Displaying publications 21 - 40 of 276 in total

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  1. Yang F, Jin C, Wang S, Wang Y, Wei L, Zheng L, et al.
    Chemosphere, 2023 May;323:138245.
    PMID: 36841450 DOI: 10.1016/j.chemosphere.2023.138245
    Due to increasing antibiotic pollution in the water environment, green and efficient adsorbents are urgently needed to solve this problem. Here we prepare magnetic bamboo-based activated carbon (MDBAC) through delignification and carbonization using ZnCl2 as activator, resulting in production of an activated carbon with large specific surface area (1388.83 m2 g-1). The influencing factors, such as solution pH, initial sulfadiazine (SD) concentration, temperature, and contact time, were assessed in batch adsorption experiments. The Langmuir isotherm model demonstrated that MDBAC adsorption capacity on SD was 645.08 mg g-1 at its maximum, being higher than majority of previously reported adsorbents. In SD adsorption, the kinetic adsorption process closely followed the pseudo-second kinetic model, and the thermodynamic adsorption process was discovered to be exothermic and spontaneous in nature. The MDBAC exhibited excellent physicochemical stability, facile magnetic recovery and acceptable recyclability properties. Moreover, the synergistic interactions between MDBAC and SD mainly involved electrostatic forces, hydrogen bonding, π-π stacking, and chelation. Within the benefits of low cost, ease of production and excellent adsorption performance, the MDBAC biosorbent shows promising utilization in removing antibiotic contaminants from wastewater.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  2. Abbasi M, Gholizadeh R, Kasaee SR, Vaez A, Chelliapan S, Fadhil Al-Qaim F, et al.
    Sci Rep, 2023 Apr 12;13(1):5987.
    PMID: 37046068 DOI: 10.1038/s41598-023-33095-1
    In recent years, mesoporous silica nanoparticles (MSNs) have been applied in various biomedicine fields like bioimaging, drug delivery, and antibacterial alternatives. MSNs could be manufactured through green synthetic methods as environmentally friendly and sustainable synthesis approaches, to improve physiochemical characteristics for biomedical applications. In the present research, we used Rutin (Ru) extract, a biocompatible flavonoid, as the reducing agent and nonsurfactant template for the green synthesis of Ag-decorated MSNs. Transmission electron microscopy (TEM), zeta-potential, x-ray powder diffraction (XRD), fourier transform infrared (FTIR) spectroscopy analysis, scanning electron microscopy (SEM), brunauer-emmett-teller (BET) analysis, and energy-dispersive system (EDS) spectroscopy were used to evaluate the Ag-decorated MSNs physical characteristics. The antimicrobial properties were evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and also different types of candida. The cytotoxicity test was performed by using the MTT assay. Based on the findings, the significant antimicrobial efficacy of Ru-Ag-decorated MSNs against both gram positive and gram negative bacteria and different types of fungi was detected as well as acceptable safety and low cytotoxicity even at lower concentrations. Our results have given a straightforward and cost-effective method for fabricating biodegradable Ag-decorated MSNs. The applications of these MSNs in the domains of biomedicine appear to be promising.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  3. Ayipo YO, Ahmad I, Alananzeh W, Lawal A, Patel H, Mordi MN
    J Biomol Struct Dyn, 2023 Nov;41(19):10096-10116.
