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

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.

Phytochemical Profiling, Pharmacological activities, Isolation and Identification of Phytochemicals from Sterculia urens Roxb. leaves

The study is intended to evaluate the pharmacological activities, isolation and characterization of the bioactive phytochemical constituents from the crude leaf extract of Sterculia urens Roxb. The extraction of the phytochemicals from the leaves was carried on Soxhlet extraction apparatus using solvents like hexane, ethyl acetate, methanol and water. Pharmacological activities such as DPPH free radical scavenging assay (antioxidant), α-amylase inhibition assay (antidiabetic), albumin denaturation assay (antiinflammatory), blood clot lysis method (thrombolytic) and well diffusion method (antibacterial) of the crude extracts were evaluated and then the semi-preparative HPLC analysis followed by spectral studies was carried for the purification and identification of bioactive compounds. The methanolic extract showed high DPPH radical scavenging activity, α-amylase inhibition activity and albumin denaturation inhibition activity with IC50 values of 29.51±0.11, 146.85±0.18 and 149.91±0.19 μg/mL respectively. The % clot lysis of the methanolic extract was found higher than the other extracts and all the extracts have potential inhibition on the growth of the bacterial studied. From the leaf methanolic extract, 4 phenolic compounds (2,4-dihydroxybenzoic acid, methyl 4- hydroxycinnamate, p-coumaric acid and stercurensin) and 3 phenolic compounds (gossypetin, farrerol and quercetin 5,7,3',4'-tetramethyl ether) were isolated and characterised. Based on the results observed, it can be concluded that the leaf extracts of Sterculia urens Roxb are having rich phytochemical constituents with prominent pharmacological activities.

Phytochemical Analysis and Comprehensive Evaluation of Pharmacological Activities, Isolation and Characterization of Bioactive Compound from the Bark of Sterculia urens Roxb.

The objective of the present study is to investigate the phytochemical constituents by qualitative and quantitative analysis, pharmacological activities such as antioxidant, antidiabetic, anti-inflammatory, thrombolytic and antibacterial activities of different crude extracts from bark of Sterculia urens Roxb. Further, the preparative HPLC isolation and spectroscopic characterization of the bioactive phytochemical constituents were also carried out. Different solvents such as n-hexane, ethyl acetate, methanol and water were used to prepare the crude extracts from the bark using Soxhlet extraction apparatus. DPPH free radical scavenging assay (antioxidant), α-amylase inhibition assay (antidiabetic), albumin denaturation assay (anti-inflammatory), blood clot lysis method (thrombolytic) and well-diffusion method (antibacterial) were performed for the determination of pharmacological activities of the bark extracts. The preparative HPLC analysis was carried for the separation and purification of bioactive compounds and the identification of isolated compounds was carried using 1H NMR, 13C NMR and mass spectroscopy. The quantitative estimation studies confirmed that methanolic extract contains 7.75 ± 0.141 GAE/g of phenolic compounds, 10.47 ± 0.033 mg of QE/g of flavonoids and 8.70 ± 0.047 mg/g of terpenoids. The ethyl acetate extract contains 2.16 ± 0.126 GAE/g of phenolic compounds whereas the aqueous extract contains 16.53 ± 0.055 mg/g of saponins. High DPPH radical scavenging was observed for methanolic extract with IC50 concentration of 85.38 ± 0.213 μg/mL. The α-amylase inhibition activity with IC50 concentrations of 145.67 ± 1.87, 98.36 ± 0.47 and 194.47 ± 0.55 μg/mL for ethyl acetate, methanol and aqueous extracts respectively. The albumin denaturation inhibition activity was found to be very high for methanolic extract with IC50 values of 132.08 ± 0.13 μg/mL which is near to the standard (107.13 ± 0.13 μg/mL). The % clot lysis of the methanolic extract in thrombolytic activity was found to be similar to the 100 μL of streptokinase (62.36 ± 0.140 %). Two terpenoids (One known terpenoid mansonone G and one new terpenoid) were isolated from the methanolic extract using preparative HPLC separation. Three known flavonoids (farrerol, apigenin and 6-hydroxyluteolin) and one new flavonoid were also isolated from the methanolic extract. The results suggested that bark extracts of Sterculia urens Roxb. having rich phytochemical constituents with high pharmacological activities.

Role of amylase and protease in germinatingSterculia urens Roxb

The present study explains the levels of proteins and enzymes like proteases and amylases associated with the breakdown of proteins and carbohydrates during various stages (0 day to 15th day) of seed germination of Sterculia urens Roxb.. Maximum protease activity (1.12 units/mg of protein) and amylase activity was observed on 12thday of seed germination (34 units/mg of protein) and decreased thereafter. Highest protein content was observed at initial stage of seed germination and decreased thereafter. Increased proteolytic activity and amylase activity proportionately increases free amino acid content and sugars that promotes the seedlings growth and development. Bangladesh J. Sci. Ind. Res.55(2), 107-112, 2020