Antiviral Activity of Four New Resin Glycosides Calysolins XIV–XVII from Calystegia soldanella against Herpes Simplex Virus

Four new resin glycosides, named calysolins XIV (1), XV (2), XVI (3), and XVII (4) were isolated from the leaves, stems, and roots of Calystegia soldanella ROEM.. et SCHULT. (Convolvulaceae). Their structures were determined based on spectroscopic and chemical evidence, and consisted of two different types: those (1) with a macrolactone structure and those (2-4) with a non-macrolactone structure. Their sugar moieties were partially acylated by specific organic acids, including tiglic, 2S-methylbutyric, and 2S,3S-nilic acids. Additionally, evaluation of the antiviral activity of 1-4 revealed effects against the herpes simplex virus type 1.