Phytochemical Analysis, Pharmacological Activities, Isolation and Characterization of Bioactive Compounds from the Roots of Sterculia urens Roxb.

Abstract

The present study was intended to explore the pharmacological significance of the crude root extract of Sterculia urens Roxb. Further the bio-active compounds were isolated and characterized using chromatographic and spectroscopic techniques. Soxhlet extraction apparatus was utilized for isolation of the chemical constituents from the root using a series of solvents such as n-hexane, ethyl acetate, methanol and water. The pharmacological activities such as inhibition of DPPH radical, α-amylase enzyme activity, albumin denaturation along with antibacterial and thrombolytic activities. The isolation of purified bioactive constituents was carried using preparative HPLC technique and the purified compounds were characterized using spectroscopic techniques like NMR, IR and mass. Among the crude root extracts, methanolic extract shows high DPPH radical scavenging activity with IC₅₀ concentration of 26.74 ± 0.08 μg/mL. The IC₅₀ concentrations in α-amylase enzyme inhibition activity was 263.96 ± 0.90, 127.73 ± 1.23 and 223.54 ± 4.76 μg/mL, respectively for ethyl acetate, methanol and water extracts, respectively. The methanolic extract shows high albumin denaturation inhibition assay than other extracts with IC₅₀ concentration as 137.09 ± 0.20 μg/mL, which is very close to standard ascorbic acid. The methanolic extract also shows high % clot lysis than other extracts and results were comparable with 100 μL of streptokinase standard. The preparative HPLC followed by spectral analysis confirm that two known alkaloids (Sterculinine I & II) and three known flavonoids (gossypetin, apigenin and 6-hydroxyluteolin) were purified and characterized from the root methanol of Sterculia urens Roxb. The purified and identified compounds were reported for the first time in Sterculia urens Roxb.