Separation and elucidation of anthocyanins in the fruit of mockstrawberry (Duchesnea indica Focke)

Anthocyanin pigments in the fruit of mockstrawberry (Duchesnea indica Focke), were extracted with 0.1% HCl in ethanol, and the crude anthocyanin extract was purified by a C₁₈ Sep-Pak cartridge open-column chromatography. High-performance liquid chromatography (HPLC) with photodiode array detection and mass spectrometry (MS) was applied for the isolation and composition analysis of anthocyanins in the fruit of mockstrawberry and their aglycones from acid hydrolysis. Three anthocyanins were found in the fruit of mockstrawberry and they were identified as cyanidin 3-O-rutinoside (61%), peonidin 3-O-rutinoside (34%), and petunidin 3-O-rutinoside (5%), respectively, by spectroscopic methods (UV-vis and MS). The two major anthocyanins were isolated by preparative HPLC, and their chemical structures were further characterised by H1 NMR. On the basis of chromatographic data, the total anthocyanin content was 205 mg g-1 of the fresh fruit of mockstrawberry.