共查询到20条相似文献,搜索用时 31 毫秒
1.
Zhongshan Zhang Quanbin Zhang Jing Wang Hong Zhang Xizhen Niu Pengcheng Li 《International journal of biological macromolecules》2009,45(1):22-26
Porphyran extracted from Porphyra haitanensis is a sulfated polysaccharide, which possesses excellent antioxidant activities. In this study, we prepared one low-molecular-weight porphyran and its sulfated, acetylated, phosphorylated and benzoylated derivatives. Their antioxidant activities were investigated including scavenging effect of superoxide, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals. The results of chemical analysis and FT-IR spectrums showed the modification was successful. And in addition, we found that certain derivative exhibited stronger antioxidant activity than low-molecular-weight porphyran. The benzoylated derivative showed the most excellent antioxidant activity in three assays, so this derivative needs to be attended to. 相似文献
2.
《Bioscience, biotechnology, and biochemistry》2013,77(4):1026-1028
Marine microorganisms degrading porphyran (POR) were found on the surface of thalli of Porphyra yezoensis. Fifteen crude microorganism groups softened and liquefied the surface of agar-rich plate medium. Among these, 11 microorganism groups degraded porphyran that consisted of sulfated polysaccharide in Porphyra yezoensis. Following isolation, 7 POR-degradable microorganisms were isolated from the 11 POR-degradable microorganism groups. 相似文献
3.
Degradation of porphyran from Porphyra haitanensis and the antioxidant activities of the degraded porphyrans with different molecular weight 总被引:2,自引:0,他引:2
Zhao T Zhang Q Qi H Zhang H Niu X Xu Z Li Z 《International journal of biological macromolecules》2006,38(1):45-50
In the present paper, ascorbate and hydrogen peroxide (H2O2) were used to degrade porphyran. It was found that porphyran could be degraded by free radical that was generated by ascorbate and H2O2 in combination. It was possible to prepare desired porphyran products with different molecular weight by adjusting ascorbate to H2O2 proportions and their concentrations. The molar ratio of 1 was demonstrated more effective than in other ratios. Higher concentrations accelerated the degradation. Moreover, results of chemical analysis and FT-IR spectra suggested that the main structure of degraded products still remained although some changes happened. The degraded and natural porphyrans possessed scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical activity and reducing power. Higher antioxidant activities were found in both systems when the molecular weight was reduced. The results indicated that the antioxidant activities were closely related to the molecular weight. The degraded porphyrans are potential antioxidant in vitro. 相似文献
4.
Porphyran, extracted from an edible red alga (Porphyra yezoensis), is a sulphated polysaccharide with a wide variety of biological activities including anti-tumour, antioxidant and immuno-modulating activities. In this study, we examined the effect of porphyran on nitric oxide (NO) production in mouse macrophage cell line RAW264.7 cells. Although no significant activity of porphyran to induce NO or tumour necrosis factor-α (TNF-α) production in RAW264.7 cells was observed at the concentration range tested (10-500 μg/ml), it was found for the first time that porphyran inhibited NO production and expression of inducible nitric oxide synthase (iNOS) in RAW264.7 cells stimulated with lipopolysaccharide (LPS). In the presence of 500 μg/ml porphyran, NO production and expression of iNOS in LPS-treated RAW264.7 cells were completely suppressed. On the other hand, porphyran showed only a marginal effect on the secretion of TNF-α from LPS-stimulated RAW264.7 cells. Electrophoretic mobility shift assay (EMSA) using infrared dye labelled oligonucleotide with nuclear factor-κB (NF-κB) consensus sequence suggested that porphyran inhibited the LPS-induced NF-κB activation. The LPS-inducible nuclear translocation of p65, and the phosphorylation and degradation of IκB-α were also inhibited by the pre-treatment with porphyran. Our results obtained in in vitro analysis suggest that porphyran suppresses NO production in LPS-stimulated macrophages by the blocking of NF-κB activation. 相似文献
5.
