A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed...A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%.展开更多
A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucop...A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucopyranoside（4）, butein-4-methoxyl-4＇-O-β-D-glucopyranoside（5）, butin-7-O-β-D-glucopyranoside（6）, isoquercitrin（7）, and sulfurein（8） was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activitv.展开更多
Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltr...Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.展开更多
This study was undertaken to optimize the solvent-free microwave extraction conditions and DPPH radicalscavenging activity of essential oil from Schisandra chinesis fruits.The uniform design method was employed for pr...This study was undertaken to optimize the solvent-free microwave extraction conditions and DPPH radicalscavenging activity of essential oil from Schisandra chinesis fruits.The uniform design method was employed for process optimization.The optimal extraction conditions were determined as follows:extraction time,50 rain;microwave power,800 W;and amount of water addition for pretreatment,40%.Under these conditions,the extraction yield of essential oil was 0.92%.A total of 35 compounds were identified by GC-MS in the obtained essential oil with a total content of 91.06%,mostly consisting of ylangene(34.81%),β-himachalene(10.74%)andα-bergamotene(9.22%).The ICs0 value of the essential oil against DPPH free radicals was determined as 3.01 mg/mL.In conclusion,solvent-free microwave extraction is a feasible method for essential oil extraction from Schisandra chinensis fruits.展开更多
Covalent conjugates of pumpkin seed protein isolate(PSPI)and different polyphenols(epigallocatechin gallate(EGCG),chlorogenic acid(CA)and gallic acid(GA))were prepared at pH 9.0 to develop covalent microparticles to p...Covalent conjugates of pumpkin seed protein isolate(PSPI)and different polyphenols(epigallocatechin gallate(EGCG),chlorogenic acid(CA)and gallic acid(GA))were prepared at pH 9.0 to develop covalent microparticles to protect the stability of polyphenols under storage and digestive conditions.The results for polyphenol-bound equivalents,free amino group contents,sulfhydryl contents and Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis(SDS-PAGE)indicated that polyphenols were covalently bonded with PSPI,while the secondary structure of conjugates became more regular and stable compared with PSPI alone due to the covalent interactions.EGCG-PSPI conjugates displayed the highest polyphenol-bound equivalents(204.75 nmol/mg)and most stable structure compared with CA-PSPI and GA-PSPI because of the eight active phenolic hydroxyl groups within EGCG,which provided more sites for covalent and non-covalent interactions.Accordingly,EGCG-PSPI microparticles(5-8μm)were fabricated by cluster aggregation of nano-and micro-sized particles through pH shifting treatment.Compared with the EGCG control,EGCG-PSPI microparticles efficiently increased the retention rate of free radical scavenging activity to 47.47%,22.04%and 39.94%under light,freeze-thaw cycle storage conditions and simulated intestinal fluids,respectively.Therefore,polyphenol-PSPI covalent conjugate microparticles had great potential to be used as efficient carriers for stabilizing the DPPH radical scavenging ability of polyphenols under illumination storage,freeze-thaw and digestive conditions.展开更多
A series of shikonin derivatives have been designed and their radical scavenging activity has been characterized by the B3LYP/6-31 ＋G（d） approach. The hydrogen bond properties of the studied structures were investi...A series of shikonin derivatives have been designed and their radical scavenging activity has been characterized by the B3LYP/6-31 ＋G（d） approach. The hydrogen bond properties of the studied structures were investigated using the atoms in molecules （AIM） theory. The calculated results reveal that the hydrogen bond is important for good scavenging activity. The introduction of electron-drawing （electron-donating） groups increases （decreases） the scavenging activities of radical and radical cations of shikonin derivatives. Shikonin derivatives appear to be good candidates for the single-electron-transfer mechanism, particularly for -N（CH3）2 derivative. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view. With the current work, we hope to highlight the radical scavenging activity of hydroxynaphtho- quinones derivatives and stimulate the interest for further studies and exploitation in pharmaceutical industry.展开更多
Objective:To identify the hepatoprotective and in vitro antioxidant activity of Lumnitzera racemosa(L.racemosa) leaf extract.Methods:Animals in Group 1 served as vehicle control. Group 2 served as hepatotoxin(CCL_4 tr...Objective:To identify the hepatoprotective and in vitro antioxidant activity of Lumnitzera racemosa(L.racemosa) leaf extract.Methods:Animals in Group 1 served as vehicle control. Group 2 served as hepatotoxin(CCL_4 treated) group.Group 3 served as positive control(Silyntarin) group,and Group 4.S and ft served as(73,150 and 300 nig/kg bw p.o.)L.racemosa leaf extract treated groups.Moreover,in vitro antioxidant DPPH,hydroxyl radical scavenging activity(HRSA),NO,ferric reducing antioxidant power(FRAP),lipid hydroperoxide(LPO) and super oxide dismutase(SOD) were also analyzed for the leaf extract.Results:The levels of the serum parameters such as serum glutamic oxaloacetic transaminase(SGOT).serum glutamic pyruvic transaminase(SGPT).alkaline phosphatase(ALP),bilirubin,cholesterol(CHL).sugar and lactate dehydrogenase(LDH) were significantly increased in COL_4 treated rats when compared with the control group(P<0.05).But the L.racemosa leaf extract treated rats showed maximum reduction of SGOT[(210.16±19.63)IU/L].SGPT[(82.37±13.87) IU/L].ALP[(197.63±23.4.3)IU/L],bilurubilt[(2.13 ±0.84) mg/dL].cholesterol[(163.83± 13.63) mg/dL].sugar[(93.00±7.63) mg/dL]and LDH[(1134.00) ±285.00)IU/L]were observed with the high dose(300 mg/kg bw) of leaf extract treated rats. Histopathological scores showed that,no visible changes were observed with high dose(300 mg/ kgbw) of leaf extract treated rats except few mild necrosis.The IC_(50) values were observed as(56.37 ±4.87)μg/mL,(57.68±1.98) μg/mL,(64.15±2.90)μg/mL,(61.94±3.98)μg/mL,(94.53± 1.68) μg/mL and(69.7±2.65)μg/mL for DPPH,HRSA,NO,FRAP,LPO and SOL) radical scavenging activities, respectively.Conclusions:In conclusion,the hepatoprotective effect of the L.racemosa leaf extract might be due to the presence of phenolic groups,terpenoids and alkaloids and in vitro antioxidant properties.展开更多
