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1.
水飞蓟果实中的黄酮类化合物   总被引:1,自引:0,他引:1  
从菊科水飞蓟属植物水飞蓟(Silybum marianum L.Gaertn)的干燥成熟果实中分离鉴定了9个化合物,分别为黄酮木质素类化合物:水飞蓟宾(1),2,3-脱氢水飞蓟宾(2),水飞蓟亭(3),2,3-脱氢水飞蓟亭(4);黄酮类化合物:4’-甲氧基紫杉叶素(5),紫杉叶素(6),二氢山奈酚(7),槲皮素(8)以及酚酸类化合物:3,4-二羟基苯甲酸(9)。其中化合物5,7,9为首次从该属植物中分得。  相似文献   

2.
Flavonoids and phenolic acids from the aerial parts of Platycodon grandiflorum A. DC. were analysed by isocratic TLC, MGD-TLC and HPLC methods. Four flavonoid compounds were determined including luteolin 7-O-glucoside as the main component and apigenin 7-O-glucoside, luteolin and apigenin. When performing HPLC analysis, 12 phenolic acids in the free, depside and glycoside forms were identified. Among them, 3,4-dimethoxycinnamic, caffeic, chlorogenic, ferulic, isoferulic, homovanillic, alpha-resorcylic, m-coumaric, p-coumaric, p-hydroxybenzoic, 2-hydroxy-4-methoxybenzoic and 2,3-dihydroxybenzoic acids.  相似文献   

3.
Metformin(1-(diaminomethylidene)-3,3-dimethyl-guanidine), an anti-hyperglycemic agent, also has antioxidant effects. Although the origin is not clearly understood, the antioxidant activity of metformin might result from a direct effect on reactive oxygen species (ROS) or could have an indirect action on the superoxide anions produced by hyperglycemia. The ability of metformin to modulate DNA damage produced by oxidative stress is not known. For this reason, we examined the short term effect of metformin (50 microM, 2 h) on the DNA damage of cumene hydroperoxide (CumOOH)-induced lymphocytes from aged and young control groups (n = 10 each). In this study, DNA damage elicited by CumOOH (1 mM) was detected with the Comet Assay and the ELISA technique. Our results showed a significant increase in apoptotic DNA fragmentation and DNA strand breaks (Comet assay tail factor %) that was detected before and after CumOOH induction in lymphocytes of healthy elderly subjects when compared with healthy young control. Metformin significantly decreased CumOOH-induced apoptotic DNA fragmentation and DNA strand breaks in lymphocytes from aged subjects, although it did not produce a long-term effect. The in vitro results indicate that the short-term effect of metformin can protect against prooxidant stimulus-induced DNA damage in lymphocytes from elderly subjects.  相似文献   

4.
Some water-soluble phenolic acids were investigated as antioxidants, scavengers of hydrogen peroxide (H(2)O(2)) and scavengers of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH(*)). The strongest antioxidant, scavenging of H(2)O(2) and DPPH(*) radical activity was exhibited by 3,4,5-trihydroxybenzoic (gallic) acid and 1,2,3-trihydroxybenzene (pyrogallol) with three hydroxyl groups bonded to the aromatic ring in an ortho position in relation to each other. Phenolic acids with two hydroxyl groups bonded to aromatic ring in the ortho position, such as 3,4-dihydroxycinnamic (caffeic), 3,4-dihydroxybenzoic (protocatechuic) and 2,3-dihydroxybenzoic (o-pyrocatechuic) acids, showed strong antioxidant and anti-radical activity; however, it was lower than that of 3,4,5-trihydroxybenzoic acid or 1,2,3-trihydroxybenzene. 3,5-Dihydroxybenzoic (alpha-resorcylic) and 2,4-dihydroxybenzoic (beta-resorcylic) acids with two hydroxyls bonded in the meta position in relation to each other showed moderate antioxidant and low DPPH(*) and hydrogen peroxide scavenging activity. Compounds with one hydroxyl group such as 3-hydroxybenzoic, 4-hydroxyphenylacetic and 2-hydroxybenzoic (salicylic) acids, exhibited the lowest anti-radical and antioxidant activity. The results obtained show that the antioxidant and anti-radical activity of phenolic acids correlated positively with the number of hydroxyl groups bonded to the aromatic ring. The model of an ortho substitution of hydroxyl groups to the aromatic ring seems to be adequate for antioxidant and H(2)O(2) or DPPH(*) scavenging activity of phenolic acids.  相似文献   

