Isolation, pharmacological evaluation and molecular docking studies of bioactive compounds from .

Background: Traditionally, is widely used for the treatment of many diseases like dysentery, fever, typhoid, diarrhea, eczema, smallpox, malaria and cough.

Methods: Shade-dried roots of were extracted with methanol. Based on HPLC results, chloroform and ethyl acetate fractions were subjected to silica column isolation and four compounds: glutaric acid , 3,5 dihydroxy phenyl acrylic acid , (2,5 dihydroxy phenyl) 3',6',8'-trihydroxyl-4H chromen-4'-one and hexanedioic acid were isolated in pure form. Ellman's assay was used to determine the anticholinesterase potential of isolated compounds while their antioxidant potential was estimated by DPPH and ABTS scavenging assays.

Results: Amongst the isolated compounds, and exhibited excellent percent inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) (83.23±1.11, 82.72±2.20 and 82.11±2.11, 82.23±1.21, respectively, at 1000 µg/mL) with IC of 76, 90, 78 and 92 µg/mL, respectively. Highest percent radicals scavenging against DPPH and ABTS (87.41±1.20 and 86.13±2.31) with IC of 64 and 65 µg/mL, respectively, were observed for compound . Molecular docking studies also supported the binding of compound and with the target enzyme. The para-hydroxyl group of the phenolic moiety is formed hydrogen bonds with the active site water molecule and the side chain carbonyl and hydroxyl residues of enzyme.

Conclusion: The isolated compounds inhibited the DPPH and ABTS-free radicals, and AChE and BChE enzymes. It was concluded that these compounds could be used in relieving the oxidative stress and pathological symptoms associated with excessive hydrolysis of acetyl and butyryl choline. The results of the study were supported by docking studies for compounds and .