In the present work,the fruits of four Morus species,namely Morus alba (white mulberry),Morus nigra (black mulberry),Morus laevigata (large white fruit),and Morus laevigata (large black fruit),were analyzed for proxim...In the present work,the fruits of four Morus species,namely Morus alba (white mulberry),Morus nigra (black mulberry),Morus laevigata (large white fruit),and Morus laevigata (large black fruit),were analyzed for proximate composition,essential minerals,and antioxidant potentials.For this purpose,the ripe fruits were collected from the northern regions of Pakistan.The major nutritional components moisture,ash,lipids,proteins,fibres,carbohydrates,and total sugar) were found to be in the suitable range along with good computed energy.Total dry weight,pH,and titratable acidity (percent citric acid) were (17.60±1.94)–(21.97±2.34) mg/100 g,(3.20±0.07)–(4.78±0.15),and (0.84±0.40)%–(2.00±0.08)%,respectively.Low riboflavin (vitamin B2) and niacin (vitamin B3) contents were recorded in all the fruits,while ascorbic acid (vitamin C) was in the range from (15.20±1.25) to (17.03±1.71) mg/100 g fresh weight (FW).The mulberry fruits were rich with regard to the total phenol and alkaloid contents,having values of (880±7.20)–(1650±12.25) mg/100 g FW and (390±3.22)–(660±5.25) mg/100 g FW,respectively.Sufficient quantities of essential macro-(K,Ca,Mg,and Na) and micro-(Fe,Zn,and Ni) elements were found in all the fruits.K was the predominant element with concentration ranging from (1270±9.36) to (1731±11.50) mg/100 g,while Ca,Na,and Mg contents were (440±3.21)–(576±7.37),(260±3.86)–(280±3.50),and (240±3.51)–(360±4.20) mg/100 g,respectivly.The decreasing order of micro-minerals was Fe>Zn>Ni.The radical scavenging activity of methanolic extract of fruits was concentration-dependent and showed a correlation with total phenolic constituents of the respective fruits.Based on the results obtained,mulberry fruits were found to serve as a potential source of food diet and natural antioxidants.展开更多
The methanolic extract obtained from the root portion of Caltha palustris var. alba was evaluated for its anthelmintic efficacy against gastrointestinal nematodes of sheep under both in vitro and in vivo conditions us...The methanolic extract obtained from the root portion of Caltha palustris var. alba was evaluated for its anthelmintic efficacy against gastrointestinal nematodes of sheep under both in vitro and in vivo conditions using worm motility inhibition(WMI) assay and fecal egg count reduction(FECR) assay, respectively. The extract was subjected to antimicrobial activity using agar-well diffusion method against different bacterial strains. In addition the extract was evaluated for cytotoxic and antioxidant activity against cultured THP-1(Leukemia), A-549(Lung), HCT-15(Colon), Cervix(HeLa) and PC-3(Prostrate) cell lines by SRB and DPPH radical scavenging assays. The extract used resulted in mean %WMI of 94.44%, as observed when the worms were put in lukewarm buffer for 30 min after exposure to different treatments. The mean mortality index of the sample was 0.95. The lethal concentration(LC50) was 0.11 mg·mL-1. Cell lines were exposed to concentration of 100 μg·mL-1 of extract for 48 h, which reduced the viability of these cell lines. The same plant extract also showed 55.58% DPPH radical scavenging activity.展开更多
In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized ...In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized and its structure was identified on the basis of NMR, FT-IR and elemental analysis. The assembly of 5,7-dihydroxylflavone-8-sulfonate with diethylamide cation afforded diethylamide 5,7-dihydroxylflavone-8-sulfonate （2, NH2（CH2CH3）2X） which was characterized by FT-IR and elemental analysis. The crystal structures of 1 and 2 were determined by X-ray single-crystal diffraction analysis. The crystal of 1 is of triclinic system, space group P1, with a = 8.5628（13）, b = 12.8916（19）, c = 13.562（2） A, α = 82.494（1）, β = 78.601（2）, γ = 84.033（2）°, C30H20Na2O15S2, Z = 2, Mr = 730.59, V = 1450.3（4） A3, Dc = 1.673 g/cm3, F（000） = 748, p = 0.295 mm^-1, the final R = 0.0641 and wR = 0.1458. The crystal of 2 crystallizes in the triclinic system, space group Pi, with a = 7.689（2）, b = 11.184（3）, c = 11.734（3） A, α = 74.268（3）, βl = 81.751（4）, γ= 87.991（3）°, C19H21NO7S, Z = 2, Mr= 407.43, V= 961.2（4） A3, Dc = 1.408 g/cm3, F（000） = 428, p = 0.210 mm^-1, the final R = 0.0484 and wR = 0.1195. In 1, the three-dimensional structure is organized into organic and inorganic regions; the flavone skeletons are stacked into organic regions by π...π staeking interactions; inorganic regions are generated by Na-O coordination bonds among sulfonate groups, coordinated water molecules and NaI. The sulfonate groups play an important role as a bridge of inorganic and organic regions. One-dimensional chain structure of 2 is extended by N-H…O hydrogen bonds and π...π stacking interactions. Furthermore, the antioxidant activity of 1 was evaluated. The scavenging activity of 1 to DPPH free radical is better than that of the parent compound chrysin.展开更多
