Minor betalains in fruits of Hylocereus species

Betacyanins in peel and flesh of fruits of different Hylocereus species were identified by means of GC/MS, electrospray MS/MS, HPLC as well as ¹H and ¹³C NMR techniques. As hitherto unknown pigments: betanidin 5-O-(2′-O-β-d-apiofuranosyl)-β-d-glucopyranoside, betanidin 5-O-(4′-O-malonyl)-β-d-glucopyranoside and betanidin 5-O-[(5″-O-E-sinapoyl)-2′-O-β-d-apiofuranosyl]-β-d-glucopyranoside were elucidated. The sinapoyl moiety attachment position in the structure of betacyanins was established for the first time. The peel contained a more complex pattern of betacyanins with apiofuranosyl moiety. Other recently identified pigments were also present in the samples and their ¹H or ¹³C NMR spectra were recorded. In the case of phyllocactin and its 4′-isomer the migration of the malonyl group was noticed.