Higher Free Radical Scavenging Effect Research Articles

One-pot three-component synthesis of novel pyrano[3,2-e]pyrazolo[1,5-a]pyrimidines and investigation of their biological activities

In this study, pyrano[3,2-e]pyrazaolo[1,5-a]pyrimidine derivatives were produced in high yields (80–89%), at room temperature, by three-component reactions involving alkyl isocyanides, dialkyl acetylenedicarboxylates, and 7‑hydroxy pyrazolo[1,5-a]pyrimidines. Using FT-IR, 1H and 13C NMR, and mass spectral data, the structure of the synthesized compounds was identified. The created molecules were tested against cancer, bacteria, and free radicals to evaluate how effective they could be. It was determined whether or not the tested substances had any cytotoxic effects on the MCF-7 (breast cancer) and the MCF-10 (breast epithelial) cell lines. Compound 4l, in comparison to other compounds, has shown the most potent anti-cancer activity (IC50=19.70±0.89 µM), which is roughly as excellent as the standard medicine etoposide (IC50= 18.71±1.09 µM). Also, the antioxidant properties of the products were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The results demonstrated that compound 4 h had the highest free radical scavenging effect (IC50= 12.12±0.40 µM), which was very close to the value for ascorbic acid (IC50= 11.85±0.30 µM), as the antioxidant standard. The Kirby-Bauer disk diffusion technique was applied to examine the bactericidal impact of the synthesized compounds. According to the findings, virtually all the compounds had a modest level of action against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus).

Cytotoxic, Antioxidant, Antibiofilm, and Antimicrobial Activities of Mushroom Species from Turkey.

Mushrooms, which have been collected to meet the nutritional needs of the world for many years, have gained medical importance thanks to the bioactive compounds they produce. Thanks to studies carried out to determine mushroom diversity, the number of species identified is increasing year by year. Accordingly, in recent years, studies conducted to determine the biological activities of metabolites produced by fungi have been increasing. The present study was conducted to determine the cytotoxic, antioxidant, antibiofilm and antimicrobial activities of the seven different mushroom species (Craterellus cornucopioides, Hymenopellis radicata, Lepista nuda, Pisolithus arhizus, Ramaria flava, Schizophyllum commune, and Tricholoma ustale) collected from Tokat and Yozgat regions located in northern and central Turkey. Laboratory studies have demonstrated that mushrooms used in this study have different degrees of antibiofilm, antimicrobial, antioxidant and cytotoxic activities. At the end of the study, it is determined that C. cornucopioides and L. nuda species have the highest antimicrobial activity. In addition, mushroom species have biofilm inhibitory effects on indicator microorganisms at varying degrees ranging between 20.7 and 96.3%. As a result of antioxidant activity studies, it was determined that T. ustale has the highest free radical scavenging effect and P. arhizus, which has the highest polyphenol content, has the highest reducing power. Finally, it is determined that, among the mushrooms used in the present study, H. radicata showed higher selectivity on the MDA-MB-231 breast cancer cell line than on the normal cell line tested, while C. cornucopioides showed higher selectivity on the MCF-7 breast cancer cell line.

Molecular Characterization and Antioxidant Potential of Three Wild Culinary-Medicinal Mushrooms from Tripura, Northeast India

The aim of this study was to characterize 3 wild culinary-medicinal mushrooms using molecular tools and to analyze their antioxidant activity. Antioxidant properties were studied by evaluating free radical scavenging, reducing power, and chelating effect. The mushrooms were identified as Lentinus squarrosulus, L. tuber-regium, and Macrocybe gigantean by amplifying internal transcribed spacer regions of ribosomal DNA. The results demonstrated that the methanolic extract of M. gigantean has the highest free radical scavenging effect and chelating effect, whereas the methanolic extract of L. squarrosulus has the highest reducing power. The highest total phenol content and the most ascorbic acid were found in the M. gigantean extracts. Among the 3 mushroom extracts, M. gigantean displayed the most potent antioxidant activity. Molecular characterization using the nuclear ribosomal internal transcribed spacer region as a universal DNA marker was an effective tool in the identification and phylogenetic analysis of the studied mushrooms. The study also indicated that these wild macrofungi are rich sources of natural antioxidants.

