Displaying publications 61 - 80 of 929 in total

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  1. Fulltext The ability of streptomycin-loaded chitosan-coated magnetic nanocomposites to possess antimicrobial and antituberculosis activities
    El Zowalaty ME, Hussein Al Ali SH, Husseiny MI, Geilich BM, Webster TJ, Hussein MZ
    Int J Nanomedicine, 2015;10:3269-74.
    PMID: 25995633 DOI: 10.2147/IJN.S74469
    Magnetic nanoparticles (MNPs) were synthesized by the coprecipitation of Fe(2+) and Fe(3+) iron salts in alkali media. MNPs were coated by chitosan (CS) to produce CS-MNPs. Streptomycin (Strep) was loaded onto the surface of CS-MNPs to form a Strep-CS-MNP nanocomposite. MNPs, CS-MNPs, and the nanocomposites were subsequently characterized using X-ray diffraction and were evaluated for their antibacterial activity. The antimicrobial activity of the as-synthesized nanoparticles was evaluated using different Gram-positive and Gram-negative bacteria, as well as Mycobacterium tuberculosis. For the first time, it was found that the nanoparticles showed antimicrobial activities against the tested microorganisms (albeit with a more pronounced effect against Gram-negative than Gram-positive bacteria), and thus, should be further studied as a novel nano-antibiotic for numerous antimicrobial and antituberculosis applications. Moreover, since these nanoparticle bacteria fighters are magnetic, one can easily envision magnetic field direction of these nanoparticles to fight unwanted microorganism presence on demand. Due to the ability of magnetic nanoparticles to increase the sensitivity of imaging modalities (such as magnetic resonance imaging), these novel nanoparticles can also be used to diagnose the presence of such microorganisms. In summary, although requiring further investigation, this study introduces for the first time a new type of magnetic nanoparticle with microorganism theranostic properties as a potential tool to both diagnose and treat diverse microbial and tuberculosis infections.
    Matched MeSH terms: Bacteria/drug effects
  2. Fulltext The Safety Of Capsules Containing Lactic Acid Bacilli
    Paraidathathu, Thomas, Lee, S.H.
    Ann Dent, 1999;6(1):-.
    MyJurnal
    The population in Malaysia use various types of health and food supplements. These products are considered safe and are used without any concern for their toxicity. Among the products used as health supplements are products that contain lactic acid bacteria. This project studied the acute and subacute toxicity of a product containing minerals, herbs, vitamins and live lactic acid bacteria, on Sprague- Dawley rats. Acute toxicity was tested 24 hours after a single dose and subacute toxicity was studied 24 hours after 7 days of daily dosing. The parameters that were studied were alanine aminotransferase (AL T,SGPT), aspartate aminotransferase (AST, SGOT), serum urea, ratios of weight of kidney and liver weight to body weight and percentage changes in body weights. The contents of capsules of the product (6, 8 or lO capsules for acute studies and 6, 10 and 12 for subacute studies) were mixed with corn oil and fed orally to rats. Control rats were fed with corn oil alone. In the acute studies, the level of ALT in the rats treated with the contents of the capsule was lower than controls. There were no significant changes in the other parameters of the rats in the treatment groups as compared to controls. There were no significant differences in all the parameters between rats in the treatment groups as compared to controls in the subacute studies. Sprague-Dawley rats fed with high doses of the product did not show signs of toxicity in the parameters that were studied.
    Matched MeSH terms: Bacteria
  3. The Potential of Mur Enzymes as Targets for Antimicrobial Drug Discovery
    Kumar D, Sarkar N, Roy KK, Bisht D, Kumar D, Mandal B, et al.
    Curr Drug Targets, 2023;24(8):627-647.
    PMID: 37291783 DOI: 10.2174/1389450124666230608150759
    The extensive development in the strains of resistant bacteria is a potential hazard to public health worldwide. This necessitates the development of newer agents with the antibacterial property having new mechanisms of action. Mur enzymes catalyze the steps related to the biosynthesis of peptidoglycan, which constitutes a major part of the cell wall in bacteria. Peptidoglycan increases the stiffness of the cell wall, helping it to survive in unfavorable conditions. Therefore, the inhibition of Mur enzymes may lead to novel antibacterial agents that may help in controlling or overcoming bacterial resistance. Mur enzymes are classified into MurA, MurB, MurC, MurD, MurE, and MurF. Until-date, multiple inhibitors are reported for each class of the Mur enzymes. In this review, we have summarized the development of Mur enzyme inhibitors as antibacterial agents in the last few decades.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Bacteria
  4. Fulltext The Importance of the Expendable: Toxin-Antitoxin Genes in Plasmids and Chromosomes
    Díaz-Orejas R, Espinosa M, Yeo CC
    Front Microbiol, 2017;8:1479.
