SEPARATION AND CHARACTERIZATION OF ANTHOCYANINS OF MONARDA-FISTULOSA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Anthocyanins and other flavonoids in the petals of Monarda fistulosa were separated on a reversed-phase column by high-performance liquid chromatography, equipped with photodiode array and variable-wavelength detectors. Detection at 280 and 510 nm revealed the presence of 16 discrete peaks including five anthocyanin pigments. The major anthocyanidin derivatives and the presence of acylation could be distinguished on the basis of retention times and UV-visible spectra. Auxiliary analytical techniques used for pigment characterization included acid hydrolysis, paper and thin-layer chromatography, and paper electrophoresis. With the combination of these techniques, peak assignments for the major anthocyanins and other flavonoids of M. fistulosa and their relative concentrations were confirmed. The total anthocyanin concentration was 214.8 mg/100 g of fresh petals. The main anthocyanin was pelargonidin 3,5-diglucoside acylated with coumaric and malonic acids, which accounted for 81% of the total anthocyanin content and 17% of the total flavonoid content. Other flavonoids included flavone and apigenin 7-O-glucosides, 5-hydroxyflavone, and a dihydroxyflavone 8-C-glucoside.