Heilaohu, the roots of Kadsura coccinea, has a long history of use in Tujia ethnomedicine for the treatment of rheumatoid arthritis and gastroenteric disorders, and a lot of work has been done in order to know the material basis of its pharmacological activities. The chemical investigation led to the isolation and characterization of three new (1–3) and twenty known (4–23) lignans. Three new heilaohulignans A-C (1–3) and seventeen known (4–20) lignans possessed dibenzocyclooctadiene skeletons. Similarly, one was a diarylbutane (21) and two were spirobenzofuranoid dibenzocyclooctadiene (22–23) lignans. Among the known compounds, 4–5, 7, 13–15 and 17–22 were isolated from this species for the first time. The structures were established, using IR, UV, MS and NMR data. The absolute configurations of the new compounds were determined by circular dichroism (CD) spectra. The isolated lignans were further evaluated for their cytotoxicity and antioxidant activities. Compound 3 demonstrated strong cytotoxic activity with an IC₅₀ value of 9.92 µM, compounds 9 and 13 revealed weak cytotoxicity with IC₅₀ values of 21.72 µM and 18.72 µM, respectively in the HepG-2 human liver cancer cell line. Compound 3 also showed weak cytotoxicity against the BGC-823 human gastric cancer cell line and the HCT-116 human colon cancer cell line with IC₅₀ values of 16.75 µM and 16.59 µM, respectively. A chemiluminescence assay for antioxidant status of isolated compounds implied compounds 11 and 20, which showed weak activity with IC₅₀ values of 25.56 µM and 21.20 µM, respectively.

Alzheimer’s disease (AD) is characterized by a progressive memory loss that leads to a profound emotional disturbance in later stages. As no safe and effective drug is yet available for the treatment of AD, secondary metabolites from plants may be instrumental in meeting this challenge. Keeping in view this point we evaluated sesquiterpenes of medicinal plant Amberboa ramosa for their cholinesterase inhibitory activity.