饿蚂蝗中黄酮类化合物的抗氧化活性的研究

提取了饿蚂蝗中的黄酮化合物,并研究了其含量及与体外抗氧化活性关系。用体积分数为75%的乙醇提取饿蚂蝗全草黄酮化合物,并采用HPD-100大孔树脂对粗提液进行精制,利用NaNO2-Al（ NO3）3-NaOH显色法和可见分光光度法测定精制黄酮的含量。采用DPPH和ABTS自由基测定法,对饿蚂蝗黄酮化合物的抗氧化活性进行评价。结果表明：在自由基清除实验中,精制饿蚂蝗黄酮类化合物自由基清除能力高于未精制的乙醇提取物。饿蚂蝗黄酮类化合物的体外抗氧化活性与黄酮含量呈正相关性。     

悬铃木球果总黄酮提取及其抗氧化活性研究

以悬铃木成熟的球果为原料,通过单因素和正交试验对超声波辅助提取悬铃木总黄酮的工艺进行优化;并通过考察总黄酮对DPPH自由基和ABTS自由基的清除率来评价其抗氧化活性。结果表明,悬铃木总黄酮的最佳提取条件如下:乙醇体积分数为60%,料液比为1∶25(g/mL),超声时间30 min,超声温度60℃,在此优化条件下,总黄酮的含量为21.82 mg/g。总黄酮质量浓度为20μg/mL时,具有较强的清除自由基能力,清除DPPH自由基和ABTS自由基为85.38%和98.84%。     

陕产长春七挥发油提取工艺优化及抗氧化活性研究

以挥发油提取率为评价指标,采用单因素实验和响应面法实验优化陕产长春七挥发油的超声提取工艺,并考察了长春七挥发油对DPPH自由基和ABTS自由基的清除能力,评价其抗氧化活性。确定长春七挥发油的最佳提取工艺为:以乙醚为提取溶剂、料液比1∶53 (g∶mL)、超声时间20 min、超声温度26℃,在此工艺条件下,挥发油提取率为13.639 2%,与理论值相差0.002 4%,说明此方法可行。长春七挥发油对DPPH自由基和ABTS自由基均有较高的清除率,且随着浓度增大清除能力增强,长春七挥发油清除DPPH自由基线性范围在1.4～1.8 mg·mL~(-1)为最佳,长春七挥发油清除ABTS自由基线性范围在2.5～3.5 mg·mL~(-1)为最佳。为进一步有效开发利用陕西"太白七药"提供了一定的理论基础。     

响应面法优化提取黄檗果实总酚和总黄酮及其抗氧化活性

在单因素实验基础上,根据Box-Behnken实验设计对提取条件进行分析和优化,以考察各因素对黄檗果实总酚(TP)和总黄酮(TF)超声辅助提取率的影响,并进一步研究TP和TF与体外抗氧化活性〔DPPH·清除能力、总自由基清除能力(TRAP)、铁离子还原能力(FRAP)〕的相关性。结果表明,黄檗果实TP和TF最佳超声辅助提取工艺条件为:乙醇体积分数43%,提取温度70℃,pH值11,超声功率500 W,液固比30∶1(m L/g),超声时间40 min,TP(以每克干样品中酚酸类化合物相当于没食子酸GA的质量表示)和TF(以每克干样品中黄酮类化合物相当于芦丁RT的质量表示)得率分别为(7.09±0.38)mgGA/g和(20.41±0.47)mgRT/g;相关性分析结果表明,TP和TF含量与三种体外抗氧化活性检测结果均为极显著相关(P<0.01),说明TP和TF可能是黄檗果实提取物抗氧化活性的物质基础。     

石上柏中双黄酮对DPPH自由基的清除作用研究

研究石上柏中双黄酮类化合物的抗氧化活性。采用乙醇回流提取,聚酰胺柱色谱和葡聚糖凝胶柱色谱纯化得到双黄酮类混合物结晶,利用液质联用法鉴定组成。采用DPPH自由基清除法测试其抗氧化活性,以抗坏血酸作为阳性对照。获得的石上柏双黄酮类混合物结晶由穗花杉双黄酮,罗波斯塔双黄酮,7-去甲基银杏双黄酮,罗波斯塔-4'-甲醚,罗汉松双黄酮A组成,在质量浓度52.3μg/mL时,总双黄酮对DPPH自由基的清除率为8.0%,而抗坏血酸为95.5%。石上柏中双黄酮类对DPPH自由基有一定的清除作用,相对于抗坏血酸较弱。     

