N-Methylneolitsine as a new and potent acetylcholinesterase inhibitor of Cissampelos pareira Linn. aerial parts: bioassay-guided isolation and quantitative densitometric analysis.

The rising geriatric population is expected to increase the demand for drugs treating neurodegenerative diseases. The present work is aimed to discover acetylcholinesterase (AChE) inhibitors from Cissampelos pareira Linn. aerial parts (Family: Menispermaceae). Bioassay-guided isolation, AChE inhibition study and estimation of the therapeutic marker in different parts of raw herbs were conducted. The structure of the compound (1) was elucidated as N-methylneolitsine by using NMR (1D and 2D) and ESI-MS/MS spectral data, which is a new natural analogue of neolitsine. It showed good AChE inhibition with an IC₅₀ value of 12.32 µg/mL. It was densitometrically estimated to be 0.074 − 0.33% in aerial parts of C. pareira, collected from various locations. The alkaloid reported here could be potentially useful for the treatment of various neurodegenerative diseases and the aerial part of C. pareira could be used as a promising ingredient for various preparations treating neurodegenerative diseases. [ABSTRACT FROM AUTHOR]