Resin glycosides. IX. Operculins I, II, V, VII and VIII, new ether-soluble resin glycosides of rhizoma Jalapae Braziliensis (the roots of Ipomoea operculata).

Abstract
Eight ether-soluble resin glycosides (jalapins), operculins I-VIII, were isolated from Phizoma Jalapae Braziliensis (the roots of Ipomoea operculata). Among them, the structures of operculins I, II, V, VII and VIII, which have a common glycosidic acid, operculinic acid A, have been determined on the basis of chemical and spectral data. Similar to the jalapins so far isolated from several Convolvulaceae plants, all of them have intramolecular macrocyclic ester structures. They have n-dodecanoic and/or n-decanoic acid as a component organic acid in place of hitherto known isobutyric, 2-methylbutyric, tiglic and nilic acids.