Saponins, Esculeosides B-1 and B-2, in Tomato Juice and Sapogenol, Esculeogenin B1

It has been shown that commercial tomato juice packaged in 900 g plastic bottles contains rare, naturally occurring steroidal solanocapsine-type tomato glycosides in which the saponins consist of esculeosides B-1 (2) and B-2 (3) in 0.041% as major components lacking esculeoside A. We suggest that these saponins are derived from esculeoside A (1) when the juice in plastic bottles is prepared by treatment with boiling water, similar to the process used in preparing canned tomatoes. Herein, the obtained tomato saponins (2) and (3) provided sapogenols esculeogenin B1 (4) and B2 (5), respectively, by acid hydrolysis. The former was identical to esculeogenin B previously reported, and the latter was a new sapogenol characterized to be (5α,22S,23S,25S)-22,26-epimino-16β,23-epoxy-3β,23,27-trihydroxycholestane.