    PMID: 36476097 DOI: 10.1080/07391102.2022.2153168
    Antibiotic resistance (AR) remains one of the leading global health challenges, mostly implicated in disease-related deaths. The Enterobacteriaceae-producing metallo-β-lactamases (MBLs) are critically involved in AR pathogenesis through Zn-dependent catalytic destruction of β-lactam antibiotics, yet with limited successful clinical inhibitors. The efficacy of relevant broad-spectrum β-lactams including imipenem and meropenem are seriously challenged by their susceptibility to the Zn-dependent carbapenemase hydrolysis, as such, searching for alternatives remains imperative. In this study, computational molecular modelling and virtual screening methods were extensively applied to identify new putative Zn-sensitive broad-spectrum inhibitors of MBLs, specifically imipenemase-1 (IMP-1) from the IBScreen database. Three ligands, STOCK3S-30154, STOCK3S-30418 and STOCK3S-30514 selectively displayed stronger binding interactions with the enzymes compared to reference inhibitors, imipenem and meropenem. For instance, the ligands showed molecular docking scores of -9.450, -8.005 and -10.159 kcal/mol, and MM-GBSA values of -40.404, -31.902 and -33.680 kcal/mol respectively against the IMP-1. Whereas, imipenem and meropenem showed docking scores of -9.038 and -10.875 kcal/mol, and MM-GBSA of -31.184 and -32.330 kcal/mol respectively against the enzyme. The ligands demonstrated good thermodynamic stability and compactness in complexes with IMP-1 throughout the 100 ns molecular dynamics (MD) trajectories. Interestingly, their binding affinities and stabilities were significantly affected in contacts with the remodelled Zn-deficient IMP-1, indicating sensitivity to the carbapenemase active Zn site, however, with non-β-lactam scaffolds, tenable to resist catalytic hydrolysis. They displayed ideal drug-like ADMET properties, thus, representing putative Zn-sensitive non-β-lactam inhibitors of IMP-1 amenable for further experimental studies.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  4. Alrabie A, Alrabie NA, AlSaeedy M, Al-Adhreai A, Al-Qadsy I, Al-Horaibi SA, et al.
    Nat Prod Res, 2023 Jul;37(13):2263-2268.
    PMID: 36441059 DOI: 10.1080/14786419.2022.2149519
    The Bombax ceiba L. tree is a member of the family Bombacaceae and the genus Bombax. Both Chinese and Indian traditional medicine have made extensive use of it in the treatment of sickness. Its chemical composition is still a mystery. B. ceiba roots methanol extract (BCRME) was analyzed by different chromatographic analytical techniques in order to identify its major chemical constituents. Twelve compounds and six compounds were identified from GC-MS and LC-MS analysis, respectively. This is the first report on the presence of lathodoratin, cedrene, 4H-1-benzopyran-4-one,8-[{dimethylamino} methyl]-7-methoxy-3-methyl-2-phenyl, asiatic acid, and (E)-2,4,4'-trihydroxylchalcone in B. ceiba roots. Methanol extract demonstrated noteworthy antibacterial activity against Staphylococcus aureus (MTCC96) (MIC: 100 µg/mL) compare to antibiotic ampicillin (MIC: 250 µg/mL) as well as the highest α-amylase inhibition (IC50=26.91 µg/mL) and α-glucosidase inhibition (IC50=21.21 µg/mL) effects, molecular docking study confirmed these findings, with some compounds having a very high docking score.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  5. Mohamad Hanafiah R, Abd Ghafar SA, Lim V, Musa SNA, Yakop F, Hairil Anuar AH
    Artif Cells Nanomed Biotechnol, 2023 Dec;51(1):549-559.
    PMID: 37847252 DOI: 10.1080/21691401.2023.2268167
    This study aims to characterize and determine the antibacterial activities of synthesized Strobilanthes crispus-mediated AgNPs (SC-AgNPs) against Streptococcus mutans, Escherichia coli and Pseudomonas aeruginosa. S. crispus water extract acts as a reducing and capping agent in the synthesis of AgNPs. The synthesized AgNPs were characterized by using UV-Vis spectrophotometer, dynamic light scattering (DLS), field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and Fourier transform infra-red (FTIR). FESEM images showed a rough surface with a spherical shape. The average size distribution of 75.25 nm with a polydispersity index (PDI) of 0.373. XRD analysis matched the face-centred cubic structure of silver. FTIR analysis revealed a shifted peak from 1404.99 to 1345.00 cm-1. MIC and MBC values of SC-AgNPs were 1.25 mg/mL and 2.5 mg/mL against E. coli, P. aeruginosa and S. mutans, respectively. Time-kill assay showed that SC-AgNPs significantly reduced bacterial growth as compared to non-treated bacteria. Morphologies of bacteria treated with SC-AgNPs were shrunk, lysed, irregular and smaller as compared to control. SC-AgNPs significantly disrupted the gene expression of eae A, gtf B and Pel A (p 
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  6. Tan YY, Wong LS, Nyam KL, Wittayanarakul K, Zawawi NA, Rajendran K, et al.
