Synthesis of New Thiazole Derivatives Bearing Thiazolidin-4(5H)-One Structure and Evaluation of Their Antimicrobial Activity

The first report about antimicrobial resistance was published in the 1940s. And today, the antimicrobial resistance has become a worldwide problem. Because of this problem, there is a need to develop new drugs. That's why we synthesized some novel thiazolidine-4-one derivatives and evaluated their antimicrobial activity. The final compounds were obtained by reacting 2-[(4,5-diphenylthiazol-2-yl)imino]thiazolidin-4-one with some aryl aldehydes. The synthesized compounds were investigated for their antimicrobial activity against four Candida species, five gram-negative and four gram-positive bacterial species. The lead compounds (4a- h) were obtained with a yield of at least 70%. All compounds showed antimicrobial activity. Compound 4f (MIC: 31.25 µg/ml) exhibited more efficacy than the other compounds against C. glabrata (ATCC 24433). Compound 4b (MIC: 62.5 µg/ml) was the most active compound against all bacterial species, particularly K. pneumoniae (NCTC 9633). Whereas, compound 4c (MIC: <31.25 µg/ml) was observed as the most active compound against E. coli (ATCC 25922). In general, all compounds (4a-4h) showed antimicrobial activity against all fungi and bacterial species. Compounds 4b (2,6-dichlorobenzylidene), 4c (2,6-dihydroxybenzylidene), 4f (1H-pyrrol-2- yl)methylene), 4g (4-triflouromethylbenzylidene) and 4h (2,3,4-trimethoxybenzylidene) were determined as the most active compounds

Characterization of Antimycins - Producing Streptomycete Strain VY46 Isolated from Slovak Soil

ABSTRACT The strain no. VY46 was isolated from agricultural soil of Slovak republic and tested for potential antimicrobial activity against various human pathogens. On the basis of results, strain VY46 significantly inhibited growth of yeast Candida albicans and therefore was used for further characterization. In order to explore the potential bioactivities, extract of the fermented broth culture was prepared with organic solvent extraction method. The ethylacetate extract was subjected to HPLC fractionation against Candida albicans and followed by LC/MS analysis for potential production of anticandidal substances. The analysis resulted in the identification of two antimycins antibiotics, which may be responsible for important anticandidal activity of the strain. On the basis of liquid chromatography and mass spectrometry the antibiotics were identified as Urauchimycin A and Kitamycin A. According tothe results from cultural, morphological, physiological, biochemical and 16S rRNA gene sequence methods, the strain was identified as Streptomyces albidoflavus. In addition, neighbor-joining phylogenetic tree confirmed the relationships of this strain to other members of Streptomyces genera.

Antifungal Activity of Roots Barks Extract of Securinega virosa (Roxb. ex Willd.) Baill and Anogeissus leiocarpa (DC.) Guill. & Perr, Two Plants Used in the Traditional Treatment of Candidiasis in Northern Côte d'Ivoire.

Aims: To evaluate the anticandidal activity of some solvent extracts of Securinega virosa and Anogeissus leiocarpa from northern Côte d'Ivoire. Study Design: In vitro assay of antifungal activity. Place and Duration of Study: Biochemical Pharmacodynamy Laboratory, Biosciences Department, University Félix Houphouët-Boigny and Bacteriology-Virology Laboratory University Hospital of Treichville, Côte d’Ivoire between January and December 2013. Methods: The herbs studied were examined for diameter of inhibition zone using agar well diffusion method; minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) using microdilution method. Results: All tested plants extracts, except the aqueous extracts, showed varying zones of inhibition against fungi tested. The diameters of inhibition zones for all organic extracts are greater than 10 mm for a sample concentration of 500 mg/ml and were significantly higher than for nystatine (p <0.05; p <0.01). The ethanol extract of Anogeissus leiocarpa revealed the strongest anticandidal activity against all tested strains with MICs ranging from 0.195 to 12.5 mg/ml, and MFCs from 0.390 to 50 mg/ml. The phytochemical screening of extracts shows the presence of polyterpenes and sterols, polyphenols, flavonoids, catechin tannins and alkaloids. Conclusion: S. virosa and A. leiocarpa possesse compounds with good anticandidal properties. This results support their traditional use in treatment of infectious diseases caused by certain Candida species.