ISOLATION OF QUERCETIN FROM FLOWER PETALS, ESTIMATION OF TOTAL PHENOLIC, TOTAL FLAVONOID AND ANTIOXIDANT ACTIVITY OF THE DIFFERENT PARTS OF RHODODENDRON ARBOREUM SMITH

The flowers of Rhododendron arboreum Smith is a source of polyphenolic compounds. A flavonol, quercetin, was isolated from ethyl acetate fraction of the methanol extract of flower petals of R. arboreum by repeated Sephadex LH-20 column chromatography. Isolated quercetin was characterized by comparing melting point, Rf values, UV and IR spectra with authentic quercetin. The isolated quercetin was used as a standard for the estimation of total flavonoids. Total phenolic and total flavonoid content in different parts of R. arboreum was carried out spectrophotometrically using Folin-Ciocalteu reagent and Aluminium chloride reagent respectively. Gallic acid and quercetin were used as standard for the construction of calibration curve of phenolic and flavonoid respectively. The results showed that the highest total phenolic content was detected in the 70% acetone extract of the flowers (600 mg GAE/g extract) and petals (600 mg GAE/g extract) and the lowest amount was detected in methanol extract of stem (188 mg GAE/g extract). Similarly, the highest total flavonoid was detected in the 70% acetone extract of the twigs (170 mg QE/g extract) and the lowest amount was detected in the methanol extract of stem (45 mg QE/g extract). The antioxidant activity of the methanol extracts obtained from different parts of R. arboreum was determined by 2, 2- diphenyl-1-picryl hydrazyl (DPPH) assay and the radical scavenging activity (IC50) was calculated. The highest free radical scavenging effect was observed in leaves with IC50=8.34 ?g/ml and lowest was observed in stem with IC50=67.83 ?g/ml. The IC50 values, total phenolic and total flavonoid content (correlation coefficient R2= 0.923 for phenolic, R2= 0.965 for flavonoid) were correlated which showed strong correlation indicating that the major components responsible for antioxidant activity is phenolics. The highest the phenolic content, the lowest the IC50 value observed. The result indicated that R. arboreum is a rich source of high value polyphenols as natural antioxidant to use in preventive medicine as well as in food and pharmaceutical industry.Scientific World, Vol. 12, No. 12, September 2014, page 34-40

Cyclodextrins enhance the antioxidant activity of essential oils from three Lamiaceae species

In the present study, the effect of β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) on the antioxidant activity and storage stability of the essential oils (EOs) from Lavandula viridis, Lavandula pedunculata subsp. lusitanica and Thymus lotocephalus (Lamiaceae) was investigated. The presence of both cyclodextrins (CDs) was found to produce a remarkable enhancement on the antioxidant activity as assessed by the oxygen radical absorbance capacity (ORAC) assay. The highest free radical-scavenging effect was observed in the EO from T. lotocephalus, particularly at the highest concentration of HP-β-CD (i.e., 1900μmolTE/gEO). Moreover, the antioxidant activity of the EO/HP-β-CD complexes was found to be considerably stable over 30 days, at 4°C, possibly due to the higher solubility of the modified β-CD. The results obtained suggest that these systems can be a very interesting alternative as a natural source of antioxidants for different applications such as in the food preservation field.

Evaluation of antioxidant activity, quantitative estimation of phenols and flavonoids in different parts of Aegle marmelos

In existing study, we carried out an efficient record of the comparative antioxidant activity in methanolic extract of the selected parts (leaves, root and stem bark) of Aegle marmelos. Total content of phenol and flavonoid was quantitatively estimated in different parts of A. marmelos. The total phenolic contents varied from 9.8367 ± 0.0235 to 1.7281 ± 0.049 mg g −1. Total flavonoid contents were between 8.248 ± 0.029 and 1.087 ± 0.002 mg g −1. Free radical scavenging activity of different extracts was evaluated by using DPPH (1,1-diphenyl-2-picryl hydrazyl) method. The highest free radical scavenging effect was observed in leaves with IC 50 = 2.096 μg ml −1. The effectiveness of radical scavenging activity of leaves extract was about 10 times greater than reference antioxidant butylated hydroxy toluene (BHT). The greater amount of phenolic compounds leads to more powerful radical scavenging effect as shown by methanolic extract of A. marmelos leaves.

Free radical scavenging activity of crude extracts and 4´-o-methylepigallocatechin isolated from roots of cassine transvaalensis burtt-davy from botswana

