Chemical constituents from the bulbs of Lilium davidii var. unicolor and anti-insomnia effect

In this work, twenty-five water-soluble constituents were isolated from the bulbs of Lilium davidii var. unicolor, including two new compounds termed liliumtides A and B (1-2), and seventeen known compounds (3-4, 6-13, 15, 17, 21-25) isolated from the genus of Lilium for the first time. Their structures were established using high-resolution electrospray ionization mass spectroscopy and 1D and 2D nuclear magnetic resonance data. To confirm furtherly the absolute configuration of liliumtide A, and to accumulate enough sample to study the anti-insomnia effect, a total synthesis for liliumtide A was achieved by four steps. The pentobarbital-induced sleeping time test showed that compared with the blank control group, the liliumtide A decreased sleep latency and significantly increased the sleep time. These results suggested that liliumtide A could be investigated as a natural anti-insomnia lead compound in the pharmaceutical and food industries.