Synthesis and Antimicrobial Properties of Naphthylamine Derivatives Having a Thiazolidinone Moiety

Objective. The aim of this study was to evaluate the influence of pharmacophores having naphthylamine and nitro groups on the antimicrobial (antibacterial and antifungal) activity of thiazolidinone derivatives. Materials and Methods. The initial 5-substituted-2-methylmercaptothiazolidin-4-ones were subjected to S-demethylation to yield 2-amino-substituted thiazolidinones. 4-Nitro-1-naphthylamine, nitrofuran aldehydes, and nitrobenzene aldehydes were used as pharmacophoric compounds having amino or aldehyde groups. Antimicrobial (antibacterial and antifungal) activity of the new compounds was tested in vitro against bacterial cultures – Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae – and fungal cultures – Candida albicans, Candida glabrata, Candida krusei, Candida kefyr, Candida tropicalis, and Candida parapsilosis. Results. Microbiological analysis showed that all new thiazolidinone derivatives with nitronaphthylamine substituent possessed antibacterial and antifungal properties. New compounds 2a-b showed similar antibacterial activity in vitro against S. aureus and B. subtilis as aminopenicillins. The lowest antibacterial activity of all newly synthesized compounds was against capsule-forming bacteria K. pneumoniae and against gram-negative bacteria E. coli (minimum inhibitory concentration range, 500–1000 μg/mL). Conclusions. The minimum inhibitory concentration of naphthylamine derivatives varied in the range of 0.4–1000 μg/mL, and activity of some newly synthesized compounds was similar to the activity of aminopenicillins and fluconazole, an antifungal preparation. Based on the results, it is possible to separate the perspective group of potential antimicrobial compounds

Naftilamino darinių, turinčių tiazolidinono ciklą, sintezė ir antimikrobinis aktyvumas

Objective. The aim of this study was to evaluate the influence of pharmacophores having naphthylamine and nitro groups on the antimicrobial (antibacterial and antifungal) activity of thiazolidinone derivatives. Materials and Methods. The initial 5-substituted-2-methylmercaptothiazolidin-4-ones were subjected to S-demethylation to yield 2-amino-substituted thiazolidinones. 4-Nitro-1-naphthylamine, nitrofuran aldehydes, and nitrobenzene aldehydes were used as pharmacophoric compounds having amino or aldehyde groups. Antimicrobial (antibacterial and antifungal) activity of the new compounds was tested in vitro against bacterial cultures – Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae – and fungal cultures – Candida albicans, Candida glabrata, Candida krusei, Candida kefyr, Candida tropicalis, and Candida parapsilosis. Results. Microbiological analysis showed that all new thiazolidinone derivatives with nitronaphthylamine substituent possessed antibacterial and antifungal properties. New compounds 2a-b showed similar antibacterial activity in vitro against S. aureus and B. subtilis as aminopenicillins. The lowest antibacterial activity of all newly synthesized compounds was against capsule-forming bacteria K. pneumoniae and against gram-negative bacteria E. coli (minimum inhibitory concentration range, 500–1000 μg/mL). Conclusions. The minimum inhibitory concentration of naphthylamine derivatives varied in the range of 0.4–1000 μg/mL, and activity of some newly synthesized compounds was similar to the activity of aminopenicillins and fluconazole, an antifungal preparation. Based on the results, it is possible to separate the perspective group of potential antimicrobial compounds

Biomarkers among terpenoids and quantity of epiphytic microflora of Artemisia L. species native for Lithuania

Chemijos institutasKauno medicinos universitetasVytauto Didžiojo universiteta

Antibiotic Resistance Mechanisms of Clinically Important Bacteria

Bacterial resistance to antimicrobial drugs is an increasing health and economic problem. Bacteria may be innate resistant or acquire resistance to one or few classes of antimicrobial agents. Acquired resistance arises from: (i) mutations in cell genes (chromosomal mutation) leading to cross-resistance, (ii) gene transfer from one microorganism to other by plasmids (conjugation or transformation), transposons (conjugation), integrons and bacteriophages (transduction). After a bacterium gains resistance genes to protect itself from various antimicrobial agents, bacteria can use several biochemical types of resistance mechanisms: antibiotic inactivation (interference with cell wall synthesis, e.g., β-lactams and glycopeptide), target modification (inhibition of protein synthesis, e.g., macrolides and tetracyclines; interference with nucleic acid synthesis, e.g., fluoroquinolones and rifampin), altered permeability (changes in outer membrane, e.g., aminoglycosides; new membrane transporters, e.g., chloramphenicol), and “bypass” metabolic pathway (inhibition of metabolic pathway, e.g., trimethoprim-sulfamethoxazole)

Determination of antimicrobial activity of raw material from Leonurus cardiaca L. and Leonurus sibiricus L

