Abstract
Investigation on the EtOH extract of the fruits of Chaenomeles speciosa led to the isolation of a new triterpene acid bearing an unusual hydroperoxyl substitute group at C-11, speciosaperoxide (1), along with six known triterpenoids, 3β-acetoxyurs-11-en-13β,28-olide (2), 3-O-acetyl ursolic acid (3), oleanolic acid (4), ursolic acid (5), masilinic acid (6), and tormentic acid (7), and three known norsesquiterpenoids, roseoside (8), vomifoliol (9) and (6S,7E,9R)-6,9-dihydroxy-4,7-megastigmadien-3-one 9-O-[β-d -xylopyranosyl (1 → 6)-glucopyranoside] (10). Their structures were elucidated on the basis of spectroscopic data and comparison with reference data. Besides compound 1, compounds 2, 8–10 were obtained from this genus for the first time. None of these compounds exhibited inhibitory activity against T-and B-lymphocyte proliferation.
Acknowledgements
We would like to express our thanks to the members of the Analytical Centre of our laboratory for the measurements of all spectral data. This work was supported in part by a grant named Xi-Bu-Zhi-Guang scholarship from the Chinese Academy of Sciences.