核桃蛋白酶解物的制备及抗氧化活性

采用碱性蛋白酶对核桃蛋白进行酶解, 检测了所得酶解物的抗氧化能力, 包括对1,1-二苯基-2-三硝基苯肼(DPPH)和羟基自由基(·OH)的清除能力; 利用Sephadex G-25 凝胶层析柱和反相柱对核桃蛋白酶解物进行分离纯化; 采用液相色谱-质谱(LC-ESI-Q-TOF)联用方法测得抗氧化能力最强的多肽的序列为Ala-Gly-Gly-Ala, 其还原力和还原型谷胱甘肽相当.     

PS-TBD triggered general protocol for the synthesis of 4H-chromene,pyrano[4,3-b]pyran and pyrano[3,2-c]chromene derivatives of 1H-pyrazole and their biological activities

A general protocol has been developed for the facile construction of titled derivatives via three component reaction between 3-substituted phenyl-1H-pyrazole-4-carbaldehyde, malononitrile and various Michael donors in presence of 5 mol% polystyrene supported 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene(PS-TBD). PS-TBD was reused for at least five runs with nearly constant catalytic activity. All compounds were screened for antimicrobial and antioxidant activities.     

Synthesis,Antimicrobial, and Antioxidant Activities of Some Fused Heterocyclic [1,2,4]Triazolo[3,4‐b][1,3,4]thiadiazole Derivatives

In the present work, we synthesized a series of [1,2,4]triazolo[3,4‐b][1,3,4]thiadiazole derivatives ( 6a , 6b , 6c , 6d , 6e , 6f and 7a , 7b , 7c , 7d , 7e , 7f ) by using simple starting materials, namely, β‐amino acids and different aromatic acid hydrazides. The newly synthesized compounds were characterized by mass, IR, ¹H, and¹³C‐NMR spectral data analysis. The newly synthesized compounds were tested for their antimicrobial activities and antioxidant properties. Compound 6c was a potent microbial agent particularly against Staphylococcus aureus (MIC 3.12 µg/mL) and Candida albicans (MIC 6.25 µg/mL) when compared with the reference drugs ciprofloxacin and fluconazole, respectively. The antioxidant activity of the synthesized compounds was also evaluated by 1,1‐diphenyl‐2‐picryl hydrazyl, nitric oxide, and hydrogen peroxide radical scavenging methods. Compounds 6c , 6f , 7c , and 7f showed good radical scavenging activity due to the presence of electron‐donating group on phenyl ring.     

Sesquiterpenoids from the Root Bark of Acanthopanax leucorrhizus and Their Biological Activities

Three furoeremophilane‐type sesquiterpenoids, including one new, 1α‐acetoxy‐6β‐(benzoyloxy)‐10β‐hydroxy‐9‐oxofuroeremophilane ( 1 ), and two known, 1β,6β‐diacetoxy‐9‐oxofuroeremophilane ( 2 ) and (6α)‐furoeremophilan‐14,6‐olide ( 3 ), were isolated from the root bark of Acanthopanax leucorrhizus from China. Their structures were elucidated on the basis of comprehensive spectroscopic analyses, including IR, HR‐ESI‐MS, 1D‐ and 2D‐NMR experiments. A preliminary bioassay revealed that compound 1 exhibits weak cytotoxicities against the human tumor cell lines MCF‐7 and SMMC‐7721 with the IC₅₀ values of 75.12±1.69 and 168.36±2.01 μg/ml, respectively. Compound 1 and 2 showed moderate activities against Escherichia coli with the MIC values of 32 and 64 μg/ml, respectively.     

Synthesis of Stable Silver Nanoparticles with Antimicrobial Activities in Room-temperature Ionic Liquids

Stable silver nanoparticles was successfully synthesized by chemical reduction of silver nitrate in an ionic liquid,1-n-butyl-3-methylimidazolium tetrafluoroborate([BMIM]·BF4) at room temperature.Results of UV-Vis diffuse reflectance spectroscopy show as-prepared Ag nanoparticles exhibit a typical emission peak at 400―430 nm.By varying the reaction temperature and the precursor concentration,the size and the shape of the silver nanoparticles could be easily controlled under mild conditions.Analyses of trans...     