    PMID: 28824602 DOI: 10.3389/fmicb.2017.01479
    Toxin-antitoxin (TA) genes were first reported in plasmids and were considered expendable genetic cassettes involved in the stable maintenance of the plasmid replicon by interfering with growth and/or viability of bacteria in which the plasmid was lost. TAs were later found in bacterial chromosomes and also in integrated mobile genetic elements; they were proposed to be involved in the bacterial response to stressful situations. At present, 100s of TAs have been identified and classified in up to six families (I to VI), with those belonging to the type II (constituted by two protein components) being the most studied. Based on well-characterized examples of several type II TAs, we discuss in this review that irrespective of their locations in plasmids or chromosomes, TAs functionally overlap as indicated by: (i) in both locations they can mediate the maintenance of genetic elements to which they are physical linked, and (ii) they can induce persistence or virulence in response to stress situations. Examples of functional confluences in homologous TA systems with different locations are also given. We also consider whether the physiological role of TAs is due to their genetic organization as operons or to their inherent properties, like the short lifespan of the antitoxin component.
    Matched MeSH terms: Bacteria; Chromosomes, Bacterial
  5. Fulltext The Impact of CRISPR-Cas System on Antiviral Therapy
    Bayat H, Naderi F, Khan AH, Memarnejadian A, Rahimpour A
    Adv Pharm Bull, 2018 Nov;8(4):591-597.
    PMID: 30607331 DOI: 10.15171/apb.2018.067
    Clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein nuclease (Cas) is identified as an adaptive immune system in archaea and bacteria. Type II of this system, CRISPR-Cas9, is the most versatile form that has enabled facile and efficient targeted genome editing. Viral infections have serious impacts on global health and conventional antiviral therapies have not yielded a successful solution hitherto. The CRISPR-Cas9 system represents a promising tool for eliminating viral infections. In this review, we highlight 1) the recent progress of CRISPR-Cas technology in decoding and diagnosis of viral outbreaks, 2) its applications to eliminate viral infections in both pre-integration and provirus stages, and 3) various delivery systems that are employed to introduce the platform into target cells.
    Matched MeSH terms: Bacteria
  6. Fulltext The CRISPR Growth Spurt: from Bench to Clinic on Versatile Small RNAs
    Bayat H, Omidi M, Rajabibazl M, Sabri S, Rahimpour A
    J Microbiol Biotechnol, 2017 Feb 28;27(2):207-218.
    PMID: 27840399 DOI: 10.4014/jmb.1607.07005
    Clustered regulatory interspaced short palindromic repeats (CRISPR) in association with CRISPR-associated protein (Cas) is an adaptive immune system, playing a pivotal role in the defense of bacteria and archaea. Ease of handling and cost effectiveness make the CRISPR-Cas system an ideal programmable nuclease tool. Recent advances in understanding the CRISPR-Cas system have tremendously improved its efficiency. For instance, it is possible to recapitulate the chronicle CRISPR-Cas from its infancy and inaugurate a developed version by generating novel variants of Cas proteins, subduing off-target effects, and optimizing of innovative strategies. In summary, the CRISPR-Cas system could be employed in a number of applications, including providing model systems, rectification of detrimental mutations, and antiviral therapies.
    Matched MeSH terms: Bacteria
  7. Fulltext The Antimicrobial efficacy of Elaeis guineensis: characterization, in vitro and in vivo studies
    Vijayarathna S, Zakaria Z, Chen Y, Latha LY, Kanwar JR, Sasidharan S
    Molecules, 2012 Apr 26;17(5):4860-77.