Antioxidants have numerous applications due to their multiple roles in diminishing harmful effects of oxidative stress. The objective of this work was to highlight the importance of green tea by evaluating the antioxi...Antioxidants have numerous applications due to their multiple roles in diminishing harmful effects of oxidative stress. The objective of this work was to highlight the importance of green tea by evaluating the antioxidant activity of the most popular green tea brands in Saudi Arabia, Lipton and Rabea. To our knowledge, no studies have so far been done to estimate the antioxidant activity of these brands. To determine the antioxidant activities of these two brands, 10 mg/ml of each brand was extracted and their total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging activity, ferric reducing power and ferrous ion chelating effect were measured. The TPC of Lipton tea was 678.7 υg of gallic acid equivalents (GAE)/10mg, whereas in Rabea tea, the TPC was 647.1 υg GAE/10mg. The presence study indicated that there were no significant differences in total phenolic contents and the percentage inhibition as shown in DPPH and H<sub>2</sub>O<sub>2</sub> assays among Lipton and Rabea green teas. Moreover, it was found that all assays have exhibited high antioxidant activity in both green teas. In conclusion, our study showed evidence for evenness and stability of the antioxidant activity of the two commercial green teas available in the markets of Saudi Arabia. Continued researches are needed to further the current knowledge on the health-promoting effects of this popular beverage using different supplements by different mechanisms.展开更多
The anthocyanin pigment extracted from green-wheat-bran was studied to identify its antioxidant activity.The antioxidant activities of the pigment were evaluated by anti-lipid peroxidation,total antioxidant activity ...The anthocyanin pigment extracted from green-wheat-bran was studied to identify its antioxidant activity.The antioxidant activities of the pigment were evaluated by anti-lipid peroxidation,total antioxidant activity （TAA）,superoxide anion radical scavenging activity （SARSA）,active oxygen scavenging activity （AOSA）,and DPPH （1,1-diphenyl-2 picrylhydrazyl free radical） radical scavenging activity.The results showed that the pigment had higher antioxidant activity and TAA,SARSA,AOSA and DPPH.scavenging activities at a certain concentration than Vc （antiscorbutic vitamin,vitamin C）,and the capacity increased with the increase of pigment concentration.Its TAA was 51.06 U mL-1,1.73 times of Vc,and SARSA 18 025.21 U mL-1,2.26% higher than Vc,and AOSA 3 776.31 U mL-1,1.24 times of Vc.As to the DPPH.scavenging activity of the pigment,there was a trend that higher concentration performed higher activity significantly improved with the company of Vc.The pigment showed significant antioxidant activities evaluated by different assays.Results will provide a better understanding on antioxidant activity of green wheat and allow the screening or breeding of green wheat varieties with higher antioxidant activity for food processing.展开更多
The immunocompatibility and antioxidative characteristics of Maillard reaction-based carbon dots(MR-CDs)have not been extensively studied.This study aimed to develop a Maillard reaction model system utilizing glucose ...The immunocompatibility and antioxidative characteristics of Maillard reaction-based carbon dots(MR-CDs)have not been extensively studied.This study aimed to develop a Maillard reaction model system utilizing glucose and arginine to synthesize carbon dots.The investigation into the MR-CD’s physicochemical properties,biocompatibility,cytoprotective effects,and antioxidant capacity revealed promising results.TEM images showed spherical carbon dots(CDs)of 3-15 nm diameter.The FTIR spectra indicated the presence of hydroxyl,amino,and carbonyl functional groups in MR-CDs surfaces.An X-ray diffractometer analysis showed that CDs are amorphous.The fluorescence spectra revealed wavelength-dependent emission with a maximum intensity of 390 nm.The response of THP-1 cells after exposure to MR-CDs was studied to assess biocompatibility,nuclear morphology,ROS levels,lysosome accumulation,and gene expression of inflammatory markers(IL6,TNFα,NF-κB,MIF,IFNA,and GSR genes).MR-CDs induced a dose-dependent proliferation of THP-1 cells without altering their nuclear morphology.A lysosome and mitochondrial membrane potential analysis also showed that MR-CDs are non-toxic.The levels of intracellular ROS did not differ from those in the control.Downregulation of in-flammatory genes was observed after exposure to MR-CDs.The expression of the Glutathione-disulfide reductase(GSR)gene was upregulated in a dose-dependent manner,indicating increased antioxidant activity in MR-CDs.The result of the DPPH assay confirmed the antioxidant ability of MR-CDs.MR-CDs performed cytoprotective effects against hydrogen peroxide-induced cell damage.These findings suggest that,besides their immuno-compatibility,MR-CDs possess potent antioxidant and cytoprotective properties,which make them ideal for a range of immunomodulatory applications,sparking optimism for future research and development in this field.展开更多
