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2005, Chemistry & Biodiversity
Life Sciences
Structure–radical scavenging activity relationships of phenolic compounds from traditional Chinese medicinal plants2006 •
Traditional Chinese medicinal plants associated with anticancer contain a wide variety of natural phenolic compounds with various structural features and possessing widely differing antioxidant activity. The structure–radical scavenging activity relationships of a large number of representative phenolic compounds (e.g., flavanols, flavonols, chalcones, flavones, flavanones, isoflavones, tannins, stilbenes, curcuminoids, phenolic acids, coumarins, lignans, and quinones) identified in the traditional Chinese medicinal plants were evaluated using the improved ABTS•+ and DPPH methods. Different categories of tested phenolics showed significant mean differences in radical scavenging activity. Tannins demonstrated the strongest activity, while most quinones, isoflavones, and lignans tested showed the weakest activity. This study confirmed that the number and position of hydroxyl groups and the related glycosylation and other substitutions largely determined radical scavenging activity of the tested phenolic compounds. The differences in radical scavenging activity were attributed to structural differences in hydroxylation, glycosylation and methoxylation. The ortho-dihydroxy groups were the most important structural feature of high activity for all tested phenolic compounds. Other structural features played a modified role in enhancing or reducing the activity. Within each class of phenolic compounds, the structure–activity relationship was elucidated and discussed. This study reveals the structure–activity relationships of a large series of representative natural phenolic compounds more systematically and fully than previous work. Structure–radical scavenging activity relationships of some natural phenolics identified in the medicinal plants were evaluated for the first time.
Brazilian Journal of Pharmaceutical Sciences
Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile2009 •
In this research, the radical scavenging activity and reducing power of the ethyl acetate fraction and subfractions of Salvia mirzayanii (SM) have been investigated. The plant material was initially extracted with ethanol. The fractionation was carried out using liquid-liquid extraction, then the ethyl acetate fraction, which showed the greatest antioxidant activity, was selected. This fraction was submitted to column chromatography on a Sephadex LH 20 column eluted with pure MeOH to obtain subfractions A-G. No significant differences exist between the IC 50 of Salvia mirzayanii ethyl acetate subfraction C (IC 50 = 37.9 ± 0.85), F (IC 50 = 40.05 ± 1.4) and quercetin (38.84 ± 0.86), (P > 0.05), indicating that the radical scavenging capacity of these two subfractions and quercetin (antioxidant standard) were similar. The reducing power of the ethyl acetate fraction was less than that of all subfractions, except for subfraction A. The greatest amount of phenolic compounds was found in subfraction E (55.23 ± 4.2) and the lowest in subfraction F (5.23 ± 0.18). The greatest total flavonoid content was established in subfraction D (1.84 ± 0.01) and the lowest was in subfraction A (0.108 ± 0.007).
Industrial Crops and Products
Phytochemical composition and in vitro antioxidant activity of by-products of Salvia verbenaca L. growing wild in different habitats2013 •
2012 •
2014 •
Potentilla polyphylla, Solanum kurzii and Paedaria foetida are used as remedies against various diseases. Free radicals are one of the critical causative factors in the pathogenesis of many degenerative diseases. Phytochemical and biological studies have made it evident that medicinal plants have potentials in the prevention and treatment of those diseases. This study aimed at screening of major phytochemicals and assessing total phenolic content and antioxidant potential of P. polyphylla, S. kurzii and P. foetida to provide a scientific basis of its ethno medical uses. Phytochemicals screening was done using standard procedures. Total phenolic content was determined using Folin-Ciocalteu’s reagent. Free radical scavenging capacity was determined by DPPH and ABTS assays. P. polyphylla, S. kurzii and P. foetida displayed strong DPPH and ABTS free radical scavenging activity. Among the extracts, P. polyphylla possess the highest free radical scavenging activity with the corresponding ...
