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1.
Lipase-catalysed synthesis of esters of ferulic acid with natural compounds and evaluation of their antioxidant properties 总被引:1,自引:0,他引:1
Nyaradzo T.L. Chigorimbo-Murefu Sergio Riva Stephanie G. Burton 《Journal of Molecular Catalysis .B, Enzymatic》2009,56(4):277-282
Lipases from Candida antarctica (Novozyme 435®), Candida rugosa, Chromobacterium viscosum and Pseudomonas sp. were used to perform transesterifications of vinyl ferulate with hydroxyl-steroids and p-arbutin. The antioxidant activity of the products was evaluated using the free radical 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical quenching antioxidant assays, and inhibition of the oxidation of low-density lipoprotein, LDL. Arbutin ferulate was found to possess a 19% higher antiradical activity against the ABTS free radical than its precursor ferulic acid, and it also inhibited the oxidation of LDL more efficiently (by 10%) than its precursors. All of the biocatalytically synthesised products exhibited higher antioxidant activity than Trolox, the well known commercial benchmark antioxidant, and their precursor, ferulic acid. 相似文献
2.
Babita Paudel Hari Datta Bhattarai Jin Sung Lee Soon Gyu Hong Hyun Woung Shin Joung Han Yim 《Polar Biology》2008,31(5):605-608
Antioxidant agents prevent reactive oxygen species, which can cause degenerative diseases. Natural antioxidants are preferred
over many synthetic antioxidants, which can be toxic, for therapeutic applications. Five lichen species were collected from
King George Island, Antarctica. Antioxidant activities as assessed by DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical and
ABTS•+ [2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging capacities were determined and compared with those
of commercial standards BHA (butylated hydroxyanisole) and trolox [(±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic
acid]. The results indicated that two lichens exhibited comparatively high antioxidant activities with the remaining three
exhibiting less activity. The antioxidant activity was concentration-dependent. When compared, the antioxidant activity of
crude extracts from polar lichens to previously published data for tropical and temperate lichen species, we concluded that
lichens of Antarctic origin may be the potent sources of strong antioxidant agents. Such species should be explored as novel
sources of effective antioxidant metabolites. 相似文献
3.
Aredes Fernández PA Stivala MG Rodríguez Vaquero MJ Farías ME 《Biotechnology letters》2011,33(2):359-364
Accelerated autolysis of Saccharomyces cerevisiae mc2 in synthetic wine medium enabled the release of 3.7 mg peptide nitrogen/l, concomitantly with an increase in antioxidant
properties (243 μmol FeSO4/l in the case of ferric reducing antioxidant power and 0.5% in 2,2-diphenyl-1-picrylhydrazyl radical scavenging) and antihypertensive
activity (22% in angiotensin I-converting enzyme inhibitory activity). Sequential inoculation of a proteolytic Oenococcus oeni strain in the synthetic medium after yeast autolysis produced an increase in peptide nitrogen concentration of 1.5 mg/l after
48 h of growth. After this incubation time an improvement in antihypertensive and antioxidant activities was detected. Oenococcus oeni X2L could give additional value to wine because of the bioactive peptides with multifunctional beneficial activity released
as consequence of its proteolytic activity. 相似文献
4.
Isolation and characterization of dihydromonacolin-MV from <Emphasis Type="Italic">Monascus purpureus</Emphasis> for antioxidant properties 总被引:4,自引:0,他引:4
Dhale MA Divakar S Kumar SU Vijayalakshmi G 《Applied microbiology and biotechnology》2007,73(5):1197-1202
The methanolic extract of Monascus purpureus cultivated by solid-state fermentation on rice showed strong 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity
and better yield as compared to other polarity based extracted fractions. It was selected for further purification of the
antioxidant. The activity-guided repeated fractionation of methanolic extract on a silica gel column chromatography yielded
a compound that exhibited strong antioxidant activity. Based on the spectroscopic analysis by UV, IR, 1H NMR, 13C NMR, 2D-HSQCT NMR, and MS, the antioxidant isolated was elucidated as a derivative of dihydromonacolin-K, where the ester
group is 2-methyl propionate, designated as dihydromonacolin-MV. The DPPH radical was significantly scavenged by the dihydromonacolin-MV
(IC50 20±1 μg ml−1). The dihydromonacolin-MV showed strong inhibition of lipid peroxidation in a liposome model with an IC50 value of 5.71±0.38 μg ml−1 and superoxide radical scavenging activity with an IC50 value of 163.97±2.68 μg ml−1. 相似文献
5.
