backbone modifications such as hydroxylation.Importantly, coordination of metal ions to hydroxylated flavone cores often improvestheir natural bioactivities, including anticancer and antimicrobial effects. In this review,we summarize transition metal complexes incorporating hydroxyflavone (OH–F) ligandsreported over the past 15 years. We provide a concise overview of synthetic approachesand structural characterization, with a particular emphasis on coordination modes (e.g.,maltol-type, acetylacetonate-type, catechol-type, and others). Furthermore, we discussbiological evaluation results, especially anticancer and antimicrobial studies, to highlightthe therapeutic potential of these complexes. Finally, we suggest directions for the futuredevelopment of metal-based agents bearing hydroxyflavone moieties through several criticalpoints in terms of the accuracy, reproducibility, and relevance of biological studiesinvolving metal-based compounds