    PMID: 22538489 DOI: 10.3390/molecules17054860
    The urgent need to treat multi-drug resistant pathogenic microorganisms in chronically infected patients has given rise to the development of new antimicrobials from natural resources. We have tested Elaeis guineensis Jacq (Arecaceae) methanol extract against a variety of bacterial, fungal and yeast strains associated with infections. Our studies have demonstrated that E. guineensis exhibits excellent antimicrobial activity in vitro and in vivo against the bacterial and fungal strains tested. A marked inhibitory effect of the E. guineensis extracts was observed against C. albicans whereby E. guineensis extract at ½, 1, or 2 times the MIC significantly inhibited C. albicans growth with a noticeable drop in optical density (OD) of the bacterial culture. This finding confirmed the anticandidal activity of the extract on C. albicans. Imaging using scanning (SEM) and transmission (TEM) electron microscopy was done to determine the major alterations in the microstructure of the extract-treated C. albicans. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the yeast cells. In vivo antimicrobial activity was studies in mice that had been inoculated with C. albicans and exhibited good anticandidal activity. The authors conclude that the extract may be used as a candidate for the development of anticandidal agent.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Negative Bacteria/growth & development; Gram-Positive Bacteria/drug effects; Gram-Positive Bacteria/growth & development
  8. Fulltext Temporal variation of bacterial respiration and growth efficiency in tropical coastal waters
    Lee CW, Bong CW, Hii YS
    Appl Environ Microbiol, 2009 Dec;75(24):7594-601.
    PMID: 19820145 DOI: 10.1128/AEM.01227-09
    We investigated the temporal variation of bacterial production, respiration, and growth efficiency in the tropical coastal waters of Peninsular Malaysia. We selected five stations including two estuaries and three coastal water stations. The temperature was relatively stable (averaging around 29.5 degrees C), whereas salinity was more variable in the estuaries. We also measured dissolved organic carbon and nitrogen (DOC and DON, respectively) concentrations. DOC generally ranged from 100 to 900 microM, whereas DON ranged from 0 to 32 microM. Bacterial respiration ranged from 0.5 to 3.2 microM O2 h(-1), whereas bacterial production ranged from 0.05 to 0.51 microM C h(-1). Bacterial growth efficiency was calculated as bacterial production/(bacterial production + respiration), and ranged from 0.02 to 0.40. Multiple correlation analyses revealed that bacterial production was dependent upon primary production (r2 = 0.169, df = 31, and P < 0.02) whereas bacterial respiration was dependent upon both substrate quality (i.e., DOC/DON ratio) (r2 = 0.137, df = 32, and P = 0.03) and temperature (r2 = 0.113, df = 36, and P = 0.04). Substrate quality was the most important factor (r2 = 0.119, df = 33, and P = 0.04) for the regulation of bacterial growth efficiency. Using bacterial growth efficiency values, the average bacterial carbon demand calculated was from 5.30 to 11.28 microM C h(-1). When the bacterial carbon demand was compared with primary productivity, we found that net heterotrophy was established at only two stations. The ratio of bacterial carbon demand to net primary production correlated significantly with bacterial growth efficiency (r2 = 0.341, df = 35, and P < 0.001). From nonlinear regression analysis, we found that net heterotrophy was established when bacterial growth efficiency was <0.08. Our study showed the extent of net heterotrophy in these waters and illustrated the importance of heterotrophic microbial processes in coastal aquatic food webs.
    Matched MeSH terms: Bacteria/growth & development*; Bacterial Physiological Phenomena*
  9. Fulltext Temporal changes in gut microbiota profile in children with acute lymphoblastic leukemia prior to commencement-, during-, and post-cessation of chemotherapy
    Chua LL, Rajasuriar R, Lim YAL, Woo YL, Loke P, Ariffin H
    BMC Cancer, 2020 Feb 24;20(1):151.
    PMID: 32093640 DOI: 10.1186/s12885-020-6654-5
    BACKGROUND: Alteration in gut microbiota has been recently linked with childhood leukemia and the use of chemotherapy. Whether the perturbed microbiota community is restored after disease remission and cessation of cancer treatment has not been evaluated. This study examines the chronological changes of gut microbiota in children with acute lymphoblastic leukemia (ALL) prior to the start-, during-, and following cessation of chemotherapy.

    METHODOLOGY: We conducted a longitudinal observational study in gut microbiota profile in a group of paediatric patients diagnosed with ALL using 16 s ribosomal RNA sequencing and compared these patients' microbiota pattern with age and ethnicity-matched healthy children. Temporal changes of gut microbiota in these patients with ALL were also examined at different time-points in relation to chemotherapy.

