Protostane triterpenes from the rhizome of Alisma plantago-aquatica

A new protostane triterpene named 11-deoxy-25-O-ethylalisol A (1), together with four known analogues (2-5), were isolated from the dried rhizome of Alisma plantago-aquatica. The structure of the new compound was established by chemical methods and spectroscopic analysis, and the single crystal X-ray diffraction analyses were conducted on the compounds 2-5. Additionally, compounds 1-5 were tested for their cytotoxicity against six human tumor cell lines, hepatoprotective and anti-inflammatory activities.