Displaying publications 1 - 20 of 56 in total

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  1. Li Y, Ouyang Y, Wu H, Wang P, Huang Y, Li X, et al.
    Eur J Med Chem, 2022 Jan 15;228:113979.
    PMID: 34802838 DOI: 10.1016/j.ejmech.2021.113979
    The shortage of new antibiotics makes infections caused by gram-negative (G-) bacteria a significant clinical problem. The key enzymes involved in folate biosynthesis represent important targets for drug discovery, and new antifolates with novel mechanisms are urgently needed. By targeting to dihydrofolate reductase (DHFR), a series of 1,3-diamino-7H-pyrrol[3,2-f]quinazoline (PQZ) compounds were designed, and exhibited potent antibacterial activities in vitro, especially against multi-drug resistant G- strains. Multiple experiments indicated that PQZ compounds contain a different molecular mechanism against the typical DHFR inhibitor, trimethoprim (TMP), and the thymidylate synthase (TS) was identified as another potential but a relatively weak target. A significant synergism between the representative compound, OYYF-175, and sulfamethoxazole (SMZ) was observed with a strong cumulative and significantly bactericidal effect at extremely low concentrations (2 μg/mL for SMZ and 0.03 pg/mL for OYYF-175), which could be resulted from the simultaneous inhibition of dihydropteroate synthase (DHPS), DHFR and TS. PQZ compounds exhibited therapeutic effects in a mouse model of intraperitoneal infections caused by Escherichia coli (E. coli). The co-crystal structure of OYYF-175-DHFR was solved and the detailed interactions were provided. The inhibitors reported represent innovative chemical structures with novel molecular mechanism of action, which will benefit the generation of new, efficacious bactericidal compounds.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  2. Xu FX, Ooi CW, Liu BL, Song CP, Chiu CY, Wang CY, et al.
    Int J Biol Macromol, 2021 Jun 30;181:508-520.
    PMID: 33775766 DOI: 10.1016/j.ijbiomac.2021.03.151
    This study aimed to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with the enhanced antibacterial property. The PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment, and the treated membrane was subsequently grafted with chitosan (CS) to obtain a CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization studies were conducted on all the synthesized nanofiber membranes. The antibacterial efficacies of nanofiber membranes prepared under different synthesis conditions were evaluated systematically. Under the optimum synthesis conditions, P-COOH-CS-Dye-PHMB was highly effective in disinfecting a high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited an outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  3. Supramaniam J, Low DYS, Wong SK, Tan LTH, Leo BF, Goh BH, et al.
    Int J Mol Sci, 2021 May 28;22(11).
    PMID: 34071337 DOI: 10.3390/ijms22115781
    Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8-10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  4. Ur-Rehman A, Khan SG, Naqvi SAR, Ahmad M, Akhtar N, Bokhari TH, et al.
    Pak J Pharm Sci, 2021 Jan;34(1(Special)):441-446.
    PMID: 34275792
    A series of new derivatives of 4-(2-chloroethyl)morpholine hydrochloride (5) were efficiently synthesized. Briefly, different aromatic organic acids (1a-f) were refluxed to acquire respective esters (2a-f) using conc. H2SO4 as catalyst. The esters were subjected to nucleophillic substitution by monohydrated hydrazine to acquire hydrazides (3a-f). The hydrazides were cyclized with CS2 in the presence of KOH to yield corresponding oxadiazoles (4a-f). Finally, the derivatives, 6a-f, were prepared by reacting oxadiazoles (4a-f) with 5 using NaH as activator. Structures of all the derivatives were elucidated through 1D-NMR EI-MS and IR spectral data. All these molecules were subjected to antibacterial and hemolytic activities and showed good antibacterial and hemolytic potential relative to the reference standards.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  5. Faheem, Kumar BK, Sekhar KVGC, Kunjiappan S, Jamalis J, Balaña-Fouce R, et al.
    Mini Rev Med Chem, 2021;21(4):398-425.