    RESULTS: Prior to commencement of chemotherapy, gut microbiota in children with ALL had larger inter-individual variability compared to healthy controls and was enriched with bacteria belonging to Bacteroidetes phylum and Bacteroides genus. The relative abundance of Bacteroides decreased upon commencement of chemotherapy. Restitution of gut microbiota composition to resemble that of healthy controls occurred after cessation of chemotherapy. However, the microbiota composition (beta diversity) remained distinctive and a few bacteria were different in abundance among the patients with ALL compared to controls despite completion of chemotherapy and presumed restoration of normal health.

    CONCLUSION: Our findings in this pilot study is the first to suggest that gut microbiota profile in children with ALL remains marginally different from healthy controls even after cessation of chemotherapy. These persistent microbiota changes may have a role in the long-term wellbeing in childhood cancer survivors but the impact of these changes in subsequent health perturbations in these survivors remain unexplored.

    Matched MeSH terms: Bacteria/classification*; Bacteria/genetics
  10. Fulltext Temporal and spatial dynamics of Bacteria, Archaea and protists in equatorial coastal waters
    Chénard C, Wijaya W, Vaulot D, Lopes Dos Santos A, Martin P, Kaur A, et al.
    Sci Rep, 2019 Nov 08;9(1):16390.
    PMID: 31704973 DOI: 10.1038/s41598-019-52648-x
    Singapore, an equatorial island in South East Asia, is influenced by a bi-annual reversal of wind directions which defines two monsoon seasons. We characterized the dynamics of the microbial communities of Singapore coastal waters by collecting monthly samples between February 2017 and July 2018 at four sites located across two straits with different trophic status, and sequencing the V6-V8 region of the small sub-unit ribosomal RNA gene (rRNA gene) of Bacteria, Archaea, and Eukaryota. Johor Strait, which is subjected to wider environmental fluctuations from anthropogenic activities, presented a higher abundance of copiotrophic microbes, including Cellvibrionales and Rhodobacterales. The mesotrophic Singapore Strait, where the seasonal variability is caused by changes in the oceanographic conditions, harboured a higher proportion of typically marine microbe groups such as Synechococcales, Nitrosupumilales, SAR11, SAR86, Marine Group II Archaea and Radiolaria. In addition, we observed seasonal variability of the microbial communities in the Singapore Strait, which was possibly influenced by the alternating monsoon regime, while no seasonal pattern was detected in the Johor Strait.
    Matched MeSH terms: Bacteria/classification; Bacteria/genetics; Bacteria/isolation & purification
  11. Taxonomic study of Weissella confusa and description of Weissella cibaria sp. nov., detected in food and clinical samples
    Björkroth KJ, Schillinger U, Geisen R, Weiss N, Hoste B, Holzapfel WH, et al.
    Int J Syst Evol Microbiol, 2002 Jan;52(Pt 1):141-148.
    PMID: 11837296 DOI: 10.1099/00207713-52-1-141
    A taxonomic study was conducted to clarify the relationships of two bacterial populations belonging to the genus Weissella. A total of 39 strains originating mainly from Malaysian foods (22 strains) and clinical samples from humans (9 strains) and animals (6 strains) were analysed using a polyphasic taxonomic approach. The methods included classical phenotyping, whole-cell protein electrophoresis, 16S and 23S rDNA RFLP (ribotyping), determination of 16S rDNA sequence homologies and DNA-DNA reassociation levels. Based on the results, the strains were considered to represent two different species, Weissella confusa and a novel Weissella species, for which the name Weissella cibaria sp. nov. is proposed. Weisella confusa possessed the highest 16S rDNA sequence similarity to Weisella cibaria, but the DNA-DNA reassociation experiment showed hybridization levels below 49% between the strains studied. The numerical analyses of Weisella confusa and Weisella cibaria strains did not reveal any specific clustering with respect to the origin of the strains. Based on whole-cell protein electrophoresis, and ClaI and HindIII ribotyping patterns, food and clinical isolates were randomly located in the two species-specific clusters obtained.
    Matched MeSH terms: Gram-Positive Bacteria/classification*; Gram-Positive Bacteria/genetics; Gram-Positive Bacteria/isolation & purification; Gram-Positive Bacterial Infections/microbiology*
  12. Fulltext Synthesis, spectroscopic investigations (X-ray, NMR and TD-DFT), antimicrobial activity and molecular docking of 2,6-bis(hydroxy(phenyl)methyl)cyclohexanone
    Barakat A, Ghabbour HA, Al-Majid AM, Soliman SM, Ali M, Mabkhot YN, et al.