Water and ethanol extracts of roots from Cassine transvaalensis Burtt-Davy (celastraceae) were assessed for in vitro antioxidant activity using 1,1- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. The ethanolic extract exhibited higher free radical scavenging effect than the water extract at all tested concentrations. Above 100μg/ml, the ethanolic extract showed 80% scavenging activity, similar to control antioxidant compounds quercetin, rutin and L-ascorbic acid. The water extract reached a similar level of activity (80%) at 200μg/ml. Between 20-50μg/ml, 4'-O-methylepigallocatechin isolated by bioassay directed fractionation exhibited scavenging activity greater than that of either the ethanolic or aqueous crude extract. However, at concentrations above 50μg/ml, the scavenging activity of the ethanolic extract exceeded that of 4'-O-methyl-epigallocatechin.The results suggest that extracts from the roots of Cassine transvaalensis have strong antioxidant activity. These findings support the ethnomedical use of this plant to promote good health. (Afr. J. Biomed. Res. 11: 55- 63) ots from Cassine transvaalensis Burtt-Davy (celastraceae) were assessed for in vitro antioxidant activity using 1,1- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. The ethanolic extract exhibited higher free radical scavenging effect than the water extract at all tested concentrations. Above 100μg/ml, the ethanolic extract showed 80% scavenging activity, similar to control antioxidant compounds quercetin, rutin and L-ascorbic acid. The water extract reached a similar level of activity (80%) at 200μg/ml. Between 20-50μg/ml, 4'-O-methylepigallocatechin isolated by bioassay directed fractionation exhibited scavenging activity greater than that of either the ethanolic or aqueous crude extract. However, at concentrations above 50μg/ml, the scavenging activity of the ethanolic extract exceeded that of 4'-O-methyl-epigallocatechin.The results suggest that extracts from the roots of Cassine transvaalensis have strong antioxidant activity. These findings support the ethnomedical use of this plant to promote good health. (Afr. J. Biomed. Res. 11: 55- 63)Key Words; Cassine transvaalensis; antioxidant; DPPH radicals; 4’-O-methylepigallocatechin;epicatechin

Evaluation of antioxidant activity, quantitative estimation of phenols and flavonoids in different parts of Aegle marmelos.

In existing study, we carried out an efficient record of the comparative antioxidant activity in methanolic extract of the selected parts (leaves, root and stem bark) ofAegle marmelos. Total content of phenol and flavonoid was quantitatively estimated in different parts of A. marmelos. The total phenolic contents varied from 9.8367 ± 0.0235 to 1.7281 ± 0.049 mg g-1. Total flavonoid contents were between 8.248 ± 0.029 to 1.087 ± 0.002 mg g-1. Free radical scavenging activity of different extracts was evaluated by using DPPH (1, 1 -Diphenyl- 2 -picryl hydrazyl) method. The highest free radical scavenging effect was observed in leaves with IC50 = 2.096µg ml –1. The effectiveness of radical scavenging activity of leaves extract was about 10 times greater than reference antioxidant butylated hydroxy toluene (BHT). The greater amount of phenolic compounds leads to more powerful radical scavenging effect as shown by methanolic extract of A. marmelos leaves. Key words: Aegle marmelos, antioxidant, flavonoids, phenols, 1, 1 –diphenyl - 2 -picryl hydrazyl.

Free Radical Scavenging Activity and Secondary Metabolites from in vitro Cultures of Sanicula graveolens

An in vitro propagation system was developed to obtain shoot and root cultures from the Andean spice Sanicula graveolens (Apiaceae). Propagation of shoots, roots and plantlets was achieved by the temporary immersion system. The free radical scavenging effect of the methanol/water (7:3 v/v) extracts was determined by the discoloration of the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). Total phenolic, flavonoid, chlorogenic acid (CA) and quercetin 3-O-glucoside content in the samples was assessed by spectrophotometry and DAD-HPLC analysis, respectively. On a dry weight basis, the crude extracts showed total phenolic values ranging from 3.57 to 6.93%, with highest content for the root culture sample. Total flavonoid content ranged from 1.23 to 2.23% and was lower for the root culture. Chlorogenic acid and neochlorogenic acid were identified by TLC in all samples. Highest free radical scavenging effect was observed for the root culture which also presented the highest CA content. Two of the shoot culture samples, with similar IC50 values in the DPPH discoloration assay, also presented close quercetin-3-O-glucoside content.

Antioxidant activity of Siamese neem tree (VP1209)

Leaves, fruits, flowers and stem bark extracts from the Siamese neem tree ( Azadirachta indica A. Juss var. siamensis Valeton, Meliaceae) were assessed for antioxidant activity in vitro using the 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging assay, total antioxidant activity and inhibition of lipid peroxidation in Chago K1 cancer cell culture by the thiobarbituric acid reactive substances (TBARS) method. The results showed that leaf aqueous extract, flower and stem bark ethanol extracts exhibited higher free radical scavenging effect on the DPPH assay with 50% scavenging activity at 26.5, 27.9 and 30.6 μg/ml, respectively. The total antioxidant activity of these extracts was found to be 0.959, 0.988 and 1.064 mM of standard trolox, respectively. At 100 μg/ml, the flower ethanol and leaf aqueous extracts significantly decreased malondialdehyde (MDA) levels (46.0 and 50.6%, respectively) by the TBARS method. The results suggest that extracts from leaf, flower and stem bark of the Siamese neem tree have strong antioxidant potential. This report supports the ethnomedical use of young leaves and flowers of this plant as a vegetable bitter tonic to promote good health.