Oxidative stress plays an indispensable role in the pathogenesis of cerebral ischemia.Inhibiting oxidative stress has been considered as an effective approach for stroke treatment.Edaravone,a free radical scavenger,ha...Oxidative stress plays an indispensable role in the pathogenesis of cerebral ischemia.Inhibiting oxidative stress has been considered as an effective approach for stroke treatment.Edaravone,a free radical scavenger,has been shown to prevent cerebral ischemic injury.However,the clinical efficacy of edaravone is limited because it has a low scavenging activity for superoxide anions（O_2-（·-））.Here,we report that 2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine,a novel small-molecule compound structurally related to edaravone,showed a stronger inhibitory effect on oxidative stress in vitro.In vivo,2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine reversed transient middle cerebral artery occlusion-induced dysfunctions of superoxide dismutases and malondialdehyde,two proteins crucial for oxidative stress,suggesting a strengthened antioxidant system.Moreover,2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine decreased blood brain barrier permeability.Then,we found that 2-methyl-5 Hbenzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine had a stronger neuroprotective effect than edaravone.More importantly,2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine decreased not only infarct size and neurological deficits in the acute phase but also modified neurological severity score and escape latency in Morris water maze task in the delayed period,indicating enhanced neuroprotection,sensorimotor function and spatial memory.Together,these findings suggest that 2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine could be a preferable option for stroke treatment.展开更多
This study was conducted to investigate the chemical constituents of Piper wallichii （Miq.） Hand.-Mazz. and evaluate their biological activity. Compounds were isolated by various column chromatographic methods, and ...This study was conducted to investigate the chemical constituents of Piper wallichii （Miq.） Hand.-Mazz. and evaluate their biological activity. Compounds were isolated by various column chromatographic methods, and their structures were elucidated on the basis of physical characteristics and spectral data. The 1, 1-diphenyl-2-picrylhydrazyl （DPPH）-scavenging activity and acetylcholinesterase （AChE）-inhibitory activity of the compounds were evaluated. Five compounds were obtained and identified as 8-C-β-D-glucopyranosylkaempferol-3-O-β-D-glucopyranoside （1）, 1, 2-dihydro-6,8-dimethoxy-7-hydroxy-l-（3, 5-dimethoxy-4-hydroxyphenyl）-N^1, N^2-bis-[2-（4-hydroxyphenyl）ethyl]-2, 3-naphthalene dicarboxamide （2）, goniothalactam （3）, aristololactam A IIla （4） and piperlonguminine （5）. Compound 1 was a new flavonol C-glycoside, 2 was a rare lignanamide, which was isolated from the family Piperaceae for the first time, and compound 3 was isolated from this plant for the first time. Among them, 2 showed potent DPPH-scavenging activity, with IC50 of 31.38 ± 0.97 μmol·L^-1; Compounds 2, 3, and 4 showed AChE inhibitory activity at 100 μmol·L^-1, with inhibition rates of 28.57% ± 1.47%, 18.48% ± 2.41% and 17.4% ±3.03%, respectively.展开更多
The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by ...The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by spectral analysis. 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl(DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid(ABTS) free radical scavenging were assayed using Vitamin C as the positive control. One new polyphenol 18, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, together with 17 known compounds, was isolated and characterized. In conclusion, Compound 18 was a new caffeoyl maloyl quinic acid type polyphenol and showed desired vitro anti-oxidant activity. Compounds 1–5, 9, 10, 14, 15, and 17 were isolated from cultured cells of Saussurea involucrata for the first time.展开更多
This present study compared antioxidant and antimicrobial activities of acetone and water extracts of <i>Theobroma cacao</i> beans against <i>Escherichia coli</i>. Total phenolic content (TPC) ...This present study compared antioxidant and antimicrobial activities of acetone and water extracts of <i>Theobroma cacao</i> beans against <i>Escherichia coli</i>. Total phenolic content (TPC) in both extracts was estimated by the Folin-Denis reagent. The present study showed that the 70% (v/v) acetone extract had a higher extraction yield and TPC (37% and 109 mg TAE g<sup>-1</sup> dry weight) than the water extract (33% and 76 mg TAE g<sup>-1</sup> dry weight). The antioxidant activities of both extracts were estimated by the DPPH Scavenging Assay. The extract obtained using 70% (v/v) acetone showed higher antioxidant activity (54%) compared to the antioxidant activity obtained using water (34%). Antimicrobial activities of acetone and water extracts from <i>Theobroma cacao</i> were measured against <i>Escherichia coli</i> and were screened by agar well diffusion method and further confirmed with the disc diffusion method. The bacterial growth was measured in Mueller Hinton agar. The extracts inhibited the growth of the <i>Escherichia coli</i> cultured, and the acetone extracts showed antimicrobial capacity comparable or equivalent, as seen in commercial ampicillin.展开更多
Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol,...Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.展开更多
From the aqueous extract of Acacia catechu,two new phenolic compounds（3R,4R）-3-（3,4-dihydroxyphenyl）-4-hydroxycy-clohexanone （1） and（4R）-5-（1-（3,4-dihydrophenyl）-3-oxobutyl）-dihydrofuran-2（3H）-one（2） w...From the aqueous extract of Acacia catechu,two new phenolic compounds（3R,4R）-3-（3,4-dihydroxyphenyl）-4-hydroxycy-clohexanone （1） and（4R）-5-（1-（3,4-dihydrophenyl）-3-oxobutyl）-dihydrofuran-2（3H）-one（2） were obtained.Their structures were determined on the basis of spectroscopic analysis.Free-radical scavenging activities of them were evaluated.展开更多
基金Supported by the Science and Technique Foundation of Jilin Province, China(No20020503-2)
文摘A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%.
