Gelsemium elegans (Loganiaceae) is a well-known toxic perennial climbing vine indigenous to Southeast Asia. It has been used in Chinese folk medicine for many years for the treatment of malignant tumors, skin diseases (e.g., psoriasis), rheumatism, and rheumatic arthritis.

Inspired by the traditional use of Gelsemium elegans in the treatment of rheumatic arthritis, an autoimmune disease that causes chronic joint inflammation, the Ethnobotany Research Group of Xishuangbanna Tropical Botanical Garden (XTBG) carried out a bioassay-guided investigation of G. elegans. As a result, two new Gelsemium alkaloids, 21-(2-oxopropyl)-koumine and 11-methoxygelselegine, and two known Gelsemium alkaloids, koumine and gelselegine were isolated from the immunosuppressively active fractions of G. elegans.

The researchers reported the isolation and structural elucidation of the new alkaloids and their biological activity evaluation. The observations indicated that Gelsemium alkaloids of different structural types possibly have potential as immunosuppressive agents.

The results suggested that the traditional use of G. elegans for the treatment of rheumatic arthritis was attributed to the presence of immunosuppressively active agents, and the plant extracts, particularly the alkaloid fractions obtained from this plant, might be a potential source for immunosuppressive drug development.