Natural and synthetic coumarin derivatives with anti-inflammatory/ antioxidant activities

Several natural products with a coumarinic moiety have been reported to have multiple biological activities. It is to be expected that, in a similar way to isomeric flavonoids, coumarins might affect the formation and scavenging of reactive oxygen species (ROS) and influence processes involving free radical-mediated injury. Coumarin can reduce tissue edema and inflammation. Moreover coumarin and its 7-hydroxy-derivative inhibit prostaglandin biosynthesis, which involves fatty acid hydroperoxy intermediates. Natural products like esculetin, fraxetin, daphnetin and other related coumarin derivatives are recognised as inhibitors not only of the lipoxygenase and cycloxygenase enzymic systems, but also of the neutrophil-dependent superoxide anion generation. Due to the unquestionable importance of coumarin derivatives considerable efforts have been made by several investigators, to prepare new compounds bearing single substituents, or more complicated systems, including heterocyclic rings mainly at 3-, 4- and/or 7-positions. In this review we shall deal with naturally occurring or synthetically derived coumarin derivatives, which possess anti-inflammatory as well as antioxidant activities.     

Synthesis of benzylated amine-substituted xanthone derivatives and their antioxidant and anti-inflammatory activities

Oxidative stress and its constant companion, inflammation, play a critical part in the pathogenesis of many acute and chronic illnesses. The discovery of new multi-targeted drug candidates with antioxidant and anti-inflammatory properties is deemed necessary. Thus, a series of novel xanthone derivatives with halogenated benzyl ( 4b – 4d , 4f – 4h ) and methoxylated benzyl groups ( 4e ) attached to the butoxy amine substituent were synthesized in this study. The synthesized xanthone derivatives exhibited stronger antioxidant activity against H₂O₂ scavenging than the standard drug, α-tocopherol, but weaker towards DPPH scavenging and ferrous ion chelation. Besides that, 4b – 4d , 4f – 4h demonstrated good anti-inflammatory activities through NO production inhibition towards lipopolysaccharide (LPS)-induced RAW 264.7 cells and showed 2–4 times stronger effects than the standard drug, diclofenac sodium. Moreover, compound 4b with two brominated benzyl groups attached to the butoxy amine substituent suppressed the production of pro-inflammatory cytokines, TNF-α and IL-1β, significantly. Structure–activity relationship elucidated that the halogenated benzylamine substituent plays an important role in contributing the antioxidant and anti-inflammatory activities of xanthones. In summary, xanthone 4b was identified as a potential lead compound to be further developed into antioxidant and anti-inflammatory drugs. Thus, further studies on the related mechanisms of action of 4b are recommended.     

Evaluation of the anti-inflammatory and antioxidant activities of the plastoquinone derivatives isolated from Roldana barba-johannis

A phytochemical study of Roldana barba-johannis afforded two triterpenic esters, an eremophilanolide and three compounds structurally related to the antioxidants vitamin E and plastoquinone. Evaluation of the anti-inflammatory and antioxidant activities of sargahydroquinoic acid, sargachromenol, their mixture, and their methyl esters showed that most of them are antioxidant and anti-inflammatory agents.     

布洛芬衍生物的合成及抗炎活性

以布洛芬为原料,通过酯化反应得到4种布洛芬衍生物,其结构经IR、1H-NMR、MS和元素分析确证.以布洛芬为阳性对照,采用小鼠耳肿胀法测试其抗炎作用,结果显示所有目标化合物均具有抗炎活性,其中化合物3和4的抗炎活性分别是布洛芬的2倍和3倍.     