5.
A new extraction technique based on the off-line combination of pressurized-liquid with solid-phase extraction (PLE–SPE) is described. The method was used for the extraction of bioactive phenolic acids (protocatechuic, p-hydroxybenzoic, 2,3-dihydroxybenzoic, chlorogenic, vanillic, caffeic, p-coumaric, salicylic acid), cinnamic acid and hydroxybenzaldehydes (p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, vanillin) from in vitro culture of two freshwater algae (Anabaena doliolum and Spongiochloris spongiosa) and from food products of marine macroalgae Porphyra tenera (nori) and Undaria pinnatifida (wakame). For the identification and quantification of the compounds the molecular ions [M−H] and specific fragments were analyzed by quadrupole mass spectrometry analyzer connected on-line with a reversed-phase HPLC system. Our analysis showed that the freshwater algae and marine algal products contained submicrogram or microgram level of above-mentioned phenols per gram of lyophilized sample. In addition, the total phenol content (Folin–Ciocalteu assay) and antioxidant activity (TEAC assay, Trolox equivalent antioxidant capacity assay) of the PLE–SPE extracts were determined and discussed.  相似文献   

6.
目的探究中药酚酸类化合物抑制DNA损伤的效应,分析其构效关系。方法以人工合成抗氧化剂水溶性维生素E Trolox为阳性对照,选取结构相近的没食子酸、咖啡酸、芥子酸、阿魏酸和对香豆酸5种天然酚酸类化合物,通过琼脂糖凝胶电泳检测其体外清除羟自由基、过氧自由基及过氧亚硝基阴离子从而抑制DNA氧化损伤的作用。对电泳结果进行吸光度分析,计算开环态DNA所占百分比,由此得出各化合物的IC50值。结果 5种酚酸类化合物均表现出抑制DNA损伤的作用,开环态DNA所占百分比随药物浓度增加而减少。5种化合物可抑制羟自由基引起的DNA损伤,IC50值分别为:没食子酸(1.13±0.03)mmol·L-1≈咖啡酸(1.14±0.07)mmol·L-1<对香豆酸(1.41±0.06)mmol·L-1<芥子酸(1.68±0.04)mmol·L-1<阿魏酸(1.80±0.04)mmol·L-1相似文献   

7.
Caffeic acid (CA) (3,4-dihydroxycinnamic acid) is among the major hydroxycinnamic acids. Hydroxycinnamic acid is the major subgroup of phenolic compounds. Methamphetamine (METH) is a potent addictive psychostimulant. Chronic use and acute METH intoxication can cause substantial medical consequences, including spleen, kidney, liver and heart. The objective of the present study was to evaluate the antioxidant activity of CA to protect against oxidative stress and DNA damage to various organs in METH toxicity. Thirty-two male Sprague Dawley (SD) rats were divided into four equal groups: group 1 was injected (i.p) with saline (1 mL/kg) while groups 2,3 and 4 were injected (i.p) with METH (10 mg/kg) twice a day over five days period. Where 100 & 200 mg/kg of CA were injected (i.p) into groups 3 and 4, respectively one day before exposure to METH injections. Tissue antioxidants and DNA content were evaluated in different tissues. METH decreased glutathione (GSH) and glutathione peroxidase (GPx) levels while increased malondialdehyde (MDA), catalase (CAT) and protein carbonyl levels in brain (hypothalamus), liver, and kidney tissues of rats. METH increased hyperdiploidy in these tissues and DNA damage results. Prior treatment of CA to animals exposed to METH restores the above parameters to the normal levels and preserves the DNA content of these tissues. These results were supported by histopathological investigations. In conclusion, METH induced oxidative stress and DNA damage and pretreatment of CA before METH injections prevented tissue oxidative stress and DNA damage in METH-treated animals.  相似文献   

