Seven new resin glycosides, ipoalbins XXII–XXVIII, from the seeds of Ipomoea alba

Seven new resin glycosides, designated ipoalbins XXII (1)-XXVIII (7), together with one known resin glycoside (8), were isolated from the seeds of Ipomoea alba L. (Convolvulaceae). Structural elucidation was accomplished primarily through comprehensive NMR and MS analyses. All newly identified compounds possessed intramolecular cyclic ester (jalapin-type) architectures, in which the sugar moieties were partially acylated by organic acids, including acetic acid, (E)-2-methylbut-2-enoic acid, and 2S-methyl-3S-hydroxybutyric acid. Notably, two of the new compounds exhibited rare jalapin-type frameworks, characterized by esterification between the carboxyl group of the aglycone moiety and the hydroxyl group of an organic acid substituent located on the sugar chain. Furthermore, the cytotoxic activities of 1-8 against HL-60 human promyelocytic leukemia cells, as well as the antiviral activities of 1-8 and previously reported ipoalbins XI-XXI against herpes simplex virus type 1 (HSV-1), were assessed. All compounds demonstrated moderate cytotoxicity, whereas all showed notable antiviral activity against HSV-1.