Comparative analysis of C-glycosidic flavonoids from Prosopis spp. and Ceratonia siliqua seed germ flour

PICARIELLO G.; SCIAMMARO L.; SIANO F.; VOLPE M.G.; PUPPO M.C.; MAMONE G.

FOOD RESEARCH INTERNATIONAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 99 p. 730 - 738

0963-9969

Seed germ of South American algarrobo (Prosopis species) and European carob (Ceratonia siliqua), a by-product of the seed processing, contains nutritionally interesting proteins, lipids and phenolics. Using reversed phase-HPLC-diode array detector and nanoflow-HPLC coupled to electrospray ionization (ESI) high resolution tandem mass spectrometry (MS/MS), we comparatively characterized and quantified polyphenols from three edible Argentinean algarrobo (Prosopis alba, Prosopis nigra and Prosopis ruscifolia) and one European carob biotypes. Polyphenol patterns were very similar among samples, confirming the taxonomic parentage of the biotypes. In all the samples, the most abundant polyphenols were apigenin 6,8-C-di-glycoside isomers, namely isoshaftoside and shaftoside, accounting for 3.22-5.18 and 0.41-0.72 mg/g seed germ flour, respectively. C. siliqua germ contained relatively high amounts of tetra- and tri-glycosilated derivatives of (iso)shaftoside, which occurred at a lower abundance in Prosopis spp. samples. Apigenin 6,8-C-di-glycosides are potent α-glucosidase inhibitors, suggesting that food preparations obtained with Prosopis spp. and C. siliqua seed germ flour as an ingredient might contribute to decrease the postprandial hyperglycemia and exert positive effects on subjects suffering from type-2 diabetes mellitus.