8.
Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses and to reduce damage to the human body. To determine whether phenolic compounds (caffeic, ferulic, and p-coumaric acids) have immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we evaluated their effect on splenocyte proliferation and lysosomal enzyme activity. We also investigated the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL). In addition, induction of the cellular antioxidant activity in splenocytes, macrophages, and red blood cells was determined by measuring the ?uorescence of the DCF product. The study first results indicated that ca?eic, ferulic, and p-coumaric acids significantly promote LPS-stimulated splenocyte proliferation, suggesting a potential activation of B cells, and enhanced humoral immune response in hosts treated by the tested natural products. Phenolic acids significantly enhanced the killing activity of isolated NK and CTL cells but had negligible effects on mitogen-induced proliferation of splenic T cells. We showed that caffeic acid enhances lysosomal enzyme activity in murine peritoneal macrophages, suggesting a potential role in activating such cells. Immunomodulatory activity was concomitant with the cellular antioxidant effect in macrophages and splenocytes of caffeic and ferulic acids. We conclude from this study that ca?eic, ferulic, and p-coumaric acids exhibited an immunomodulatory effect which could be ascribed, in part, to their cytoprotective effect via their antioxidant capacity. Furthermore, these results suggest that these natural products could be potentially used to modulate immune cell functions in physiological and pathological conditions.  相似文献   

9.
The prooxidant effect of hydroxycinnamic acids (HCAs), i.e., caffeic acid (CaA), chlorogenic acid (ChA), sinapic acid (SA), ferulic acid (FA), 3-hydroxycinnamic acid (3-HCA) and 4-hydroxycinnamic acid (4-HCA) on supercoiled pBR322 plasmid DNA strand breakage and calf thymus DNA damage in the presence of Cu(II) ions has been studied. It was found that the compounds bearing ortho-dihydroxyl group (CaA and ChA) or bearing 4-hydroxy-3-methoxyl group (SA and FA) exhibited remarkably higher activity in the DNA damage than the ones bearing no such functionalities. The good correlation between the DNA damaging activity and the oxidative potential of the compounds indicates that the electron transfer between HCAs and Cu(II) plays a crucial role in the reaction. UV-Visible spectral changes demonstrated that CaA or ChA can chelate with Cu(II) as a bidentate ligand, hence facilitating intramolecular electron transfer between CaA or ChA and Cu(II). The involvement of reactive oxygen species (ROS) and Cu(I) ions in the DNA damage were affirmed by the inhibition of DNA breakage using mannitol, glutathione (GSH), catalase and bathocuproinedisulfonic acid (BCDS). These results may have important implications regarding the proposed mechanism of apoptosis induced by phenol and endogenous metal ions.  相似文献   

10.
Fernblock, an aqueous extract of the aerial parts of the fern Polypodium leucotomos, used as raw material for topical and oral photoprotective formulations, was fractioned by HPLC and the main components with antioxidant capability were identified by means of UV spectra, electrochemical detection, and MSn. Phenolic compounds were identified as 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, vanillic acid, caffeic acid, 4-hydroxycinnamic acid, 4-hydroxycinnamoyl-quinic acid, ferulic acid, and five chlorogenic acid isomers. Total ferric antioxidant capacity (FRAP) of HPLC eluted fractions was measured. The results suggest that the herein identified compounds support, at least partially, the antioxidant and radical scavenging capacities of Fernblock.  相似文献   

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