Cholinesterase inhibiting Bisbenzylisoquinoline alkaloids from Cocculus pendulus

Cocculus pendulus (Menispermaceae), is a plant with extensive ethnobotanical uses. The extract of the plant is used externally for the treatment of eczema, prurigo and impetigo [1]. The juice of the leaves is taken as a tonic and is useful against gonorrhoea [2]. The root is bitter, alterative, laxative, refrigerant, sudorific and demulcent, and is used with other ingredients in bilious, dyspepsia and stomach-ache in children [1]. In our research on C. pendulus, we reported the isolation and structural determination of three bisbenzylisoquinoline alkaloids i.e. Kurramine 2'-β-N-oxide (1), Kurramine 2'-α-N-oxide (2) [3] and 1,2-dihydrokurramine (new) (3), along with eight known alkaloids. All the compounds were evaluated for their cholinesterase inhibiting activity, an effective mean for the therapy of Alzheimer's disease which initially concentrated on AChE inhibition. Some of these compounds exhibited significant inhibitory activity while others were found to have mild to moderate activities with the IC₅₀ values ranging between 10.0–150.0 µM.

Acknowledgements: Presentation of this work is supported by the French Foreign Office (MAE grant from Agrocampus, Rennes)

References: 1. Sastri, B. N. (1950)The Wealth of India A Dictionary of Indian Raw Materials and Industrial Products, Vol. II. Insdoc, Delhi-12.

2. Siddiqi, M. A. (1974) „Flora of Pakistan“. Nasir, E., Ali, S. I., Ferozson's. Karachi.

3. Atta-ur-Rahman, et al. (2004) Chem. Pharm. Bull. 52: 802.