Quanbin Zhang Pengzhan Yu Zhien Li Hong Zhang Zuhong Xu Pengcheng Li 《Journal of applied phycology》2003,15(4):305-310
Three sulfated polysaccharide fractions (F1, F2, and F3) were isolated from Porphyra haitanesis, an important economic alga in China, through anion-exchange column chromatography and their in vitro antioxidant activities were investigated in this study. Galactose was the main sugar unit of the three fractions. The analytical results indicated that polysaccharide fractions from P. haitanesis had similar chemical components to porphyran from other species, but differed in their high sulfate content. The sulfate content of F1, F2 and F3 was 17.4%, 20.5% and 33.5% respectively. All three polysaccharide fractions showed antioxidant activities. They had strong scavenging effect on superoxide radical, and much weaker effect on hydroxyl free radical. Lipid peroxide in rat liver microsome was significantly inhibited, and H2O2 induced hemolysis of rat erythrocyte was partly inhibited by F1, F2 and F3. Among them, F3 showed strongest scavenging effect on superoxide radical; F2 had strongest effect on hydroxyl radical and lipid peroxide. 相似文献
6.
Zhang Z Wang X Yu S Yin L Zhao M Han Z 《International journal of biological macromolecules》2011,49(5):1012-1015
Sulfated polysaccharide extracted from blue algae Enteromorpha linza is proved to possess excellent antioxidant activities. Two derivatives by means of oversulfated and acetylated coupling were synthesized and investigated their antioxidant activities including scavenging effect of superoxide, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals. And then the relationship between antioxidant activity and chemical characteristics was characterized. The results of chemical analysis and FT-IR showed that the modification of polysaccharide was successful. In addition, it was found that certain derivatives exhibited stronger antioxidant activity than raw material. They could serve as free-radical inhibitors or scavengers, acting possibly as primary antioxidants. 相似文献
7.
Christos A. Kontogiorgis Kyriakos Savvoglou Dimitra J. Hadjipavlou-Litina 《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):21-29
Several coumarin derivatives have been reported to present multiple biological activities and especially anti-inflammatory/antioxidant activities. Recently the synthesis and in vivo/in vitro anti-inflammatory /antioxidant activities of several new coumarin derivatives with a 7-azomethine linkage have been reported. In the present study these derivatives were further tested for their antioxidant ability. Some of them were found in vitro to inhibit lipid peroxidation and to strongly scavenge superoxide radicals. Compound 3 was found to potently inhibit cyclooxygenase-1 (COX-1) and the yeast-induced rat paw oedema. The most active compounds within the set were tested against adjuvant-induced arthritis. Compound 3 was found to significantly protect the rats from adjuvant-induced arthritis (when it is administered from the first day or when it is administered the fourteenth day, with the first symptoms of the disease). An attempt was made to delineate the possible mechanism of action of the studied compounds. 相似文献
8.
Svetlana A. Popova Oksana G. Shevchenko Irina Y. Chukicheva Aleksander V. Kutchin 《化学与生物多样性》2019,16(3)
Coumarins with terpene and tert‐butyl substituents were synthesized via Pechmann condensation reaction. New derivatives were investigated in different model system for the exhibition of antioxidant, radical scavenging and membrane‐protective activities. It has been found that 4‐methylcoumarin derivatives with monoterpene moieties exhibit high antioxidant activities. The most active and promising for further investigations is 5‐hydroxy‐6,8‐diisobornyl‐4‐methylcoumarin, containing two isobornyl substituents on the benzopyran ring. 相似文献
9.
