Ether-soluble resin glycosides from the roots of Ipomoea batatas

Two new resin glycosides, batataosides I (1) and II (2), and five known compounds, friedelin (3), scopoletin (4), octadecyl caffeate (5), beta-sistosterol (6) and daucosterol (7), were isolated from the roots of Ipomoea batatas. Their structures have been determined based on the chemical and spectral data. Batataosides I and II have novel structures because the core simonic acid B was esterised with cinnamic acid for the first time, and three different substituent esterification groups in one resin glycoside is scarce. The absolute configuration of the aglycone was elucidated to be S by Mosher's method.