树莓根黄酮类化合物的抗氧化活性及其结构分析

目的分析树莓根黄酮类化合物的抗氧化活性及其结构。方法采用响应面试验优化超声/微波协同提取树莓根黄酮类化合物的条件;优化后获得的产物经去离子水及20%、40%、60%、80%乙醇进行梯度洗脱纯化,分别测定不同洗脱液对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)及2,2′-联氨-双-3-乙基苯并噻唑啉-6-磺酸(2,2′-azinobis-3-ethylbenzothia zoline-6-sulphonic acid,ABTS)自由基清除能力,并对具有较高抗氧化活性的组分进行结构分析。结果黄酮类化合物最适提取工艺参数为:微波功率431 W,液料比20. 3∶1,提取温度72. 2℃,提取时间30. 46 min,该条件下获得树莓根提取物得率为(10. 05±0. 2)%。40%、60%及80%乙醇洗脱液中黄酮类化合物纯度可达80%;DPPH及ABTS自由基清除能力IC50分别为等浓度抗坏血酸(Vc)的0. 34和0. 59倍。树莓根黄酮类化合物中主要包括原花青素B1、原花青素C1、儿茶素、(4β,8)-非瑟酮醇-儿茶素、原花青素B2等5种组分。结论成功分离并鉴定了具有较高抗氧化功能的树莓根黄酮类化合物结构,为树莓根的资源利用提供了理论依据。     

酶法制备猪肺抗氧化肽

为了分离制备猪肺抗氧化肽,该文研究了中心组合设计和响应面分析优化猪肺抗氧化肽的提取工艺,以DPPH自由基清除率为响应值,分析了料液比、水解时间和酶浓度对制备抗氧化肽的影响,再通过葡聚糖凝胶Sephadex G-50、G-25和G-10对抗氧化肽进行分离纯化,得到了具有抗氧化活性的肽段,测定其清除DPPH自由基、超氧阴离子、ABTS自由基、羟基自由基以及金属螯合的能力。猪肺抗氧化肽的最佳提取工艺参数为：新鲜猪肺质量与水质量的比例为（料液比）1:3,水解6h,酶浓度为6500U/g,此时DPPH自由基清除率为66.89%;抗氧化活性最强的组分A5清除DPPH自由基、超氧阴离子、ABTS自由基和羟基自由基的IC50分别为0.073g/L、0.989 g/L、0.192 g/L和1.261 g/L,金属螯合能力的IC50为6.505 g/L;其相对分子质量为175.00Da。     

红柳黄酮提取工艺优化及其抗氧化、抑菌活性初探

以红柳黄酮得率为评价指标,通过单因素实验和响应面法对红柳黄酮的提取工艺进行了优化,通过测定红柳不同部位黄酮提取物对DPPH自由基的清除率评价了其抗氧化活性,并考察了其对金黄色葡萄球菌、大肠杆菌、白色念珠菌的抑菌活性。结果表明,红柳黄酮的最佳提取工艺为：提取温度79.7℃、乙醇体积分数71.0%、提取时间2.19 h,在此条件下,红柳黄酮得率为5.24 mg·g^-1;红柳不同部位黄酮提取物对DPPH自由基均有较强的清除能力;红柳不同部位黄酮提取物对金黄色葡萄球菌、大肠杆菌和白色念珠菌均有一定的抑菌活性。     

糙枝金丝桃抗氧化活性的研究

通过测定糙枝金丝桃提取物对DPPH自由基(DPPH.),羟基自由基(.OH),超氧自由基(O2-.)的清除能力研究了糙枝金丝桃的抗氧化活性。结果表明:糙枝金丝桃对DPPH自由基(DPPH.),羟基自由基(.OH),超氧自由基(O2-.)有着良好的清除能力,即糙枝金丝桃提取物具有良好的抗氧化活性。     

