A new thiophene and two new monoterpenoids from Xanthium sibiricum

Abstract

Three new compounds (1–3), together with six known compounds (4–9), were isolated from the fruits of Xanthium sibiricum. The structures and the absolute configurations of sibiricumthionol (1), (+)-(5Z)-6-methyl-2-ethenyl-5-hepten-1,2,7-triol [(+)-2], ( − )-(5Z)-6-methyl-2-ethenyl-5-hepten-1,2,7-triol [( − )-2], (2E,4E,1′S, 2′R, 4′S, 6′R)-dihydrophaseic acid (3), (+)-xanthienopyran [(+)-4] and ( − )-xanthienopyran [( − )-4] were established by extensive spectroscopic analyses, X-ray crystallographic analysis, ECCD analysis and ECD calculations. Caffeic acid (7) and caffeic acid ethyl ester (8) weekly inhibited α-glucosidase enzymatic activity by 44.5% and 40.2%, respectively, at 40 μM. Protocatechuic acid (9) selectively exhibited cytotoxicity against HepG2 cell lines, with an IC₅₀ value of 2.92 μM.

Keywords::

• Xanthium sibiricum
• thiophene
• monoterpenoid
• sesquiterpene

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This project was financially supported by grants from the Natural Science Foundation of China (No. 21132009) and the National Science and Technology Project of China (No. 2012ZX09301002-002).