Synthesis and screening of anti-cancer,antioxidant, and anti-inflammatory activities of novel galloyl pyrazoline derivatives

A novel series of galloyl-2-pyrazoline derivatives were synthesized and screened for their cytotoxic effect against hepatocellular carcinoma (Hep-G2) and colon carcinoma (HCT-116) cells using the MTT assay, proliferative effect on the immune cells RAW macrophage 264.7 using the MTT assay, anti-inflammatory activity through measurement of the accumulation of nitrites using Griess reagent, and for their antioxidant activity through scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Most of the tested compounds had a concomitant weak cytotoxic effect against both Hep-G2 and HCT-116 cells, except 5-(2-furyl)-4,5-dihydro-1-(3,4,5-trihydroxybenzoyl)-3-(3,4-dimethoxyphenyl)-1H-pyrazole (IC₅₀ 8.4 μg/mL and 18.6 μg/mL) and 5-(4-cyanophenyl)-4,5-dihydro-1-(3,4,5-trihydroxybenzoyl)-3-(3,4-dimethoxy-phenyl)-1H-pyrazole (IC₅₀ 15.2 μg/mL, 31.5 μg/mL), which exhibited a cytotoxic effect against Hep-G2 and HCT-116 cells, respectively, while only 5-(2,6-dichlorophenyl)-4,5-dihydro-1-(3,4,5-trihydroxybenzoyl)-3-(3,4-dimethoxyphenyl)-1H-pyrazole was a significant dose-dependent inducer of macrophage proliferation. On the other hand, all of the tested compounds were significant inhibitors of LPS-stimulated NO generation and potential scavengers of the DPPH radical, except 1-(3,4,5-trihydroxybenzoyl)-4,5-dihydro-5-(4-methoxyphenyl)-3-(3,4-dimethoxyphenyl)-1H-pyrazole.     

吲哚美辛衍生物的合成及其抗炎活性

目的:合成吲哚美辛衍生物,以寻找新的对胃肠道毒不良反应更小的非甾体抗炎药.方法:吲哚美辛与卤代烃、硝基苄醇、硝基苄基氯等化合物进行缩合以及硝酸酯化反应,制备相应结构的衍生物.结果与结论:合成的6个化合物中,化合物3a,3c和5b的抗炎活性明显高于吲哚美辛.     

青藤碱衍生物的合成及其抗炎镇痛活性青藤碱衍生物的合成及其抗炎镇痛活性

目的为定向设计合成高效低毒的新一代青藤碱类药物提供线索。方法以青藤碱为先导物,对C环进行结构改造。结果共合成7个衍生物,进行了抗炎镇痛活性的筛选,结果表明,化合物2和5具有较好的抗炎镇痛作用。结论C环结构修饰值得进一步研究。     

In vitro antioxidant and anti-inflammatory activities of Angelica decursiva

Mounting evidences continue to support the involvement of oxidative/nitrosative stress and inflammation in the pathogenesis of many diseases. Plant constituents having antioxidant activities together with anti-inflammatory activities may provide better opportunities to develop anti-inflammatory agents. In view of this, we evaluated the antioxidant and antiinflammatory activities of methanolic extract of whole plants of Angelica decursiva, and its solvent soluble fractions via in vitro activities against lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells, as well as in vitro scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid, NO, and peroxynitrite. Among the tested fractions, the ethyl acetate fraction was found as the most active antioxidant fraction together with significant anti-inflammatory effect. From the active ethyl acetate fraction, four coumarin derivatives consisting of nodakenin, nodakenetin, umbelliferone, and umbelliferone-6-carboxylic acid, along with a phenolic compound, vanillic acid, were isolated. Among them, umbelliferone 6-carboxylic acid and vanillic acid were isolated for the first time from this plant. In all antioxidant assays, vanillic acid showed the highest antioxidant potential followed by umbelliferone 6-carboxylic acid among the isolated compounds. In the anti-inflammatory assay, umbelliferone 6-carboxylic acid exhibited the highest inhibitory activity against lipopolysaccharide-induced NO production in RAW 264.7 cells with an IC₅₀ value of 72.98 μg/mL. Therefore, the present study reveals the potential antioxidant and antiinflammatory activities of whole plants of A. decursiva and its constituents, mainly umbelliferone 6-carboxylic acid, which could be used in the development of therapeutic and preventive agents for oxidative stress-related inflammatory diseases.     