Phytofabrication of silver nanoparticles from Limonia acidissima leaf extract and their antimicrobial,antioxidant and its anticancer prophecy

Green synthesis of nanoparticles by eco-friendly methods is a recent technique which draws the attention of researchers because of the reward over many conventional chemical methods. The present work focuses on aqueous Limonia acidissima leaf extract in synthesizing silver nanoparticles and its applications in a simple way. The silver nanoparticles formed were characterized by Infrared, Ultra violet-visible, X-ray diffraction, transmission electron microscopic, and atomic force microscopic techniques. The powder X-ray diffraction studies and transmission electron microscopic images reveal that the silver nanoparticles synthesized were approximately 10–40 nm and have a spherical structure. The nanoparticles were assayed for their antibacterial, antifungal and antioxidant activity. The antimicrobial studies for the silver nanoparticles show a maximum zone of inhibition of 8.8 mm for Bacillus subtilis bacteria and 8.5 mm for Candida albicans fungi at 3 and 1 μg/mL respectively. In-silico ADMET studies reveal that the toxicity, bioactivity, pharmacokinetics and drug-likeness properties of Limonia acidissima leaf extract is good. The molecular docking studies show that the microbial activity is high for Bacillus subtilis and Candida albicans showing the coincidence of the in silico and in vitro studies as expected. The free radical scavenging activity of nanoparticles is 80 for 100 μg/mL. The 50% of inhibition of silver nanoparticles against human breast cancer cell lines is 18 μg/mL. It is evident that silver nanoparticles would be helpful in treating cancer cell lines and have great perspectives in the biomedical sector.     

Concise Synthesis and Antimicrobial Activities of New Substituted 5‐Isoxazolpenicillins

The synthesis of a series of new 5‐isoxazolpenicillins is described, which were obtained by coupling substituted isoxazoles with 6‐APA. Concise large‐scale synthesis of 3,5‐disubstituted isoxazoles by 1,3‐dipolar cycloaddition using copper(I) as catalyst was also investigated. Representative compounds were assayed for antimicrobial activities, showing satisfactory antimicrobial activities against Gram‐negative bacteria.     

Isolation and bioactivities of organic acids and phenols from walnut shell pyroligneous acid

Based on differences in acidity, organic acids and phenols were enriched by pH gradient extraction method from walnut shell pyroligneous acid. Contents of organic acids and phenols were measured by acid-base titration method and Folin colorimetric assay, respectively to assess the effectiveness of the extraction. In addition, the antimicrobial activity of the organic acids and antioxidant activity of phenols extracted were investigated. Chemical components of the extracts that were from the optimal concentrations of NaHCO₃ and NaOH were measured by GC-MS. The results showed that 5% NaHCO₃ could enrich the highest amount of organic acids, whereas 4% NaOH could enrich the highest amount of phenols. The enriched organic acids exhibited high antimicrobial activity, and the enriched phenols exhibited antioxidant activity under low concentrations, and demonstrated dosage dependency.     

Green synthesis of iron (Fe) nanoparticles using Plumeria obtusa extract as a reducing and stabilizing agent: Antimicrobial,antioxidant and biocompatibility studies

