Isolation and Characterization of Bioactive Phenolic Compounds from Abies Pindrow Aerial Parts

Abstract

Abies pindrow Royle (Himalayan silver fir, family Pinaceae) has a long tradition of use as anxiolytic but not investigated scientifically. Previously, antianxiety activity of chloroform extract (CE) and ethyl acetate fraction (EAF) of methanol extract of the plant have been reported at the dose of 400 and 50 mg/kg, respectively. CE and EAF were subjected to bioactivity-guided-fractionation using column chromatography with a view to isolate anxiolytic constituents. The antianxiety activity of test samples was assessed by comparing with control as well as standard drug, diazepam (2 mg/kg, p.o.) using the elevated plus maze model. Among six fractions (F₁ – F₆) of CE obtained after column chromatography, F₂ and F₃ exhibited significant antianxiety activity at doses of 45 and 40 mg/kg, respectively. Further column chromatography of F₂ and F₃ led to the isolation of maltol and dipalmitin. Column chromatography of EAF yielded five fractions (F₁ – F₅). F₁ Exhibited antianxiety activity at the dose of 15 mg/kg. Column chromatography of F₁ led to the isolation of gallic acid, maltol, p-coumaric acid, 4-hydroxy benzoic acid, 3,4-dihydroxy benzoic acid, shikimic acid, pinitol, hesperitin, and apigenin. Among these compounds, maltol, gallic acid, p-coumaric acid, hesperitin, and apigenin exhibited antianxiety activity at doses of 100, 10, 30, 50 and 2 mg/kg, p.o., respectively.