    PMID: 33001013 DOI: 10.2174/1389557520666201001130114
    β-Carboline, a naturally occurring indole alkaloid, holds a momentous spot in the field of medicinal chemistry due to its myriad of pharmacological actions like anticancer, antiviral, antibacterial, antifungal, antileishmanial, antimalarial, neuropharmacological, anti-inflammatory and antithrombotic among others. β-Carbolines exhibit their pharmacological activity via diverse mechanisms. This review provides a recent update (2015-2020) on the anti-infective potential of natural and synthetic β-carboline analogs focusing on its antibacterial, antifungal, antiviral, antimalarial, antileishmanial and antitrypanosomal properties. In cases where enough details are available, a note on its mechanism of action is also added.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  6. Siaw YM, Jeevanandam J, Hii YS, Chan YS
    Naunyn Schmiedebergs Arch Pharmacol, 2020 Dec;393(12):2253-2264.
    PMID: 32632566 DOI: 10.1007/s00210-020-01934-x
    In recent times, magnesium oxide (MgO) nanoparticles are proven to be an excellent antibacterial agent which inhibits the growth of bacteria by generating reactive oxygen species (ROS). Release of ROS by nanoparticles will damage the cell membrane of bacteria and leads to the leakage of bacterial internal components and cell death. However, chemically synthesized MgO nanoparticles may possess toxic functional groups which may inhibit healthy human cells along with bacterial cells. Thus, the aim of the present study is to synthesize MgO nanoparticles using leaf extracts of Amaranthus tricolor and photo-irradiation of visible light as a catalyst, without addition of any chemicals. Optimization was performed using Box-Behnken design (BBD) to obtain the optimum condition required to synthesize smallest nanoparticles. The parameters such as time of reaction, the concentration of precursor, and light intensity have been identified to affect the size of biosynthesized nanoparticles and was optimized. The experiment performed with optimized conditions such as 0.001 M concentration of magnesium acetate as precursor, 5 cm distance of light (intensity), and 15 min of reaction time (light exposure) has led to the formation of 74.6 nm sized MgO nanoparticles. The antibacterial activities of MgO nanoparticles formed via photo-irradiation and conventional biosynthesis approach were investigated and compared. The lethal dosage of E. coli for photo-irradiated and conventional biosynthesis MgO nanoparticles was 0.6 ml and 0.4 ml, respectively. Likewise, the lethal dosage of S. aureus for both biosynthesis approaches was found to be 0.4 ml. The results revealed that the antibacterial activity of MgO nanoparticles from both biosynthesis approaches was similar. Thus, photo-irradiated MgO nanoparticles were beneficial over heat-mediated conventional method due to the reduced synthesis duration.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  7. Mohammed AAM, Suaifan GARY, Shehadeh MB, Okechukwu PN
    Eur J Med Chem, 2020 Sep 15;202:112513.
    PMID: 32623216 DOI: 10.1016/j.ejmech.2020.112513
    Herein we report the design, synthesis and biological evaluation of structurally modified ciprofloxacin, norfloxacin and moxifloxacin standard drugs, featuring amide functional groups at C-3 of the fluoroquinolone scaffold. In vitro antimicrobial testing against various Gram-positive bacteria, Gram-negative bacteria and fungi revealed potential antibacterial and antifungal activity. Hybrid compounds 9 (MIC 0.2668 ± 0.0001 mM), 10 (MIC 0.1358 ± 00025 mM) and 13 (MIC 0.0898 ± 0.0014 mM) had potential antimicrobial activity against a fluoroquinolone-resistant Escherichia coli clinical isolate, compared to ciprofloxacin (MIC 0.5098 ± 0.0024 mM) and norfloxacin (MIC 0.2937 ± 0.0021 mM) standard drugs. Interestingly, compound 10 also exerted potential antifungal activity against Candida albicans (MIC 0.0056 ± 0.0014 mM) and Penicillium chrysogenum (MIC 0.0453 ± 0.0156 mM). Novel derivatives and standard fluoroquinolone drugs exhibited near-identical cytotoxicity levels against L6 muscle cell-line, when measured using the MTT assay.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  8. Abbasi MA, Irshad M, Aziz-Ur-Rehman -, Siddiqui SZ, Nazir M, Ali Shah SA, et al.
