Synthesis, Characterization and Antibacterial Activity of Chitosan/TiO2 Microspheres

2014 ◽  
Vol 912-914 ◽  
pp. 362-365
Author(s):  
Wen Ying Qi ◽  
Sai Sai Chen ◽  
Dan Yang ◽  
Qin Long Li ◽  
Xiao Rong Wu ◽  
...  

In this study, chitosan (CS)/titanium dioxide (TiO2) microspheres with different nanoTiO2 content were obtained by suspension cross-linking technique and characterized by FT-IR and SEM. The strong peak of C=N stretching vibrations at 1641 cm-1 were found which demonstrated that amino groups of CS reacted with aldehyde group of glutaraldehyde. SEM photographs showed that the CS/TiO2 microspheres were spherical, and the size of the CS/TiO2 microspheres ranging from 50 to 170 μm was analyzed with the software of Image J. The entrapment efficiency of the CS/TiO2 microspheres was up to 67.7%. Compared with CS, CS/TiO2 microspheres had better antibacterial activity against S. aureus and E. coli with a MIC value of 0.0125%.

2019 ◽  
Vol 2 (1) ◽  
pp. 9-14
Author(s):  
Subur P Pasaribu ◽  
Jamaran Kaban ◽  
Mimpin Ginting ◽  
Kasmirul Ramlan Sinaga

Telah dilakukan sintesa hidrogel hibrid maleoil kitosan (MKS)-dialdehid alginat (DAA) melalui reaksi basa Schiff antara gugus amina dari MKS dengan gugus aldehid dari DAA pada berbagai rasio perbandingan dalam larutan buffer fosfat pH 7,4. Hidrogel yang diperoleh dikarakterisasi dengan spektrofotometer FT-IR dan dilakukan uji aktivitas antibakterinya terhadap E.coli dan S. aureus untuk mengevaluasi potensinya sebagai antibakteri. Berdasarkan spektrum FT-IR, hidrogel telah berhasil disintesa dengan munculnya puncak karakteristik dari struktur hemiasetal pada 864,11 cm-1 merupakan vibrasi stretching dari ikatan -C-N- yang menunjukkan bahwa telah terjadi reaksi kopling diantara gugus CHO pada DAA dan NH2 dari MKS dan didukung dengan adanya puncak pada 1627,92 cm-1 yang berhubungan dengan terbentuknya gugus –C=N-. Pada uji aktivitas antibakteri hidrogel hanya perbandingan 5:5, 3:7 dan 1:9 (MKS:DAA) yang menunjukkan adanya aktivitas terhadap E.coli masing-masing 6,18 , 8,15 dan 6,80 (mm), sedangkan terhadap S. aureus seluruh hidrogel menunjukkan aktivitas yaitu, 8,00, 10,10, 10,08, 8,15 dan 7,00 (mm). Aktivitas antibakteri akan meningkat seiring dengan peningkatan jumlah DAA tetapi menurun kembali seiring dengan penurunan MKS. Hal ini dapat dikaikan dengan banyaknya ikatan basa Schiff yang terbentuk pada saat pembentukan hidrogel yang menyebabkan atom N bersifat kationik sehingga dapat mengikat muatan negatif pada permukaan sel bakteri. Hidrogel hibrid MKSDAA dengan rasio perbandingan 5:5 sangat potensial digunakan sebagai hidrogel yang bersifat antibakteri untuk aplikasi biomedis.   Maleoyl chitosan (MaCs) – alginate dialdehyde (AD) hybrid hydrogel had been synthesized through Schiff base reaction between amine group from MaCs and aldehyde group from AD at various ratio in pH phosphate buffer pH 7.4. The obtained hydrogels were characterized by FT-IR spectrophotometer and their antibacterial activity was tested against E. coli and S. aureus to evaluate their potential as antibacterial. Based on the FT-IR spectrum, the hydrogel was successfully synthesized with the appearance of the characteristic peaks of the hemiasetal structure at 864.11 cm-1 which was a stretching vibration of the -CN bond showing that there had been a reaction of coupling between CHO groups in DAA and NH2 from MaCs and supported with the peak at 1627.92 cm-1 associated with the formation of the group –C = N-. In the test of the antibacterial activity of the hydrogels, only the ratio of 5 : 5, 3 : 7 and 1 : 9 (MaCs : AD) showed there were activities of E. coli 6.18, 8.15 and 6.80 mm respectively, whereas against S. aureus the entire hydrogel showed activity namely, 8.00, 10.10, 10.08, 8.15 and 7.00 mm. Antibacterial activity would increase along with the increase in the amount of ADA but decreased again as the MaCS decreased. This could be attributed to the number of Schiff base bonds formed during the formation of the hydrogel which caused the N atom to be cationic so that it could bind the negative charge on the surface of the bacterial cell. MaCs - AD hybrid hydrogels with a ratio of 5: 5 were very potential to be used as antibacterial hydrogels for biomedical applications.


