白术挥发油GC-MS指纹图谱与抗氧化活性的谱效关系研究

目的 研究白术挥发油指纹图谱与抗氧化活性的谱效关系,筛选主要抗氧化活性成分。方法 采用GC-MS测定不同产地的15批白术饮片挥发油指纹图谱,通过清除1,1-二苯基-2-苦腈基（DPPH）和Fe³⁺还原/抗氧化能力法测定白术挥发油的抗氧化能力,运用偏最小二乘回归法进行数据分析,研究白术挥发油指纹图谱和抗氧化活性的相关性,并筛选活性色谱峰。结果 28个匹配指纹峰中,对挥发油清除DPPH自由基活性贡献度最大的前5个峰依次为：峰11 > 峰25 > 峰2 > 峰4 > 峰24;对挥发油还原Fe³⁺能力贡献度最大的前5个峰依次为：峰11 > 峰8 > 峰14 > 峰19 > 峰26。其中峰11的峰面积与挥发油清除DPPH自由基能力和还原Fe³⁺能力均呈正相关。通过与对照品比对确定峰11为苍术酮,并具有显著的抗氧化活性。结论 苍术酮不仅是白术挥发油的主要成分,还是主要的抗氧化活性物质。     

2种藏紫草体外抗氧化及抗菌活性比较

目的 比较长花滇紫草和团花滇紫草75％乙醇提取物的体外抗氧化及抗菌活性.方法 采用ABTS法、FRAP法、邻苯三酚自氧化法测定体外抗氧化能力,并采用肉汤连续稀释法初步考察了 2种藏紫草体提取物体外对15种不同菌株的抗菌作用.结果 不同浓度藏紫草的75％乙醇提取物对ABTS自由基和超氧阴离子都有较强的清除能力,与BHT阳...     

Free radical scavenging and antioxidant activities of Glinus oppositifolius (carpet weed) using different in vitro assay systems

Glinus oppositifolius (L.) Aug. DC. (Aizoceae), commonly called slender carpet weed, is a prostrate or diffuse herb which acts as stomachic, uterine stimulant, aperient and lochia. It is used traditionally in the treatment of earache, itch and skin diseases. Glinus oppositifolius was extracted with ethanol (70%) and used for the evaluation of various in vitro antioxidant assays which includes H-donor activity, nitric oxide scavenging, superoxide anion scavenging, reducing ability, hydroxyl radical, hydrogen peroxide scavenging, total phenolic content, total flavonoid content, total antioxidant activity by thiocyanate and phosphomolybdenum method, metal chelating, β-carotene bleaching, total peroxy radical assays. The pro-oxidant activity was measured using bleomycin-dependent DNA damage. Ex vivo models such as lipid peroxidation were used to study the antioxidant property of the extract. The various antioxidant activities were compared with suitable standard antioxidants such as ascorbic acid, butylated hydroxyl toluene (BHT), α-tocopherol, curcumin, quercetin and Trolox. The generation of free radicals, viz., O₂^·?, OH^·, H₂O₂, NO^· and peroxyl radicals, were effectively scavenged by the ethanol extract of Glinus oppositifolius. The antioxidant activity depends on concentration and increases with increasing amounts of the extract. The total phenolic content, flavonoid content and total antioxidant activity in Glinus oppositifolius were determined as microgram (μg) pyrocatechol, quercetin and α-tocopherol equivalent/mg, respectively. The extract did not exhibit any pro-oxidant activity when compared with ascorbic acid. The results obtained in this study indicate that Glinus oppositifolius scavenges free radicals and reduces lipid peroxidation, ameliorating the damage imposed by oxidative stress in different disease conditions and serve as a potential source of natural antioxidant.     

Antioxidant activities and molecular docking of 2-thioxobenzo[g]quinazoline derivatives

BackgroundOxidative stress and related diseases resulting from the overproduction of free radicals can be counteracted by designing and developing novel antioxidative agents that can protect the human body against the damage caused by free radicals.MethodsThe present study evaluated the antioxidant activities of 15 derivatives of 2-thioxobenzo[g]quinazoline using three different assays: 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, reducing power capability, and ferric reduction antioxidant power.ResultsSome benzoquinazolines had good activity and had the capacity to deplete DPPH and free radicals compared to a positive control butylated hydroxyl toluene (BHT). A docking study identified the possible interactions between binding models and the antioxidant activities of the target compounds.ConclusionsThe active compounds can be used as templates for further development of more potent antioxidative agents.     

