Novel Tetrazole-Based Antimicrobial Agents Targeting Clinical Bacteria Strains: Exploring the Inhibition of Staphylococcus aureus DNA Topoisomerase IV and Gyrase

Eleven novel imide-tetrazoles were synthesized. In the initial stage of research, in silico structure-based pharmacological prediction was conducted. All compounds were screened for antimicrobial activity using standard and clinical strains. Within the studied group, compounds 1–3 were recognized as leading structures with the most promising results in antimicrobial studies. Minimal inhibitory concentration values for compounds 1, 2, 3 were within the range of 0.8–3.2 μg/mL for standard and clinical Gram-positive and Gram-negative bacterial strains, showing in some cases higher activity than the reference Ciprofloxacin. Additionally, all three inhibited the growth of all clinical Staphylococci panels: Staphylococcus aureus (T5592; T5591) and Staphylococcus epidermidis (5253; 4243) with MIC values of 0.8 μg/mL. Selected compounds were examined in topoisomerase IV decatenation assay and DNA gyrase supercoiling assay, followed by suitable molecular docking studies to explore the possible binding modes. In summary, the presented transition from substrate imide-thioureas to imide-tetrazole derivatives resulted in significant increase of antimicrobial properties. The compounds 1–3 proposed here provide a promising basis for further exploration towards novel antimicrobial drug candidates.

Antioxidant and antimicrobial studies of nanochitosan, carboxymethyl cellulose and graphene oxide binary and ternary composites

The present study aimed to prepare binary and ternary composites of nanochitosan (NCS), carboxymethyl cellulose (CMC) and graphene oxide (GO) for the biological and biomedical application. The prepared NCS/CMC, CMC/GO and NCS/CMC/GO composites were characterized using FTIR, XRD and SEM studies. The results revealed the suitability of the material for biological application with increased amorphous nature for cell adhesion. Antimicrobial studies were carried out against selected bacterial and fungal species. DPPH scavenging activity was done for the prepared biocomposites. NCS/CMC/GO ternary composite have the highest action against Bacillus sp (21 mm) followed by Klebsilla sp. (19 mm) and Proteus sp. (16 mm). For selected fungal species of Candida, Rhizopus and Aspergillus niger the ternary composites shows 28 mm, 26 mm and 24 mm inhibitory zone. The overall results exhibit the potential antioxidant and antimicrobial activity of the prepared composites.

Phytochemical screening and evaluation of antimicrobial activity of Albizia ferruginea (Fabaceae) leaves extract

Phytochemical and antimicrobial activity of methanol extract of Albizia ferruginea (Guill and Perr) which belongs to the family of Fabaceae were studied. Phytochemical studies on the plant leaves showed that they contained alkaloids, tannins, flavonoids, steroids, saponins, cardiac glycoside and carbohydrate. Methanol extract of Albizia ferruginea showed growth inhibitory effects of varying degrees on S. feacalis, S. typhi, S. paratyphi, Shigella dysentriae and Klebsiella pneumonia but was not active on Streptococcus pyogenes and Pseudomonas aeruginosa. The minimum inhibitory concentration (MIC) of the extract was determined for the organisms whose growths were inhibited. The extract had MIC of 3.25mg/ml for S. feacalis, S. paratyphi, S. dysentriae and K. pneumoniae respectively. The antimicrobial studies of the extracts really justify the numerous folkloric uses of the plant parts in the treatment of some common ailments such as diarrhea, dysentery, fever, cough, pain and skin infections.

Novel Pyrimidinone Linked 1,2,3-Triazole Scaffolds as Anti-Microbial and Antioxidant Agents: Synthesis, In-vitro and In-silico Studies

The present study states the synthesis of a novel series of pyrimidinone linked 1,2,3-triazole scaffolds by click chemistry method. Further, the synthesized compounds were evaluated for their antimicrobial studies against S. aureus and S. pneumoniae. Among the synthesized compounds, almost all compounds demonstrated significant antimicrobial activity against S. aureus, S. pneumoniae, E.coli and P. aeruginosa, as evident from the zone of inhibition resulted. In addition, synthesised compounds were screened for their antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay method. Furthermore, computational study was performed to understand the interactions between synthesised compounds with dehydrosqualene synthase of Staphylococcus aureus (PDB ID: 2ZCS) and few Compound revealed the highest binding energies ΔG = -9.5, -9.8, and -10.1 Kcal/mol.