Background: Leonurus cardiaca L. and Leonurus sibiricus L. – are herbaceous perennial plants in the Lamiaceae family. Various preparations of Leonurus L. herb have different antimicrobial activity [1,2]. In this study used medicinal raw: Leonurus sibiricus L. and Leonurus cardiaca L. obtained from Kaunas Botanical Garden of Vytautas Magnus University, Leonurus cardiaca L. - Mažeikiai district, Leonurus sibiricus L. – Mexico. Materials and methods: Leonurus L. medicinal raw was extracted by different solvents. The extraction method of ethanolic and methanolic extracts – percolation. The aqueous extract preparation - dry herb material was added into distilled water and the water was heated until it started boil. Antibacterial activity of ethanolic and methanolic extracts were performed by agar dilution in Petri dishes, aqueous using agar diffusion method. The minimum inhibitory concentration (MIC) was established. Results: Aqueous extracts inhibited Enterococcus faecalis and Candida albicans, methanolic and ethanolic - Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus cereus, Bacillus subtillis, Proteus vulgaris. All of methanolic and ethanolic extracts showed the least MIC value against Bacillus cereus. The lowest MIC value was determined of Leonurus cardiaca L ethanolic extract (Kaunas Botanical Garden of Vytautas Magnus University) - 4,25 mg/mL against Staphylococcus aureus and methanolic extract of Leonurus cardiaca L. (Mažeikiai district) - 5 mg/mL against Klebsiella pneumoniae. Conclusions: Methanolic and ethanolic extracts of Leonurus cardiaca L. showed better antimicrobial activity than methanolic and ethanolic extracts of Leonurus sibiricus L. Plants habitat did not had the significant effect on antimicrobial activityLietuvos sveikatos mokslų universitetas. Medicinos akademijaLietuvos sveikatos mokslų universitetas. Veterinarijos akademija. Mikrobiologijos ir virusologijos institutasVytauto Didžiojo universiteta

Synthesis of novel sulphamethoxazole derivatives and exploration of their anticancer and antimicrobial properties.

A series of new derivatives based on sulfamethoxazole were designed and synthesized in this study. The structures of the new compounds were confirmed based on a comprehensive characterization of spectral data by applied IR and 1H as well as 13C NMR spectroscopy. The prepared compounds were tested for their anticancer and antimicrobial properties. Hydrazone 16b demonstrated convincing anticancer effect against all tested cell cultures such as human prostate carcinoma PPC-1 and human kidney carcinoma CaKi-1 cell lines, and human fibroblasts HF, n = 3. The most promising compound 16b showed higher activity against CaKi-1 cell line than the anticancer drugs axitinib and pazopanib used to treat renal cancer. Also, it was more active in the PPC-1 cell line compared to the approved PARP inhibitor Olaparib. Hydrazone 16b was also found to possess good antimicrobial properties against gram-positive bacteria strains of Staphylococcus aureus, Staphylococcus epidermidis, as well as Bacillus cereus

Formulation and Characterization of Potential Antifungal Oleogel with Essential Oil of Thyme

The aim of this research was to formulate oleogel with thyme essential oil with potential antimicrobial activity, design optimal formulation, and evaluate the influence of ingredients on texture parameters of preparation. Central composite design was applied to statistical optimization of colloidal silica and paraffin oil mixture for the modeling of oleogel delivery system. The influence of designed formulations on response variables (texture parameters), firmness, cohesiveness, consistency, and index of viscosity, was evaluated. Quality of essential oil of thyme was assessed by determinate concentration of thymol and carvacrol using gas chromatography with flame ionization detection (GC-FID). Microbiological tests have shown that oleogel with thyme essential oil affects Candida albicans microorganism when thyme essential oil’s concentration is 0,05% in oleogel mixture

Application of Antiviral, Antioxidant and Antibacterial <i>Glycyrrhiza glabra</i> L., <i>Trifolium pratense</i> L. Extracts and <i>Myristica fragrans</i> Houtt. Essential Oil in Microcapsules

Viruses and bacteria can disrupt normal human functions; therefore, ways to use the beneficial properties of plants to promote health are constantly being researched. Plant materials that accumulate biologically active compounds can be used to create a new pharmaceutical form. This study aimed to investigate the biological activity of selected plant extracts and essential oil and to produce microcapsules. The main compounds in extracts and essential oil were determined using chromatographic methods, antioxidant activity was evaluated spectrophotometrically, antimicrobial activity was assessed by monitoring the growth of nine pathogens, and the antiviral effect on infected bird cells with coronavirus was evaluated. Trifolium pratense L. extract had the highest antioxidant (26.27 ± 0.31 and 638.55 ± 9.14 µg TE/g dw by the DPPH and ABTS methods, respectively) and antiviral activity (56 times decreased titre of virus). Liquorice extract expressed antibacterial activity against Gram-positive pathogens and the highest antioxidant activity using the FRAP method (675.71 ± 4.61 mg FS/g dw). Emulsion stability depended on excipients and their amount. Microcapsules with extracts and essential oil were 1.87 mm in diameter, and their diameter after swelling was increased more than two times in intestinal media, while less than 0.5 times in gastric media