    Pak J Pharm Sci, 2020 Sep;33(5):2161-2170.
    PMID: 33824125
    In the presented work, 2,3-dihydro-1,4-benzodioxin-6-amine (1) was reacted with 4-chlorobenzenesulfonyl chloride (2) in presence of aqueous basic aqueous medium to obtain 4-chloro-N-(2,3-dihydro-1,4-benzodioxin-6-yl)benzenesulfonamide (3). In parallel, various un/substituted anilines (4a-l) were treated with bromoacetyl bromide (5) in basified aqueous medium to obtain corresponding 2-bromo-N-(un/substituted)phenylacetamides (6a-l) as electrophiles. Then the compound 3 was finally reacted with these electrophiles, 6a-l, in dimethylformamide (DMF) as solvent and lithium hydride as base and activator to synthesize a variety of 2-[[(4-chlorophenyl)sulfonyl](2,3-dihydro-1,4-benzodioxin-6-yl)amino]-N-(un/substituted)phenylacetamides (7a-l). The synthesized compounds were corroborated by IR, 1H-NMR and EI-MS spectral data for structural confirmations. These molecules were then evaluated for their antimicrobial and antifungal activities along with their %age hemolytic activity. Some compounds were found to have suitable antibacterial and antifungal potential, especially the compound 2-[[(4-chlorophenyl)sulfonyl](2,3-dihydro-1,4-benzodioxin-6-yl)amino]-N-(3,5-dimethylphenyl)acetamide (7l) exhibited good antimicrobial potential with low value of % hemolytic activity.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  9. Yu L, Lu M, Zhang W, Alarfaj AA, Hirad AH, Zhang H
    Microb Pathog, 2020 Apr;141:103960.
    PMID: 31953224 DOI: 10.1016/j.micpath.2019.103960
    BACKGROUND: Mycoplasma pneumoniae (MP) is a common cause of community-acquired pneumonia (CAP) among the children and adults that results upper and lower respiratory tract infections.

    OBJECTIVE: This study was aimed to inspect the ameliorative action of A. chinensis synthesized ZnONPs against M. pneumoniae infected pneumonia mice model.

    MATERIALS AND METHODS: ZnO NPs was synthesized from Albizia chinensis bark extract and characterized by UV-Vis spectroscopy, Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), energy dispersive X-ray (EDX) and atomic force microscope (AFM) analyses. The antibacterial effectual of synthesized ZnONPs were examined against clinical pathogens. The pneumonia was induced to BALB/c mice via injecting the M. pneumoniae and treated with synthesized ZnONPs, followed by the total protein content, total cell counts and inflammatory mediators level was assessed in the BALF of experimental animals. The Histopathological investigation was done in the lung tissues of test animals.

    RESULTS: The outcomes of this work revealed that the formulated ZnONPs was quasi-spherical, radial and cylindrical; the size was identified as 116.5 ± 27.45 nm in diameter. The in vitro antimicrobial potential of formulated ZnO-NPs displayed noticeable inhibitory capacity against the tested fungal and bacterial strains. The administration of synthesized ZnO-NPs in MP infected mice model has significantly reduced the levels of total protein, inflammatory cells, inflammatory cytokines such as IL-1, IL-6, IL-8, tumour necrosis factor-alpha (TNF-a) and transforming growth factor (TGF). Besides, the histopathological examination of MP infected mice lung tissue showed the cellular arrangements were effectively retained after administration of synthesized ZnO-NPs.

    CONCLUSION: In conclusion, synthesized ZnO-NPs alleviate pneumonia progression via reducing the level of inflammatory cytokines and inflammatory cells in MP infected mice model.

    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  10. Walayat K, Ahmad M, Rasul A, Aslam S, Anjum MN, Sultan S, et al.
