Composition analysis and structural identification of anthocyanins in fruit of waxberry

Abstract

Anthocyanin pigments in the fruit of waxberry (Myrica rubra Sieb. et Zucc.), were extracted with 0.1% HCl in ethanol, and the crude anthocyanin extract was purified by C18 Sep-Pak cartridge open-column chromatography. High-performance liquid chromatography (HPLC) with photodiode array detection (PAD) and matrix-assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDI-TOF-MS) was applied for the separation and identification of anthocyanins in the fruit of waxberry and their aglycones resulting from acid hydrolysis. Three anthocyanins were found in the fruit of waxberry and identified as Cyanidin 3-O-β-galacopyranoside (14.8%), Cyanidin 3-O-β-gluco-<br />pyranoside (60.5%), and petunidin 3-O-β-glucopyranoside (24.7%), respectively, using spectroscopic methods (UV-Vis<br />and MS). The three anthocyanins were isolated and purified by preparative HPLC, and their chemical structures were further characterised by H<sup>1</sup> NMR. On the basis of chromatographic data, the total anthocyanin content was 286 mg/g in fresh fruit of waxberry.