    Molecules, 2023 Sep 22;28(19).
    PMID: 37836592 DOI: 10.3390/molecules28196749
    Zinc oxide nanoparticles have high levels of biocompatibility, a low impact on environmental contamination, and suitable to be used as an ingredient for environmentally friendly skincare products. In this study, biogenically synthesized zinc oxide nanoparticles using Dendrobium anosum are used as a reducing and capping agent for topical anti-acne nanogels, and the antimicrobial effect of the nanogel is assessed on Cutibacterium acne and Staphylococcus aureus. Dendrobium anosmum leaf extract was examined for the presence of secondary metabolites and its total amount of phenolic and flavonoid content was determined. Both the biogenically and chemogenic-synthesized zinc oxide nanoparticles were compared using UV-Visible spectrophotometer, FE-SEM, XRD, and FTIR. To produce the topical nanogel, the biogenic and chemogenic zinc oxide nanoparticles were mixed with a carbomer and hydroxypropyl-methyl cellulose (HPMC) polymer. The mixtures were then tested for physical and chemical characteristics. To assess their anti-acne effectiveness, the mixtures were tested against C. acne and S. aureus. The biogenic zinc oxide nanoparticles have particle sizes of 20 nm and a high-phase purity. In comparison to chemogenic nanoparticles, the hydrogels with biogenically synthesized nanoparticles was more effective against Gram-positive bacteria. Through this study, the hybrid nanogels was proven to be effective against the microbes that cause acne and to be potentially used as a green product against skin infections.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  7. Wei YM, Tong WY, Tan JS, Lim V, Leong CR, Tan WN
    Curr Microbiol, 2024 Mar 10;81(4):108.
    PMID: 38461425 DOI: 10.1007/s00284-024-03627-7
    Methicillin-resistant Staphylococcus aureus (MRSA) infections have become one of the most threatening multidrug-resistant pathogens. Thus, an ongoing search for anti-MRSA compounds remains an urgent need to effectively treating MRSA infections. Phomopsidione, a novel antibiotic isolated from Diaporthe fraxini, has previously demonstrated potent anti-candidal activity. The present study aimed to investigate the effects of phomopsidione on the viability, virulence, and metabolites profile of MRSA. MRSA was sensitive to phomopsidione in a concentration-dependent manner. Phomopsidione exhibited minimum inhibitory concentration and minimum bactericidal concentration of 62.5 and 500.00 µg/mL against MRSA on broth microdilution assay. The compound showed significant reduction in virulence factors production including extracellular polymeric substances quantification, catalase, and lipase. An untargeted metabolomics analysis using liquid chromatography-high resolution mass spectrometry revealed a significant difference in the metabolites profile of MRSA with 13 putatively identified discriminant metabolites. The present study suggested the potential of phomopsidione as a promising anti-MRSA agent.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  8. Tran TV, Jalil AA, Nguyen DTC, Nguyen TTT, Nguyen LTT, Nguyen CV, et al.
    Chemosphere, 2024 May;355:141599.
    PMID: 38548079 DOI: 10.1016/j.chemosphere.2024.141599
    Several activities such as aquaculture, human and feedstock therapies can directly release antibiotics into water. Due to high stability, low hydrolysis and non-biodegradation, they can accumulate in the aqueous environment and transport to aquatic species. Here, we synthesized amine-functionalized porous carbons (ANC) by a direct-pyrolysis process of NH2-MIL-53(Al) as a sacrificial template at between 600 and 900 °C and utilized them to eliminate chloramphenicol antibiotic from water. The NH2-MIL-53(Al)-derived porous carbons obtained high surface areas (304.7-1600 m2 g-1) and chloramphenicol adsorption capacities (148.3-261.5 mg g-1). Several factors such as hydrogen bonding, Yoshida hydrogen bonding, and π-π interaction, hydrophobic interaction possibly controlled adsorption mechanisms. The ANC800 could be reused four cycles along with high stability in structure. As a result, NH2-MIL-53(Al)-derived porous carbons are recommended as recyclable and efficient adsorbents to the treatment of antibiotics in water.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  9. Kandel S, Zaidi STR, Wanandy ST, Ming LC, Castelino RL, Sud K, et al.