In vitro Antioxidant and Antibacterial Activities of Methanol Extract of Kyllinga nemoralis

The present study was designed to evaluate the antioxidant and antibacterial activity of methanol extract of Kyllinga nemoralis. Six different in vitro antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide anion radical, hydrogen peroxide radical, ferric reducing antioxidant power assay and reducing power were carried out to ensure the scavenging effect of the plant on free radicals. In addition, total antioxidant capacity assay, total phenolic contents, tannins, flavonoids and flavonol contents of the plant were also analysed by the standard protocols. Kyllinga nemoralis exhibited high antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl assay (IC₅₀= 90 μg/ml), superoxide radical scavenging assay (IC₅₀= 180 μg/ml) and hydrogen peroxide radical scavenging assay (IC₅₀= 200 μg/ml), compared with standards. These observations provide comprehensible supporting evidence for the antioxidant potential of the plant extract. Reducing power (IC₅₀= 213.16 μg/ml) and hydroxyl radical scavenging activity (IC₅₀= 223 μg/ml) of the plant extract was remarkable. The methanol extract of K. nemoralis exhibited significant antimicrobial activity against Gram-positive human pathogenic bacteria. Standard in vitro antioxidant assays assessed the electron donating ability of the plant extract in scavenging free radicals. The inhibitory effect of the plant extract against bacterial pathogens may be due to the presence of phytochemicals. Thus, the results suggest that Kyllinga nemoralis is a potential source of antioxidants and could serve as the base for drug development.     

Design and synthesis of some new theophylline derivatives with bronchodilator and antibacterial activities

Methylxanthines especially theophylline have been recognized as potent bronchodilators for the relief of acute asthma for over 65 years. Recently, it was found that bacterial infection plays a role in asthma pathogenesis. Accordingly, the present work involves the synthesis of 6-(4-(un)substituted phenyl)thiazolo[2,3-f]theophyllines 2a–g and different series of 8-(1,2,4-triazol-3-ylmethylthio)theophyllines 6–9. The chemical structures of the target compounds were proved by IR, ¹H NMR, ¹³C NMR, EI-MS and HRMS spectroscopic techniques along with elemental analyses. The bronchodilator activity of fifteen compounds was determined in vivo by acetylcholine induced bronchospasm in anaesthetized guinea pigs. Results revealed that all compounds showed moderate to good activity; in addition, five compounds exhibited a bronchodilator activity nearly similar to that of aminophylline as a standard. The antibacterial activity of all the target compounds was investigated in vitro against both Gram-positive and Gram-negative bacterial strains. Results revealed that some compounds showed more potent antibacterial activity than ampicillin as a standard. Acute toxicity study for four target compounds revealed that none of these derivatives showed significant toxicity up to 300 mg/kg. It was found that compound 8c combined both promising bronchodilator and antibacterial activities. This compound could be subjected for further investigations as a new possible candidate in the treatment of bronchial asthma.     

Protective mechanism of turmeric (Curcuma longa) on carbofuran-induced hematological and hepatic toxicities in a rat model

Context: Turmeric (Curcuma longa L. [Zingiberaceae]) is used in the treatment of a variety of conditions including pesticide-induced toxicity.

Objective: The study reports the antioxidant properties and the protective effects of turmeric against carbofuran (CF)-induced toxicity in rats.

Materials and methods: The antioxidant potential was determined by using free radicals scavenging activity and ferric reducing antioxidant power values. Male Wistar rats were randomly divided into four groups, designated as control, turmeric (100?mg/kg/day), CF (1?mg/kg/day) and turmeric (100?mg/kg/day)?+?CF (1?mg/kg/day) treatments. All of the doses were administered orally for 28 consecutive days. The biological activity of the turmeric and CF was determined by using several standard biochemical methods.

Results: Turmeric contains high concentrations of polyphenols (8.97?±?0.15?g GAEs), flavonoids (5.46?±?0.29?g CEs), ascorbic acid (0.06?±?0.00?mg AEs) and FRAP value (1972.66?±?104.78?μM Fe²⁺) per 100?g of sample. Oral administration of CF caused significant changes in some of the blood indices, such as, mean corpuscular volume, corpuscular hemoglobin, white blood cell, platelet distribution width and induced severe hepatic injuries associated with oxidative stress, as observed by the significantly higher lipid peroxidation (LPO) levels when compared to control, while the activities of cellular antioxidant enzymes (including superoxide dismutase and glutathione peroxidase) were significantly suppressed in the liver tissue.

