Iridoid glucosides from Chinese herb Lonicera chrysatha and their antitumor activity

A new bis-iridoid glucosides, secologanin methyl hemiacetal-yl-6'- secologanin dimethyl acetal (chrysathain, 1), was isolated from the methanol extract of the leaves of Chinese medicinal plant Lonicera chrysatha along with nine known iridoid glucosides, i.e., loganin (2), secologanin (3), secologanin dimethylacetal (4), 8-epi-kingiside (5) 7a-morroniside (6), 7β-morroniside (7), vogeloside (8) 7-epi-vogeloside (9) and sarracenin (10). Their structures were elucidated by spectroscopic methods. Compounds 1-5 showed moderate in vitro antitumour activity against human promyelocytic leukemia (HL-60) cells.