Isolation of flavonoides from Artemisia macrocephala anticholinesterase activity: Isolation, characterization and its in vitro anticholinesterse activity supported by molecular docking

In this study the flavonoids isolated from Artemisia macrocephala were screened out for anticholinesterase activity. The isolated flvanoids were characterized by HNMR, NOESY, COSY, HMBC, HSQC and mass spectroscopy. The compounds (1-4) in appropriate quantities were isolated from chloroform fraction using gravity column chromatography by eluting ethyl acetate/n-hexane solvent system. The flavonoids were characterized and resulted in the form of mono substituted methoxy flavones to tri substituted flavones. Ellman's assay techniques were used to find out enzyme inhibition. Operating environment (MOE) software was used for molecular docking studies. Compounds (1), (2) and (3) showed 88.42 +/- 2.76, 84.50 +/- 1.60 and 90.16 +/- 2.98 percent inhibition of the acetyl cholinesterase (AChE) respectively at 1000 mu g/mL concentrations with IC50 value 165, 60, 65 mu g/mL respectively which were comparable to that of standard galanthamine. While for butyryl cholinesterase (BChE), (1), (2) and (3) showed 91.63 +/- 4.32, 81.03 +/- 3.53 and 87.69 +/- 2.84 percent inhibitions respectively at 1mg/mL as compared to the standard galanthamine which caused 96.50 +/- 2.41 percent inhibition at the same concentration. Whereas, compound (4) exhibited moderate activity for both the enzymes. Molecular docking studies confirmed the experimental AChE and BChE inhibitory activities of the test samples by their virtue of multiple interactions with target enzymes. The results confirm that the specie has biologically active constituents that are more useful for the management of several neurodegenerative ailments like ataxia, Parkinson's disease, Alzeimer's disease and some other types of dementia.