Discussion and conclusion: Turmeric supplementation could protect against CF-induced hematological perturbations and hepatic injuries in rats, plausibly by the up-regulation of antioxidant enzymes and inhibition of LPO to confer the protective effect.     

Protective mechanism of quercetin and rutin on 2,2′-azobis(2-amidinopropane)dihydrochloride or Cu-induced oxidative stress in HepG2 cells

Protective effects of quercetin and rutin against oxidative stress were evaluated using in vitro and intracellular antioxidant assay. Quercetin showed higher peroxyl and hydroxyl radical-scavenging activity in a dose-dependent manner than did rutin in oxygen-radical absorbance capacity (ORAC). At 10 and 100 μM, quercetin had higher metal-chelating activity than rutin carrying rutinose at position C-3 and was also more efficient than rutin in reducing intracellular oxidative stress caused by peroxyl radicals and Cu²⁺. The protective activities of 10 and 100 μM quercetin against Cu²⁺-induced intracellular oxidation were 13.8% and 44.8%, respectively. Rutin showed no protective activity against Cu²⁺-induced oxidative stress. Quercetin showed significantly lower intracellular Cu²⁺-chelating activity than did 1,10-phenanthroline but offered greater protection from Cu²⁺-induced oxidative stress. Thus, quercetin may diffuse through the cell membrane more efficiently than rutin because quercetin does not carry rutinose, is hydrophilic, and reduces Cu²⁺-induced oxidative stress by scavenging radicals instead of chelating with metal ions.     

白芍总苷体外抗氧化活性研究

目的研究白芍总苷体外对不同化学体系和生物体系的抗氧化活性。方法通过Fenton反应生成·OH自由基,采用DPPH·自由基,观察不同质量浓度的白芍总苷溶液对化学体系自由基的清除作用。利用邻二氮菲-Fe2+-H2O2产生的·OH自由基造成红细胞膜破裂,以及肝、脑细胞脂质的过氧化,观察不同质量浓度的白芍总苷溶液对生物体系自由基的清除作用。结果白芍总苷对·OH有一定的清除作用,其IC50为0.62 g/L。白芍总苷对DPPH·自由基有较强的清除作用,IC50为6.6 mg/L;对·OH自由基引发的红细胞膜破裂有一定的抑制作用,其IC50为30.17 mg/L,对肝、脑匀浆脂质过氧化有一定的抑制作用,其IC50分别为6.9、16.3 mg/L。结论白芍总苷具有清除自由基作用,在不同体外实验体系中抗氧化量效关系存在差异。     

Microwave-assisted synthesis and biological evaluation of carbazole-based chalcones,aurones and flavones

A new class of chalcones, aurones and flavones derived from carbazole is designed as potential antimicrobial and antioxidant agents. Synthesis of (Z)-2-((9-ethyl-9H-carbazol-3-yl)methylene)benzofuran-3(2H)-ones and 2-(9-ethyl-9H-carbazol-3-yl)-4H-chromen-4-ones was carried out by the oxidation of (E)-3-(9-ethyl-9H-carbazol-3-yl)-1-(2-hydroxyphenyl)prop-2-en-1-ones under microwave irradiation and conventional heating. All the newly synthesized compounds were characterized on the basis of IR, ¹H NMR, ¹³C NMR, mass and analytical data. All the synthesized compounds were evaluated for their antibacterial, antifungal and antioxidant activities. Synthesized compounds were screened in vitro for antibacterial activity against two gram-positive bacterial strains like Staphylococcus aureus and Bacillus subtilis and two gram-negative bacterial strains like Escherichia coli and Klebsiella pneumonia and antifungal activity by inhibitory action against three fungal strains like Fusarium oxysporum, Aspergillus niger and Aspergillus flavus. The synthesized compounds were also evaluated for their DPPH radical scavenging activity. All the newly synthesized compounds have shown good antibacterial, antifungal and antioxidant activities.     

Antioxidant,anticholinesterase and antibacterial activities of Stachys guyoniana and Mentha aquatica

Context: Stachys guyoniana Noë ex. Batt. and Mentha aquatica L. are two Algerian Lamiaceae used in folk medicine.

Objective: To investigate their antioxidant, anticholinesterase and antibacterial activities.

