Saponins esculeosides B-1 and B-2 in Italian canned tomatoes

Italian canned tomatoes contain the tomato glycosides esculeosides B-1 (1, 0.0052%) and B-2 (2, 0.0068%) without esculeoside A. Herein, the structure of esculeoside B-1 (1) is characterized to be 3-O-β-lycotetraosyl (5S,22R,23S,25S)-22,26-epimino-16β,23-epoxy-3β,23,27-trihydroxycholestane 27-O-β-D-glucopyranoside. We hypothesized that these substances might be derived from esculeoside A when the cans are prepared with treatment in boiling water. To confirm that hypothesis, we refluxed esculeoside A with water for 6.5 h, providing esculeosides B-1 (1) and B-2 (2) in yields of 25.8% and 31.0%, respectively.