THE ANTHOCYANIN METAL INTERACTIONS: AN OVERVIEW

Anthocyanin is one of the phenolic compounds found in various parts of plants. Its study has become an area of scientific exploration due to reports gathered on its reactivity, bioactive properties, and usefulness in pharmaceutics, agriculture and food production. This study investigated recently characterized anthocyanins to identify variations based on plants, plant parts, the ligand characteristics of the isolated anthocyanin, and the need for quick reference for natural product chemists in the areas of isolation and synthesis. The in vivo and in vitro metal anthocyanin complexes (MAC) were investigated to expand isolated compounds, synthesis, characterization, and study probable kinetics involving new MAC and its applications. The data reviewed was obtained from research reports found on the Web from 2014 to 2023. Results of the reviewed studies indicate anthocyanins have been isolated and characterized from different plants and all plant parts: leaves, pulp, seeds, peels, stems, and roots. The anthocyanidins (aglycone) have been derivatized through hydroxylation, methylation, glycosylation, and acylation due to the presence of many reactive centers, producing over 800 forms of anthocyanins characterized to date. Chelation of anthocyanin in vitro has been studied with several metals and metalloids, using the outcome in some cases to monitor and re-produce compounds formed in vivo. Several applications of anthocyanins and MAC have been found and are still under investigation, anthocyanins and its derivatives are being screened for ethnobotanical roles and their random applications in other human endeavors.