文摘A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucopyranoside（4）, butein-4-methoxyl-4＇-O-β-D-glucopyranoside（5）, butin-7-O-β-D-glucopyranoside（6）, isoquercitrin（7）, and sulfurein（8） was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activitv.
文摘Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.
文摘This study was undertaken to optimize the solvent-free microwave extraction conditions and DPPH radicalscavenging activity of essential oil from Schisandra chinesis fruits.The uniform design method was employed for process optimization.The optimal extraction conditions were determined as follows:extraction time,50 rain;microwave power,800 W;and amount of water addition for pretreatment,40%.Under these conditions,the extraction yield of essential oil was 0.92%.A total of 35 compounds were identified by GC-MS in the obtained essential oil with a total content of 91.06%,mostly consisting of ylangene(34.81%),β-himachalene(10.74%)andα-bergamotene(9.22%).The ICs0 value of the essential oil against DPPH free radicals was determined as 3.01 mg/mL.In conclusion,solvent-free microwave extraction is a feasible method for essential oil extraction from Schisandra chinensis fruits.
基金the National Natural Science Foundation of China(32001626)Tianjin 14th-Fifth-plan of Educational science(BIE210023)Natural Science Foundation of Shandong Province(ZR2020KC029)for financial support.
文摘Covalent conjugates of pumpkin seed protein isolate(PSPI)and different polyphenols(epigallocatechin gallate(EGCG),chlorogenic acid(CA)and gallic acid(GA))were prepared at pH 9.0 to develop covalent microparticles to protect the stability of polyphenols under storage and digestive conditions.The results for polyphenol-bound equivalents,free amino group contents,sulfhydryl contents and Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis(SDS-PAGE)indicated that polyphenols were covalently bonded with PSPI,while the secondary structure of conjugates became more regular and stable compared with PSPI alone due to the covalent interactions.EGCG-PSPI conjugates displayed the highest polyphenol-bound equivalents(204.75 nmol/mg)and most stable structure compared with CA-PSPI and GA-PSPI because of the eight active phenolic hydroxyl groups within EGCG,which provided more sites for covalent and non-covalent interactions.Accordingly,EGCG-PSPI microparticles(5-8μm)were fabricated by cluster aggregation of nano-and micro-sized particles through pH shifting treatment.Compared with the EGCG control,EGCG-PSPI microparticles efficiently increased the retention rate of free radical scavenging activity to 47.47%,22.04%and 39.94%under light,freeze-thaw cycle storage conditions and simulated intestinal fluids,respectively.Therefore,polyphenol-PSPI covalent conjugate microparticles had great potential to be used as efficient carriers for stabilizing the DPPH radical scavenging ability of polyphenols under illumination storage,freeze-thaw and digestive conditions.
文摘A series of shikonin derivatives have been designed and their radical scavenging activity has been characterized by the B3LYP/6-31 ＋G（d） approach. The hydrogen bond properties of the studied structures were investigated using the atoms in molecules （AIM） theory. The calculated results reveal that the hydrogen bond is important for good scavenging activity. The introduction of electron-drawing （electron-donating） groups increases （decreases） the scavenging activities of radical and radical cations of shikonin derivatives. Shikonin derivatives appear to be good candidates for the single-electron-transfer mechanism, particularly for -N（CH3）2 derivative. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view. With the current work, we hope to highlight the radical scavenging activity of hydroxynaphtho- quinones derivatives and stimulate the interest for further studies and exploitation in pharmaceutical industry.
文摘Objective:To identify the hepatoprotective and in vitro antioxidant activity of Lumnitzera racemosa(L.racemosa) leaf extract.Methods:Animals in Group 1 served as vehicle control. Group 2 served as hepatotoxin(CCL_4 treated) group.Group 3 served as positive control(Silyntarin) group,and Group 4.S and ft served as(73,150 and 300 nig/kg bw p.o.)L.racemosa leaf extract treated groups.Moreover,in vitro antioxidant DPPH,hydroxyl radical scavenging activity(HRSA),NO,ferric reducing antioxidant power(FRAP),lipid hydroperoxide(LPO) and super oxide dismutase(SOD) were also analyzed for the leaf extract.Results:The levels of the serum parameters such as serum glutamic oxaloacetic transaminase(SGOT).serum glutamic pyruvic transaminase(SGPT).alkaline phosphatase(ALP),bilirubin,cholesterol(CHL).sugar and lactate dehydrogenase(LDH) were significantly increased in COL_4 treated rats when compared with the control group(P<0.05).But the L.racemosa leaf extract treated rats showed maximum reduction of SGOT[(210.16±19.63)IU/L].SGPT[(82.37±13.87) IU/L].ALP[(197.63±23.4.3)IU/L],bilurubilt[(2.13 ±0.84) mg/dL].cholesterol[(163.83± 13.63) mg/dL].sugar[(93.00±7.63) mg/dL]and LDH[(1134.00) ±285.00)IU/L]were observed with the high dose(300 mg/kg bw) of leaf extract treated rats. Histopathological scores showed that,no visible changes were observed with high dose(300 mg/ kgbw) of leaf extract treated rats except few mild necrosis.The IC_(50) values were observed as(56.37 ±4.87)μg/mL,(57.68±1.98) μg/mL,(64.15±2.90)μg/mL,(61.94±3.98)μg/mL,(94.53± 1.68) μg/mL and(69.7±2.65)μg/mL for DPPH,HRSA,NO,FRAP,LPO and SOL) radical scavenging activities, respectively.Conclusions:In conclusion,the hepatoprotective effect of the L.racemosa leaf extract might be due to the presence of phenolic groups,terpenoids and alkaloids and in vitro antioxidant properties.
