LC-MS identification of anthocyanins in boysenberry extract and anthocyanin metabolites in human urine following dosing

The anthocyanin composition of boysenberry (Rubusloganbaccus x baileyanus Britt) extract was determined by LC-ESI-MS. Four anthocyanins were identified, all comprising a cyanidin-anthocyanidin-type skeleton. The two major components were identified as the disaccharide cyanidin-3-O-sophoroside and the monosaccharide cyanidin-3-O-glucoside. The two less abundant components were identified as the rutinosides, cyanidin-3-O-2G-glucosylrutinoside and cyanidin-3-O-rutinoside, respectively. These same four anthocyanins were also detected in human urine following a dosing study with boysenberry extract indicating that glycosylated anthocyanins can be absorbed from the gut and excreted intact in the urine. Several anthocyanin metabolites were also detected in the urine and were identified by LC-ESI-MS as monoglucuronides of peonidin, cyanidin and pelargonidin. The results suggest that anthocyanins consumed as part of a diet are bioavailable and are present as intact or metabolized forms in the body.