Antibacterial and Anticandidal Activities of New Flavonoids from Streptomyces sp. HK17; an Endophyte in Curcuma longa Linn.

Aims: The purpose of this study was to investigate the antibacterial and anticandidal activities of new flavonoids from Streptomyces sp. HK17 which was isolated from the root tissue of Curcuma longa Linn. Study Design: Experimental study. Place and Duration of Study: The study was carried out at the Department of Microbiology and Department of Chemistry, Faculty of Science, Silpakorn University, between February and May 2014. Methodology: The major active ingredients from the crude extract were purified by silica gel column chromatography, thin-layer chromatography. The diameters of the zones of inhibition and the Minimum Inhibitory Concentration (MIC) were determined using the paper disc diffusion and the microbroth dilution methods respectively. Results: The crude extract and purified compounds were tested for their antibacterial activity against Staphylococcus aureus ATCC25932, Bacillus cereus ATCC7064 and Bacillus subtilis ATCC6633, Escherichia coli ATCC10536 and Pseudomonas aeruginosa ATCC27853 and anticandidal activity against Candida albicans ATCC190088. The crude extract showed the highest activity against S. aureus and C. albicans, with MIC values of 32 μg/ml. The purified compounds 3 showed the lowest MIC (32 μg/ml) and Minimum Microbicidal Concentration (MMC) (128 μg/ml) against S. aureus and C. albicans with corresponding large diameter of the zone of inhibitions (25.5 and 25.2 mm respectively). Conclusion: This study has shown that the new flavonoids were first isolated and identified. These flavonoids produced by Streptomyces sp. HK17 have potential in antibacterial and anticandidal activities.

Assessment of antifungal activity of herbal and conventional toothpastes against clinical isolates of Candida albicans

Objective: To detect the anticandidal activity of nine toothpastes containing sodium fluoride, sodium monofluorophosphate and herbal extracts as an active ingredients against 45 oral and non oral Candida albicans (C. albicans) isolates. Methods: The antifungal activity of these toothpaste formulations was determined using a standard agar well diffusion method. Statistical analysis was performed using a statistical package, SPSS windows version 15, by applying mean values using one-way ANOVA with post-hoc least square differences (LSD) method. A P value of less than 0.05 was considered significant. Results: All toothpastes studied in our experiments were effective in inhibiting the growth of all C. albicans isolates. The highest anticandidal activity was obtained from toothpaste that containing both herbal extracts and sodium fluoride as active ingredients, while the lowest activity was obtained from toothpaste containing sodium monofluorophosphate as an active ingredient. Antifungal activity of Parodontax toothpaste showed a significant difference (P< 0.001) against C. albicans isolates compared to toothpastes containing sodium fluoride or herbal products. Conclusions: In the present study, it has been demonstrated that toothpaste containing both herbal extracts and sodium fluoride as active ingredients are more effective in control of C. albicans, while toothpaste that containing monofluorophosphate as an active ingredient is less effective against C. albicans. Some herbal toothpaste formulations studied in our experiments, appear to be equally effective as the fluoride dental formulations and it can be used as an alternative to conventional formulations for individuals who have an interest in naturally-based products. Our results may provide invaluable information for dental professionals.

Gallic acid: An anticandidal compound in hydrolysable tannin extracted from the barks of Rhizophora apiculata Blume.

A research was conducted to study the anticandidal compound of tannin extracted from the barks of a mangrove tree, Rhizophora apiculata Blume. Tannin obtained from the barks of Rhizophora apiculata Blume was further separated into condensed and hydrolysable tannins. A strong anticandidal activity was detected in the hydrolysable tannin, which exhibited minimal inhibitory concentration (MIC) of 6.25 mg/ml, and it was found to have yeastostatic activity at lower concentration (below MIC value) and yeastocidal activity at higher concentration (more than the MIC value). Furthermore, the isolation of the bioactive compound in hydrolysable tannin that responsible for the anticandidal activity was also determined using thin layer chromatography and high-performance liquid chromatography (HPLC). The results obtained confirmed that gallic acid was the bioactive compound that plays role in inhibiting and killing the Candida albicans cells.