Regalado EL Rodríguez M Menéndez R Concepción AA Nogueiras C Laguna A Rodríguez AA Williams DE Lorenzo-Luaces P Valdés O Hernandez Y 《Marine biotechnology (New York, N.Y.)》2009,11(1):74-80
Daily topical application of the aqueous ethanolic extract of the marine sea grass, Thalassia testudinum, on mice skin exposed to UVB radiation resulted in a dose-dependent recovery of the skin macroscopic alterations over a 6-day
period. Maximal effect (90%) occurred at a dose of 240 μg/cm2, with no additional effects at higher doses. Bioassay-guided fractionation of the plant extract resulted in the isolation
of thalassiolin B (1). Topical application of 1 (240 μg/cm2) markedly reduces skin UVB-induced damage. In addition, thalassiolin B scavenged 2,2-diphenyl-2-picrylhydrazyl radical with
an EC50 = 100 μg/ml. These results suggest that thalassiolin B is responsible for the skin-regenerating effects of the crude extract
of T. testudinum.
Erik L. Regalado and María Rodríguez have contributed equally to this work and should be considered as first authors. 相似文献
6.
The present study deals with the decomposition of CF3OCF2O radical formed from a hydrofluoroether, CF3OCHF2 (HFE-125), in the atmosphere. The study is performed using ab initio quantum mechanical methods. Two plausible pathways of
decomposition of the titled species have been considered, one involving C-O bond scission and the other occurring via F atom
elimination. The geometries of the reactant, products and transition states involved in the decomposition pathways are optimized
and characterized at DFT (B3LYP) level of theory using 6-311G(d,p) basis set. Single point energy calculations have been performed
at G2M(CC,MP2) level of theory. Out of the two prominent decomposition channels considered, the C-O bond scission is found
to be dominant involving a barrier height of 15.3 kcal mol−1 whereas the F-elimination path proceeds with a barrier of 26.1 kcal mol−1. The thermal rate constants for the above two decomposition pathways are evaluated using canonical transition state theory
(CTST) and these are found to be 1.78 × 106 s−1 and 2.83 × 10−7 s−1 for C-O bond scission and F-elimination respectively at 298 K and 1 atm pressure. Transition states are searched on the potential
energy surfaces involved during the decomposition channels and each of the transition states is characterized. The existence
of transition states on the corresponding potential energy surface is ascertained by performing intrinsic reaction coordinate
(IRC) calculation. 相似文献
7.
Several studies reported the antioxidant activity of bifidobacteria using assays in vitro. In present study, the in vitro
and in vivo antioxidant activity of Bifidobacterium animalis 01 was investigated. Culture supernatant, intact cells, and intracellular cell-free extracts of B. animalis 01 were involved in this study. The antioxidant assays in vitro included lipid peroxidation assay, 1,1-diphenyl-2-picrylhydrazyl
(DPPH) assay, hydroxyl radical (
•
OH) assay and superoxide anion (
\textO2 - {\text{O}}_{2}^{ - } ) assay. The antioxidant assays in vivo were conducted using mice model. Activities of antioxidative enzymes, malondialdehyde
(MDA) content in serums and livers of aging mice were evaluated. Monoamine oxidase (MAO) activity and lipofuscin level in
brains of aging mice were also characterized. Results showed that culture supernatant, intact cells and intracellular cell-free
extracts of B. animalis 01 could effectively scavenge free radicals, significantly enhance mice’s activities of antioxidative enzymes and reduce
mice’s MDA content, lipofuscin level and MAO activity. Our results indicated that B. animalis 01 has the potential to be developed into a dietary antioxidant supplements. 相似文献
8.
《Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism》1998,1389(2):81-90
The antioxidant activities of isoorientin-6″-O-glucoside were studied using various models. Isoorientin-6″-O-glucoside was more potent than Trolox, probucol and butylated hydroxytoluene (BHT) in reducing the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). It also scavenged superoxide anion, peroxyl and hydroxyl radicals that were generated by xanthine/xanthine oxidase, 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) and Fe3+–ascorbate–EDTA–H2O2 system, respectively. The IC50 value, stoichiometry factor and second-order rate constant were 9.0 ± 0.8 μM, 1.8 ± 0.1 and 2.6 × 1010 M−1 s−1 for superoxide generation, peroxyl and hydroxyl radicals. However, isoorientin-6″-O-glucoside did not inhibit xanthine oxidase activity or scavenge hydrogen peroxide (H2O2), carbon radical or 2,2′-azobis(2,4-dimethylvaleronitrile) (AMVN)-derived peroxyl radical in hexane. Isoorientin-6″-O-glucoside inhibited Cu2+-induced oxidation of human low-density lipoprotein (LDL) as measured by fluorescence intensity, thiobarbituric acid-reactive substance formation and electrophoretic mobility. Since isoorientin-6″-O-glucoside did not possess pro-oxidant activity, it may be an effective water-soluble antioxidant that can prevent LDL against oxidation. 相似文献
9.
Yun-Jun Liu Zhen-Hua Liang Zheng-Zheng Li Cheng-Hui Zeng Jun-Hua Yao Hong-Liang Huang Fu-Hai Wu 《Biometals》2010,23(4):739-752
A new ligand DBHIP and its two ruthenium(II) complexes [Ru(dmb)2(DBHIP)](ClO4)2 (1) and [Ru(dmp)2(DBHIP)](ClO4)2 (2) have been synthesized and characterized. The cytotoxicity of DBHIP and complexes 1 and 2 has been assessed by MTT assay. The apoptosis studies were carried out with acridine orange/ethidium bromide (AO/EB) staining
methods. The binding behaviors of these complexes to calf thymus DNA (CT-DNA) were studied by absorption titration, viscosity
measurements, thermal denaturation and photoactivated cleavage. The DNA-binding constants of complexes 1 and 2 were determined to be 8.64 ± 0.16 × 104 (s = 1.34) and 2.79 ± 0.21 × 104 (s = 2.17) M−1. The results suggest that these complexes interact with DNA through intercalative mode. The studies on the mechanism of photocleavage
demonstrate that superoxide anion radical (O2
•–) and singlet oxygen (1O2) may play an important role in the DNA cleavage. The experiments on antioxidant activity show that these compounds also exhibit
good antioxidant activity against hydroxyl radical (OH•). 相似文献
10.
Emmanouil H. Papaioannou Nikolaos G. Stoforos Maria Liakopoulou-Kyriakides 《World journal of microbiology & biotechnology》2011,27(4):851-858
Blakeslea trispora produces carotenoids mixtures consisting mainly of lycopene, γ-carotene and β-carotene, together with trace amounts of other
carotenoid precursors. The yield of these carotenoids and their composition are greatly affected by culture substrate. The
scavenging capacity of carotenoids extract from cultures of B. trispora growing in various substrates was estimated using the 2,2-diphenyl-1-picrylhydrazyl method. Fractions enriched in β-carotene,
γ-carotene and lycopene, obtained after column chromatography in alumina basic II, were also examined. Substrates containing
starch and oils mixture, Ni2+, and that with pantothenic acid presented higher antioxidant activity. An increase in the antioxidant activity of the crude
carotenoid extract compared to that of the isolated fractions enriched in β-carotene, γ-carotene and lycopene respectively,
observed in most samples, indicated a possible synergistic effect. The results are of interest and by expanding this study
to more substrates and other microorganisms- producing antioxidants, a formulation of extract with high free radical scavenging
potential could be produced. 相似文献
11.