In the current study, a green and facile route for the synthesis of iron nanoparticles (FeNPs) was adopted. The FeNPs were fabricated via a single step green route using aqueous leaves extract of Plumeria obtusa (P. obtusa) as a capping/reducing and stabilizing agents. The FeNPs were characterized by UV/Vis (Ultraviolet/Visible), FTIR (Fourier Transform Infra-Red spectroscopy), TEM (Transmission Electron Microscopy), SEM (Scanning Electron Microscopy) and XRD (X-Ray Diffraction) techniques. The FeNPs were of spheroidal shape with average size of 50 nm. The biosynthesized FeNPs were further evaluated for their biological activities like antimicrobial, antioxidant and biocompatibility. The FeNPs displayed auspicious antimicrobial activity against bacterial (E. coli, B. subtilis) and fungal strains (A. niger) and S. commune. The test performed against red blood cells (RBCs) lysis (1.22 ± 0.02%) and macrophage (31 ± 0.09%) showed biocompatible nature of FeNPs. In vitro cytotoxicity against AU565 (82.03 ± 0.08–23.65 ± 0.065%) and HeLa (88.61 ± 0.06–33.34 ± 0.06%) cell lines showed cell viability loss in dose dependent manner (FeNPs 25–100 μg/mL). The antioxidant activities values were determined through DPPH, TRPA, NO and H₂O₂ assays with values 70.23 ± 0.02%, 76.65 ± 0.02 μg AAE/mg, 74.43 ± 0.04% and 67.34 ± 0.03%, respectively. Based on the bioactivities, the green synthesized FeNPs have potential for therapeutic applications.     

BSA mediated Ag@Bi2S3 composites: synthesis,characterization, photodegradation of mixed dyes via metal-semiconductor interface,antimicrobial and antioxidant activities

Nowadays, the development of metal-metal sulfide interface semiconductors using green approach is best material for the photocatalytic and biological applications. Here, we provided for the first time, an environmentally friendly route to fabricate bovine serum albumin (BSA) assisted Ag@Bi₂S₃ composites through a metal-metal sulphide interface via a simple hydrothermal method for the evaluation of photochemical and biological applications. The synthesized composites were characterized by UV–vis DRS, PL, XRD, TEM, and N₂ adsorption-desorption isotherms. The UV–vis DRS and PL spectra show that the obtained nano-sized Ag@Bi₂S₃ composite displays enhanced visible-light absorption and a decreased fluorescence emission compared to that of Bi₂S₃ nanorods (NRs). The photocatalytic performances of the synthesized composites were evaluated by the degradation of the single (RhB and MB) and mixed dye (RhB+MB) under sunlight irradiation. The results indicated that the Ag@Bi₂S₃ composite exhibits superior photocatalytic activity (98.38%) than that of individual Ag NPs and Bi₂S₃ NRs due to the synergistic effect of Ag and Bi₂S₃ nanophases in the Ag@Bi₂S₃ composite, which results in an effective charge separation, fast electron transfer from Ag to Bi₂S₃, and a low recombination of photo-induced electron-hole pairs. The Ag@Bi₂S₃ composite also has good recycling stability up to 5 cycles and its mechanism also investigated. The evaluation of reactive species during the photocatalytic reaction was also carried out. Further, the effects of Bi₂S₃ and Ag NPs on the antimicrobial and antioxidant activity of the resultant Ag@Bi₂S₃ composite were also systematically investigated.     

Preparation,Antibacterial, and Antioxidant Activities of Silver/Chitosan Composites

Hybrid silver/chitosan composites were prepared and transmission electron microscopy (TEM) exhibited that silver nanoparticles were embedded in chitosan. The antibacterial activities of these composites were screened against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, and Bacillus subtilis, which were much higher than that of chitosan. The TEM images of the treated bacteria showed that silver nanoparticles adhered to the bacterial cell surface and entered the interior of the cell, assuming that silver nanoparticles released from silver/chitosan composites could efficiently destroy the cell integrity of bacteria. Moreover, the composites exhibited higher antioxidant activity than chitosan based on the assessment of 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging and reducing power.     

