Chemical Investigation Of Anticholinesterase Agent From Physostigma Venenosum (Calabar Bean)

ABSTRACT

In the present investigation, the plant Physoslima venenosum (Esere) was selected based on its poisonous strength as the typical Calabar people see it as "Ordeal poison". The plant was extracted by percolation using ethanol. The residue F°was partitioned to obtain chloroform fraction 1 FA, water fraction 1 FB, methanol fraction 2FA and pet-ether 2FB . The chloroform was discovered as very active in anti-cholinesterase activity (with concentrations of l0mls to 65.41% , 20m1s to 70.31% and 30m1s to 99.59% ) and giving the highest number of compounds with wide range of Rfvalue in TLC as (0.18 , 0.34, 0.41, 0.51, 0.79and 0.86) in 50/50% of CHC13and pet-ether. The column gave relative pure compounds confirmed with TLC in which compound X labelled 1K-B and IX labeled 1K-A were among them. IR, MS, 'H NMR, '3C NMR, 13C DEPT 90 and 135, HSQC and COSY spectra were used to propose the structures of the compounds. Phytochemical screening of the seed shows presence of Alkaloid (1.00% ± 0.3). Tanins (0.03% ± 0.00 1) Phenols (0.55% ± 0.2) Saponins (5.20%± 0.1) .Flavonoids (2.90% ± 0.3). The result of the study revealed presence of positive anti-cholinesterase activities of the partitioned fractions.