Alkylamides from Zanthoxylum armatum DC. and their neuroprotective activity

Zanthoxylum armatum DC. is an important medicinal plant, and its pericarps are commonly used as a natural spice in Asian countries. In this study, fifteen alkylamides were isolated and elucidated from the pericarps of Z. armatum, including five undescribed alkylamides (1–5) and ten known compounds (6–15). The molecular structures of all compounds were elucidated by 1D and 2D NMR spectroscopic analysis and mass spectrometry, among which the absolute configuration of compound 15 was determined by the Mo2(OAc)4-induced circular dichroism method. Moreover, all compounds were screened for their neuroprotective activity against H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells for the evaluation of their neuroprotective activity. Especially, compounds 2–4 expressed potential neuroprotective activity, and further research showed that the cell viability was significantly enhanced in a concentration dependent manner when the cells were treated for 6 h. Moreover, compounds 2–4 could decrease reactive oxygen species accumulation. This paper enriched structure types of alkylamides in Zanthoxylum armatum.