In this report, a new series of fluoroquinolone agents which was derived from levofloxacin was synthesized and evaluated against Gram-positive (Bacillus subtillis, Staphylococcus aureus, Staphylococcus epidermidis and Micrococcus luteus) and Gram-negative (Esherichio coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens) organisms. The results showed that some of the synthesized compounds are strong antibacterial agents. All the synthesized compounds showed remarkable activities against Staphylococcus epidermidis and Staphylococcus aureus (MIC = 0. 03-1 μ g/mL and 0. 06-1 μ g/mL respectively).

Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) cause difficulties in the management of skin and soft tissue infections and have led to morbidity and mortality in hospital-acquired infections especially in susceptible individuals, those who are generally sick or immunosuppressed. Currently approaches in antibacterial agents offer opportunities to manage the trouble using novel anti-infection systems. Therefore, nanotechnology, a most promising field for generating new applications in medicine, has introduced a most prominent nanoproduct named as nanosilver that revealed excellent antimicrobial activity against some of the hazardous infections. Also cathelicidin peptides which are a part of native immune defense system in the skin and epithelia exhibit excellent antimicrobial activity against some of these perilous infections.

In the current study, copper-oxide (CuO) nanoparticles were synthesized using solution combustion method with copper (II) nitrate as the precursor and using two different fuels, urea and citric acid. The nanoparticles were synthesized at two different temperatures of 300 C and 500 C. In total, four copper oxide nanoparticles were synthesized. The fuel and precursors were mixed with distilled water and placed in a muffle furnace until no visible combustion was observed. Furthermore, the synthesized nanoparticles were characterized by UV-Visible spectrophotometry (UV-Vis), Powder X-Ray Diffraction (PXRD), and Fourier Transform Infrared Resonance (FTIR) spectrophotometry. These synthesized nanoparticles were investigated for their antibacterial properties against gram-negative bacteria; E. Coli and the results revealed that at 5 and 10 mg /mL concentrations, there was a significant zone of inhibition of 12 mm and 16 mm when compared with other tested samples.

Microorganisms play a major role in initiation and perpetuation of pulpal and periapical diseases. Therefore, elimination of the microorganisms present in the root canal system is the fundamental objective of endodontic treatment. The use of mechanical debridement, chemical irrigation or other antimicrobial protocols and intra-canal medicaments are critical to attain this goal. The aim of this article was to review the antimicrobial agents and their properties in endodontics.

Background: Nowadays the use of herbs as an alternative to the chemical drug is considered by researchers. Aloe vera belongs to the Asphodelaceae family, a medicinal plant that has been used since ancient times for different pharmaceutical products. This study aimed to evaluate the antibacterial properties of Aloe vera grown in Khouzestan, southwest of Iran. Materials and Methods: For this purpose, ethanol extract was prepared from aerial parts of Aloe vera and its activity was tested against some gram-positive (Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus) and gram-negative (Pseudomonass aeruginosa, Salmonella Typhi, Proteus mirabilis) bacterial species through standard Kirby-Bauer disc diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration were also investigated. Results: The Aloe vera extract showed antibacterial activity against the majority of bacteria. The highest activity (about 25mm inhibition zone) happened against P. aeruginosa but it did not show any inhibitory activity against S. aureus and P. mirabilis. The MIC was found as 10 mg/ml while MBC ≥ 80. Conclusion: Based on the results of this study it can be suggested that Aloe vera contains active antibacterial substances that can be used efficiently for bacterial pathogen control and it should be considered as a potent antimicrobial source for finding new antibiotics, especially against resistant species.

Nanomaterials are interesting candidates as heterogeneous catalysts for different organic reactions. In this research SiO2 nanoparticles was applied for synthesis of some new 2-chloro-1,8-naphthyridine-3-carbaaldehyde (1) through vilsmeier – haack cyclization of N-(pyridine-2-yl)acetamide has been reported and transformation to new chalcones containing morpholine ring from reaction of 2-morpholine-3-formyl-1,8-naphthyridine (2) and 2-aminoacetophenone to produce E-3-(2-morpholino-1,8-naphthyridine-3-yl)-1-(4-aminophenyl) prop-2-en-1-one (3) through Claisen-Schmidt reaction by used (Nano silicon dioxide imidazolidin sulfite propyl silyl trifloroacetate) as catalyst . which on treatment with N-chloroacetyl-4,6-diphenyl pyrimidinyl amine (4) gave compound (5). Compound (3) treated chloro acetyl arylamine (4) in presence of small amount of carbonate in DMF gave compound (6). The structures of the final compounds were confirmed by IR and 1HNMR. These compounds were evaluated for their antibacterial activity against gram positive and gram-negative bacteria using dilution procedure showed activity against the bacteria under study; 1,8-naphthyridine derivatives boost the fluoroquinolone antibiotics’ efficiency against multi-resistant bacteria, and therefore appealing prospects for development of treatments against bacterial infections caused by multidrug-resistant strains.

Heterocyclic compounds containing a pyrimidine nucleus are of special interests thanks to their applications in medicinal chemistry as they are the basic skeleton of several bioactive compounds such as antifungal, antibacterial, antitumor and antitubercular. As a part of our research in the synthesis of pyrimidine derivatives containing biological activities, some new tetrahydropyrimidine derivatives (1-10) were synthesized via Biginelli reaction using HCl or DABCO as a catalyst with good yields. All structures of products were confirmed by IR, 1H NMR and 13C NMR spectroscopy. The antibacterial activity of some synthesized compounds was investigated against Staphylococcus aureus (ATCC 6538), Staphylococcus epidermidis (ATCC 12228), Bacillus cereus (ATCC14579), Esherichia coli (ATCC 25922), Klebsiella pneumonia (ATCC 13883) and Pseudomonas aeruginosa (PAO1) bacteria. Some of these compounds such as 8 and 10 exhibited a good to significant antibacterial activity.

Introduction: Bacterial infection and the growing resistance of the bacteria to drugs is a global issue which challenges the health system. Therefore, the development of drugs with a different mechanism of action is a reasonable approach to overcome the drug resistance. Nitrofurans are antibacterial agents with broad-spectrum effects on various types of bacteria. In the present study, we aimed to review the reported derivatives of nitrofurans with antibacterial impacts to evaluate the potency and efficiency of these agents as candidates for antibacterial drug development.Methods: A systematic literature search was performed on April 2021 in databases using “Nitrofurans” and “antibacterial” as the keywords using all their equivalents, similar terms, and known forms. The search was first limited to original articles in the English language, and all the relevant articles were included for data extraction. The main outcomes in all the included studies were antibacterial efficacy and bactericidal power. Results: Overall, 36 articles were found and used for data extraction. Findings showed that nitrofuran-based compounds have satisfactory antimicrobial effects at the micromolar level. Most of these agents also revealed high efficacy on gram-positive and gram-negative bacteria with minimal toxicity on human cells. Findings suggested that chemical modification of nitrofurans with appropriate functional groups and molecules can enhance the efficiency of these agents.Conclusion: According to the included studies, nitrofuran and its derivatives can be considered promising candidates for future drug discovery to combat drug-resistant bacteria.