Piperidine alkaloids and xanthone from the roots of Caulophyllum robustum Maxim.

Two undescribed piperidine racemates, (±)-caulophines A and B (1 and 2), a new N-containing xanthone derivative (3), together with six known piperidines, were isolated from the roots of Caulophyllum robustum Maxim. Their structures were determined by extensive spectroscopic techniques. Compounds 3 and 7 exhibited weak cytotoxicities against human palace cancer hela cell line with inhibitory rates of 32.2% and 39.7%, respectively, at the concentration of 40 μM.