Four new resin glycosides, calyhedins VII–X, from the rhizomes of <i>Calystegia hederacea</i>
Masateru Ono, Takaaki Shimohara, Nobuyoshi Yuhara, Souta Matsubara, Shin Yasuda, Ryota Tsuchihashi, Masafumi Okawa, Junei Kinjo, Hitoshi Yoshimitsu, Toshihiro Nohara
Abstract
Four new resin glycosides with macrolactone structures (jalapins), namely, calyhedins VII (1)–X (4), were isolated from the rhizomes of Calystegia hederacea Wall. (Convolvulaceae). The structures of 1–4 were determined based on spectroscopic data. They were classified into three ring types: a 27-membered ring (1), a 22-membered ring (2, 3), and a 23-membered ring (4). Their sugar moieties were partially acylated using five organic acids, including (E)-2-methylbut-2-enoic acid, 2S-methylbutyric acid, and 2 R-methyl-3R-hydroxybutyric acid. Compound 4 was the first genuine resin glycoside with calyhedic acid F as the glycosidic acid component. Additionally, the cytotoxic activities of 1, 2, and 4 towards HL-60 human promyelocytic leukaemia cells were evaluated. All compounds demonstrated almost the same activity as the positive control, cisplatin.