Juan Wang Wenyuan Gao Beimei Zuo Hui Liu Liming Zhang Luqi Huang 《Plant Growth Regulation》2012,67(1):101-105
A scale-up culture of adventitious roots of ginseng was established using a balloon-type bubble bioreactor (BTBB). Maximum
growth rates of ~52-fold and ~50-fold in 3 and 5 L BTBBs were obtained, respectively after 40 days of inoculation, which was
significantly higher than that in 0.5 L conical flask (~15-fold). Gradually scale-up culture of adventitious roots increased
the root biomass, while the contents of ginsenoside and polysaccharides were not affected. This study also revealed that radical
scavenging activity of dried adventitious roots on 1,1-diphenyl-2-picrylhydrazyl was higher than that of native roots at 20–100 mg L−1 methanolic extract. 相似文献
12.
The effects of Ca(NO3)2 stress on biomass production, oxidative damage, antioxidant enzymes activities and polyamine contents in roots of grafted
and non-grafted tomato plants were investigated. Results showed that when exposed to 80 mM Ca(NO3)2 stress, the biomass production reduction in non-grafted plants was more significant than that of grafted plants. Under Ca(NO3)2 stress, superoxide anion radical (O2•−) producing rate, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents of non-grafted plants roots were significantly higher than those of grafted plants, however,
nitrate (NO3
−), ammonium (NH4
+) and proline contents, superoxide dismutase (SOD, EC1.15.1.1), peroxidase (POD, EC1.11.1.7), catalase (CAT, EC1.11.1.6) and
arginine decarboxylase (ADC, EC 4.1.1.19) activities of grafted plants roots were significantly higher than those of non-grafted
plants. Regardless of stress, free, conjugated and bound polyamine contents in roots of grafted plants were significantly
higher than those of non-grafted plants. The possible roles of antioxidant enzymes, prolines and polyamines in adaptive mechanism
of tomato roots to Ca(NO3)2 stress were discussed.
Gu-Wen Zhang and Zheng-Lu Liu contributed equally to this work. 相似文献
13.
Mechanism of antioxidant action of carnosine 总被引:2,自引:0,他引:2
The comparative study of the antiradical activity of carnosine and vitamin C was carried out by the means of the evaluation of quenching of ESR signals of 2,2-diphenyl-1-picrylhydrazyl (DFPH) and semiquinone radical of alpha-tocopherol. It was shown that carnosine is not able to quench the ESR signals of the stable radical of DFPH and semiquinone radical of alpha-tocopherol. It permits to conclude that: a) carnosine does not interact directly with highly active free radicals; b) carnosine is unable to regenerate the radical of alpha-tocopherol to form the antiradical synergistic couple. The data obtained are consistent with the idea that there is a difference between on the antioxidant mechanism action of vitamin C and carnosine due to the difference in the antiradical activity of these compounds. 相似文献
14.
Quercetin, one of the most common dietary flavonols, was investigated in the presence of Cu(II) ions in methanolic solution
in order to obtain some explanation on the mechanism interaction and its action against free radical-mediated damage. The
spectroscopic studies (UV–VIS, IR, ESI–MS) were used to assess the extent to which it undergo complex formation through chelation
or modification through oxidation. The reaction of quercetin with Cu(II) resulted in the formation of 1:1 metal–ligand complex
(λmax = 436 nm) through the carbonyl oxygen and 3-OH group in C ring. Then quercetin is oxidized to the benzoquinone type products.