遗传算法优选山豆根黄酮的超声-微波协同提取工艺及其抗氧化抑菌活性研究

目的 采用遗传算法优选山豆根黄酮的超声-微波协同提取工艺,并研究其抗氧化抑菌活性。方法 以黄酮得率为指标,通过单因素试验和正交试验设计对料液比、乙醇体积分数、微波功率和提取时间4个影响因素进行考察,并采用遗传算法对工艺条件进行优化。以山豆根黄酮对1,1-二苯基-2-苦肼基自由基（?DPPH）、超氧阴离子自由基（?O2-）和羟基自由基（?OH）的清除能力评价其体外抗氧化活性,以过氧化值（POV值）评定山豆根黄酮对猪油、花生油和玉米油的抗油脂活性,采用滤纸片扩散法研究黄酮对7种常见菌的抑菌活性。结果 最优提取工艺条件为：液料比24.9:1(mL/g)、乙醇体积分数为87%、微波功率699 W,提取时间3 min,该工艺条件下黄酮得率达10.38mg/g,是模型预测值的99.69%;山豆根黄酮对DPPH?、O2-?和?OH有良好的清除作用,当黄酮浓度为30 礸/mL时,山豆根黄酮对?DPPH、?O2-和?OH的清除率分别为96.38%、91.35%和82.23%;抗油脂试验表明山豆根黄酮在试验时间范围内可明显减缓猪油、花生油和玉米油的氧化速度,抗油脂氧化作用与同质量分数BHT相当;抑菌试验表明山豆根黄酮对7种常见菌的抑制作用大小依次为金黄色葡萄球菌＞沙门氏菌＞志贺氏菌＞枯草芽孢杆菌＞大肠杆菌＞酵母,在试验范围内对黑曲霉无明显抑制作用。结论 采用遗传算法优选提取工艺条件可靠,更符合生产实际,山豆根黄酮具有良好的抗氧化和抑菌活性,可作为食品的天然抗氧化剂和防腐剂。     

Antimicrobial, Antiproliferative and Proapoptotic Activities of Extract, Fractions and Isolated Compounds from the Stem of Erythroxylum caatingae Plowman

In the study, we have examined the antitumor and antimicrobial activities of the methanol extract, the fractions, a fraction of total alkaloids and two alkaloids isolated from the stem of Erythroxylum caatingae Plowman. All test fractions, except the hexane fractions, showed antimicrobial activity on gram-positive bacteria and fungi. The acetate: methanol (95:5), acetate, chloroform and hexane fractions show the highest cytotoxicity activity against the NCI-H292, HEp-2 and K562 cell lines using MTT. The absence of hemolysis in the erythrocytes of mice was observed in these fractions and 6β-Benzoyloxy-3α-(3,4,5- trimethoxybenzoyloxy) tropane (catuabine B). Staining with Annexin V-FITC and JC-1 was used to verify the mechanism of action of the compounds of E. caatingae that showed cytotoxicity less than 30 μg/mL in leukemic cells. After 48 h of incubation, we observed that the acetate: methanol (95:5), acetate, and chloroform fractions, as well as the catuabine B, increased in the number of cells in early apoptosis, from 53.0 to 74.8%. An analysis of the potential of the mitochondrial membrane by incorporation of JC-1 showed that most cells during incubation of the acetate: methanol (95:5) and acetate fractions (63.85 and 59.2%) were stained, suggesting the involvement of an intrinsic pathway of apoptosis.     

Evaluation of Antioxidant,Antidiabetic and Anticholinesterase Activities of Smallanthus sonchifolius Landraces and Correlation with Their Phytochemical Profiles

The present study aimed to investigate the phytochemical profile of leaf methanol extracts of fourteen Smallanthus sonchifolius (yacon) landraces and their antioxidant, anticholinesterase and antidiabetic activities that could lead to the finding of more effective agents for the treatment and management of Alzheimer’s disease and diabetes. For this purpose, antioxidant activity was assessed using different tests: ferric reducing ability power (FRAP), 2,2-diphenyl-1-picryl hydrazyl (DPPH), nitric oxide (˙NO) and superoxide (O₂˙⁻) scavenging and lipid peroxidation inhibition assays. Anticholinesterase activity was investigated by quantifying the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, whereas antidiabetic activity was investigated by α-amylase and α-glucosidase inhibition tests. To understand the contribution of metabolites, phytochemical screening was also performed by high performance liquid chromatography-diode array detector (HPLC-DAD) system. Among all, methanol extract of PER09, PER04 and ECU44 landraces exhibited the highest relative antioxidant capacity index (RACI). ECU44 was found to be rich in 4,5-di-O-caffeoylquinic acid (CQA) and 3,5-di-O-CQA and displayed a good α-amylase and α-glucosidase inhibition, showing the lowest IC₅₀ values. Flavonoids, instead, seem to be involved in the AChE and BChE inhibition. The results of this study revealed that the bioactive compound content differences could be determinant for the medicinal properties of this plant especially for antioxidant and antidiabetic activities.     