    Perit Dial Int, 2017 11 21;38(1):49-56.
    PMID: 29162678 DOI: 10.3747/pdi.2017.00115
    BACKGROUND: Intraperitoneal (IP) administration of ceftazidime is recommended for the treatment of peritoneal dialysis-associated peritonitis (PDAP) from Pseudomonas. Patients with PDAP may also need IP heparin to overcome problems with drainage of turbid peritoneal dialysis (PD) fluids and blockage of catheters with fibrin. Physico-chemical stability of ceftazidime and heparin, and biological stability of heparin in many types of PD solutions is unknown. Therefore, we investigated the stability of ceftazidime and heparin in 4 types of PD solutions.

    METHODS: A total of 12 PD bags (3 for each type of solution) containing ceftazidime and heparin were prepared and stored at 4°C for 120 hours, and then at 25°C for 6 hours, and finally at 37°C for 12 hours. An aliquot was withdrawn after predefined time points and analyzed for the concentration of ceftazidime and heparin using high-performance liquid-chromatography (HPLC). Samples were assessed for pH, color changes, particle content, and anticoagulant activity of heparin.

    RESULTS: Ceftazidime and heparin retained more than 91% of their initial concentration when stored at 4°C for 120 hours followed by storage at 25°C for 6 hours and then at 37°C for 12 hours. Heparin retained more than 95% of its initial activity throughout the study period. Particle formation was not detected at any time under the storage conditions. The pH and color remained essentially unchanged throughout the study.

    CONCLUSIONS: Ceftazidime-heparin admixture retains its stability over long periods of storage at different temperatures, allowing its potential use for PDAP treatment in outpatient and remote settings.

    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  10. Al-Mijalli SH, Mrabti NN, Ouassou H, Sheikh RA, Assaggaf H, Bakrim S, et al.
    Molecules, 2022 Oct 28;27(21).
    PMID: 36364152 DOI: 10.3390/molecules27217329
    The purposes of this investigatory study were to determine the chemical composition of the essential oils (EOs) of Origanum compactum from two Moroccan regions (Boulemane and Taounate), as well as the evaluation of their biological effects. Determining EOs' chemical composition was performed by a gas chromatography-mass spectrophotometer (GC-MS). The antioxidant activity of EOs was evaluated using free radical scavenging ability (DPPH method), fluorescence recovery after photobleaching (FRAP), and lipid peroxidation inhibition assays. The anti-inflammatory effect was assessed in vitro using the 5-lipoxygenase (5-LOX) inhibition test and in vivo using the carrageenan-induced paw edema model. Finally, the antibacterial effect was evaluated against several strains using the disk-diffusion assay and the micro-dilution method. The chemical constituent of O. compactum EO (OCEO) from the Boulemane zone is dominated by carvacrol (45.80%), thymol (18.86%), and α-pinene (13.43%). However, OCEO from the Taounate zone is rich in 3-carene (19.56%), thymol (12.98%), and o-cymene (11.16%). OCEO from Taounate showed higher antioxidant activity than EO from Boulemane. Nevertheless, EO from Boulemane considerably inhibited 5-LOX (IC50 = 0.68 ± 0.02 µg/mL) compared to EO from Taounate (IC50 = 1.33 ± 0.01 µg/mL). A similar result was obtained for tyrosinase inhibition with Boulemane EO and Taounate EO, which gave IC50s of 27.51 ± 0.03 μg/mL and 41.83 ± 0.01 μg/mL, respectively. The in vivo anti-inflammatory test showed promising effects; both EOs inhibit and reduce inflammation in mice. For antibacterial activity, both EOs were found to be significantly active against all strains tested in the disk-diffusion test, but O. compactum EO from the Boulemane region showed the highest activity. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for O. compactum EO from the Boulemane region ranged from 0.06 to 0.25% (v/v) and from 0.15 to 0.21% (v/v) for O. compactum from the Taounate region. The MBC/MIC index revealed that both EOs exhibited remarkable bactericidal effects.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  11. Lim AC, Tang SGH, Zin NM, Maisarah AM, Ariffin IA, Ker PJ, et al.