2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.


2021 ◽  
Author(s):  
Amalanathan.M ◽  
Aravind.M ◽  
Sony Michael Mary.M ◽  
Razan A. Alshgari ◽  
Asma A. Alothman ◽  
...  

Abstract In this work, jasmine flower derived activated carbon were successfully synthesized by hydrothermal carbonization process at the different annealing temperature. The Crystallinity, phase, structural, morphological and optical properties of activated carbon were investigated using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscope (TEM), and UV-visible spectroscopy analysis. The graphitic phase of carbon was obtained from the XRD pattern. Surface morphology reveals irregular-shaped nanoparticles. The photodegradation of methylene blue (MB) was carried out under the visible light irradiation technique to study its photocatalytic activity. The activated carbon obtained at 400oC, 500oC and 600oC shows a photocatalytic degradation efficiency of 86%, 90%, and 94%, respectively. Antibacterial activity of activated carbon was examined against S. Aureus (MTCC-737) and E-Coli (MTCC- 443) microbial pathogens, and their potent antibacterial activity was examined from the zone of inhibition layer.


2021 ◽  
Vol 26 (1) ◽  
pp. 8-15
Author(s):  
Shiv Nandan Sah ◽  
Ramesh Majhi ◽  
Sunil Regmi ◽  
Arjun Ghimire ◽  
Bhageshwor Biswas ◽  
...  

Realizing an increasing need for a novel antibiotic, this study was carried out to screen antibacterial metabolites producing actinomycetes from 15 soil samples collected from Taplejung. Antibacterial metabolites producing actinomycetes were confirmed by primary screening and secondary screening. Macroscopic, microscopic, and biochemical characteristics were used for presumptive identification of probable actinomycetes genera. The potential isolate was cultured in starch casein broth for production of possible antibacterial compound. The antibacterial compound was extracted from fermented broth using organic solvents like ethyl acetate, n-butanol, chloroform, dichloromethane, and methanol. Among 24 isolates, only one (T18) showed antibacterial activity against both Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Salmonella Typhi and Pseudomonas aeruginosa) test-bacteria. The isolate was considered as Streptomyces spp based on microscopy and various biochemical, and physiological characteristics. Extracted antibacterial metabolite showed antibacterial activity with a MIC value of 1.2 mg/mL against E. coli (ATCC 25922). The chromatogram in Thin Layer Chromatography showed only one spot exhibited by extract with Rf value 0.87 suggested that the isolate produced a compound that was completely different from the spot with Rf value 0.94 produced by gentamicin (standard). This study revealed the distribution of the potent antibacterial metabolite producing actinomycetes in the soils of Taplejung.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Naheed Zafar ◽  
Bushra Uzair ◽  
Muhammad Bilal Khan Niazi ◽  
Shamaila Sajjad ◽  
Ghufrana Samin ◽  
...  

