Durre Shahwar

Antioxidant potential of the extracts of Putranjiva roxburghii , Conyza bonariensis , Woodfordia fruiticosa and Senecio chrysanthemoids

Putranjiva roxburghii , Conyza bonariensis , Woodfordia fruiticosa and Senecio chrysanthemoids were collected from different areas of Pakistan and extracted in methanol. The crude methanolic extract was dissolved in water and further partitioned with n-hexane, chloroform and n-butanol successively. Total phenols of all extracts were calculated using Folin-Ciocalteu (FC) reagent, while antioxidant activities were determined using standard protocols. All extracts contained reasonable amount of phenolic contents ranging from 36.9 ± 0.3 to 911.7 ± 1.4 mg GAE/g of extract, and maximum total phenols were present in the ethyl acetate extract of S. chrysanthemoids (911.7 ± 1.4 mg GAE/g of extract). Antiradical activity was measured as decrease in absorbance at 517 nm using diphenylpicrylhydrazyl radical (DPPH). The ethyl acetate extract of W. fruiticosa exhibited the highest activity (92.1 ± 1.6% with IC 50 = 4 ± 0 µg). The reducing potential of the extracts was determined with ferric reducing antioxidant power (FRAP) and total antioxidant capacity (TAC) assays. The ethyl acetate extract of C. bonariensis showed the highest activity in FRAP (671.9 ± 1.6 µM) and the extract of W. fruiticosa (ethyl acetate) was the most active (1.882 ± 0.041) in TAC among the other extracts of the selected medicinal plants.

3-Acetyl-1-(2-methylphenyl)thiourea.

In the title compound, C10H12N2OS, the toluene and the N-carbamothioylacetamide units are oriented at dihedral angle of 78.75 (5)°. An intramolecular N—H⋯O hydrogen bond generates an S(6) ring. In the crystal, molecules are linked into [101] chains by pairs of N—H⋯S hydrogen bonds [which generate R 2 2(8) loops] and pairs of O—H⋯O hydrogen bonds [which generate R 2 2(4) loops]. The two motifs alternate in the chain.

Ferric reducing antioxidant power of essential oils extracted from Eucalyptus and Curcuma species

Abstract Objective Eucalyptus and Curcuma species are well reputed for their traditional medicinal uses in south east Asia, therefore, the present study was designed to determine reducing potential of their essential oils. Method Essential oils of the selected medicinal species Eucalyptus sideroxylon , E. teriticornis , E. citriodora , Curcuma longa and C. aromatic were extracted using hydro distillation method, separated with diethyl ether and dried over anhydrous sodium sulphate. Column chromatography of Curcuma aromatica was carried out and six fractions were collected using gradient solvent system of n-hexane-ethyl acetate. Ferric reducing antioxidant power (FRAP) of oils were evaluated using standard protocol and results were expressed in μM equivalent to FeSO 4 .7H 2 O. Results The essential oil of Eucalyptus sideroxylon was found to possess highest reducing potential among the Eucalyptus species. Curcuma longa essential oil showed most significant reducing potential with 138.4±1.1 FRAP equivalents. Conclusions It was concluded that the all essential oil and the column fractions of C. aromatic a possess significant reducing capacity ranged from 95.8±1.0 to 152.4±1.4 μM in a dose dependent manner.

An investigation of phenolic compounds from plant sources as trypsin inhibitors.

In the search of new trypsin inhibitors caffeic acid (1), cinnamic acid (2), gallic acid (3) and eugenol (4) from Cinnamomum zeylanicum, ferulic acid (5) from Impatiens bicolor, vanillin (6) from Melia azedarach and catechol (7) from Allium cepa were isolated through bioassay guided fractionation of the plant extracts. IC 50 values of the compounds 1, 2 and 5 were found to be 0.35 ± 0.02 mM, 0.96 ± 0.05 mM and 1.22 ± 0.06 mM, respectively. Lineweaver–Burk and Dixon plots and their secondary replots showed that 1 was non-competitive inhibitor of this enzyme with Ki value 0.102 ± 0.006 mM.

Antioxidant potential of phenolic extracts of Mimusops elengi

OBJECTIVE To evaluate the antioxidant potential of the phenolic extracts of Mimusops elengi (M. elengi) L. (Sapotaceae). METHODS The extract of stem bark and seeds of M. elengi were prepared in methanol and acetone:water (7:3). The acetone: water was further partitioned with ethyl acetate and n-butanol. Antioxidant activity of the extracts and partitioned fractions of M. elengi was evaluated in terms of radical scavenging potential (DPPH), inhibition of lipid peroxidation [ferric thiocyanate (FTC)], and total antioxidant activity (phosphomolybdate method). Total phenolics content were calculated using Folin-Ciocalteu reagent. RESULTS The stem bark extract partitioned with ethyl acetate exhibited highest amount of total phenols (98.0 mg GAE/g dry weight), among all other extracts, with 92.0% DPPH radical scavenging activity at concentration of 0.5 mg/mL, while methanol extract (stem bark) had maximum inhibition of lipid peroxidation (62.0%) and total antioxidant activity (771.0 mg/g GAE/g). A positive correlation occurred between total phenols and radical scavenging activity (R (2) = 0.922 9) and total antioxidant activity (R (2) = 0.945 1). CONCLUSIONS Our study suggested that antioxidant activity of stembark extract of M. elengi is due the presence of phenolic compounds. Furthermore, the bark extract is a valuable source of natural antioxidants.

