Neuroprotective carbazole alkaloids from the stems and leaves of Clausena lenis

Abstract

The investigation on the stems and leaves of Clausena lenis led to the isolation of a previously undescribed carbazole alkaloid, clausenalenine A (1), along with seven known analogues (2–8). The structure of 1 was elucidated based on comprehensive spectroscopic analyses and the known compounds were identified by comparisons with data reported in the literatures. All known compounds (2–8) were isolated from C. lenis for the first time. All isolated compounds were evaluated for their neuroprotective activities against 6-hydroxydopamine induced cell death in human neuroblastoma SH-SY5Y cells in vitro. Compounds 1–8 showed significant neuroprotective effects with EC₅₀ values ranging from 0.68 to 18.76 μM.

GRAPHICAL ABSTRACT

Keywords:

• Clausena lenis
• carbazole alkaloid
• clausenalenine A
• neuroprotective activities

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China (Nos. 31660097 and 21662011), the Key Research and Development Project of Haikou (No. 2017050), the Program for Innovative Research Team in University (No. IRT-16R19) and the Special Project of the Central Government for the Development of Local Science and Technology (No. ZY2018HN07).