New oxindole alkaloids with selective osteoclast inhibitory activity from Gelsemium elegans

Abstract

A new alkaloid 14-hydroxygelseziridine (1), along with four known oxindoles (2-5), was isolated and characterized from the well-known toxic medicine Gelsemium elegans. Their structures were elucidated by means of spectroscopic techniques and quantum chemistry calculations. Structurally, new compound 1 has a three membered oxygen ring at N-4/C-20. All compounds were tested for osteoclast (MOC-1) inhibitory activity in vitro. Compound 2 exhibited the selective osteoclast inhibitory activity. Flow cytometry revealed that the apoptosis of osteoclasts induced by 2. Furthermore, the PCR bioassay suggested that compound 2 may activate the apoptotic pathway of osteoclasts by reducing the expression of IL-6 and c-Jun, and increasing caspase 9. This work provided the evidence for the rationality as the traditional treatment for bone related diseases of G. elegans, and shed a new light on its further research.

Graphical Abstract

Keywords:

• Gelsemium elegans
• oxindole alkaloids
• osteoclast inhibitory
• PCR bioassay

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 32000276), Guizhou Science and Technology Project (Xue Shu Xin Miao) (QKHPT RC[2018]5766-12), Digitalization, Development and Application of Biotic Resource (202002AA100007).