    Pak J Pharm Sci, 2020 Mar;33(2(Supplementary)):855-860.
    PMID: 32863262
    The drug resistance phenomenon in microbes is resulting in the ineffectiveness of available drugs to treat the infections. Thus, there is a continued need to discover new molecules to combat the drug resistance phenomenon. Norfloxacin is a fluoroquinolone antibiotic that is used for the treatment of urinary tract infections. In this research work, norfloxacin is structurally modified by hybridizing with a range of substituted acetohydrazidic moieties through a multistep reaction. The first step involves the coupling of norfloxacin 1 with methyl chloroacetate followed by the treatment with hydrazine hydrate to result in corresponding acetohydrazide 3. A range of substituted benzaldehydes were reacted with the acetohydrazide to form the targeted series of norfloxacin derivatives 4a-i. The final compounds were screened for antimicrobial activity. Among the tested compounds, 4c, 4d, 4e and 4f displayed better antifungal activity against F.avenaceum, while compound 4c and 4e were active against F. bubigeum.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  11. Iqbal J, Rehman A, Abbasi MA, Siddiqui SZ, Khalid H, Laulloo SJ, et al.
    Pak J Pharm Sci, 2020 Jan;33(1):149-160.
    PMID: 32122843
    A series of new compounds (5a-q), derived from 5-(1-(4-nitrophenylsulfonyl) piperidin-4-yl)-4-phenyl-4H-1,2,4-triazole-3-thiol (3) were proficiently synthesized to evaluate their biological activities. 1-(4-Nitrophenylsulfonyl) piperidine-4-carbohydrazide (2) was refluxed with phenylisothiocyanate to yield an adduct which was cyclized to compound 3 by reflux reaction with 10 % potassium hydroxide. The targeted compounds 5a-q, were synthesized by stirring alkyl/aralkyl halides (4a-q) and compound 3 in a polar aprotic solvent. 1H-NMR, 13C-NMR, EI-MS and IR spectral techniques were employed to confirm the structures of all the synthesized compounds. The compounds were biologically evaluated for BSA binding studies followed by anti-bacterial, anti-inflammatory and acetylcholinesterase (AChE) activities. The active sites responsible for the best AChE inhibition were identified through molecular docking studies. Compound 5e bearing 4-chlorobenzyl moiety found most active antibacterial and anti-inflammatory agent among the synthesized compounds. The whole library of synthesized compounds except compounds 5d and 5f was found highly active for AChE inhibition and recommended for in vivo studies so that their therapeutic applications may come in utilization.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  12. AlMatar M, Albarri O, Makky EA, Var I, Köksal F
    Mini Rev Med Chem, 2020;20(18):1908-1916.
    PMID: 32811410 DOI: 10.2174/1389557520666200818211405
    The need for new therapeutics and drug delivery systems has become necessary owing to the public health concern associated with the emergence of multidrug-resistant microorganisms. Among the newly discovered therapeutic agents is cefiderocol, which was discovered by Shionogi Company, Japan as an injectable siderophore cephalosporin. Just like the other β-lactam antibiotics, cefiderocol exhibits antibacterial activity via cell wall synthesis inhibition, especially in Gram negative bacteria (GNB); it binds to the penicillin-binding proteins, but its unique attribute is that it crosses the periplasmic space of bacteria owing to its siderophore-like attribute; it also resists the activity of β-lactamases. Among all the synthesized compounds with the modified C-7 side chain, cefiderocol (3) presented the best and well-balanced activity against multi-drug resistant (MDR) Gram negative bacteria, including those that are resistant to carbapenem. İn this article, an overview of the recent studies on cefiderocol was presented.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  13. Ngaini Z, Mortadza NA
    Nat Prod Res, 2019 Dec;33(24):3507-3514.
