Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Differe...Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.展开更多
The extracts from hulls, brans and flours of Fagopyrum esculentum M6ench （FEM, three varieties） and Fagopyrum tartaricum L. Gaerth （FTG, seven varieties） were screened for free and bound phenolic content or total ...The extracts from hulls, brans and flours of Fagopyrum esculentum M6ench （FEM, three varieties） and Fagopyrum tartaricum L. Gaerth （FTG, seven varieties） were screened for free and bound phenolic content or total phenolic content （TPC）, as well as 1,1 diphenyl-2-picryl hydrazyl （DPPH） free radical scavenging activity and reducing power. Free phenolics were predominant in buckwheat hulls, brans and flours. FEM hulls extract exhibited the highest reducing power and DPPH free radical scavenging activity with the average ECs0 84.54 μg mL^-1 and IC50 11.54 μg mL^-1 respectively, FTG brans extract had the highest average TPC （24.87 mg GAE g^-1 DW）, and FEM flours extract showed the lowest TPC, reducing power and radical scavenging activity. Furthermore, the correlations among TPC, DPPH free radical scavenging activity and reducing power of all the samples were investigated. The rank correlation coefficient （rs） between reducing power and DPPH free radical scavenging activity of buckwheat hulls, between TPC and DPPH free radical scavenging activity of buckwheat flours were 0.76 and 0.79, respectively （P〈0.05）. However, there is no significant correlation between the remaining indexes of hulls and flours, as well as the ten buckwheat brans. This result indicated that some non-phenolic compounds also contributed to the total antioxidant activity in hulls, brans and flours of buckwheats. This study demonstrated that buckwheat hulls and brans, rather than flours, are good source of antioxidants.展开更多
Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of...Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of leaf,root and rhizome from E.acoroides were tested for total phenolic content,proanthocyanidins and in vitro antioxidant activity in terms of total antioxidant assay,DPPH assay and FRAP assay.Results:The leaf sample was found to have high levels of phenolic(0.323±0.028 mg TAE/g) and proanthocyanidins(0.570 0±0.000 3 mg TAE/g) when compared to root and rhizome.The leaf samples exhibited higher total antioxidant activity (11.770±0.026 mg Ascorbic acid equivalent/g),higher percentage of DPPH radical scavenging activity(25.76±0.04) and higher reducing power(18.060±0.073) in terms of mg GAE/g.In addition, there was a significant correlation between total phenolic content and total antioxidant activity (R^2=0.923),DPPH assay(R^2=0.509).FRAP assay(R^2=0.994).Similarly,significant correlation was found between the proanthocyanidin and total antioxidant activity(R^2=0.977),DPPH assay (R^2=0.464) and the FRAP assay(R^2=0.998).Conclusions:These results suggested that E.acoroides have strong antioxidant potential.Further study is necessary for isolation and characterization of the active antioxidant agents,which can be used to treat various oxidative stress-related diseases.展开更多
Red rice gains popularity as a functional crop owing to its high polyphenols content and antioxidant activity. However, active components are discarded in common milling. Superfine ground technology was employed in th...Red rice gains popularity as a functional crop owing to its high polyphenols content and antioxidant activity. However, active components are discarded in common milling. Superfine ground technology was employed in this paper. To evaluate the influence of superfine ground processing on the physicochemical properties and functional effect of red rice (Oryza sativa L.), four powders with the size of 156.74 μm, 69.53 μm, 26.35 μm, and 10.68 μm were prepared by superfine grinding technology in this paper. Results showed that the size was smaller for red rice powders, greater for the bulk density (from 0.624 g/ml to 0.745 g/ml), and smaller for the angle of repose (from 74.67°to 61.41°) and slide (from 38.99°to 26.42°). The values of water solubility index, water holding capacity and enzymatic digestibility by α-amylase significantly increased with the decreasing particle size (P < 0.05). In addition, antioxidant activity and phenolic content were enhanced by superfine ground. These results indicated that superfine ground would improve the physicochemical and functional properties of red rice, which was helpful to promote the overall quality and healthy effect of foods containing red rice.展开更多