Effects of Oxygen on Nicotine and Tropane Alkaloid Production in Cultured Roots Duboisia myoporoides
《Bioscience, biotechnology, and biochemistry》2013,77(10):1824-1827
The effects of oxygen on nicotine and tropane alkaloid production in root cultures of Duboisia myoporoides were investigated. Duboisia roots cultured in air produced both nicotine and tropane alkaloids equally. However, when roots were cultured in pure oxygen, the metabolic flux to tropane alkaloids increased, and that to nicotine alkaloids decreased. Intermediate product analysis by GC-MS showed an increase in tropine, but decreases in acetyl derivatives of tropane alkaloids and tropine esters with low-class fatty acids. Furthermore, hyoscyamine 6β-hydroxylase (H6H, EC 1.14.11.11, the key enzyme in the pathway from hyosyamine to scopolamine) also increased. These results suggest that pure oxygen contributes to scopolamine production not only by activating the biosynthetic steps for scopolamine, but also by inactivating the biosynthetic steps for nicotine and other tropine derivatives. 相似文献
10.
Porphyrans, the sulfated polysaccharides, are the main components of Porphyra. The potential apoptotic activities of porphyran were evaluated using AGS human gastric cancer cells. Porphyran did not affect the growth of normal cells, but did induce cancer cell death in a dose-dependent manner. The addition of 0.1% porphyran also reduced DNA synthesis after 24 h of exposure, suggesting that porphyran inhibits cancer cell growth by both decreasing cell proliferation and inducing apoptosis. AGS cells treated with porphyran displayed a marked increase in poly(ADP-ribose) polymerase (PARP) cleavage, as well as caspase-3 activation. The ability of porphyran to promote apoptosis may contribute to its usefulness as an agent capable of significantly inhibiting cell growth in AGS human gastric cancer cells. Insulin-like growth factor-I receptor (IGF-IR) phosphorylation was decreased in porphyran-treated AGS cells compared to control cells, which correlated with Akt activation. Thus, porphyran appears to negatively regulate IGF-IR phosphorylation by causing a decrease in the expression levels in AGS gastric cancer cells, and then inducing caspase-3 activation. 相似文献
11.
The enzymic degradation of porphyran 总被引:6,自引:5,他引:1
1. The algal galactan, porphyran, was incubated with enzymes from a Cytophaga sp. and the products were examined. 2. Only about 30% of the porphyran was recovered in the form of oligosaccharides, the remainder being of high molecular weight. 3. Among the saccharides were d-galactose, 6-O-methyl-d-galactose, neoagarobiose, neoagarotetraose and oligosaccharides containing 6-O-methyl-d-galactose, the principal of which has been tentatively identified as 6(3)-O-methyl-neoagarotetraose. Fragments containing sulphate were also isolated but not identified. 4. Within the alternating sequence of the d- and l-forms of derivatives of galactose in porphyran, 6-O-methyl-d-galactose replaces d-galactose in a random manner. 相似文献
12.
Abalone enzymes, Cellulase R-10, Macerozyme and agarase fromPseudomonas atlantica were tested for activity on agarose, cellulose, xylan, the cell wall matrix and porphyran isolated fromPorphyra linearis. Agarase, and to a lesser extent Macerozyme, digested both agarose and porphyran. Abalone enzymes and Cellulase R-10 reacted only weakly with porphyran. A simple standardized protocol for making protoplasts fromPorphyra linearis was developed using 0.025% agarase in seawater without added organic osmoticants. Protoplasts prepared with agarase remained viable for at least 24 h in the digestion medium. Regeneration of the protoplasts followed the normal pattern for this species. Agarase can be used to obtain large number of protoplasts which could substitute for conchospores in seeding nets for the aquaculture ofP. linearis
Author for correspondenceIssued as NRCC no. 34897 相似文献
13.
Four novel N-isobutyryl-l-cysteine/2-mercaptoethylamine (MEA, cysteamine) conjugates have been designed and synthesized. The antioxidant activities of these new series were evaluated by three different free radical scavenging methods (DPPH test, ABTS test, and deoxyribose assay) and their metal binding capacity was evaluated by the ethidium bromide fluorescence binding assay. These results were compared with those obtained with their pro-GSH acetyl analogues recently developed in our laboratory. We observed that most of these compounds exhibit free radical-scavenging activities similar to those of Trolox, but always superior than NAC. While none of these new derivatives had pro-GSH activities, they displayed anti-HIV properties in human monocyte-derived macrophages infected in vitro. The present study demonstrates that these new N-isobutyryl derivatives, which are expected to have a greater bioavailability than their acetyl analogues, may have useful applications in HIV infection in respect to their antioxidant and anti-HIV activities. 相似文献
14.