Material and methods: n-Butanol (BESG), ethyl acetate (EESG) and chloroform (CESG) extracts of S. guyoniana and methanol (MEMA) and chloroform (CEMA) aerial part extracts of M. aquatica and methanol (MERMA) and acetone (AERMA) roots extracts of M. aquatica were evaluated for their antioxidant activity by the β-carotene-linoleic acid, DPPH^? and ABTS^?+?scavenging, CUPRAC and metal chelating assays. The anticholinesterase activity was tested against AChE and BChE. The antibacterial activity was assessed by MICs determination against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella heidelberg, Klebsiella pneumoniae, Enterobacter aerogenes and Morganella morganii strains.

Results: In the β-carotene test, the CESG (IC₅₀: 2.3?±?1.27?μg/mL) exhibited the highest activity. The BESG was the best scavenger of DPPH^? (IC₅₀: 2.91?±?0.14?μg/mL). In the ABTS test, AERMA was the most active (IC₅₀: 4.21?±?0.28?μg/mL). However, with the CUPRAC, the BESG exhibited the best activity (A_0.50: 0.15?±?0.05?μg/mL) and was active in metal chelating assay with 48% inhibition at 100?μg/mL. The BESG was the best AChE inhibitor (IC₅₀: 5.78?±?0.01?μg/mL) however, the AERMA showed the highest BChE inhibitory activity (IC₅₀: 19.23?±?1.42?μg/mL). The tested extracts exhibited a good antibacterial activity.

Conclusion: This study demonstrated good antioxidant, anticholinesterase and antibacterial potential of S. guyoniana and M. aquatica, which fits in well with their use in folk medicine.     

Antioxidant and antigenotoxic activities in Acacia salicina extracts and its protective role against DNA strand scission induced by hydroxyl radical

The antioxidant potency of Acacia salicina extracts was investigated. Total antioxidant capacity was determined using an ABTS⁺ assay. Superoxide radical scavenging was measured using riboflavin-light-nitro blue tetrazolium (NBT) assay. In addition, the content of phenols, total flavonoids and sterols were measured in the tested extracts. The petroleum ether exhibited a potent scavenging activity toward ABTS radical cations. Whereas, chloroform extract showed the highest activity against superoxides radicals and was also able to protect pKS plasmid DNA against hydroxyl radicals induced DNA damages. The antimutagenicity of these extracts was assayed using the Ames assay against Salmonella typhimurium TA98 and S. typhimurium TA 1535 tester strains at different concentrations. These extracts decreased significantly the mutagenecity induced by sodium azide (SA) and 4-nitro-o-phenylenediamine (NOP). The antioxidant and antimutagenecity activities exhibited by A. salicina depended on the chemical composition of the tested extracts.     

Compounds from Sedum caeruleum with antioxidant,anticholinesterase, and antibacterial activities

Context: This is the first study on the phytochemistry, antioxidant, anticholinesterase, and antibacterial activities of Sedum caeruleum L. (Crassulaceae).

Objective: The objective of this study is to isolate the secondary metabolites and determine the antioxidant, anticholinesterase, and antibacterial activities of S. caeruleum.

Materials and methods: Six compounds (1–6) were isolated from the extracts of S. caeruleum and elucidated using UV, 1D-, 2D-NMR, and MS techniques. Antioxidant activity was investigated using DPPH^?, CUPRAC, and ferrous-ions chelating assays. Anticholinesterase activity was determined against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the Ellman method. Antibacterial activity was performed according to disc diffusion and minimum inhibitory concentration (MIC) methods.

Results: Isolated compounds were elucidated as ursolic acid (1), daucosterol (2), β-sitosterol-3-O-β-d-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6). The butanol extract exhibited highest antioxidant activity in all tests (IC₅₀ value: 28.35?±?1.22?µg/mL in DPPH assay, IC₅₀ value: 40.83?±?2.24?µg/L in metal chelating activity, and IC₅₀ value: 23.52?±?0.44?µg/L in CUPRAC), and the highest BChE inhibitory activity (IC₅₀ value: 36.89?±?0.15?µg/L). Moreover, the chloroform extract mildly inhibited (MIC value: 80?µg/mL) the growth of all the tested bacterial strains.

Discussion and conclusion: Ursolic acid (1), daucosterol (2), β-sitosterol-3-O-β-d-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6) were isolated from Sedum caeruleum for the first time. In addition, a correlation was observed between antioxidant and anticholinesterase activities of bioactive ingredients of this plant.     