1-Phenyl-1H-indazole derivatives with analgesic and anti-inflammatory activities.

The synthesis of 4-hydroxy-1-phenyl-1H-indazole-5-acetic acid 5 4-methoxy-1-phenyl-1H-indazole-5-yl-acetic acid 7 and 5-benzyl-1-phenyl-1H-indazol-4-ol 8, starting from 1,5,6,7-tetrahydro-1-phenyl-4H-indazol-4-one, is described. These compounds showed in mice an analgesic activity superior to that of acetylsalicylic acid and comparable to that of dipyrone; moreover, compound 5 exhibited an appreciable anti-inflammatory activity in rats. Grossbehavioral effects and acute toxicity in mice are also reported.     

Synthesis,anti-inflammatory and antioxidant activity of ring-A-monosubstituted chalcone derivatives

A library of ring-A-monosubstituted chalcone derivatives (4a–4i, 5a and 5b) was designed and synthesised. The structures as well as the identities of these compounds were established on the basis of spectral (¹H NMR, ¹³C NMR, FT-IR and Mass) and elemental (C, H, N) analyses. All the derivatives were evaluated for their anti-inflammatory and antioxidant activities in vitro using the inhibition of protein denaturation and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays, respectively. The results indicated a promising anti-inflammatory activity for most of the synthesised compounds with many derivatives showing activities similar to or greater than that of the standard. The sulphonamide-substituted chalcones 4h, 4i, 5a and 5b were found to be the most active derivatives across the concentration range tested. However, all the derivatives exhibited rather mild antioxidant activity compared to the ascorbic acid standard. Interestingly, it was observed that the unsubstituted parent chalcone was one of the optimal compounds with only the trifluoromethyl analogue 4a showing better activity as an antioxidant. The two regioisomeric aminochalcones and 4′-cyanochalcone 4b also seemed to possess decent antioxidant potential.     

Synthesis of new imidazolyl acetic acid derivatives with anti-inflammatory and analgesic activities

We synthesized 2-(4-(4-fluorobenzylidene)-2-(4-fluorophenyl) 5-oxo-4,5-dihydroimidazol-1-yl) acetic acid 3. Chlorination afforded the chloro derivative 4, which reacted with different amines and hydrazine to afford compounds 5–8. Pyrazole, pyrazolone, and thiazolidinone derivatives were also synthesized from Imidazol-1-ylacetic acid hydrazide 8 to give compounds 9–12. Compounds were then evaluated for their anti-inflammatory activity against carrageenan-induced rat paw edema and their analgesic activity using the writhing test in albino mice. Compounds 5, 9, 10, 12 exhibited maximum anti-inflammatory activity, and all the compounds inhibited writhing, with 10 and 12 being two times more effective than the reference standard.     

Potential anti-inflammatory,antioxidant and antimicrobial activities of Sambucus australis

Context: Sambucus australis Cham. &; Schltdl. (Adoxaceae) is used in Brazilian folk medicine to treat inflammatory disorders.

Objective: To evaluate the in vitro anti-inflammatory, antioxidant and antimicrobial properties of S. australis.

Materials and methods: The anti-in?ammatory activity of ethanol extracts of the leaf and bark of S. australis (1–100?μg/mL) were studied in lipopolysaccharide/interferon γ stimulated murine macrophages RAW 264.7 cells (24?h incubation) by investigating the release of nitric oxide (NO) and tumour necrosis factor-alpha (TNF-α) and in the TNF-α-induced nuclear factor kappa (NF-κB) assay. Minimum inhibitory concentration (MIC) was determined by the microdilution test (24?h incubation). Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and the NO scavenging assays. Chemical composition was assessed by LC-MS/MS.