The addition of EDTA destroyed the complex but did not regenerate the whole original spectrum of quercetin. From the other
hand, the presence of EDTA inhibits formation of copper–quercetin complex and quercetin oxidation. The antioxidant activity
of the Q + Cu solutions was evaluated by using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH∙) radical scavenging method and
from an electrochemical point of view. The complex is much more effective as free radical scaveninger than the free flavonoid. 相似文献
15.
The objective of this study was to evaluate the antioxidant properties of extracts of the lucanid beetle, Serrognathus platymelus castanicolor Motschulsky, obtained at different growth stages. The antioxidant activities of six different extracts were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and singlet oxygen (1O2). The activity level of pupal methanol extracts (PME) was higher in the DPPH and ABTS radical scavenging assays, whereas that of the water extracts was weaker in all assays. The 1O2 quenching ability of the PME was comparable to that of ascorbic acid (effective concentration of 50% 1O2 quenching: EC50 = 0.184 mg/ml-1 and 0.167 mg/ml-1, respectively). The free radical scavenging antioxidant ability of the extracts significantly altered phenolic contents, important factors in the potency of antioxidant capacity. Our results suggest that these extracts may reduce oxidative stress in living organisms and reduce oxidative damage in insects under unfavorable conditions. 相似文献
16.
E. S. Alinkina T. A. Misharina L. D. Fatkullina 《Applied Biochemistry and Microbiology》2013,49(1):73-78
In model reactions with the stable free 2,2-diphenyl-1-picrylhydrazyl radical, the antiradical properties of essential oils of thyme (Thymus vulgare), oregano (Origanum vulgare), and savory (Satureja hortensis) that are similar in the qualitative composition, but differ in the quantitative content of the main components, were studied and compared with the properties of synthetic antioxidant ionol. The reaction rates of components of essential oils with the radical were almost identical for all essential oils and were twice the reaction rate of ionol. The antiradical efficiency values were close to each other for all essential oils and by an order of magnitude smaller than for ionol. 相似文献
17.
Neda S. Lakić Neda M. Mimica-Dukić Jelena M. Isak Biljana N. Božin 《Central European Journal of Biology》2010,5(3):331-337
The antioxidant properties of methanol extracts of Lady’s Bedstraw (Galium verum L., Rubiaceae) herb from two different localities in Serbia were evaluated. Antioxidant activity was assessed in four different
model systems. Free radical scavenging capacity (RSC) was examined by measuring the scavenging activity of extracts on 2,2-diphenyl-1-pycrylhydrazil
(DPPH) and hydroxyl radical (OH), as well as on hydrogen peroxide. In addition, the protective effects of lipid peroxidation
(LP) in corn oil were evaluated by the TBA-assay using the Fe2+/ascorbate system of induction. The amount of dried extract, the content of total phenolics, flavonoids and chlorophylls was
also determined. Extracts from both locations expressed very strong scavenger activity, reducing the DPPH⊙ (IC50=3.10 μg/mland 8.04 μg/ml) and OH radical formation (IC50=0.05 μg/ml and 0.54 μg/ml) and neutralising H2O2 (IC50=4.98 μg/ml and 3.80 μg/ml), in a dose dependant manner. Also, examined extracts showed notable inhibition of LP (IC50=11.69 μg/ml and 19.47 μg/ml). The observed differences in antioxidant activity could be partially explained by the levels
of phenolics (2.44–4.65 mg and 4.57–5.16 mg gallic acid equivalents/g dry extract), flavonoids (6.38–10.70 μg and 15.56–17.96
μg quercetin equivalents/g dry extract) and chlorophylls in the investigated Lady’s Bedstraw extracts. 相似文献
18.