AIM:To investigate the antioxidant activity and total phenolic content from the crude extracts and crude fractions of ten species of Phellinus mushrooms collected from northeast Thailand.METHODS:The samples were teste...AIM:To investigate the antioxidant activity and total phenolic content from the crude extracts and crude fractions of ten species of Phellinus mushrooms collected from northeast Thailand.METHODS:The samples were tested for their radical scavenging activity toward 2,2-diphenyl-1-pricylhydrazyl (DPPH) radical (DPPH method) and total phenolic content (Folin-Ciocalteu method).RESULTS:Some of the investigated extracts exhibited potent radical scavenging activity with the IC 50 ranging from (7.30±0.34) to (19.80±0.13) μg·mL-1.IC 50 were in the range of the standard antioxidant used;quercetin,ascorbic acid and butylated hydroxytoluene (BHT).The strongest scavenging activity as comparable to quercetin was found in the crude 80% EtOH extract of P.torulosus.The crude EtOAc fraction of P.pini showed the highest total phenolic content with a value of 87.76±1.00 equivalent gallic acid (EGA) while the samples with potent antioxidant activity were also determined to have high amount of total phenolics (78.34±0.27 to 51.01±0.38) EGA.CONCLUSION:These results indicated that crude extracts from Phellinus mushrooms have a potential to be natural antioxidant source.展开更多
A comparative study was carried out with ethanolic (80%) extracts from leaves and cell cultures of three Callistemon species, namely C. lanceolatus (CL), C. viridiflorous (CV), and C. comboynensis (CC). Cell suspensio...A comparative study was carried out with ethanolic (80%) extracts from leaves and cell cultures of three Callistemon species, namely C. lanceolatus (CL), C. viridiflorous (CV), and C. comboynensis (CC). Cell suspensions of the three species were grown in liquid Murashige and Skoog (MS) medium (100 ml) supplemented with 0.9 mg·g-1 kinetin in combination with 1.1 mg·g-1 NAA. The CL leaf extract was standardized to contain the highest amount of phenolics (104 ± 2.0 mg·g-1), followed by CC (95.8 ± 1.2 mg·g-1) and CV (79.8 ± 4.6 mg·g-1). On the other hand, cell cultures of CV contained more phenolics (14.9 ± 0.6 mg·g-1) than those of the other two species, CL and CC, which contained 12.2 ± 0.16 and 9.12 ± 0.16 mg·g-1, respectively. Nevertheless, CV leaf extract exhibited the highest antioxidant activity (91.4% ± 0.4%) at a concentration of 1000 μg·ml-1, comparable to 100 μg·ml-1 gallic acid (90.8% ± 1.5%).展开更多
基金funded by the Deanship of Scientific Research at King Saud University with the research group project No.RGP-VPP-010
文摘Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.
基金supported by the Fundamental Research Funds for the Central Universities,China (XDJK2012B014)
文摘The extracts from hulls, brans and flours of Fagopyrum esculentum M6ench （FEM, three varieties） and Fagopyrum tartaricum L. Gaerth （FTG, seven varieties） were screened for free and bound phenolic content or total phenolic content （TPC）, as well as 1,1 diphenyl-2-picryl hydrazyl （DPPH） free radical scavenging activity and reducing power. Free phenolics were predominant in buckwheat hulls, brans and flours. FEM hulls extract exhibited the highest reducing power and DPPH free radical scavenging activity with the average ECs0 84.54 μg mL^-1 and IC50 11.54 μg mL^-1 respectively, FTG brans extract had the highest average TPC （24.87 mg GAE g^-1 DW）, and FEM flours extract showed the lowest TPC, reducing power and radical scavenging activity. Furthermore, the correlations among TPC, DPPH free radical scavenging activity and reducing power of all the samples were investigated. The rank correlation coefficient （rs） between reducing power and DPPH free radical scavenging activity of buckwheat hulls, between TPC and DPPH free radical scavenging activity of buckwheat flours were 0.76 and 0.79, respectively （P〈0.05）. However, there is no significant correlation between the remaining indexes of hulls and flours, as well as the ten buckwheat brans. This result indicated that some non-phenolic compounds also contributed to the total antioxidant activity in hulls, brans and flours of buckwheats. This study demonstrated that buckwheat hulls and brans, rather than flours, are good source of antioxidants.
