Optimization of Conditions for the Chromatographic Isolation of Isohexenyl Naphthazarin Derivatives from the Rhizome Callus of Echium vulgare

Recently, naphthazarin derivatives have attracted huge attention due to their broad variety of biological activity. The wide spectra of their biological activity includes wound healing, anti-inflammatory effects, antitumor, antimicrobial and antithrombotic activity, etc. The importance of these compounds does not only lie in their biological activity (and medicinal applications), but in industry as well (food coloring, cosmetics, wood coating, etc.)

In this study, three naphthazarin derivatives have been isolated and identified (deoxyshikonin, acetylshikonin and β-hydroxylisovalerylshikonin). The plant, Echium vulgare, is abundant on the territory of Serbia as a self-sown and cultivated species. The plant itself has been characterized as having a low naphthazarin pigment content compared to Onosma visianii, Onosma paniculata, Alkanna tinctoria and Lithospermum erythrorhizon, which are used for mass production of these pigments. The isolation method described in this study makes preparation of a concentrated extract from Echium vulgare possible. This concentrated extract can complement the extracts of plants with higher naphthazarin pigment content that either are non native or endangered on the territory of Europe.