The Effects of Processing on Bioactive Compounds and Biological Activities of Sorghum Grains

Sorghum is ranked the fifth most commonly used cereal and is rich in many kinds of bioactive compounds. Food processing can affect the accumulation and decomposition of bioactive compounds in sorghum grains, and then change the biological activities of sorghum grains. The present review aims to analyze the effects of processing technologies on bioactive compounds and the biological activities of sorghum grains. Decortication reduces the total phenols, tannins, and antioxidant activity of sorghum grains. The effects of thermal processes on bioactive compounds and potential biological activities of sorghum grains are complicated due to thermal treatment method and thermal treatment conditions, such as extrusion cooking, which has different effects on the bioactive compounds and antioxidant capacity of sorghum due to extrusion conditions, such as temperature and moisture, and food matrices, such as whole grain and bran. Emerging thermal processes, such as microwave heating and high-pressure processing, could promote the release of bound phenolic substances and procyanidins, and are recommended. Biological processes can increase the nutritive and nutraceutical quality and reduce antinutritional compounds, except for soaking which reduces water-soluble compounds in sorghum.     

Determination of the polyphenolic content of a Capsicum annuum L. extract by liquid chromatography coupled to photodiode array and mass spectrometry detection and evaluation of its biological activity

The present study was aimed to investigate the polyphenolic profile of a pepper (Capsicum annuum L.) extract from Algeria and evaluate its biological activity. The total polyphenol content of the extract was determined as 1.373 mg of gallic acid equivalents (±0.0046), whereas the flavonoids were determined as 0.098 mg of quercetin (±0.0015). The determination of the complete polyphenolic profile of the extract was achieved by liquid chromatography with an RP‐amide column in combination with photodiode array and mass spectrometry detection through an electrospray ionization interface. A total of 18 compounds were identified, of which five were reported for the first time in the sample tested. Quercetin rhamnoside was the most abundant compound (82.6 μg/g of fresh pepper) followed by quercetin glucoside (19.86 μg/g). The antioxidant activity and antimicrobial effects were also determined. For the antimicrobial tests assessed against Gram‐positive and Gram‐negative bacteria, kaempferol showed the strongest inhibitory effect followed by quercetin and caffeic acids. In the study of the cytotoxicity of the extract, the cancer cells (U937) were more affected than the normal cells (peripheral blood mononucleated cells), with more than 62% inhibition at the highest concentration.     

基于光谱分析的姜黄素碱性自氧化及其产物的抗氧化活性

在室温及弱碱性条件下进行姜黄素自氧化反应,应用柱色谱分离、紫外吸收光谱(UV)、红外光谱(IR)、核磁共振波谱(NMR)和质谱(MS)等分析技术,分离并鉴定了主要自氧化产物的化学结构.针对反应进程,采用高效液相色谱-二极管阵列检测器(HPLC-DAD)分析技术,从底物消除和产物生成2个方面进行了定性及定量研究.以抗坏血酸作阳性对照,采用1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、羟自由基(·OH)和超氧阴离子自由基(O_2~(-·))体系,定量比较了产物和姜黄素的体外抗氧化活性.结果表明,姜黄素在室温及弱碱性条件下的降解消除以自氧化反应为主,姜黄素消除过程和自氧化产物生成过程均符合一级动力学特征.自氧化产物具有双环乙酰丙酮的骨架结构,并显示有DPPH·,·OH和O_2~(-·)等自由基清除活性,但作用强度均显著低于姜黄素,因此在姜黄素应用过程中应严格控制pH条件,避免发生自氧化反应.     

Clerodendrumic Acid,a New Triterpenoid from Clerodendrum glabrum (Verbenaceae), and Antimicrobial Activities of Fractions and Constituents

One new triterpenoid, (3β,11α,19β)‐3‐(butanoyloxy)‐11‐hydroxytaraxast‐20(30)‐ene‐23,28‐dioic acid (clerodendrumic acid; 1 ) was isolated from the hexane extract of the leaves of Clerodendrum glabrum var. glabrum along with heptadecanoic acid ( 2 ). The structure of the new compound was elucidated by interpretation of its NMR (1D and 2D), MS, and IR data. Combined fractions C and D from the column chromatography of the hexane extract exhibited significant antifungal activities (average MIC of 0.10 mg/ml) against Candida albicans and Cryptococcus neoformans. C. albicans was relatively resistant to clerodendrumic acid ( 1 ; MIC 125 μg/ml) and was resistant to heptadecanoic acid ( 2 ; MIC 188 μg/ml). Both compounds had low antibacterial activities against two Gram‐positive and two Gram‐negative bacteria with average MIC values of 157 and 172 μg/ml, respectively. Compounds 1 and 2 were relatively nontoxic against monkey kidney Vero cells in vitro with IC₅₀ values of 202.6 and 108.4 μg/ml, respectively.     

