Displaying publications 1 - 20 of 188 in total

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  1. Sivasothy Y, Ibrahim H, Paliany AS, Alias SA, Awang K
    Bioorg. Med. Chem. Lett., 2013 Dec 1;23(23):6280-5.
    PMID: 24144849 DOI: 10.1016/j.bmcl.2013.09.082
    The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  2. Ibrahim D, Hong LS, Kuppan N
    Nat Prod Commun, 2013 Apr;8(4):493-6.
    PMID: 23738462
    The antibacterial efficiency of the methanolic extract of Phyllanthus niruri Linn. was investigated against pathogenic bacteria responsible for common infections of skin, and urinary and gastrointestinal tracts. The extract demonstrated antibacterial activities against all the Gram-positive and Gram-negative bacteria tested. The results obtained suggested that at higher concentrations the extract would eradicate the growth of bacterial cells. The bacterial cells, after exposure to the extract, showed complete alteration in their morphology, followed by collapse of the cells beyond repair. The study revealed that the methanolic extract of P. niruri may be an effective antibacterial agent to treat bacterial infections since the extract exhibited significant antimicrobial potency, comparable with that of the standard antibiotic chloramphenicol.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  3. Teow SY, Wong MM, Yap HY, Peh SC, Shameli K
    Molecules, 2018 06 06;23(6).
    PMID: 29882775 DOI: 10.3390/molecules23061366
    Nanoparticles (NPs) are nano-sized particles (generally 1⁻100 nm) that can be synthesized through various methods. The wide range of physicochemical characteristics of NPs permit them to have diverse biological functions. These particles are versatile and can be adopted into various applications, particularly in biomedical field. In the past five years, NPs’ roles in biomedical applications have drawn considerable attentions, and novel NPs with improved functions and reduced toxicity are continuously increasing. Extensive studies have been carried out in evaluating antibacterial potentials of NPs. The promising antibacterial effects exhibited by NPs highlight the potential of developing them into future generation of antimicrobial agents. There are various methods to synthesize NPs, and each of the method has significant implication on the biological action of NPs. Among all synthetic methods, green technology is the least toxic biological route, which is particularly suitable for biomedical applications. This mini-review provides current update on the antibacterial effects of NPs synthesized by green technology using plants. Underlying challenges in developing NPs into future antibacterials in clinics are also discussed at the present review.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  4. 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*
  5. 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*
  6. 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*
  7. 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
  8. 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*
  9. 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
  10. Ponnuchamy S, Kanchithalaivan S, Ranjith Kumar R, Ali MA, Choon TS
    Bioorg. Med. Chem. Lett., 2014 Feb 15;24(4):1089-93.
    PMID: 24472146 DOI: 10.1016/j.bmcl.2014.01.007
    A series of novel hybrid heterocycles comprising arylidene thiazolidine-2,4-dione and 1-cyclopropyl-2-(2-fluorophenyl)ethanone were synthesized. These compounds were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv in High Throughput Screen. Most of the hybrid arylidene thiazolidine-2,4-diones displayed moderate to good activity with MIC of less than 50 μM. Compound 1m exhibited maximum potency being 5.87 fold more active at EC50 and 6.26 fold more active at EC90 than the standard drug pyrimethamine.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  11. Palanisamy NK, Ferina N, Amirulhusni AN, Mohd-Zain Z, Hussaini J, Ping LJ, et al.
    PMID: 24422704 DOI: 10.1186/1477-3155-12-2
    Nanomedicine is now being introduced as a recent trend in the field of medicine. It has been documented that metal nanoparticles have antimicrobial effects for bacteria, fungi and viruses. Recent advances in technology has revived the use of silver nanoparticles in the medical field; treatment, diagnosis, monitoring and control of disease. It has been used since ancient times for treating wide range of illnesses. Bacterial cells adheres to surfaces and develop structures known as biofilms. These structures are natural survival strategy of the bacteria to invade the host. They are more tolerant to commonly used antimicrobial agents, thus being more difficult to be controlled. This leads to increase in severity of infection. In this study, we have investigated the effect of silver nanoparticles in the formation of biofilm in multidrug resistant strains of Pseudomonas aeruginosa. Observation showed that biofilm formation occurred at bacterial concentration of 10(6) cfu/ml for the sensitive strain of P. aeruginosa while in the resistant strain, the biofilm was evident at bacterial concentration of about 10(3) cfu/ml. The biofilm were then tested against various concentrations of silver nanoparticles to determine the inhibitory effect of the silver nanoparticles. In the sensitive strain, 20 μg/ml of silver nanoparticles inhibited the growth optimally at bacterial concentration of 10(4) cfu/ml with an inhibition rate of 67%. Similarly, silver nanoparticles inhibited the formation of biofilm in the resistant strain at an optimal bacterial concentration of 10(5) cfu/ml with an inhibition rate of 56%. Thus, silver nanoparticles could be used as a potential alternative therapy to reduce severity of disease due to P. aeruginosa infections.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  12. 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
  13. 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*
  14. 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*
  15. Teh CH, Nazni WA, Lee HL, Fairuz A, Tan SB, Sofian-Azirun M
    Med. Vet. Entomol., 2013 Dec;27(4):414-20.