    Molecules, 2015;20(7):13240-63.
    PMID: 26197312 DOI: 10.3390/molecules200713240
    The synthesis of 2,6-bis(hydroxy(phenyl)methyl)cyclohexanone 1 is described. The molecular structure of the title compound 1 was confirmed by NMR, FT-IR, MS, CHN microanalysis, and X-ray crystallography. The molecular structure was also investigated by a set of computational studies and found to be in good agreement with the experimental data obtained from the various spectrophotometric techniques. The antimicrobial activity and molecular docking of the synthesized compound was investigated.
    Matched MeSH terms: Bacteria/growth & development*; Bacterial Proteins/chemistry*
  13. Synthesis, spectral analysis and biological evaluation of Nalkyl/aralkyl/aryl-4-chlorobenzenesulfonamide derivatives
    Rehman A, Abbasi MA, Siddiqui SZ, Mohyuddin A, Nadeem S, Shah SA
    Pak J Pharm Sci, 2016 Sep;29(5):1489-1496.
    PMID: 27731801
    New potent organic compounds were synthesized with an aim of good biological activities such as antibacterial and anti-enzymatic. Three series of sulfonamide derivatives were synthesized by treating N-alkyl/aryl substituted amines (2a-f) with 4-chlorobenzensulfonyl chloride (1) to yield N-alkyl/aryl-4-chlorobenzenesulfonamide(3af) that was then derivatized by gearing up with ethyl iodide (4), benzyl chloride (5) and 4-chlorobenzyl chloride (6) using sodium hydride as base to initialize the reaction in a polar aprotic solvent (DMF) to synthesize the derivatives, 7a-f, 8af and 9a-f respectively. Structure elucidation was brought about by IR, 1H-NMR and EIMS spectra for all the synthesized molecules which were evaluated for their antibacterial activities and inhibitory potentials for certain enzymes.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*; Anti-Bacterial Agents/pharmacology*; Bacteria/drug effects*; Bacteria/growth & development
  14. Synthesis, in vitro antimycobacterial evaluation and docking studies of some new 5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one schiff bases
    Narender M, Jaswanth S B, Umasankar K, Malathi J, Raghuram Reddy A, Umadevi KR, et al.
    Bioorg Med Chem Lett, 2016 Feb 01;26(3):836-840.
    PMID: 26755393 DOI: 10.1016/j.bmcl.2015.12.083
    Development of multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis (TB) has been considered as major health burden, globally. In order to develop novel, potential molecules against drug resistant TB, twenty two (22) new 3-substituted-7-benzyl-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one (6a-k) and 3-substituted-7-benzyl-2-methyl-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one (7a-k) derivatives were designed and synthesized by using appropriate synthetic protocols. Pantothenate synthetase (PS) was considered as the target for the molecular docking studies and evaluated the binding pattern at active site, as PS plays a significant role in the biosynthesis of pantothenate in Mycobacterium tuberculosis (MTB). The preliminary in vitro antibacterial screening of test compounds was carried out against two strains of Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. The antimycobacterial screening was performed against MTB H37Rv and an isoniazid-resistant clinical isolate of MTB. The compounds 6b, 6c, 6d, 6k, 7b, 7c, 7d and 7k exhibited promising antibacterial activity MIC in the range of 15-73 μM against all bacterial strains used and compounds 6d and 7b showed antimycobacterial activity (IC50 <340 μM in LRP assay) and (MIC <9 μM in broth microdilution method).
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Negative Bacteria/metabolism; Gram-Positive Bacteria/drug effects; Gram-Positive Bacteria/metabolism
  15. Synthesis, characterization, antibacterial, hemolytic and thrombolytic activity evaluation of 5-(3-chlorophenyl)-2-((N-(substituted)-2-acetamoyl)sulfanyl)-1,3,4-oxadiazole derivatives
    Aziz-Ur-Rehman -, Khan SG, Bokhari TH, Anjum F, Akhter N, Rasool S, et al.
    Pak J Pharm Sci, 2020 Mar;33(2(Supplementary)):871-876.