Results: Antioxidant activities in the DPPH (IC₅₀ 43.5 and 66.2?μg/mL), FRAP (IC₅₀ 312.6 and 568.3?μg/mL) and NO radical scavenging assays (IC₅₀ 285.0 and 972.6?μg/mL) were observed in the leaf and bark ethanol extracts, respectively. Solely the leaf extract showed significant inhibition of NO and TNF-α production in RAW264.7 cells at concentrations of 2 and 100?μg/mL, respectively, and suppression of TNF-α inhibition of NF-κB by 12.8 and 20.4% at concentrations of 50 and 100?μg/mL, respectively. The extract also exhibited antibacterial activity against Salmonella typhimurium (MIC 250?μg/mL) and Klebsiella pneumoniae (MIC 250?μg/mL). LC-MS/MS revealed the presence of chlorogenic acid and rutin as major compounds.

Discussion and conclusion: The results indicate that the ethanol leaf extract of S. australis exhibit prominent anti-in?ammatory effects.     

Synthesis and anti-inflammatory activities of new cyanopyrane derivatives fused with steroidal nuclei

Thirteen new heterocyclic derivatives containing a cyanopyrane ring fused to a steroidal moiety were conveniently synthesized and screened for their anti-inflammatory potencies comparable to that of the glucocorticoid prednisolone. Four compounds 5a, 5b, 6b, and 8 exhibited superior anti-inflammatory indices (in rats, protection against carrageenan induced edema and inhibition of plasma PGE). All the candidates were less toxic than the reference drug concerning LD(50) values. Synthetic steroidal structures fused to a substituted cyanopyrane ring seem to be a promising approach in search for novel leads for potent anti-inflammatory agents.     

Synthesis and analgesic and anti-inflammatory activities of 1,2-benzothiazine derivatives

Three 1,2-benzothiazine derivatives were synthesized, and their analgesic/anti-inflammatory efficacy and their effects on gastric irritation were evaluated. Among the three compounds, 39 exhibited the most potent analgesic action, but the effect was weaker than that of piroxicam. Nonetheless, the compound showed 4 times more potent analgesic action with less gastric damage than did ibuprofen. These compounds did not show anti-inflammatory effect at an oral dose of 5 mg/kg.     

Synthesis and anti-inflammatory and analgesic activities of phenoxyalkanoic acid derivatives

The synthesis of phenoxyalkanoic acid derivatives and their anti-inflammatory and analgesic activities are described. Analysis of structure-activity relationships shows that in trichlorophenoxy derivatives anti-edematous potency is associated with the presence of 1-thiopropyl moiety and 2 or 4-aminopyridyl moiety at R′ position contributes to the analgesic activity.     

Synthesis of new pyrimidine derivatives with evaluation of their anti-inflammatory and analgesic activities

5-Formyl-6-aminopyrimidine-2,4-(1H, 3H)-dione (2) has been previously prepared fromcompound 1. Cyclocondensation reaction of compound 2 with cyanoacetamide gave substituted pyridopyrimidine 3. Also, compound 2 was condensed with p-amino acetophenone and hydrazine derivatives to give 5-([(4-acetylphenyl)imino]methyl)-6-aminopyrimidine (4) and 5-substituted carboaldehyde-6-amino pyrimidine derivatives (5a-d), respectively. Moreover, cyclocondensation reaction of compound 2 with thiosemcarbazide and semicarbazide hydrochloride gave 5-(5-thioxo or oxo-triazol-3-yl)-6-amino pyrimidine (6) and (7), respectively. Cyclocondensation reaction of compound 2 with thiourea and ethyl acetoacetate led to the formation of substituted ethyl bipyrimidine-5-carboxylate 8. Also, compound 2 was reacted with acetoacetic acid hydrazide and 2-cyanoacetohydrazide to give 5-(acetylpyrazol-6-aminopyrimidine 9 and 3-(6-aminopyrimidine-5-yl) pyrazole-4-carboxamide 10, respectively. Furthermore, compound 1 was diazotized to afford the diazonium salt 11. Its coupling with ethyl acetoacetate, ethyl cyanoacetate, acetylacetone, malononitrile, cyanoacetamide, diethylmalonate, in sodium acetate buffered solution afforded substituted hydrazonopyrimidines: ethylhydrazono-3-oxobutanoate 12, ethylhydrazono-3-oxopropanoate 13, pentane-2,3,4-trione hydrazone 14, cyanohydrazonoacetamide 15, diazenyl malonamide 16 and diethylhydrazonomalonate 17, respectively. Moreover, substituted pyrazolediazenylpyrimidine derivatives 18a,b, 19a,b, 20, 21a-c, 22 were synthesized by the cyclization of substituted hydrazonopyrimidines 12, 17, 15, 14 and 13, respectively. The analgesic and anti-inflammatory activities of some of the synthesized compounds were evaluated. Compounds C18a, C20, C21b and C22 showed the most significant analgesic effects among synthesized moieties. All tested compounds, nonetheless, C18b showed significant anti-inflammatory effect in carrageenan induced paw edema model.     