文摘In the present work,the fruits of four Morus species,namely Morus alba (white mulberry),Morus nigra (black mulberry),Morus laevigata (large white fruit),and Morus laevigata (large black fruit),were analyzed for proximate composition,essential minerals,and antioxidant potentials.For this purpose,the ripe fruits were collected from the northern regions of Pakistan.The major nutritional components moisture,ash,lipids,proteins,fibres,carbohydrates,and total sugar) were found to be in the suitable range along with good computed energy.Total dry weight,pH,and titratable acidity (percent citric acid) were (17.60±1.94)–(21.97±2.34) mg/100 g,(3.20±0.07)–(4.78±0.15),and (0.84±0.40)%–(2.00±0.08)%,respectively.Low riboflavin (vitamin B2) and niacin (vitamin B3) contents were recorded in all the fruits,while ascorbic acid (vitamin C) was in the range from (15.20±1.25) to (17.03±1.71) mg/100 g fresh weight (FW).The mulberry fruits were rich with regard to the total phenol and alkaloid contents,having values of (880±7.20)–(1650±12.25) mg/100 g FW and (390±3.22)–(660±5.25) mg/100 g FW,respectively.Sufficient quantities of essential macro-(K,Ca,Mg,and Na) and micro-(Fe,Zn,and Ni) elements were found in all the fruits.K was the predominant element with concentration ranging from (1270±9.36) to (1731±11.50) mg/100 g,while Ca,Na,and Mg contents were (440±3.21)–(576±7.37),(260±3.86)–(280±3.50),and (240±3.51)–(360±4.20) mg/100 g,respectivly.The decreasing order of micro-minerals was Fe>Zn>Ni.The radical scavenging activity of methanolic extract of fruits was concentration-dependent and showed a correlation with total phenolic constituents of the respective fruits.Based on the results obtained,mulberry fruits were found to serve as a potential source of food diet and natural antioxidants.
文摘The methanolic extract obtained from the root portion of Caltha palustris var. alba was evaluated for its anthelmintic efficacy against gastrointestinal nematodes of sheep under both in vitro and in vivo conditions using worm motility inhibition(WMI) assay and fecal egg count reduction(FECR) assay, respectively. The extract was subjected to antimicrobial activity using agar-well diffusion method against different bacterial strains. In addition the extract was evaluated for cytotoxic and antioxidant activity against cultured THP-1(Leukemia), A-549(Lung), HCT-15(Colon), Cervix(HeLa) and PC-3(Prostrate) cell lines by SRB and DPPH radical scavenging assays. The extract used resulted in mean %WMI of 94.44%, as observed when the worms were put in lukewarm buffer for 30 min after exposure to different treatments. The mean mortality index of the sample was 0.95. The lethal concentration(LC50) was 0.11 mg·mL-1. Cell lines were exposed to concentration of 100 μg·mL-1 of extract for 48 h, which reduced the viability of these cell lines. The same plant extract also showed 55.58% DPPH radical scavenging activity.
基金Supported by the National Basic Research Program of China (973 Program,2009CB219906)NNSFC(20776117)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education of China(20070698037)Natural Science Foundation of Shaanxi Province (No.2005B01)
文摘In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized and its structure was identified on the basis of NMR, FT-IR and elemental analysis. The assembly of 5,7-dihydroxylflavone-8-sulfonate with diethylamide cation afforded diethylamide 5,7-dihydroxylflavone-8-sulfonate （2, NH2（CH2CH3）2X） which was characterized by FT-IR and elemental analysis. The crystal structures of 1 and 2 were determined by X-ray single-crystal diffraction analysis. The crystal of 1 is of triclinic system, space group P1, with a = 8.5628（13）, b = 12.8916（19）, c = 13.562（2） A, α = 82.494（1）, β = 78.601（2）, γ = 84.033（2）°, C30H20Na2O15S2, Z = 2, Mr = 730.59, V = 1450.3（4） A3, Dc = 1.673 g/cm3, F（000） = 748, p = 0.295 mm^-1, the final R = 0.0641 and wR = 0.1458. The crystal of 2 crystallizes in the triclinic system, space group Pi, with a = 7.689（2）, b = 11.184（3）, c = 11.734（3） A, α = 74.268（3）, βl = 81.751（4）, γ= 87.991（3）°, C19H21NO7S, Z = 2, Mr= 407.43, V= 961.2（4） A3, Dc = 1.408 g/cm3, F（000） = 428, p = 0.210 mm^-1, the final R = 0.0484 and wR = 0.1195. In 1, the three-dimensional structure is organized into organic and inorganic regions; the flavone skeletons are stacked into organic regions by π...π staeking interactions; inorganic regions are generated by Na-O coordination bonds among sulfonate groups, coordinated water molecules and NaI. The sulfonate groups play an important role as a bridge of inorganic and organic regions. One-dimensional chain structure of 2 is extended by N-H…O hydrogen bonds and π...π stacking interactions. Furthermore, the antioxidant activity of 1 was evaluated. The scavenging activity of 1 to DPPH free radical is better than that of the parent compound chrysin.