Treatment of pandrug resistant (PDR) Escherichia coli strain is the leading causative agent of bovine mastitis worldwide. Hence, becoming a potential threat to veterinary and public health. Therefore, to control the infection new nontoxic, biocompatible antimicrobial formulation with enhanced antibacterial activity is massively required. Current study was planned to synthesize chitosan coated titanium dioxide nanoparticles (CS-NPs coated TiO2). Coating was being done by chitosan nanoparticles (CS-NPs) using ionic gelation method. Aqueous solution of Moringa concanensis leaf extract was used to synthesize titanium dioxide nanoparticles (TiO2 NPs). The synthesized nanoformulations were characterized by using XRD, SEM, and FTIR. X-ray diffraction (XRD) analysis indicated the crystalline phase of TiO2 NPs and CS-NPs coated TiO2 NPs. Scanning Electron Microscopy (SEM) confirmed spherical shaped nanoparticles size of chitosan NPs ranging from 19–25 nm and TiO2 NPs 35–50 nm. Thesize of CS-NPs coated TiO2 NPs was in the range of 65–75 nm. The UV-Vis Spectra and band gap values illustrated the red shift in CS-NPs coated TiO2 NPs. Fourier transform infrared (FTIR) spectroscopy confirmed the linkages between TiO2 NPs and chitosan biopolymer, Zeta potential confirmed the stability of CS-NPs coated TiO2 NPs by showing 95 mV peak value. In-vitro antibacterial activity of CS-NPs coated TiO2 NPs and Uncoated TiO2 NPs was evaluated by disc diffusion method against PDR strain of E. coli isolated from mastitic milk samples. The antibacterial activity of all the synthesized nanoformulations were noted and highest antibacterial activity was shown by CS-NPs coated TiO2-NPs against pandrug resistant (PDR) E. coli strain with the prominent zone of inhibition of 23 mm. Morphological changes of E. coli cells after the treatment with MIC concentration (0.78 μg/ml) of CS-NPs coated TiO2 NPs were studied by transmission electron microscopy TEM showedrigorous morphological defectand has distorted the general appearance of the E. coli cells. Cytotoxicity (HepG2 cell line) and hemolytic (human blood) studies confirmed nontoxic/biocompatible nature of CS-NPs coated biologically synthesized TiO2 NPs. The results suggested that biologically synthesized and surface modified TiO2 NPs by mucoadhesive polysaccharides (e.g. chitosan) coating would be an effective and non-toxic alternative therapeutic agent to be used in livestock industry to control drug resistant veterinary pathogens.


2018 ◽  
Vol 34 (5) ◽  
pp. 2495-2501 ◽  
Author(s):  
Sarmd D. Noori ◽  
Mazin N. Mousa ◽  
Shaker A. N. Al-Jadaan

Five compounds containing (2,4,5-triphenyl triphenyl-1H-) and azetidinone (beta-lactam) moiety were synthesized. The physical data and yield of synthesized compounds were recorded, the chemical structure of prepared compounds were characterized using FT-IR, 1H-NMR and elemental analysis. The antibacterial activity was evaluated using disc diffusion method that involve tow Gram positive (staph. aureus, E. Faecalis), two Gram negative (E. coli and ‎K. pneumoniae), and one anaerobic bacteria (streptococcus. Pyogen). Different concentration of the prepared compounds has been used, and the obtained result were compared with standard (ceftazidime). Compound (5c) showed the best antibacterial activity against all bacterial species while 5a and 5e does not. Other compounds showed activity against some species.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5109
Author(s):  
Cynthia Torres-Alvarez ◽  
Sandra Castillo ◽  
Eduardo Sánchez-García ◽  
Carlos Aguilera González ◽  
Sergio Arturo Galindo-Rodríguez ◽  
...  