    PMID: 23650928 DOI: 10.1111/mve.12012
    The emergence of multidrug-resistant bacterial strains has prompted the reintroduction of maggot therapy in the treatment of chronic, infected wounds. Many previous studies have demonstrated the potent antibacterial activity of larval excretions/secretions of the blowfly Lucilia sericata (Meigen) (Diptera:Calliphoridae) against bacteria. However, the antibacterial activity of its sibling species, Lucilia cuprina (Wiedemann) (Diptera:Calliphoridae) against a wide range of pathogenic bacteria has never been determined. The aim of this study was to develop a new procedure to produce whole body extract of larvae of L. cuprina via methanol extraction as well as to demonstrate the in vitro antibacterial activity of this extract against seven selected wound pathogens (Staphylococcus aureus, methicillin-resistant S. aureus, S. epidermidis, Streptococcus pyogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli). The turbidimetric assay demonstrated that L. cuprina larval extract was significantly potent against all bacteria tested (P 
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  16. 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
  17. Gwaram NS, Ali HM, Khaledi H, Abdulla MA, Hadi AH, Lin TK, et al.
    Molecules, 2012;17(5):5952-71.
    PMID: 22609786 DOI: 10.3390/molecules17055952
    A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  18. Ngaini Z, Fadzillah SM, Hussain H
    Nat Prod Res, 2012;26(10):892-902.
    PMID: 21678160 DOI: 10.1080/14786419.2010.502896
    A series of (E)-1-(4-alkyloxyphenyl)-3-(hydroxyphenyl)-prop-2-en-1-one have been successfully synthesised via Claisen-Schmidt condensation. The synthesised chalcone derivatives consisted of hydroxyl groups at either ortho, meta or para position and differed in the length of the alkyl groups, C (n) H(2) (n) (+1,) where n = 6, 10, 12 and 14. The structures of all compounds were defined by elemental analysis, IR, (1)H- and (13)C-NMR. The antimicrobial studies were carried out against wild-type Escherichia coli American Type Culture Collection 8739 to evaluate the effect of the hydroxyl and the alkyl groups of the synthesised chalcones. All the synthesised compounds have shown significant antimicrobial activities. The optimum inhibition was dependent on the position of the hydroxyl group as well as the length of the alkyl chains.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  19. Wong KC, Hag Ali DM, Boey PL
    Nat Prod Res, 2012;26(7):609-18.
    PMID: 21834640 DOI: 10.1080/14786419.2010.538395
    The aqueous methanolic extracts of Melastoma malabathricum L. exhibited antibacterial activity when assayed against seven microorganisms by the agar diffusion method. Solvent fractionation afforded active chloroform and ethyl acetate fractions from the leaves and the flowers, respectively. A phytochemical study resulted in the identification of ursolic acid (1), 2α-hydroxyursolic acid (2), asiatic acid (3), β-sitosterol 3-O-β-D-glucopyranoside (4) and the glycolipid glycerol 1,2-dilinolenyl-3-O-β-D-galactopyanoside (5) from the chloroform fraction. Kaempferol (6), kaempferol 3-O-α-L-rhamnopyranoside (7), kaempferol 3-O-β-D-glucopyranoside (8), kaempferol 3-O-β-D-galactopyranoside (9), kaempferol 3-O-(2″,6″-di-O-E-p-coumaryl)-β-D-galactopyranoside (10), quercetin (11) and ellagic acid (12) were found in the ethyl acetate fraction. The structures of these compounds were determined by chemical and spectral analyses. Compounds 1-4, the flavonols (6 and 11) and ellagic acid (12) were found to be active against some of the tested microorganisms, while the kaempferol 3-O-glycosides (7-9) did not show any activity, indicating the role of the free 3-OH for antibacterial activity. Addition of p-coumaryl groups results in mild activity for 10 against Staphylococcus aureus and Bacillus cereus. Compounds 2-5, 7 and 9-12 are reported for the first time from M. malabathricum. Compound 10 is rare, being reported only once before from a plant, without assignment of the double bond geometry in the p-coumaryl moiety.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  20. Chung PY, Navaratnam P, Chung LY
    PMID: 21658242 DOI: 10.1186/1476-0711-10-25
    There has been considerable effort to discover plant-derived antibacterials against methicillin-resistant strains of Staphylococcus aureus (MRSA) which have developed resistance to most existing antibiotics, including the last line of defence, vancomycin. Pentacyclic triterpenoid, a biologically diverse plant-derived natural product, has been reported to show anti-staphylococcal activities. The objective of this study is to evaluate the interaction between three pentacyclic triterpenoid and standard antibiotics (methicillin and vancomycin) against reference strains of Staphylococcus aureus.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
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