Pakistan Journal of Pharmaceutical Sciences
In vitro free radical scavenging activity of five Salvia species2007 •
Citrus sinensis has intensively been used for its nutritional and therapeutic values, usually attributed to their antioxidant properties. Several studies have earlier focused on its fruits, seeds, oils, juice and flowers. This study focuses on leaves and aimed at determining radical scavenging capacity (RSC), antiradical power(ARP), total polyphenols (TPC) and flavonoids (TFC) content of the aqueous (AE), hydroethanolic (HEE) and ethanolic (EE) extracts and their activities on free radicals DPPH•, ABTS+ and NO. Phenolic compounds of all the extracts were measured by Folin-Ciocalteu assays. RSC of 1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) and nitric oxide (NO•) radicals were measured. Also, the reducing power of extracts on phosphomolybdenum was evaluated by total antioxidant capacity (TAC) assay, antiradical power and EC 50 were determined. All the extracts possessed high TPC ranging from 306.67 ± 43.72 to 353.33 ± 30.55 µg of Eq Catechin /mg respectively for EA and EE. EE, EA, EC showed their ability to scavenge all the radicals and an important reducing power. Aqueous extracts presented the lower EC 50 (mg/ml) 4.60, 4.27, and 4.01x10-4 with DPPH•, ABTS + , NO• respectively and the highest ARP. Many correlations observed between TAC and ABTS +-RSC (r = 0.958, p<0.001), TAC and DPPH•-RSC (r= 0.934, p<0.001); TPC and DPPH•-RSC (r=0.738, p<0.05) justified its ability. leaves' Aqueous Extracts possess high radical scavenging activity and total polyphenols, good TAC and ARP. Leaves' extracts can be used as natural antioxidant source and deserve to be further explored for biological activities.
Revista de Ensino de Ciências e Matemática
A reformulação de um objeto de aprendizagem de matemática buscando melhorar sua usabilidadePacific Studies
No Tobacco, No Hallelujah": Missions and the Early History of Tobacco in Eastern Papua1991 •
International Journal of Ambient Energy
Unsteady free convective boundary layer flow of a nanofluid past a stretching surface using a spectral relaxation method2013 •
2009 •
강릉안마ᗕ〘dalpocha6、com〙 강릉오피 강릉엔조이∪강릉오피
강릉안마ᗕ〘dalpocha6、com〙 강릉오피 강릉엔조이∪강릉오피ᗕ강릉오피1960 •
JNMA: Journal of the Nepal Medical Association
Cesarean Section in a Maternity Unit of a Tertiary Care Center of Nepal: A Descriptive Cross-sectional Study2021 •
Géotechnique
The influence of the anisotropic stress state on the intermediate strain properties of granular material2017 •
Jurnal Media Elektro
Analisis Propagasi Pada Kawasan Kampus Universitas Nusa Cendana Penfui Kupang2019 •
2020 •
Journal of Physics: Conference Series
Monte Carlo Entropic sampling algorithm applied to 3D spin crossover nanoparticles: role of the environment on the thermal hysteresis2021 •
Environmental Fluid Mechanics
Turbulence and aeration in hydraulic jumps: free-surface fluctuation and integral turbulent scale measurements2012 •
Jurnal Abdimas Ilmiah Citra Bakti
Penanaman Pohon Dan Pembersihan Daerah Aliran Sungai Matawae DI Kelurahan Mataloko Sebagai Wujud Cinta Lingkungan1995 •
International Journal of Environmental Research and Public Health
Vitamin D Levels in Children with Recurrent Acute Tonsillitis in Jordan: A Case-Control Study2022 •
Journal of the American Association of Nurse Practitioners
Evaluation of a rheumatology patient prioritization triage system2016 •
Journal of Addiction Medicine
The Role of Gender in Factors Associated With Addiction Treatment Satisfaction Among Long-Term Opioid Users2015 •
Journal of Cleaner Production
Catalytic abatement of dichloromethane over transition metal oxide catalysts: Thermodynamic modelling and experimental studies2019 •
Scientia in educatione
Peer-feedback as a part of collaborative problem solving2022 •
Cold Regions Science and Technology
Freeze–thaw fracturing in building granites2015 •