    Molecules, 2022 Jul 31;27(15).
    PMID: 35956846 DOI: 10.3390/molecules27154895
    The essential oil of Backhousia citriodora, commonly known as lemon myrtle oil, possesses various beneficial properties due to its richness in bioactive compounds. This study aimed to characterize the chemical profile of the essential oil isolated from leaves of Backhousia citriodora (BCEO) and its biological properties, including antioxidant, antibacterial, and antibiofilm activities. Using gas chromatography-mass spectrometry, 21 compounds were identified in BCEO, representing 98.50% of the total oil content. The isomers of citral, geranial (52.13%), and neral (37.65%) were detected as the main constituents. The evaluation of DPPH radical scavenging activity and ferric reducing antioxidant power showed that BCEO exhibited strong antioxidant activity at IC50 of 42.57 μg/mL and EC50 of 20.03 μg/mL, respectively. The antibacterial activity results showed that BCEO exhibited stronger antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) than against Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). For the agar disk diffusion method, S. epidermidis was the most sensitive to BCEO with an inhibition zone diameter of 50.17 mm, followed by S. aureus (31.13 mm), E. coli (20.33 mm), and K. pneumoniae (12.67 mm). The results from the microdilution method showed that BCEO exhibited the highest activity against S. epidermidis and S. aureus, with the minimal inhibitory concentration (MIC) value of 6.25 μL/mL. BCEO acts as a potent antibiofilm agent with dual actions, inhibiting (85.10% to 96.44%) and eradicating (70.92% to 90.73%) of the biofilms formed by the four tested bacteria strains, compared with streptomycin (biofilm inhibition, 67.65% to 94.29% and biofilm eradication, 49.97% to 89.73%). This study highlights that BCEO can potentially be a natural antioxidant agent, antibacterial agent, and antibiofilm agent that could be applied in the pharmaceutical and food industries. To the best of the authors' knowledge, this is the first report, on the antibiofilm activity of BCEO against four common nosocomial pathogens.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  12. Tan KK, Khoo TJ, Rajagopal M, Wiart C
    Nat Prod Res, 2015;29(24):2346-9.
    PMID: 25738993 DOI: 10.1080/14786419.2015.1013954
    Chloroform extract of bark of Artabotrys crassifolius Hook.f. & Thomson exhibited antibacterial activities against both American Type Culture Collection and clinical bacterial strains in vitro with zones of inhibition ranging from 7 to 14 mm. Further analysis of this extract yielded artabotrine, liridine, lysicamine and atherospermidine. Artabotrine displayed a broad array of antibacterial activity mostly against Gram-positive bacteria with minimum inhibitory concentration (MIC) values ranging from 1.25 μg/mL to 5 μg/mL. Of note, artabotrine, liridine and lysicamine are bactericidal against Gram-negative extended-spectrum beta-lactamase-producing Klebsiella with MIC values equal 2.5, 2.5 and 10 μg/mL, respectively, and minimum bactericidal concentrations values equal to 2.5, 5 and 20 μg/mL.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  13. Ramaiya SD, Bujang JS, Zakaria MH
    ScientificWorldJournal, 2014;2014:167309.