Comparison of free radical formation induced by baicalein and pentamethyl-hydroxychromane in human promyelocytic leukemia cells using electron spin resonance

Baicalein and pentamethyl-hydroxychromane (PMC) have been investigated for use as antioxidants. However, antioxidants may stimulate free radical formation under certain conditions. The aim of our study was to determine whether PMC and baicalein exhibit both pro-oxidant and antioxidant activities in human promyelocytic leukemia (HL-60) cells. In this study, electron spin resonance spectrometry was used to investigate the effects of baicalein and PMC on free radical formation. In HL-60 cells, baicalein and PMC produced hydroxyl and phenoxyl radicals, respectively, but each inhibited radical formation by the other. The PMC pro-oxidant activity required H₂O₂, whereas baicalein produced hydroxyl radicals during the cell resting state only. The antioxidant effect of baicalein on PMC-induced oxidative stress in HL-60 cells may involve myeloperoxidase inhibition, which produces the myeloperoxidase-protein radical. Our investigation of the antioxidant effects of baicalein on arachidonic acid (AA)-induced oxidative stress in HL-60 cells showed that the baicalein-phenoxyl radical was the primary product, and that either carbon-centered or acyl radicals were the secondary products. However, the antioxidant effects of PMC on AA-induced oxidative stress produced only nonradical products. In conclusion, we showed that baicalein displayed both pro-oxidant and antioxidant activities in HL-60 cells. PMC exhibited no pro-oxidant activity during the cells' resting state but produced the PMC-phenoxyl radical in the presence of H₂O₂.The reaction of baicalein with AA in HL-60 cells produced baicalein-derived phenoxyl radicals that may initiate various pro-oxidative reactions. However, PMC does not produce radicals when it acts as an antioxidant. Thus, PMC is more beneficial as an antioxidant than baicalein.     

Antimicrobial and antioxidant activities of crude extracts of two Nigerian chewing sticks

In vitro determinations of the antimicrobial and antioxidant activities of ethanol and aqueous extracts of Disthemonanthus benthamianus Baill. (Caesalpiniaceae) and Zanthoxylum zanthoxyloides Lam. (Rutaceae), which are used as chewing sticks in Nigeria, were investigated. The extracts were screened against eight strains of Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, one methicillin-resistant strain of Staphylococcus epidermidis, twelve strains of Pseudomonas aeruginosa, five strains of Candida albicans and four strains of Bacillus cereus. The in vitro antimicrobial assay was performed by using a Mast Multipoint Inoculator based on the principles of an agar dilution technique. The aqueous extracts had no inhibitory effects on any of the tested microorganisms. The ethanol D. benthamianus extract inhibited P. aeruginosa, E. faecalis, and B. cereus with MIC ≤ 2.64?mg mL^?1 and S. aureus and S. epidermidis with MIC ≤ 0.44?mg mL^?1. Z. zanthoxyloides ethanol extract was less effective but noteworthy was the MIC ≤ 2.52?mg mL^?1 against C. albicans and 0.28?mg mL^?1 against some S. aureus strains. D. benthamianus ethanol extract had the best antioxidant activity and Z. zanthoxyloides ethanol extract second best. IC₅₀ for DPPH free radical scavenging of these extracts were 87.76 and 128.28?μg mL^?1/mL, respectively; ascorbic acid equivalents were 2.4 and 9.5?mg mg^?1 and total antioxidant capacities using the FRAP assay were 4068.06?mM Fe⁺⁺ mg^?1 and 624.86?mM Fe⁺⁺ mg^?1, respectively. The ethanol extracts of D. benthamianus and Z. zanthoxyloides showed significant antimicrobial and antioxidant activities which could be beneficial in oral hygiene.     

Maltol,an antioxidant component of Korean red ginseng,shows little prooxidant activity

Some antioxidant phenolic compounds exhibit prooxidant activity mainly due to their abilities to reduce Fe¹⁺ to Fe²⁺. Reducing ability and prooxidant activity of maltol, an antioxidant component of Korean red ginseng, were compared with those of pyrogallol. Maltol at 2 mM did not appreciably reduce Fe¹⁺ to Fe²⁺ and also failed to reduce nitroblue tetrazolium. Stimulation of hydroxyl radical mediated-deoxyribose degradation by pyrogallol was maximal at 60 μM. Maltol stimulated the deoxyribose degradation to a much less extent, and a similar stimulatory effect was observed at a concentration of more than 100-fold higher than that of pyrogallol. The stimulatory effect of maltol reached a plateau over 1 mM, suggesting the removal of hydroxyl radicals by excess maltol. In bleomycin-Fe³⁺-DNA assay, maltol at 2 mM produced a 2.5-fold increase of the iron-bleomycin-dependent DNA degradation over the basal value, whereas pyrogallol at 10 μM accelerated DNA degradation by ca. 10-fold. Furthermore, maltol inhibited Fe²⁺-stimulated DNA degradation by bleomycin. These results strongly suggested that maltol is an antioxidant with little prooxidant activity.     