In this study, the synthesis of new spiropyrazoles, pyrazole and hydantoin heterocycles is reported by three component reactions of parabanic acids, hydrazine derivatives, and phenacyl bromides in the presence of triphenylphosphine as a nucleophile and triethylamine as a base in good to high yields (69–91 %). Evaluation of the synthesized compounds revealed a good to excellent antioxidant activities (37.6–96.2 %) using DPPH inhibitory potency. Among these compounds, hydantoin derivatives displayed higher antioxidant activities (93.7–96.2 %) comparing with spiropyrazoles and pyrazoles. The obtained results showed that Cl and Br substituents on the phenyl ring increased antioxidant activities of the related heterocycles. The antibacterial activities of the synthesized compounds were examined against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. Among the synthesized heterocycles, 2-[1,3-dimethyl-2,5-dioxo-4-(2-oxo-2-phenylethyl)imidazolidin-4-yl]hydrazine-1-carbothioamide exhibited the excellent antibacterial activity against both Gram-positive and Gram-negative bacteria. 相似文献
15.
Ibrahim S. Al Nasr Jana Jentzsch Amin Shaikh Priti Singh Shuveksh Waleed S. Koko Tariq A. Khan Khursheed Ahmed Rainer Schobert Klaus Ersfeld Bernhard Biersack 《化学与生物多样性》2021,18(1):e2000839
New pyranonaphthoquinone derivatives were synthesized and investigated for their activity against Trypanosoma brucei, Leishmania major, and Toxoplasma gondii parasites. The pentafluorophenyl derivative was efficacious against T. brucei with single digit micromolar EC50 values and against T. gondii with even sub-micromolar values. The 3-chloro-4,5-dimethoxyphenyl derivative showed an activity against amastigotes of Leishmania major parasites comparable to that of amphotericin B. In addition, antioxidant activities were observed for the bromophenyl derivatives, and their redox behavior was studied by cyclovoltammetry. Anti-parasitic and antioxidative activities of the new naphthoquinone derivatives appear uncorrelated. 相似文献
16.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(6):813-818
A series of N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives were synthesized by treating N-(benzoxazol-2-yl)hydrazinecarboxamide with different isatin derivatives. The newly synthesized compounds were characterized on the basis of spectral analyses. All the synthesized derivatives (Va-l) were screened for anticancer and antioxidant activities. The results showed the anticancer activity of test compounds against HeLa, IMR-32 and MCF-7 cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. All the synthetic compounds produced a dose-dependant inhibition of growth of the cells. The IC50 values of some compounds were comparable with standard anticancer agent, cisplatin. All the title compounds effectively scavenged the free radical, α,α-diphenyl-β-picryl hydrazyl. The test compounds having substitution with different halides (electron withdrawing groups) at C5 position showed more potent anticancer and antioxidant activities than those at C7 position. These results indicate that C5-substituted derivatives may be useful for developing antioxidant agents that play a protective role in many pathological conditions such as cancer, diabetes and so on. 相似文献
17.
Jin M Lu Z Huang M Wang Y Wang Y 《International journal of biological macromolecules》2011,48(4):607-612
Nine modification conditions were designed to sulfate exopolysaccharides (EPS) produced by Enterobacter cloacae Z0206 by chlorosulfonic acid-pyridine (CSA-Pyr) method according to the orthogonal test and focusing on three affecting factors such as the ratio of CSA to Pyr, reaction temperature and reaction time. And nine sulfated derivatives with various degrees of substitution (DS) were obtained. Their antioxidant activities were evaluated in vitro, by scavenging abilities on superoxide radical and hydroxyl radical. The results indicated that sulfated derivatives of EPS showed noticeable effects on scavenging superoxide radical and hydroxyl radical compared with native one, and sulfated derivative with moderate DS of 0.60 showed highest antioxidant activities. The optimum sulfated conditions of EPS were the ratio of CSA to Pyr of 1:2, the reaction time of 2h and reaction temperature of 70 °C. 相似文献
18.
