EXTRACTION OF CU(II) AND ZN(II) IONS USING FLAVONOID CONSTITUENTS FROM ISATIS TINCTORIA L.

Abstract

Isatis tinctoria L. (woad), a historically significant medicinal and dye plant, is rich in flavonoid compounds such as vicenin2, isovitexin, isoscoparin, and quercetin derivatives [1][2]. Flavonoids are polyphenolic secondary metabolites capable of forming coordination complexes with transition metal ions through chelation, a property extensively documented across plant systems [3]. This research evaluates the feasibility of extracting Cu(II) and Zn(II) ions from aqueous solutions using I. tinctoria flavonoids as natural chelating agents. An optimized extraction method was developed involving aqueous and methanolic extracts of I. tinctoria leaf biomass followed by complexation with divalent metal ions. Spectrophotometric and atomic absorption spectroscopy confirmed the formation of stable metalflavonoid complexes. Results demonstrate significant binding affinities of I. tinctoria flavonoids to both Cu(II) and Zn(II) ions under controlled pH conditions, suggesting potential applications in phytoremediation and green separation technologies. These findings expand the utility of plant flavonoids beyond traditional pharmacology toward environmentally relevant metal extraction systems.