Unusual formation of N-hydroxy-3,3-dimethyl-2,6-diarylpiperidin-4-one and its thiosemicarbazide derivative — synthesis and antimicrobial activity

A series of novel N-hydroxy-3,3-dimethyl-2,6-diarylpiperidin-4-one thiosemicarbazones 28–32 is synthesized, characterized by melting point, elemental analysis, and MS, FT-IR, NMR (¹H & ¹³C) spectroscopic data and evaluated for their in vitro antibacterial and antifungal activities. Of all the compounds synthesized, compound 31 exerted a wide range of antibacterial activities against the entire tested gram-positive and gram-negative bacterial strains except Escherichia coli. Compound 31 exerted strong antifungal activities against Aspergillus flavus, Mucor, and Microsporum gypseum.     

Synthesis and evaluation of antioxidant activity of 2-styrylchromones

Antioxidants are emerging as potential prophylactic and therapeutic agents which scavenge free radicals otherwise reactive oxygen species and prevent the damage caused by them. Free radicals have been associated with pathogenesis of various disorders like cancer, diabetes, cardiovascular diseases, autoimmune diseases, neurodegenerative disorders and are implicated in aging. Chromones and their derivatives display important biological activities such as anti-tumor, anti-hepatotoxic, anti-inflammatory, anti-spasmolytic, oestrogenic and antibacterial activities, in particular the antioxidant behavior of these compounds continue to draw attention of researchers. In the present communication a series of halo substituted 2-styrylchromones 4a–4k were prepared and tested for the antioxidant activity by using DPPH (1, 1 diphenyl 2, picryl hydrazyl) method, and among the synthesized compounds 4e and 4h shows strong antioxidant activity while remaining compounds show antioxidant activity in the normal range.     

橙皮素微量元素配合物的合成及其生物活性研究

目的 合成橙皮素钙、铁、硒、锌、铬配合物5种中药新药,并研究其抗菌、抗肿瘤活性和清除自由基的能力。方法 在碱性条件下通过合成得到橙皮素钙、铁、硒、锌、铬配合物,采用倍比稀释法测定橙皮素及其配合物对大肠杆菌等8种菌的抑制活性,采用MTT法测定橙皮素及其配合物对Tca-8113等6种肿瘤细胞增殖的影响,采用超氧阴离子自由基清除法测定橙皮素及其配合物对超氧阴离子自由基的清除能力。结果 合成的5种配合物配位比均为2∶1（橙皮素∶微量元素）,产率均>70%,小鼠急性毒性试验显示5种配合物均无明显毒性,5种配合物最小抑菌浓度均低于橙皮素,抗菌活性至少提升至1~4倍;5种配合物对肿瘤细胞的IC₅₀均小于橙皮素,抗肿瘤活性至少提升至1.19~2.41倍;橙皮素及其配合物对超氧阴离子自由基均有一定的清除作用,且均呈浓度依赖性,配合物对超氧阴离子自由基的清除率均高于橙皮素。结论 5种橙皮素微量元素配合物的抗菌、抗肿瘤活性和自由基清除能力均强于橙皮素。     

Antibacterial and free radical scavenging potential of synthesized 7-hydroxy-2-aryl-6-aryldiazenyl-4H-chromen-4-ones

A series of 7-hydroxy-2-aryl-6-aryldiazenyl-4H-chromen-4-one derivatives (6a–m) was synthesized in quantitative yields and their structures were corroborated on the basis of FT-IR, ¹H, ¹³C NMR, ESI–MS, and elemental analysis data. The synthesized compounds were screened for in vitro antibacterial activities against a representative panel of Gram-positive and Gram-negative bacteria, as well as to evaluate their antioxidant potential using DPPH assay method. Bio-evaluation studies revealed that compounds 6c, 6d, 6e, 6j, and 6l exhibited moderate to good antibacterial activity against all the tested bacterial strains. Furthermore, from the antioxidant screening results, it has been observed that compounds 6c, 6e, and 6g manifested profound antioxidant potential (IC₅₀ <7.68 μM) in comparison to the standard antioxidant ascorbic acid.