Structure of anthocyanins from Eugenia jambolana fruit.

The purple color of the ripe Eugenia jambolana fruit is attributed to anthocyanins, a class of plant pigments that has attracted immense attention due to the potential health benefits of these compounds. There is disagreement in the literature on whether E. jambolana fruit anthocyanins are found as 3,5- or 3-diglucosides. Therefore, we used a combination of HPLC-UV, tandem LC-MS, and NMR techniques to identify the structures of anthocyanins present in E. jambolana fruit collected in the U.S.A. and India. Our results indicate that the anthocyanins from both locations occur as 3,5-, but not 3-diglucosides, of delphinidin, cyanidin, petunidin, peonidin, and malvidin. This is the first report to use a combination of spectrometric and spectroscopic methods to identify unequivocally the structures of E. jambolana fruit anthocyanins.