    PMID: 25028673 DOI: 10.1155/2014/167309
    This study focused on total phenolic content (TPC) and antioxidant and antibacterial activities of the leaves and stems of Passiflora quadrangularis, P. maliformis, and P. edulis extracted using three solvents: petroleum ether, acetone, and methanol. The maximum extraction yields of antioxidant components from the leaves and stems were isolated using methanol extracts of P. edulis (24.28%) and P. quadrangularis (9.76%), respectively. Among the leaf extracts, the methanol extract of P. maliformis had the significantly highest TPC and the strongest antioxidant activity, whereas among the stem extracts, the methanol extract of P. quadrangularis showed the highest phenolic amount and possessed the strongest antioxidant activity. The antibacterial properties of the Passiflora species were tested using the disc diffusion method against 10 human pathogenic bacteria. The largest inhibition zone was observed for the methanol extract of P. maliformis against B. subtilis. Generally, extracts from the Passiflora species exhibit distinct inhibition against Gram-positive but not Gram-negative bacteria. Based on the generated biplot, three clusters of bacteria were designated according to their performance towards the tested extracts. The present study revealed that methanol extracts of the Passiflora contain constituents with significant phenolic, antioxidant, and antibacterial properties for pharmaceutical and nutraceutical uses.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  14. Razmavar S, Abdulla MA, Ismail SB, Hassandarvish P
    Biomed Res Int, 2014;2014:521287.
    PMID: 25028658 DOI: 10.1155/2014/521287
    This study was based on screening antibacterial activity of the ethanol extract of Baeckea frutescens L. against MRSA clinical isolates, analyzes the potential antibacterial compound, and assesses the cytotoxicity effect of the extract in tissue culture. Leaves of Baeckea frutescens L. were shade dried, powdered, and extracted using solvent ethanol. Preliminary phytochemical screening of the crude extracts revealed the presence of alkaloids, flavonoids, steroids, terpenoids, phenols, and carbohydrates. The presence of these bioactive constituents is related to the antibacterial activity of the plant. Disc diffusion method revealed a high degree of activity against microorganisms. The results confirm that Baeckea frutescens L. can be used as a source of drugs to fight infections caused by susceptible bacteria.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  15. Chen GX, He WW, Wang Y, Zou YD, Liang JB, Liao XD, et al.
    Sci Total Environ, 2014 May 1;479-480:241-6.
    PMID: 24561929 DOI: 10.1016/j.scitotenv.2014.01.124
    The degradation behavior of veterinary antibiotics in soil is commonly studied using the following methods of adding antibiotics to the soil: (i) adding manure collected from animals fed with a diet containing antibiotics, (ii) adding antibiotic-free animal manure spiked with antibiotics and (iii) directly adding antibiotics. No research simultaneously comparing different antibiotic addition methods was found. Oxytetracycline (OTC) was used as a model antibiotic to compare the effect of the three commonly used antibiotic addition methods on OTC degradation behavior in soil. The three treatment methods have similar trends, though OTC degradation half-lives show the following significant differences (P<0.05): manure from swine fed OTC (treatment A)
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  16. Wei W, Jiang N, Mei YN, Chu YL, Ge HM, Song YC, et al.
    Phytochemistry, 2014 Apr;100:103-9.
    PMID: 24529576 DOI: 10.1016/j.phytochem.2014.01.003
    In searching for symbionts derived from bioactive natural products, six sulfureous diketopiperazines designated as lasiodiplines A-F (1-6) were characterized from the culture of Lasiodiplodia pseudotheobromae F2, previously residing in the apparently normal flower of Illigera rhodantha (Hernandiaceae). Identification of structures was accomplished by a combination of spectroscopic and computational approaches, in conjunction with the low-temperature (100K) single-crystal X-ray diffraction with Cu Kα radiation. Lasiodipline E (5) was demonstrated to be antibacterial against the clinical strains Streptococcus sp., Bacteroides vulgates, Peptostreptococcus sp. and Veillonella parvula, respectively, with an minimum inhibitory concentration (MIC) range of 0.12-0.25 μg/mL. In addition, compounds 4 and 6 exemplify two unusual architectures of natural cyclodipeptides, signifying the unique biochemical characteristics of the producing fungus.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  17. Kamada T, Vairappan CS
    Nat Prod Commun, 2013 Mar;8(3):287-8.