Comparison of antioxidant abilities of magnolol and honokiol to scavenge radicals and to protect DNA 总被引:3,自引:0,他引:3
The antioxidant properties of magnolol and honokiol were evaluated in the experimental systems of reducing ONOO− and 1O2, bleaching β-carotene in linoleic acid (LH) emulsion, and trapping 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS+) and 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), and then were applied to inhibit the oxidation of DNA induced by Cu2+/glutathione (GSH) and 2,2′-azobis(2-amidinopropane hydrochloride) (AAPH). Magnolol and honokiol were active to reduce ONOO− and 1O2. Honokiol showed a little higher activity to protect LH and to inhibit Cu2+/GSH-induced oxidation of DNA than magnolol. In addition, honokiol exhibited higher activities to trap ABTS+ and DPPH than magnolol. In particular, honokiol trapped 2.5 radicals while magnolol only trapped 1.8 radicals in protecting DNA against AAPH-induced oxidation. The obtained results suggested that low antioxidant ability of magnolol may be related to the intramolecular hydrogen bond formed between di-ortho-hydroxyl groups, which hindered the hydrogen atom in hydroxyl group to be abstracted by radicals. Therefore, the antioxidant capacity of magnolol was lower than that of honokiol. 相似文献
19.
Pilar Pérez Aitor Alonso Gloria Zita Rosa Morcuende Rafael Martínez-Carrasco 《Plant Growth Regulation》2011,65(3):439-447
Increases in growth temperature have been observed to affect photosynthesis differently under long-term exposure to ambient-
and twice ambient-air CO2 concentrations. This study investigates the causes of this interaction in wheat (Triticum aestivum L.) grown in the field over two consecutive years under temperature gradient chambers in ambient (370 μmol mol−1) or elevated (700 μmol mol−1) atmospheric CO2 concentrations and at ambient or ambient +4°C temperatures, with either a low or a high nitrogen supply. The photosynthesis-internal
CO2 response curves and the activity, activation state, kcat and amount of Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) were measured, as well as the soluble protein concentration
in flag leaves at ear emergence and 8–15 days after anthesis. A high nitrogen supply increased Vcmax, the Rubisco amount and activity and soluble protein contents, but did not significantly change the Rubisco kcat. Both elevated CO2 and above ambient temperatures had negative effects on Vcmax and Rubisco activity, but at elevated CO2, an increase in temperature did not decrease Vcmax or Rubisco activity in relation to ambient temperature. The amounts of Rubisco and soluble protein decreased with elevated
CO2 and temperature. The negative impact of elevated CO2 on Rubisco properties was somewhat counteracted at elevated temperatures by an increase in kcat. This effect can diminish the detrimental effects on photosynthesis of combined increases of CO2 and temperature. 相似文献
20.
Chengxu Cao Yiming Liu Yang Li Yan Zhang Yue Zhao Rina Wu Junrui Wu 《Glycoconjugate journal》2020,37(3):307-317
The aim of this study was to characterize the exopolysaccharide (EPS) produced by Bacillus velezensis SN-1 (B. velezensis SN-1) (EPS-SN-1), which was isolated from the fermented Da jiang. The microbe made crude exopolysaccharides EPS-SN-1 was produced throughout the bacterial growth period, and the highest yield (2.7 g/L) was obtained with sucrose as the carbon source. As per high performance liquid chromatography (HPLC), EPS-SN-1 is a heteropolysaccharide consisting of glucose, mannose and fructose, with a high molecular weight of 2.21 × 105 Da. FTIR spectra further indicated the presence of hydroxyl and carbonyl groups, and NMR analysis confirmed both α- and β-glycosidic bonds. Furthermore, differential scanning calorimetry (DSC) showed that EPS-SN-1 has high thermal stability with fusion point of 270.7 °C. Finally, EPS-SN-1 demonstrated strong antioxidant capacity via its ability to scavenge hydroxyl radical (•OH), 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical, ABTS radical (ABTS•+) and oxygen radical (O2−•). Taken together, EPS-SN-1 is a promising natural antioxidant and probiotic with potential applications in the food industry. 相似文献