文摘Antioxidants have numerous applications due to their multiple roles in diminishing harmful effects of oxidative stress. The objective of this work was to highlight the importance of green tea by evaluating the antioxidant activity of the most popular green tea brands in Saudi Arabia, Lipton and Rabea. To our knowledge, no studies have so far been done to estimate the antioxidant activity of these brands. To determine the antioxidant activities of these two brands, 10 mg/ml of each brand was extracted and their total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging activity, ferric reducing power and ferrous ion chelating effect were measured. The TPC of Lipton tea was 678.7 υg of gallic acid equivalents (GAE)/10mg, whereas in Rabea tea, the TPC was 647.1 υg GAE/10mg. The presence study indicated that there were no significant differences in total phenolic contents and the percentage inhibition as shown in DPPH and H<sub>2</sub>O<sub>2</sub> assays among Lipton and Rabea green teas. Moreover, it was found that all assays have exhibited high antioxidant activity in both green teas. In conclusion, our study showed evidence for evenness and stability of the antioxidant activity of the two commercial green teas available in the markets of Saudi Arabia. Continued researches are needed to further the current knowledge on the health-promoting effects of this popular beverage using different supplements by different mechanisms.
基金supported by the National Technologies R&D Program of China (2006BAD01A02)the Excellent Medium-Youth Scientist Scientific Research Reward Fundation of Shandong Province, China (BS2009NY036)the Youth Science and Technology Creative Fundation Item of Shandong Agricultural University, China
文摘The anthocyanin pigment extracted from green-wheat-bran was studied to identify its antioxidant activity.The antioxidant activities of the pigment were evaluated by anti-lipid peroxidation,total antioxidant activity （TAA）,superoxide anion radical scavenging activity （SARSA）,active oxygen scavenging activity （AOSA）,and DPPH （1,1-diphenyl-2 picrylhydrazyl free radical） radical scavenging activity.The results showed that the pigment had higher antioxidant activity and TAA,SARSA,AOSA and DPPH.scavenging activities at a certain concentration than Vc （antiscorbutic vitamin,vitamin C）,and the capacity increased with the increase of pigment concentration.Its TAA was 51.06 U mL-1,1.73 times of Vc,and SARSA 18 025.21 U mL-1,2.26% higher than Vc,and AOSA 3 776.31 U mL-1,1.24 times of Vc.As to the DPPH.scavenging activity of the pigment,there was a trend that higher concentration performed higher activity significantly improved with the company of Vc.The pigment showed significant antioxidant activities evaluated by different assays.Results will provide a better understanding on antioxidant activity of green wheat and allow the screening or breeding of green wheat varieties with higher antioxidant activity for food processing.
基金funded by the National Plan of Science,Technology,and Innovation(MAARIFAH),King Abdulaziz City for Science and Technology,Kingdom of Saudi Arabia.Award Number:15-MED5103-02.
文摘The immunocompatibility and antioxidative characteristics of Maillard reaction-based carbon dots(MR-CDs)have not been extensively studied.This study aimed to develop a Maillard reaction model system utilizing glucose and arginine to synthesize carbon dots.The investigation into the MR-CD’s physicochemical properties,biocompatibility,cytoprotective effects,and antioxidant capacity revealed promising results.TEM images showed spherical carbon dots(CDs)of 3-15 nm diameter.The FTIR spectra indicated the presence of hydroxyl,amino,and carbonyl functional groups in MR-CDs surfaces.An X-ray diffractometer analysis showed that CDs are amorphous.The fluorescence spectra revealed wavelength-dependent emission with a maximum intensity of 390 nm.The response of THP-1 cells after exposure to MR-CDs was studied to assess biocompatibility,nuclear morphology,ROS levels,lysosome accumulation,and gene expression of inflammatory markers(IL6,TNFα,NF-κB,MIF,IFNA,and GSR genes).MR-CDs induced a dose-dependent proliferation of THP-1 cells without altering their nuclear morphology.A lysosome and mitochondrial membrane potential analysis also showed that MR-CDs are non-toxic.The levels of intracellular ROS did not differ from those in the control.Downregulation of in-flammatory genes was observed after exposure to MR-CDs.The expression of the Glutathione-disulfide reductase(GSR)gene was upregulated in a dose-dependent manner,indicating increased antioxidant activity in MR-CDs.The result of the DPPH assay confirmed the antioxidant ability of MR-CDs.MR-CDs performed cytoprotective effects against hydrogen peroxide-induced cell damage.These findings suggest that,besides their immuno-compatibility,MR-CDs possess potent antioxidant and cytoprotective properties,which make them ideal for a range of immunomodulatory applications,sparking optimism for future research and development in this field.