Updated Information on Antimicrobial Activity of Hydrazide–Hydrazones

Hydrazide–hydrazones possess a wide spectrum of bioactivity, including antibacterial, antitubercular, antifungal, anticancer, anti-inflammatory, anticonvulsant, antidepressant, antiviral, and antiprotozoal properties. This review is focused on the latest scientific reports regarding antibacterial, antimycobacterial, and antifungal activities of hydrazide–hydrazones published between 2017 and 2021. The molecules and their chemical structures presented in this article are the most active derivatives, with discussed activities having a hydrazide–hydrazone moiety as the main scaffold or as a side chain. Presented information constitute a concise summary, which may be used as a practical guide for further design of new molecules with antimicrobial activity.     

Structure and Antitumor and Immunomodulatory Activities of a Water-Soluble Polysaccharide from Dimocarpus longan Pulp

A new water-soluble polysaccharide (longan polysaccharide 1 (LP1)) was extracted and successfully purified from Dimocarpus longan pulp via diethylaminoethyl (DEAE)-cellulose anion-exchange and Sephacryl S-300 HR gel chromatography. The chemical structure was determined using Infrared (IR), gas chromatography (GC) and nuclear magnetic resonance (NMR) analysis. The results indicated that the molecular weight of the sample was 1.1 × 10⁵ Da. Monosaccharide composition analysis revealed that LP1 was composed of Glc, GalA, Ara and Gal in a molar ratio of 5.39:1.04:0.74:0.21. Structural analysis indicated that LP1 consisted of a backbone of →4)-α-d-Glcp-(1→4)-α-d-GalpA-(1→4)-α-d-Glcp-(1→4)-β-d-Glcp-(1→ units with poly saccharide side chains composed of →2)-β-d-Fruf-(1→2)-l-sorbose-(1→ attached to the O-6 position of the α-d-Glcp residues. In vitro experiments indicated that LP1 had significantly high antitumor activity against SKOV3 and HO8910 tumor cells, with inhibition percentages of 40% and 50%, respectively. In addition, LP1 significantly stimulated the production of the cytokine interferon-γ (IFN-γ), increased the activity of murine macrophages and enhanced B- and T-lymphocyte proliferation. The results of this study demonstrate that LP1 has potential applications as a natural antitumor agent with immunomodulatory activity.     

Enhanced antibacterial and anti-biofilm activities of silver nanoparticles against Gram-negative and Gram-positive bacteria

Silver nanoparticles (AgNPs) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. The present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. Here, we show that a simple, reliable, cost effective and green method for the synthesis of AgNPs by treating silver ions with leaf extract of Allophylus cobbe. The A. cobbe-mediated synthesis of AgNPs (AgNPs) was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the antibacterial and anti-biofilm activity of antibiotics or AgNPs, or combinations of AgNPs with an antibiotic was evaluated using a series of assays: such as in vitro killing assay, disc diffusion assay, biofilm inhibition, and reactive oxygen species generation in Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumonia. The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics. The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively. These data suggest that combining antibiotics and biogenic AgNPs can be used therapeutically for the treatment of infectious diseases caused by bacteria. This study presented evidence of antibacterial and anti-biofilm effects of A. cobbe-mediated synthesis of AgNPs and their enhanced capacity against various human pathogenic bacteria. These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.     

Pereskia aculeata Muller (Cactaceae) Leaves: Chemical Composition and Biological Activities

The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC₅₀ 7.09 mg/mL) and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE)/g). The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY) expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC₅₀ value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression.     

Antiproliferative,Antibacterial and Antifungal Activity of the Lichen Xanthoria parietina and Its Secondary Metabolite Parietin

Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances.     