文摘Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of leaf,root and rhizome from E.acoroides were tested for total phenolic content,proanthocyanidins and in vitro antioxidant activity in terms of total antioxidant assay,DPPH assay and FRAP assay.Results:The leaf sample was found to have high levels of phenolic(0.323±0.028 mg TAE/g) and proanthocyanidins(0.570 0±0.000 3 mg TAE/g) when compared to root and rhizome.The leaf samples exhibited higher total antioxidant activity (11.770±0.026 mg Ascorbic acid equivalent/g),higher percentage of DPPH radical scavenging activity(25.76±0.04) and higher reducing power(18.060±0.073) in terms of mg GAE/g.In addition, there was a significant correlation between total phenolic content and total antioxidant activity (R^2=0.923),DPPH assay(R^2=0.509).FRAP assay(R^2=0.994).Similarly,significant correlation was found between the proanthocyanidin and total antioxidant activity(R^2=0.977),DPPH assay (R^2=0.464) and the FRAP assay(R^2=0.998).Conclusions:These results suggested that E.acoroides have strong antioxidant potential.Further study is necessary for isolation and characterization of the active antioxidant agents,which can be used to treat various oxidative stress-related diseases.
文摘Red rice gains popularity as a functional crop owing to its high polyphenols content and antioxidant activity. However, active components are discarded in common milling. Superfine ground technology was employed in this paper. To evaluate the influence of superfine ground processing on the physicochemical properties and functional effect of red rice (Oryza sativa L.), four powders with the size of 156.74 μm, 69.53 μm, 26.35 μm, and 10.68 μm were prepared by superfine grinding technology in this paper. Results showed that the size was smaller for red rice powders, greater for the bulk density (from 0.624 g/ml to 0.745 g/ml), and smaller for the angle of repose (from 74.67°to 61.41°) and slide (from 38.99°to 26.42°). The values of water solubility index, water holding capacity and enzymatic digestibility by α-amylase significantly increased with the decreasing particle size (P < 0.05). In addition, antioxidant activity and phenolic content were enhanced by superfine ground. These results indicated that superfine ground would improve the physicochemical and functional properties of red rice, which was helpful to promote the overall quality and healthy effect of foods containing red rice.
基金supported by Center of Excellence for Innovation in Chemistry (PERCH-CIC) and Faculty of Science,Mahasarakham University
文摘AIM:To investigate the antioxidant activity and total phenolic content from the crude extracts and crude fractions of ten species of Phellinus mushrooms collected from northeast Thailand.METHODS:The samples were tested for their radical scavenging activity toward 2,2-diphenyl-1-pricylhydrazyl (DPPH) radical (DPPH method) and total phenolic content (Folin-Ciocalteu method).RESULTS:Some of the investigated extracts exhibited potent radical scavenging activity with the IC 50 ranging from (7.30±0.34) to (19.80±0.13) μg·mL-1.IC 50 were in the range of the standard antioxidant used;quercetin,ascorbic acid and butylated hydroxytoluene (BHT).The strongest scavenging activity as comparable to quercetin was found in the crude 80% EtOH extract of P.torulosus.The crude EtOAc fraction of P.pini showed the highest total phenolic content with a value of 87.76±1.00 equivalent gallic acid (EGA) while the samples with potent antioxidant activity were also determined to have high amount of total phenolics (78.34±0.27 to 51.01±0.38) EGA.CONCLUSION:These results indicated that crude extracts from Phellinus mushrooms have a potential to be natural antioxidant source.
文摘A comparative study was carried out with ethanolic (80%) extracts from leaves and cell cultures of three Callistemon species, namely C. lanceolatus (CL), C. viridiflorous (CV), and C. comboynensis (CC). Cell suspensions of the three species were grown in liquid Murashige and Skoog (MS) medium (100 ml) supplemented with 0.9 mg·g-1 kinetin in combination with 1.1 mg·g-1 NAA. The CL leaf extract was standardized to contain the highest amount of phenolics (104 ± 2.0 mg·g-1), followed by CC (95.8 ± 1.2 mg·g-1) and CV (79.8 ± 4.6 mg·g-1). On the other hand, cell cultures of CV contained more phenolics (14.9 ± 0.6 mg·g-1) than those of the other two species, CL and CC, which contained 12.2 ± 0.16 and 9.12 ± 0.16 mg·g-1, respectively. Nevertheless, CV leaf extract exhibited the highest antioxidant activity (91.4% ± 0.4%) at a concentration of 1000 μg·ml-1, comparable to 100 μg·ml-1 gallic acid (90.8% ± 1.5%).
