The investigation on the stems and leaves of led to the isolation of a previously undescribed carbazole alkaloid, clausenalenine A (), along with seven known analogues (-). The structure of was elucidated based on comprehensive spectroscopic analyses and the known compounds were identified by comparisons with data reported in the literatures. All known compounds (-) were isolated from 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 . Compounds - showed significant neuroprotective effects with EC values ranging from 0.68 to 18.76 μM.