    PMID: 32863264
    A novel series of 5-(3-Chlorophenyl)-2-((N-(substituted)-2-acetamoyl)sulfanyl)-1,3,4-oxadiazole derivatives was efficiently synthesized and screened for antibacterial, hemolytic and thrombolytic activities. The molecule 7c remained the best inhibitor of all selected bacterial strains and furthermore possessed very low toxicity, 8.52±0.31. Compound 7a 7b and 7f showed very good thrombolytic activity relative to Streptokinase employed as reference drug. In addition to low toxicity and moderately good thrombolytic activity, the synthesized compounds possessed excellent to moderate antibacterial activity, relative to ciprofloxacin. All compounds especially 7b and 7f can be consider for further clinical studies and might be helpful in synthesis of new drugs for treatment of cardiovascular diseases.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry*; Bacteria/drug effects
  16. Fulltext Synthesis, characterization, and antimicrobial properties of copper nanoparticles
    Usman MS, El Zowalaty ME, Shameli K, Zainuddin N, Salama M, Ibrahim NA
    Int J Nanomedicine, 2013;8:4467-79.
    PMID: 24293998 DOI: 10.2147/IJN.S50837
    Copper nanoparticle synthesis has been gaining attention due to its availability. However, factors such as agglomeration and rapid oxidation have made it a difficult research area. In the present work, pure copper nanoparticles were prepared in the presence of a chitosan stabilizer through chemical means. The purity of the nanoparticles was authenticated using different characterization techniques, including ultraviolet visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The antibacterial as well as antifungal activity of the nanoparticles were investigated using several microorganisms of interest, including methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella choleraesuis, and Candida albicans. The effect of a chitosan medium on growth of the microorganism was studied, and this was found to influence growth rate. The size of the copper nanoparticles obtained was in the range of 2-350 nm, depending on the concentration of the chitosan stabilizer.
    Matched MeSH terms: Bacteria/drug effects*
  17. Fulltext Synthesis, characterization, and antimicrobial activity of an ampicillin-conjugated magnetic nanoantibiotic for medical applications
    Hussein-Al-Ali SH, El Zowalaty ME, Hussein MZ, Geilich BM, Webster TJ
    Int J Nanomedicine, 2014;9:3801-14.
    PMID: 25143729 DOI: 10.2147/IJN.S61143
    Because of their magnetic properties, magnetic nanoparticles (MNPs) have numerous diverse biomedical applications. In addition, because of their ability to penetrate bacteria and biofilms, nanoantimicrobial agents have become increasingly popular for the control of infectious diseases. Here, MNPs were prepared through an iron salt coprecipitation method in an alkaline medium, followed by a chitosan coating step (CS-coated MNPs); finally, the MNPs were loaded with ampicillin (amp) to form an amp-CS-MNP nanocomposite. Both the MNPs and amp-CS-MNPs were subsequently characterized and evaluated for their antibacterial activity. X-ray diffraction results showed that the MNPs and nanocomposites were composed of pure magnetite. Fourier transform infrared spectra and thermogravimetric data for the MNPs, CS-coated MNPs, and amp-CS-MNP nanocomposite were compared, which confirmed the CS coating on the MNPs and the amp-loaded nanocomposite. Magnetization curves showed that both the MNPs and the amp-CS-MNP nanocomposites were superparamagnetic, with saturation magnetizations at 80.1 and 26.6 emu g(-1), respectively. Amp was loaded at 8.3%. Drug release was also studied, and the total release equilibrium for amp from the amp-CS-MNPs was 100% over 400 minutes. In addition, the antimicrobial activity of the amp-CS-MNP nanocomposite was determined using agar diffusion and growth inhibition assays against Gram-positive bacteria and Gram-negative bacteria, as well as Candida albicans. The minimum inhibitory concentration of the amp-CS-MNP nanocomposite was determined against bacteria including Mycobacterium tuberculosis. The synthesized nanocomposites exhibited antibacterial and antifungal properties, as well as antimycobacterial effects. Thus, this study introduces a novel β-lactam antibacterial-based nanocomposite that can decrease fungus activity on demand for numerous medical applications.
    Matched MeSH terms: Bacteria/drug effects
  18. Synthesis, characterization and antibacterial activity of mono-, di- and tri-tosylate of glycerol
    Yusrabbil Amiyati Yusof, Azhar Ariffin
    Sains Malaysiana, 2016;45:621-625.