Concentrated orange oils (5x, 10x, 20x) are ingredients used in different industries as components of flavors and aromas due to their great organoleptic qualities. This research focuses on the search for alternative uses for their application through encapsulation in inclusion complexes with β-cyclodextrin (β–CD). Inclusion complexes of concentrated orange oils (COEO) and β–CD were developed by the co-precipitated method in ratios of 4:96, 12:88, and 16:84 (w/w, COEO: β–CD). The best powder recovery was in the ratio 16:84 for the three oils, with values between 82% and 84.8%. The 20x oil in relation 12:88 showed the highest entrapment efficiency (89.5%) with 102.3 mg/g of β–CD. The FT-IR analysis may suggest an interaction between the oil and the β–CD. The best antioxidant activity was observed in the ratio 12:88 for the three oils. The antifungal activity was determined for all the inclusion complexes, and the 10x fraction showed the highest inhibition at a concentration of 10 mg/mL in ratios 12:88 and 16:84. Antibacterial activity was determined by the minimum inhibitory concentration (MIC) and was found at a concentration of 1.25 mg/mL in ratios 12:88 and 16:84 for 5x and 20x oils.


2021 ◽  
Vol 17 ◽  
pp. 711-718
Author(s):  
Zafar Iqbal ◽  
Lijuan Zhai ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
...  

The diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam-based second generation β-lactamase inhibitors. As part of our efforts, we have synthesized a series of DBO derivatives A1–23 containing amidine substituents at the C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds did not show antibacterial activity when tested alone (MIC >64 mg/L), however, they exhibited a moderate inhibition activity in the presence of meropenem by lowering its MIC values. The compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L to 2 mg/L, and is comparable to avibactam against both E. coli strains with a MIC value of <0.125 mg/L.


2020 ◽  
Vol 11 (3) ◽  
pp. 10082-10088

Marine sponge Callyspongia sp. is one full of potency as a source for discovering and developing novel antibacterial. This study aims to isolate the Callypsongia sp. and assay their antibacterial activity. Callyspongia sp. were macerated with ethyl acetate (3x24 hrs), isolated with vacuum liquid chromatography (VLC) and RC (radial chromatography), and determined their structure with 1H and 13C-NMR. The antibacterial activity was assayed with the microdilution method. From ethyl acetate extract of Callyspongia sp. was successfully 2 isolated compounds, namely, isolate C1 (cholesterol) and isolate C2 (Unknown alkaloid with carbonyl from aldehyde group). The extract has MIC>512 µg/mL against Bacillus subtilis, Escherichia coli, Streptococcus mutans, and Salmonella enterica. While in both isolates provided MIC value >256 µg/mL against B. subtilis, E. coli, and S. mutans, yet in S. enterica provided 128 µg/mL for isolate C1 and 256 µg/mL for isolate C2. In conclusion, ethyl acetate extract of Callyspongia sp. contains cholesterol and Unknown alkaloid with carbonyl from the aldehyde group, and they both exhibited low antibacterial susceptibility.


2021 ◽  
Vol 8 (2) ◽  
pp. 21-27
Author(s):  
Abeer Abd Saleh ◽  
Quraish Abbas ◽  
Seenaa Ibraheim ◽  
Ibrahim Muhammed ◽  
Mayes Sameer Hameed ◽  
...  

In this research, preparation of titanium dioxide nanomaterial (TiO2) using sol-gel method was achieved. 2.5 g weight of the titanium dioxide nanoparticles were added to the local paint using the casting method. Thin films were prepared by drop casting the paint onto the surface of pre-prepared samples, then several tests were carried out including adhesion test, hardness test (Shore B), brightness and whiteness, friction test, contact angle, and antibacterial activity. The nanomaterial at a percentage of 12% showed the best results when it was added to the paint. These results include adhesion strength, hardness strength, and exposing to weather conditions of temperature, and humidity. The adhesive strength increased when adding the nanomaterial from 112 to 139 before exposure to the weather and from 58 to 108 after exposure. The hardness also increased from 77.9 to 86.5 before exposure to the surrounding environment and from 94.2 to 96.8 after exposure. In addition, the paint with TiO2 nanoparticles exhibited antibacterial activity against two types of bacteria Escherichia coli (E. coli), staphylococcus aurous (S. aurous) and antifungal candida. Paint with TiO2 nanoparticles is more efficient as antibacterial agents with E. coli as compared with S. aurous and candida.


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