Anti-Inflammatory and Analgesic Activities of a Novel Biflavonoid from Shells of Camellia oleifera

Shells are by-products of oil production from Camellia oleifera which have not been harnessed effectively. The purpose of this research is to isolate flavonoid from shells of Camellia oleifera and evaluate its anti-inflammatory and analgesic effects. The flavonoid was identified as bimolecular kaempferol structure by UV, MS, ¹H NMR and ¹³C NMR spectra, which is a new biflavonoid and first found in Camellia oleifera. It showed dose-dependent anti-inflammatory activity by carrageenin-induced paw oedema in rats and croton oil induced ear inflammation in mice, and analgesic activity by hot plate test and acetic acid induced writhing. The mechanism of anti-inflammation of biflavonoid is related to both bradykinin and prostaglandins synthesis inhibition. The biflavonoid showed both central and peripheral analgesic effects different from aspirin, inhibition of the synthesis or action of prostaglandins may contribute to analgesic effect of biflavonoid. The biflavonoid significantly decreased malonaldehyde (MDA) and increased superoxidase dismutase (SOD) and Glutathione peroxidase (GSH-Px) activity in serum (p < 0.01), revealed strong free radical scavenging activity in vivo. It indicates the biflavonoid can control inflammation and pain by eliminating free radical so as to inhibit the mediators and decrease the prostaglandins. The biflavonoid can be used as a prospective medicine for inflammation and pain.     

Phenolic Compounds from Halimodendron halodendron (Pall.) Voss and Their Antimicrobial and Antioxidant Activities

Halimodendron halodendron has been used as forage in northwestern China for a long time. Its young leaves and flowers are edible and favored by indigenous people. In this study, eleven phenolic compounds were bioassay-guided and isolated from the aerial parts of H. halodendron for the first time. They were identified by means of physicochemical and spectrometric analysis as quercetin (1), 3,5,7,8,4′-pentahydroxy-3′-methoxy flavone (2), 3-O-methylquercetin (3), 3,3′-di-O-methylquercetin (4), 3,3′-di-O-methylquercetin-7-O-β-d-glucopyranoside (5), isorhamentin-3-O-β-d-rutinoside (6), 8-O-methylretusin (7), 8-O-methylretusin-7-O-β-d-glucopyranoside (8), salicylic acid (9), p-hydroxybenzoic acid (ferulic acid) (10), and 4-hydroxy-3-methoxy cinnamic acid (11). They were sorted as flavonols (1–6), soflavones (7 and 8), and phenolic acids (9–11). Among the compounds, flanools 1–4 revealed a strong antibacterial activity with minimum inhibitory concentration (MIC) values of 50–150 μg/mL, and median inhibitory concentration (IC₅₀) values of 26.8–125.1 μg/mL. The two isoflavones (7 and 8) showed moderate inhibitory activity on the test bacteria. Three phenolic acids (9, 10 and 11) showed strong antibacterial activity with IC₅₀ values of 28.1–149.7 μg/mL. Antifungal activities of the compounds were similar to their antibacterial activities. All these phenolic compounds showed significant antimicrobial activity with a broad spectrum as well as antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching assays. In general, the flavonol aglycones with relatively low polarity exhibited stronger activities than the glycosides. The results suggest the potential of this plant as a source of functional food ingredients and provide support data for its utilization as forage as well.     

Antinociceptive and Anti-Inflammatory Activities of the Ethanol Extract of Annona muricata L. Leaves in Animal Models

Antinociceptive and anti-inflammatory activities of the ethanol extract from Annona muricata L. leaves were investigated in animal models. The extract delivered per oral route (p.o.) reduced the number of abdominal contortions by 14.42% (at a dose of 200 mg/kg) and 41.41% (400 mg/kg). Doses of 200 and 400 mg/kg (p.o) inhibited both phases of the time paw licking: first phase (23.67% and 45.02%) and the second phase (30.09% and 50.02%), respectively. The extract (p.o.) increased the reaction time on a hot plate at doses of 200 (30.77% and 37.04%) and 400 mg/kg (82.61% and 96.30%) after 60 and 90 minutes of treatment, respectively. The paw edema was reduced by the ethanol extract (p.o.) at doses of 200 (23.16% and 29.33%) and 400 mg/kg (29.50% and 37.33%) after 3 to 4 h of application of carrageenan, respectively. Doses of 200 and 400 mg/kg (p.o.), administered 4 h before the carrageenan injection, reduced the exudate volume (29.25 and 45.74%) and leukocyte migration (18.19 and 27.95%) significantly. These results suggest that A. muricata can be an active source of substances with antinociceptive and anti-inflammatory activities.