Expanded Application of Piper nigrum : Guided Isolation of Alkaloids with Inhibitory Activities of AChE/BuChE and Aβ Aggregation.

Piper nigrum is a popular crop that can be used as seasoning or as an additive but its active ingredients also have an effect on the nervous system. Nineteen new amide alkaloids ( 1a / 1b , 2 - 5 , 6a / 6b , 7 , 8a / 8b , 9 , 10a / 10b , 11a - 11b , 12 - 14 ) were isolated from P. nigrum , guided by inhibitory activity of AChE and LC-MS/MS based on GNPS. The configurations were determined by extensive spectral analysis, Bulkiness rule, and NMR calculations. The inhibitory activities of AChE/BuChE and Aβ aggregation were tested, and the results showed compounds 2 , 7 , and 12 had significant inhibitory activities. These components were identified in the crude fraction and their relative quantities were tested, which suggested that compound 2 was the index component in the active site from P. nigrum .