    PMID: 23678792
    A Bomean red algal population of Laurencia similis Nam et Saito was analyzed for its secondary metabolite composition. Seven compounds were identified: ent-1(10)-aristolen-9beta-ol (1), (+)-aristolone (2), axinysone B (3), 9-aristolen-1alpha-ol (4), 2,3,5,6-tetrabromoindole (5), 1-methyl-2,3,5,6-tetrabromoindole (6), and 1-methyl-2,3,5-tribromoindole (7). Compound 1 was identified as a new optical isomer of 1(10)-aristolen-9beta-ol. Compounds 1, 4 and 5 exhibited good antibacterial activity against antibiotic resistant clinical bacteria and cytotoxic effects against selected cancer cell lines.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  18. Iqbal MS, Bahari MB, Darwis Y, Iqbal MZ, Hayat A, Venkatesh G
    J AOAC Int, 2013 6 19;96(2):290-4.
    PMID: 23767352
    A simple and selective RP-HPLC-UV method with SPE was developed and validated for the quantification of cefotaxime in all-in-one total parenteral nutrition (AIO-TPN) admixtures. Chromatographic separation was achieved on a 5 pm particle size C18 DB column (250 x 4.6 mm id) using the mobile phase ammonium acetate (25 mM, pH 4.0)-50% acetonitrile in methanol (80 + 20, v/v). The flow rate was 0.9 mL/min and the detection wavelength was 254 nm. The analyte was extracted from AIO-TPN admixtures by means of an SPE method. The cefotaxime calibration curve was linear over a concentration range of 100-1400 microg/mL with a correlation coefficient of > or = 0.9994. The intraday accuracy and precision for cefotaxime were < or = -3.15 and < or = 3.08%, respectively, whereas the interday accuracy and precision were < or = -2.48 and < or = 2.25%, respectively. The method was successfully applied to stability studies of cefotaxime in the presence of micronutrients together with low and high concentrations of macronutrients in AIO-TPN admixtures. Cefotaxime was degraded by 13.00 and 26.05% at room temperature (25 +/- 2 degrees C) after 72 h in low and high macronutrient concentration formulations of AIO-TPN admixtures, respectively. The values of cefotaxime degradation rates for low and high macronutrient concentration formulations of AIO-TPN admixtures were -0.164 and -0.353, respectively. These results indicated that there was a higher rate of degradation in the AIO-TPN admixture formulations containing high concentrations of macronutrients.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  19. Azizi S, Ahmad MB, Hussein MZ, Ibrahim NA
    Molecules, 2013 May 28;18(6):6269-80.
    PMID: 23760028 DOI: 10.3390/molecules18066269
    Synthesis of ZnO-Ag heterostructure nanoparticles was carried out by a precipitation method with cellulose nanocrystals (CNCs) as a stabilizer for antimicrobial and thermal studies. ZnO-Ag nanoparticles were obtained from various weight percentages of added AgNO₃ relative to Zn precursors for evaluating the best composition with enhanced functional properties. The ZnO-Ag/CNCs samples were characterized systematically by TEM, XRD, UV, TGA and DTG. From the TEM studies we observed that ZnO-Ag heterostructure nanoparticles have spherical shapes with size diameters in a 9-35 nm range. The antibacterial activities of samples were assessed against the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The CNC-stabilized ZnO-Ag exhibited greater bactericidal activity compared to cellulose-free ZnO-Ag heterostructure nanoparticles of the same particle size. The incorporation of ZnO-Ag hetreostructure nanoparticles significantly increased the thermal stability of cellulose nanocrystals.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  20. Wibowo A, Ahmat N, Hamzah AS, Low AL, Mohamad SA, Khong HY, et al.
    Fitoterapia, 2012 Dec;83(8):1569-75.
    PMID: 22982329 DOI: 10.1016/j.fitote.2012.09.004
    A new oligostilbenoid tetramer, malaysianol B (1), was isolated from the acetone extract of the stem bark of Dryobalanops lanceolata along with seven oligostilbenoids tetramers; hopeaphenol (2), stenophyllol A (3), nepalensinol B (4), vaticanol B (5) and C (6), upunaphenol D (7), and flexuosol A (8). The structures of the isolated compounds were established on the basis of their spectroscopic data evidence. The antibacterial activity of the isolated compounds was evaluated using resazurin microtitre-plate assay.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
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