Identification of flavonoids with trypsin inhibitory activity extracted from orange peel and green tea leaves

BACKGROUND Orange peel (Citrus sinensis) and green tea (Camellia sinensis) leaves, rich sources of food flavonoids, were analyzed for their trypsin inhibitory potential. Hesperetin, rutin and hesperidin from orange peel, and catechin from green tea leaves, were isolated and their chemical structures were analyzed. All four compounds were evaluated for their trypsin inhibitory potential. RESULTS Among all the isolated compounds, rutin exhibited the highest protease inhibition activity (75.4 ± 0.9%) with IC50 = 16 ± 2 µmol L(-1), followed by catechin (65.3 ± 1.4%; IC50 = 83 ± 9 µmol L(-1)), hesperetin (62.1 ± 1.3%; IC50 = 104 ± 12 µmol L(-1)) and hesperidin (59.7 ± 1.1%; IC50 = 127 ± 14 µmol L(-1)). Lineweaver-Burk and Dixon plots and their secondary replots indicated that all four compounds possessed non-competitive inhibition. The Ki values of hesperetin, rutin, hesperidin and catechin were calculated as 90.2 ± 1.1, 17.5 ± 0.6, 84.2 ± 1.5 and 65.1 ± 1.5 µmol L(-1) respectively. CONCLUSION The present results suggest that the four isolated flavonoids can be used as a supplement in food for the treatment of pathologies associated with the degradation of a specific protein.

Phenyl N-phenyl­carbamate

In the title compound, C13H11NO2, the aromatic rings are oriented at a dihedral angle of 42.52 (12)°. The crystal structure is stabilized by intermolecular N—H⋯O hydrogen bonds, which form infinite one-dimensional polymeric chains extending along the a axis. C—H⋯π interactions between the aromatic rings are also present.

Bioactive constituents from Croton sparsiflorus Morong.

Whole plant extracts of Croton sparsiflorus in methanol have shown significant enzyme inhibition and antioxidant activities. Bioassay-guided isolation of chloroform fraction at pH 3 resulted in the identification of crotsparinine (1) and crotsparine (2), while sparsiflorine (3) was purified from the chloroform fraction at pH 9. The structures of the compounds were confirmed through spectral analyses (EI-MS, 1H and 13C NMR). The isolated compounds 1–3 exhibited remarkable enzyme inhibition activity with IC50 values 27.01 ± 1.1, 22.26 ± 1.0 and 18.02 ± 1.3 μM in xanthine oxidase and 48.42 ± 1.5, 48.05 ± 1.4 and 7.42 ± 1.0 μM in acetylcholine esterase assays, respectively. These compounds also showed potent radical scavenging and reducing properties in DPPH and FRAP assays, respectively. The present results suggest the validity of the traditional uses of C. sparsiflorus in rheumatism and gout. Furthermore, the isolated noraporphine alkaloids can be useful in the treatment of neurodegenerative diseases.

Phenyl N-(2-methyl­phen­yl)carbamate

In the title compound, C14H13NO2, the aromatic rings attached to the O and N atoms make dihedral angles of 62.65 (9) and 38.28 (11)°, respectively, with the central carbamate group. The benzene rings are oriented at a dihedral angle of 39.22 (10)°. In the crystal, a very weak C—H⋯π interaction occurs.

Radical Scavenging, Proteases Activities, and Phenolics Composition of Bark Extracts from 21 Medicinal Plants

Stem barks derived from twenty-one medicinal plants were extracted in methanol (100%) and acetone-water (70 : 30 v/v) and at room as well as at reflux temperature conditions. Total phenolic contents, determined using FC (Folin Ciocalteu) reagent, ranged from 528 to 715 mg GAE/g of crude extract. 15 out of 21 plants showed DPPH activity more than 90% and the rest of plants exhibited the activity in the range of 87–89%. The methanolic extract of P. granatum obtained at room temperature showed the highest antiradical activity (96%). The extracts with similar % radical scavenging of DPP showed significant variation in EC50 value. Radical scavenging activity of E. rostrata, M. champaca, A. modesta, P. roxburghii, P. longifolia, E. suberosa, and F. infectoria was evaluated for the first time. A strong correlation between total phenols and antiradical activity was exhibited with R values ranging from 0.7580 to 0.8874 indicating a linear relationship The extracts phenolic composition was studied by HPLC. All extracts showed remarkable antioxidant activity (87 to 96%) while moderate activity was exhibited against protease (22 to 56%). Gallic acid, tannic acid, quercetin, rutin, catechin, hesperidin, and cinnamic acid were identified as the major phenolic acids in the extracts of selected medicinal plants.