基金supported by grants from NationalNatural Science Foundation of China(31530091,91232304)National Key Research and Development Program of China(2016YFC1306703)+1 种基金Natural Science Foundation of Jiangsu Province(BK20140905)by the Collaborative Innovation Center for Cardiovascular Disease Translational Medicine
文摘Oxidative stress plays an indispensable role in the pathogenesis of cerebral ischemia.Inhibiting oxidative stress has been considered as an effective approach for stroke treatment.Edaravone,a free radical scavenger,has been shown to prevent cerebral ischemic injury.However,the clinical efficacy of edaravone is limited because it has a low scavenging activity for superoxide anions（O_2-（·-））.Here,we report that 2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine,a novel small-molecule compound structurally related to edaravone,showed a stronger inhibitory effect on oxidative stress in vitro.In vivo,2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine reversed transient middle cerebral artery occlusion-induced dysfunctions of superoxide dismutases and malondialdehyde,two proteins crucial for oxidative stress,suggesting a strengthened antioxidant system.Moreover,2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine decreased blood brain barrier permeability.Then,we found that 2-methyl-5 Hbenzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine had a stronger neuroprotective effect than edaravone.More importantly,2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine decreased not only infarct size and neurological deficits in the acute phase but also modified neurological severity score and escape latency in Morris water maze task in the delayed period,indicating enhanced neuroprotection,sensorimotor function and spatial memory.Together,these findings suggest that 2-methyl-5 H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine could be a preferable option for stroke treatment.
基金supported by the National Natural Science Foundation of China(Nos.30271647,81073005)Shandong Province Young and Middle-Aged Scientists Research Awards Fund(No.BS2010YY032)Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry in China(No.42)
文摘This study was conducted to investigate the chemical constituents of Piper wallichii （Miq.） Hand.-Mazz. and evaluate their biological activity. Compounds were isolated by various column chromatographic methods, and their structures were elucidated on the basis of physical characteristics and spectral data. The 1, 1-diphenyl-2-picrylhydrazyl （DPPH）-scavenging activity and acetylcholinesterase （AChE）-inhibitory activity of the compounds were evaluated. Five compounds were obtained and identified as 8-C-β-D-glucopyranosylkaempferol-3-O-β-D-glucopyranoside （1）, 1, 2-dihydro-6,8-dimethoxy-7-hydroxy-l-（3, 5-dimethoxy-4-hydroxyphenyl）-N^1, N^2-bis-[2-（4-hydroxyphenyl）ethyl]-2, 3-naphthalene dicarboxamide （2）, goniothalactam （3）, aristololactam A IIla （4） and piperlonguminine （5）. Compound 1 was a new flavonol C-glycoside, 2 was a rare lignanamide, which was isolated from the family Piperaceae for the first time, and compound 3 was isolated from this plant for the first time. Among them, 2 showed potent DPPH-scavenging activity, with IC50 of 31.38 ± 0.97 μmol·L^-1; Compounds 2, 3, and 4 showed AChE inhibitory activity at 100 μmol·L^-1, with inhibition rates of 28.57% ± 1.47%, 18.48% ± 2.41% and 17.4% ±3.03%, respectively.
基金financially supported by National Major New Drugs Innovation and Development Program(No.2011ZX09307-002-01)China Postdoctoral Science Foundation(No.2012T60303)the National High Technology Research and Development Program("863" Program) of China(No.SS2014AA 022201)
文摘The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by spectral analysis. 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl(DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid(ABTS) free radical scavenging were assayed using Vitamin C as the positive control. One new polyphenol 18, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, together with 17 known compounds, was isolated and characterized. In conclusion, Compound 18 was a new caffeoyl maloyl quinic acid type polyphenol and showed desired vitro anti-oxidant activity. Compounds 1–5, 9, 10, 14, 15, and 17 were isolated from cultured cells of Saussurea involucrata for the first time.
文摘This present study compared antioxidant and antimicrobial activities of acetone and water extracts of <i>Theobroma cacao</i> beans against <i>Escherichia coli</i>. Total phenolic content (TPC) in both extracts was estimated by the Folin-Denis reagent. The present study showed that the 70% (v/v) acetone extract had a higher extraction yield and TPC (37% and 109 mg TAE g<sup>-1</sup> dry weight) than the water extract (33% and 76 mg TAE g<sup>-1</sup> dry weight). The antioxidant activities of both extracts were estimated by the DPPH Scavenging Assay. The extract obtained using 70% (v/v) acetone showed higher antioxidant activity (54%) compared to the antioxidant activity obtained using water (34%). Antimicrobial activities of acetone and water extracts from <i>Theobroma cacao</i> were measured against <i>Escherichia coli</i> and were screened by agar well diffusion method and further confirmed with the disc diffusion method. The bacterial growth was measured in Mueller Hinton agar. The extracts inhibited the growth of the <i>Escherichia coli</i> cultured, and the acetone extracts showed antimicrobial capacity comparable or equivalent, as seen in commercial ampicillin.
基金the financial support of Govan Mbeki Research Development Centre, University of Fort Hare, South Africa (Grant number: C127)
文摘Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.
基金supported by the National Science and Technology Project of China(No2009zx09301-003-4-1)and the Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine,Peking Union Medical College,Ministry of Education
文摘From the aqueous extract of Acacia catechu,two new phenolic compounds（3R,4R）-3-（3,4-dihydroxyphenyl）-4-hydroxycy-clohexanone （1） and（4R）-5-（1-（3,4-dihydrophenyl）-3-oxobutyl）-dihydrofuran-2（3H）-one（2） were obtained.Their structures were determined on the basis of spectroscopic analysis.Free-radical scavenging activities of them were evaluated.