Expansion of Nanosized MgSiO3/Chitosan Nanocomposite Structural and Spectroscopic for Loading Velosef by Nanomaterial Intervention

The aim of this study is to investigate the effect of different doses of Velosef in magnesium silica/chitosan nanocomposite in terms of structural, morphology, optical properties, and bioactivity. Loading Velosef in fine-sized magnesium silica/chitosan is an efficient engineering approach for drug delivery. The sol-gel process was used to prepare magnesium silica fine-sized before being blended into chitosan matrix, which acts as a potential morphogenetic biomaterial. The Velosef/magnesium silica/chitosan nanocomposites were characterized by XRD, TEM, SEM, FTIR, UV-absorption, and antimicrobial studies. The XRD was characteristic of the crystallinity degree of the MgO-SiO2/chitosan/Velosef nanocomposites with three maximum peaks at 26.37°, 33.34o, 36.9°. FTIR results indicated the structural change occurred with the Velosef sol-gel polymerization process. UV-absorbance reveals that the MgO-SiO2/chitosan nanocomposite appeared a high performance for loading Velosef at two absorption bands at 253 and 347 nm. The MgO-SiO2/Chitosan/Velosef nanocomposites showed considerable antimicrobial activity in opposition to the tested representative microorganisms. The maximum antimicrobial activity was obtained with MgO-SiO2/Chitosan against both Escherichia coli and Candida albicans (37 mm), while the minimum antimicrobial activity (30 mm) was recorded against B. mycoides and E. coli with control.

Formulation of Nanoemulgel from Extracts of Musa acuminata: In-Vitro Kinetics and Antimicrobial Studies

The study was intended to formulate nanoemulgel from the leaf extract of Musa acuminata. Ethanol and Chloroform were used as solvents in the ratio of 1:8 (%w/v). DL- alpha-Tocopherol, characterized by GCMS, was identified to be the major component with potential biological activities. Based on a pseudo ternary plot, the 1:1 Smix (Surfactant: Co- Surfactant) ratio was optimized as it posed maximum regions of emulsion. The prepared nanoemulgel was evaluated for physical appearance, pH, spreadability, and swelling index. The appearance was pale yellowish-white, translucent within a pH range of 5-5.8. Antimicrobial studies were performed against dandruff-causing microbes (Staphylococcus epidermidis and Malassezia furfur). Invitro studies were carried out for optimized formulations of EG2, EG4, CG2, and CG3. The drug release of 94.28% after 12 h with Higuchi plot of R2 value as 0.99 was observed for EG2. The kinetically optimized formulation, EG2 was found to have good spreadability of 12.2 (g cm) s−1 and a swelling index of 64%.

Synthesis, Characterization and Antimicrobial studies of N-tert-amyl acrylamide (NTA) and 7-methacryloyloxy-4- methylcoumarin (MACU) Copolymers

Copolymers of N-tert-amylacrylamide (NTA) and 7-methacryloyloxy-4-methylcoumarin (MACU) were prepared by free radical polymerization in DMF at 600C using AIBN as an initiator. The copolymer compositions were determined by 1H-NMR analysis. The reactivity ratios of monomers were determined by Fineman-Ross (FR) (r1 = 1.33 and r2 = 0.60), KelenTudos (KT) (r1 = 1.33and r2 = 0.59). The r1.r2 = 0.798 indicated the formation of random copolymers.Tg found to increasing feed content of MACU. The antimicrobial studies showed that the copolymers are active against both Bacteria and Fungi.

Chemical profile and antiperiodontal potential of Thymus linearis Benth. Essential oil using ADMET prediction, In silico and in vitro tools

Periodontitis is an important health concern that is associated with long term complications. Development of resistance to antibiotics limits the treatment options in periodontitis. We investigated Thymus linearis essential oil for treatment of periodontitis. The essential oil was collected using hydrodistillation and characterized using GC-MS. The constituents were further analyzed for druglikeness, ADMET properties and molecular docking using transcription regulators 2UV0 and 3QP5. The GC-MS results revealed that carvacrol was a major constituent (76.26%) followed by caryophyllene oxide (6.83%) and L-borneol (6.08%). The in vitro antimicrobial studies showed significant inhibition against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa (MIC range 0.024 –0.312μg/mL). The essential oil showed a good inhibition of bacterial biofilm produced by S. aureus (72%) and S. epidermidis (70%). Finally, the antiquorum sensing property (30 mm zone of inhibition) was recorded with violacein inhibition (58%). Based on in silico and in vitro findings, it was concluded that T. linearis essential oil can be used for the treatment of periodontal infections.