Preliminary Study on the Chromatographic Identification and Bioinorganic Stabilization of Anthocyanins from Dioscorea trífida L. Through Magnesium Complexation

The interest in replacing artificial colorants, which can have mutagenic, carcinogenic, and teratogenic effect, has driven the search for safe natural pigments. In this context, this preliminary study aimed to explore the chromatographic identification of anthocyanins and anthocyanidins from Dioscorea trifida L. (purple sachapapa) and to evaluate a preliminary bioinorganic stabilization method using magnesium complexes. Samples were collected in Nuevo Oriente, District of Mazán, Loreto Region, and tubers were mechanically processed. Extraction was performed with HCl-acidified methanol. Pigment identification was carried out using paper chromatography with BAW and 1% HCl systems for anthocyanins, and formic acid and forestal systems for anthocyanidins, comparing Rf values and color with scientific literature. The identified anthocyanidins were cyanidin, peonidin, malvidin and pelargonidin, and their corresponding glucosides were cyanidin-3-rhamnosyl-glucoside, pelargonidin-3,5-diglucoside, malvidin-3,5-diglucoside, and peonidin-3,5-diglucoside. Stabilization was explored via a hexacoordinated complex [η6(anthocyanin)6Mg2+].6Cl-, whose formation is based on the stoichiometry pf the reactants and the sp3d2 structure of Mg2+, according to bioinorganic chemistry studies. Preliminary results suggest that this method can enhance anthocyanin stability and provide a foundation for future toxicity studies and applications in the natural colorant industry.