《Phytomedicine》2014,21(3):240-246
BackgroundCoumarins, also known as benzopyrones, are plant-derived products with several pharmacological properties, including antioxidant and anti-inflammatory activities. Based on the wide distribution of coumarin derivatives in plant-based foods and beverages in the human diet, our objective was to evaluate both the antioxidant and intestinal anti-inflammatory activities of six coumarin derivatives of plant origin (scopoletin, scoparone, fraxetin, 4-methyl-umbeliferone, esculin and daphnetin) to verify if potential intestinal anti-inflammatory activity was related to antioxidant properties.MethodsIntestinal inflammation was induced by intracolonic instillation of TNBS in rats. The animals were treated with coumarins by oral route. The animals were killed 48 h after colitis induction. The colonic segments were obtained after laparotomy and macroscopic and biochemical parameters (determination of glutathione level and myeloperoxidase and alkaline phosphatase activities) were evaluated. The antioxidant properties of these coumarins were examined by lipid peroxidation and DPPH assays.ResultsTreatment with esculin, scoparone and daphnetin produced the best protective effects. All coumarin derivatives showed antioxidant activity in the DPPH assay, while daphnetin and fraxetin also showed antioxidant activity by inhibiting lipid peroxidation. Coumarins, except 4-methyl-umbeliferone, also showed antioxidant activity through the counteraction of glutathione levels or through the inhibition of myeloperoxidase activity.DiscussionThe intestinal anti-inflammatory activity of coumarin derivatives were related to their antioxidant properties, suggesting that consumption of coumarins and/or foods rich in coumarin derivatives, particularly daphnetin, esculin and scoparone, could prevent intestinal inflammatory disease. 相似文献
19.
Yukari Miura Sari Honda Akiko Masuda 《Bioscience, biotechnology, and biochemistry》2013,77(8):1452-1455
This study investigated antioxidant activities of cysteine derivatives of amino and carboxylic acid moieties against lipid oxidation in anhydrous acetonitrile. Only cysteine derivatives bearing free amino or carboxylate ion were found to exert potent antioxidant activities. Sequential proton loss and electron transfer-like proton shift and subsequent electron transfer (PS-ET) mechanism may facilitate the antioxidant activities of cysteine derivatives against lipid oxidation in anhydrous media. 相似文献
20.
Krystalia Lytra Ekaterina-Michaela Tomou Antonios Chrysargyris Maria-Dolores Christofi Panagiota Miltiadous Nikolaos Tzortzakis Helen Skaltsa 《化学与生物多样性》2021,18(3):e2000966
Sideritis cypria Post is an endemic and endangered species of Northern Cyprus. The overall aim of the present study was to evaluate the total phenolic content, the antioxidant, the cytotoxic and the antimicrobial activity of the methanol extract obtained from the aerial parts of cultivated S. cypria. A bio-guided approach led to the isolation of 27 chemical compounds by using various analytical techniques. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopy. The crude extract exerted strong antioxidant activity (DPPH and FRAP assays) which was attributed to its high total phenolic content. Furthermore, groups rich in phenolic content showed highest antioxidant property, whereas groups with phytosterols, diterpenoids and apigenin derivatives exerted cytotoxic effects in MDA-MB231 cancer cell line by the MTT method. Moreover, the cytotoxic activity of four isolated apigenin derivatives was evaluated in the same cancer cells. The antimicrobial activity of the extract and groups were measured, demonstrating lack of activity. To the best of our knowledge, this survey is the first report on the biological activities of the methanol extract of S. cypria. 相似文献