    Glycerol is a valuable co-product from oleochemical industry such as from fatty acid and biodiesel production. By having three hydroxyl groups in its molecule, glycerol can undergo chemical modifications that lead to many possible applications. This paper reports the tosylation process of glycerol with para-toluenesulfonyl chloride (p-TsCl). Reaction of glycerol with p-TsCl in the presence of a base produced mono-, di- and tri-tosylate of glycerol even though the reaction was carried out at the mole ratio of 1.2:1.0 of glycerol to p-TsCl. The compounds were successfully isolated and characterized. Mono-, di- and tri-tosylate of glycerol exhibited inhibitory activity against Staphylococcus aureus (gram positive bacteria) and Pseudomonas aeruginosa (gram negative bacteria).
    Matched MeSH terms: Gram-Negative Bacteria; Gram-Positive Bacteria
  19. Fulltext Synthesis, biological evaluation and corrosion inhibition studies of transition metal complexes of Schiff base
    Kashyap S, Kumar S, Ramasamy K, Lim SM, Shah SAA, Om H, et al.
    Chem Cent J, 2018 Nov 20;12(1):117.
    PMID: 30460466 DOI: 10.1186/s13065-018-0487-1
    BACKGROUND: The transition metal complexes formed from Schiff base is regarded as leading molecules in medicinal chemistry. Because of the preparative availability and diversity in the structure of central group, the transition metals are important in coordination chemistry. In the present work, we have designed and prepared Schiff base and its metal complexes (MC1-MC4) and screened them for antimicrobial, anticancer and corrosion inhibitory properties.

    METHODOLOGY: The synthesized metal complexes were characterized by physicochemical and spectral investigation (UV, IR, 1H and 13C-NMR) and were further evaluated for their antimicrobial (tube dilution) and anticancer (SRB assay) activities. In addition, the corrosion inhibition potential was determined by electrochemical impedance spectroscopy (EIS) technique.

    RESULTS AND DISCUSSION: Antimicrobial screening results found complexes (MC1-MC4) to exhibit less antibacterial activity against the tested bacterial species compared to ofloxacin while the complex MC1 exhibited greater antifungal activity than the fluconazole. The anticancer activity results found the synthesized Schiff base and its metal complexes to elicit poor cytotoxic activity than the standard drug (5-fluorouracil) against HCT116 cancer cell line. Metal complex MC2 showed more corrosion inhibition efficiency with high Rct values and low Cdl values.

    CONCLUSION: From the results, we can conclude that complexes MC1 and MC2 may be used as potent antimicrobial and anticorrosion agents, respectively.

    Matched MeSH terms: Anti-Bacterial Agents; Bacteria
  20. Synthesis, antibacterial activity and cytotoxicity of new fused pyrazolo[1,5-a]pyrimidine and pyrazolo[5,1-c][1,2,4]triazine derivatives from new 5-aminopyrazoles
    Al-Adiwish WM, Tahir MI, Siti-Noor-Adnalizawati A, Hashim SF, Ibrahim N, Yaacob WA
    Eur J Med Chem, 2013 Jun;64:464-76.
    PMID: 23669354 DOI: 10.1016/j.ejmech.2013.04.029
    New 5-aminopyrazoles 2a-c were prepared in high yields from the reaction of known α,α-dicyanoketene-N,S-acetals 1a-c with hydrazine hydrate under reflux in ethanol. These compounds were utilized as intermediates to synthesize pyrazolo[1,5-a]-pyrimidines 3a-c, 4a-d, 5a-c, and 6a-c, as well as pyrazolo[5,1-c][1,2,4]triazines 7a-c and 8a-c, by the reaction of 2-[bis(methylthio)methylene]malononitrile, α,α-dicyanoketene-N,S-acetals 1a-b, acetylacetone, acetoacetanilide as well as acetylacetone, and malononitrile, respectively. Furthermore, cyclization of 2a-c with pentan-2,5-dione yielded the corresponding 5-pyrrolylpyrazoles 9a-c. Moreover, fusion of 2a-c with acetic anhydride resulted in the corresponding 1-acetyl-1H-pyrazoles 10a-c. The antibacterial activity and cytotoxicity against Vero cells of several selected compounds are also reported.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis; Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry; Bacteria/drug effects*
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