    PMID: 29911437 DOI: 10.1080/14786419.2018.1486310
    Chemical modification of medicines from natural product-based molecules has become of interest in recent years. In this study, a series of halogenated azo derivatives 1a-d were synthesised via coupling reaction, followed by Steglich esterification with aspirin (a natural product derivative) to form azo derivatives 2a-d. While, halogenated azo-aspirin 3a-d were synthesised via direct coupling reaction of aspirin and diazonium salt. Bacteriostatic activity was demonstrated against E. coli and S. aureus via turbidimetric kinetic method. Compound 3a-d showed excellent antibacterial activities against E. coli (MIC 75-94 ppm) and S. aureus (MIC 64-89 ppm) compared to ampicillin (MIC 93 and 124 ppm respectively), followed by 1a-d and 2a-d. The presence of reactive groups of -OH, N=N, C=O and halogens significantly contribute excellent interaction towards E. coli and S. aureus. Molecular dockings analysis of 3a against MIaC protein showed binding free energy of -7.2 kcal/mol (E. coli) and -6.6 kcal/mol (S. aureus).
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  14. Bayrami A, Ghorbani E, Rahim Pouran S, Habibi-Yangjeh A, Khataee A, Bayrami M
    Ultrason Sonochem, 2019 Nov;58:104613.
    PMID: 31450359 DOI: 10.1016/j.ultsonch.2019.104613
    The leaf extract of a medicinally important plant, watercress (Nasturtium officinale), was obtained through an ultrasound-facilitated method and utilized for the preparation of ZnO nanoparticles via a joint ultrasound-microwave assisted procedure. The characteristics of the extract enriched nanoparticles (Ext/ZnO) were determined by SEM, TEM, XRD, EDX, BET, FTIR, TGA, and UV-Vis DRS analyses and compared to that of ZnO prepared in the absence of the extract (ZnO). The presence of carbon and carbonaceous bonds, changes in the morphology, size, band gap energy, and weight-decay percentage were a number of differences between ZnO and Ext/ZnO that confirmed the link of extract over nanoparticles. Ext/ZnO, watercress leaf extract, ZnO, and insulin therapies were administrated to treat alloxan-diabetic Wister rats and their healing effectiveness results were compared to one another. The serum levels of the main diabetic indices such as insulin, fasting blood glucose, and lipid profile (total triglyceride, total cholesterol, and high-density lipoprotein cholesterol) were estimated for healthy, diabetic, and the rats rehabilitated with the studied therapeutic agents. The watercress extract-enriched ZnO nanoparticles offered the best performance and suppressed the diabetic status of rats. Moreover, both ZnO samples satisfactory inhibited the activities of Staphylococcus aureus and Escherichia coli bacteria. Based on the results, the application of Nasturtium officinale leaf extract can strongly empower ZnO nanoparticles towards superior antidiabetic and enhanced antibacterial activities.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  15. Nazir M, Abbasi MA, Aziz-Ur-Rehman -, Siddiqui SZ, Ali Shah SA, Shahid M, et al.
    Pak J Pharm Sci, 2019 Nov;32(6):2585-2597.
    PMID: 31969290
    In the study presented here, the nucleophilic substitution reaction of 5-[3-(1H-indol-3-yl)propyl]-1,3,4-oxadiazol-2-ylhydrosulfide was carried out with different alkyl/aralkyl halides (5a-r) to form its different S-substituted derivatives (6a-r), as depicted in scheme 1. The structural confirmation of all the synthesized compounds was done by IR, 1H-NMR, 13C-NMR and CHN analysis data. Bacterial biofilm inhibitory activity of all the synthesized compounds was carried out against Bacillus subtilis and Escherichia coli. The anticancer activity of these molecules was ascertained using anti-proliferation (SRB) assay on HCT 116 Colon Cancer Cell lines while the cytotoxicity of these molecules was profiled for their haemolytic potential. From this investigation it was rational that most of the compounds exhibited suitable antibacterial and anticancer potential along with a temperate cytotoxicity.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  16. Abbasi MA, Fatima Z, Rehman AU, Siddiqui SZ, Ali Shah SA, Shahid M, et al.
    Pak J Pharm Sci, 2019 Sep;32(5):1957-1964.