Antimicrobial,Mosquito Larvicidal and Antioxidant Properties of the Leaf and Rhizome of Hedychium coronarium

The essential oil, methanolic and aqueous extracts of the leaves and rhizomes of Hedychium coronarium Koen. (Zingiberaceae) were assayed for their antimicrobial, mosquito larvicidal and antioxidant properties. The chemical composition of the essential oil of two organs was analyzed by GC/MS analysis. β‐Pinene (33.9%), α‐pinene (14.7%), 1,8‐cineole (13.3%), r‐elemene (11.0%) and carotol (9.1%) were the main components in the leaf oil, including 82.0% terpenoid compounds. The major constituents of the rhizome oil were 1,8‐cineole (37.3%), β‐pinene (23.0%), α‐terpineol (10.4%) and α‐pinene (9.9%), comprising 80.6% of the oil. The leaf and rhizome essential oil displayed significant antimicrobial activity, as determined by the disc‐diffusion method, inhibiting the growth of all five fungal and four bacterial strains tested. The antimicrobial nature of the essential oil is related to high terpenoid contents. The leaf oil exhibited the mosquito larvicidal activity with 2 h and 24 h LC₅₀ values of 111 and 90 ppm, respectively, while the rhizome oil showed the larvicidal activity with 2 h and 24 h LC₅₀ values of 86 and 47 ppm, respectively. β‐Pinene, α‐pinene and 1,8‐cineol in H. coronarium serve as the principal larvicidal components of both oils. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. The present study demonstrated that the polar extracts of H. coronarium possessed anti‐oxidant. Appreciable total phenolic content (18.5‐26.3 mg/g) was also detected by Folin‐Ciocalteu test.     

Effects of PAHs on Biotransformation Enzymatic Activities in Fish

Biotransformation and detoxification responses to the exposure to five polycyclic aromatic hydrocarbons were investigated in crucian(Carassius auratus). Juvenile crucian were treated with a single intraperitoneal injection of each compound at dosages of 0.1, 1.0, 2.0, 5.0 and 8.0(or 10.0) mg/kg and sacrificed 15 d later to determine 7-ethoxyresorufin-O-deethylase(EROD) and glutathione S-transferases(GST) activities in gill S9 fractions. EROD activity is significantly increased by benzo(b)fluoranthene and in...     

1,2,5-硒二唑嘧啶衍生物ASPO的合成及抗氧化与抗肿瘤活性

合成了5-氨基-[1,2,5]硒二唑[3,4-d]嘧啶-7-酮(ASPO), 研究了其抗氧化与抗肿瘤活性, 并初步阐述了其作用机制. 结果表明, ASPO具有良好的抗氧化活性, 可抑制溶液中1,1-二苯基-2-苦基肼(DPPH)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基的形成, 并呈剂量效应. 此外, ASPO能有效抑制5种肿瘤细胞的生长, 其中, A-375黑色素瘤细胞对ASPO具有良好的敏感性, 其IC₅₀值为14.1 μg/mL. 对作用机制的研究发现, ASPO处理可诱导肿瘤细胞中 Sub-G1 凋亡峰的累积、 染色质固缩及凋亡小体的形成, 说明诱导细胞凋亡是 ASPO发挥抗肿瘤活性的主要机制. 进一步利用光谱滴定和黏度实验研究了ASPO与CT-DNA的相互作用, 发现ASPO以沟面结合方式与CT-DNA结合, 表明ASPO可能通过与DNA相互作用而触发肿瘤细胞凋亡通路.