In vitro anti-influenza virus and anti-inflammatory activities of theaflavin derivatives

The theaflavins fraction (TF80%, with a purity of 80%) and three theaflavin (TF) derivatives from black tea have been found to exhibit potent inhibitory effects against influenza virus in vitro. They were evaluated with a neuraminidase (NA) activity assay, a hemagglutination (HA) inhibition assay, a real-time quantitative PCR (qPCR) assay for gene expression of hemagglutinin (HA) and a cytopathic effect (CPE) reduction assay. The experimental results showed that they all exerted significant inhibitory effects on the NA of three different subtypes of influenza virus strains [A/PR/8/34(H1N1), A/Sydney/5/97(H3N2) and B/Jiangsu/10/2003] with 50% inhibitory concentration (IC(50)) values ranging from 9.27 to 36.55 μg/mL, and they also displayed an inhibitory effect on HA; these inhibitory effects might constitute two major mechanisms of their antiviral activity. Time-of-addition studies demonstrated that TF derivatives might have a direct effect on viral particle infectivity, which was consistent with the inhibitory effect on HA. Subsequently, the inhibitory effect of TF derivatives on the replication of the viral HA gene as assayed by qPCR and on the nuclear localization of the influenza virus vRNP further demonstrated that they may primarily act during the early stage of infection. Interestingly, besides the activity against functional viral proteins, TF derivatives also decreased the expression level of the inflammatory cytokine IL-6 during viral infection, expression of which may result in serious tissue injury and apoptosis. Our results indicated that TF derivatives are potential compounds with anti-influenza viral replication and anti-inflammatory properties. These findings will provide important information for new drug design and development for the treatment of influenza virus infection.     

Enhancement of antioxidant and anti-inflammatory activities of bioflavonoid rutin by complexation with transition metals

The antioxidant and anti-inflammatory activities of two transition metal complexes of bioflavonoid rutin, Fe(rut)Cl(3) and Cu(rut)Cl(2), were studied. It was found that Cu(rut)Cl(2) was a highly efficient in vitro and ex vivo free radical scavenger that sharply decreased (by 2-30 times compared to the parent rutin): oxygen radical production by xanthine oxidase, rat liver microsomes, and rat peritoneal macrophages; the formation of thiobarbituric acid-reactive products in microsomal lipid peroxidation; and the generation of oxygen radicals by broncho-alveolar cells from bleomycin-treated rats. The copper-rutin complex was also a superior inhibitor of inflammatory and fibrotic processes (characterized by such parameters as macrophage/neutrophil ratio, wet lung weight, total protein content, and hydroxyproline concentration) in the bleomycin-treated rats. The antioxidant activity of Fe(rut)Cl(3) was much lower and in some cases approached that of rutin. Fe(rut)Cl(3) also stimulated to some degree spontaneous oxygen radical production by macrophages. We suggested that the superior antioxidant and anti-inflammatory activity of the copper-rutin complex is a consequence of its acquiring the additional superoxide-dismuting copper center. The inhibitory activity of Fe(rut)Cl(3) was lower, probably due to the partial reduction into Fe(rut)Cl(2) in the presence of biological reductants; however, similarly to the copper-rutin complex, this complex efficiently suppressed lung edema.