    PMID: 31813858
    The present study comprises the synthesis of a new series of benzenesulfonamides derived from N-sulfonation of 2-(4-methoxyphenyl)-1-ethanamine (1). The synthesis was initiated by the reaction of 2-(4-methoxyphenyl)-1-ethanamine (1) with benzenesulfonyl chloride (2), to yield N-(4-methoxyphenethyl)benzenesulfonamide (3). This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides (4a-j) in N,N-dimethylformamide (DMF) and in the presence of a weak base lithium hydride (LiH) to obtain various N-(alkyl/aralkyl)-N-(4-methoxyphenethyl) benzenesulfonamides (5a-j). The characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. Elemental analysis also supported this data. The biofilm inhibitory action of all the synthesized compounds was carried out on Escherichia coli and some of the compounds were identified to be very suitable inhibitors of this bacterial strain. Furthermore, the molecules were also tested for their cytotoxicity behavior to assess their utility as less cytotoxic therapeutic agents.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  17. Pulingam T, Thong KL, Ali ME, Appaturi JN, Dinshaw IJ, Ong ZY, et al.
    Colloids Surf B Biointerfaces, 2019 Sep 01;181:6-15.
    PMID: 31103799 DOI: 10.1016/j.colsurfb.2019.05.023
    The antibacterial nature of graphene oxide (GO) has stimulated wide interest in the medical field. Although the antibacterial activity of GO towards bacteria has been well studied, a deeper understanding of the mechanism of action of GO is still lacking. The objective of the study was to elucidate the difference in the interactions of GO towards Gram-positive and Gram-negative bacteria. The synthesized GO was characterized by Ultraviolet-visible spectroscopy (UV-vis), Raman and Attenuated Total Reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR). Viability, time-kill and Lactose Dehydrogenase (LDH) release assays were carried out along with FESEM, TEM and ATR-FTIR analysis of GO treated bacterial cells. Characterizations of synthesized GO confirmed the transition of graphene to GO and the antibacterial activity of GO was concentration and time-dependent. Loss of membrane integrity in bacteria was enhanced with increasing GO concentrations and this corresponded to the elevated release of LDH in the reaction medium. Surface morphology of GO treated bacterial culture showed apparent differences in the mechanism of action of GO towards Gram-positive and Gram-negative bacteria where cell entrapment was mainly observed for Gram-positive Staphylococcus aureus and Enterococcus faecalis whereas membrane disruption due to physical contact was noted for Gram-negative Escherichia coli and Pseudomonas aeruginosa. ATR-FTIR characterizations of the GO treated bacterial cells showed changes in the fatty acids, amide I and amide II of proteins, peptides and amino acid regions compared to untreated bacterial cells. Therefore, the data generated further enhance our understanding of the antibacterial activity of GO towards bacteria.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  18. Rajeshkumar S, Menon S, Venkat Kumar S, Tambuwala MM, Bakshi HA, Mehta M, et al.
    J. Photochem. Photobiol. B, Biol., 2019 Aug;197:111531.
    PMID: 31212244 DOI: 10.1016/j.jphotobiol.2019.111531
    Environment friendly methods for the synthesis of copper nanoparticles have become a valuable trend in the current scenario. The utilization of phytochemicals from plant extracts has become a unique technology for the synthesis of nanoparticles, as they possess dual nature of reducing and capping agents to the nanoparticles. In the present investigation we have synthesized copper nanoparticles (CuNPs) using a rare medicinal plant Cissus arnotiana and evaluated their antibacterial activity against gram negative and gram positive bacteria. The morphology and characterization of the synthesized CuNPs were studied and done using UV-Visible spectroscopy at a wavelength range of 350-380 nm. XRD studies were performed for analyzing the crystalline nature; SEM and TEM for evaluating the spherical shape within the size range of 60-90 nm and AFM was performed to check the surface roughness. The biosynthesized CuNPs showed better antibacterial activity against the gram-negative bacteria, E. coli with an inhibition zone of 22.20 ± 0.16 mm at 75 μg/ml. The antioxidant property observed was comparatively equal with the standard antioxidant agent ascorbic acid at a maximum concentration of 40 μg/ ml. This is the first study reported on C. arnotiana mediated biosynthesis of copper nanoparticles, where we believe that the findings can pave way for a new direction in the field of nanotechnology and nanomedicine where there is a significant potential for antibacterial and antioxidant activities. We predict that, these could lead to an exponential increase in the field of biomedical applications, with the utilization of green synthesized CuNPs, due to its remarkable properties. The highest antibacterial property was observed with gram-negative strains mainly, E. coli, due to its thin peptidoglycan layer and electrostatic interactions between the bacterial cell wall and CuNPs surfaces. Hence, CuNPs can be potent therapeutic agents in several biomedical applications, which are yet to be explored in the near future.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
  19. Ranjani B, Pandian K, Kumar GA, Gopinath SCB
    Int J Biol Macromol, 2019 Jul 15;133:1280-1287.
    PMID: 31051204 DOI: 10.1016/j.ijbiomac.2019.04.196
    Silver nanoparticle was synthesized using D-glucosamine chitosan base as green reducing agent at elevated temperature in alkaline pH ranges. The excess of D-glucosamine chitosan base was used as it is both stabilizing and reducing agent at different pHs, regulates the shape and size of the silver nanoparticles. The progressive growth of silver nanoparticles was monitored by UV-Visible spectral studies. A sharp peak at 420 nm indicates the formation of spherical silver nanoparticles. The size and shape of silver nanoparticles were observed from Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) methods. The anisotropically grown nanoparticles were used as probe for Surface Enhanced Raman Studies (SERS) using ATP (4-aminothiophenol) as a model system. The catalytic behavior of silver nanoparticles was exploited for 4-nitrophenol reduction and observed that the reduction reaction follows pseudo first order kinetics with a rate constant 0.65 min. The antibacterial activity of silver nanoparticles was also tested for both gram-positive and -negative microorganisms, in which higher zone of inhibition was observed for gram negative microorganism.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*
  20. Surendra TV, Mohana Roopan S, Khan MR
    Biotechnol Prog, 2019 07;35(4):e2823.
    PMID: 31017346 DOI: 10.1002/btpr.2823
    The rare earth metal oxide nanoparticles such as gadolinium oxide nanoparticles (Gd2 O3 NPs) have been synthesized by green synthesis process using methanolic extract of Moringa oleifera (M oleifera) peel. In this process, the Gd2 O3 NPs formation was observed at 280-300 nm in UV-Vis spectroscopy. The XRD pattern of the synthesized Gd2 O3 NPs was exactly matched with JCPDS No 3-065-3181which confirms the crystalline nature of Gd2 O3 NPs. In addition, Energy-dispersive X-ray spectroscopy (EDX) analysis was stated that Gd and O elements were present as 70.31 and 29.69%, respectively in Gd2 O3 NPs. The SEM and TEM analysis were said Gd2 O3 NPs are in rod shape and 26 ± 2 nm in size. Further the synthesized Gd2 O3 NPs were confirmed by X-ray photoemission spectroscopy (XPS). The synthesized Gd2 O3 NPs were further examined for anti-fungal activity against Alternaria saloni (A saloni) and Sclerrotium rolfsii (S rolfsii) and it showed moderate activity. Also, Gd2 O3 NPs evaluated as good antibacterial agent against different Gram +ve and Gram -ve bacteria. Moreover, the toxicity of the Gd2 O3 NPs on red blood cells (RBCs) of the human blood was determined using hemolytic assay, the obtained results were stated the synthesized Gd2 O3 NPs are nontoxic to the human erythrocytes. The photocatalytic activity against malachite green (MG) dye was tested and confirmed as 92% of dye was degraded within 2 hr by Gd2 O3 NPs. The results were stated the green synthesized Gd2 O3 NPs are good anti-fungal agents, nontoxic and we can use as a photocatalyst. Copyright © 2019 John Wiley & Sons, Ltd.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis
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