Search results for "Microbial Sensitivity Tests"
showing 10 items of 333 documents
Antifungal activity and tautomeric cyclization equilibria of formylphenylboronic acids
2019
2-Formylphenylboronic acid and four isomeric fluoro-2-formylphenylboronic acids have been found active against a series of fungal strains: Aspergillus, Fusarium, Penicillium and Candida. The level of antifungal activity was evaluated by agar diffusion tests as well as the determination of minimum inhibitory concentrations (MICs) by serial dilution method. Among the tested compounds, 4-fluoro-2-formylphenylboronic acid - an analogue of the known antifungal drug Tavaborole (AN2690) - proved to be the most potent antifungal agent. The tautomeric equilibrium leading to the formation of 3-hydroxybenzoxaboroles as well as the position of the fluorine substituent were revealed to play a crucial ro…
Synthesis, Properties and Antimicrobial Activity of 5-Trifluoromethyl-2-formylphenylboronic Acid
2020
2-Formylphenylboronic acids display many interesting features, not only from synthetic but also from an application as well as structural points of view. 5-Trifluoromethyl-2-formyl phenylboronic acid has been synthesized and characterized in terms of its structure and properties. The presence of an electron-withdrawing substituent results in a considerable rise in the acidity in comparison with its analogues. In some solutions, the title compound isomerizes with formation of the corresponding 3-hydroxybenzoxaborole. Taking into account the probable mechanism of antifungal action of benzoxaboroles, which blocks the cytoplasmic leucyl-tRNA synthetase (LeuRS) of the microorganism, docking stud…
Synthesis and antifungal activity of new N-(1-phenyl-4-carbetoxypyrazol-5-yl)-, N-(indazol-3-yl)- and N-(indazol-5-yl)-2-iodobenzamides
2002
N-(1-Phenyl-4-carbetoxypyrazol-5-yl)-, N-(indazol-3-yl)- and N-(indazol-5-yl)-2-iodobenzamides 6, with a Benodanil-like structure, were synthesized by refluxing in acetic acid the corresponding benzotriazinones 5 with potassium iodide for 1 h in order to study the role on the antifungal activity of the N-substitution with an aromatic heterocyclic system on benzamide moiety. Among the tested iododerivatives, compounds 6d,f,g,h possess interesting activities toward some phytopathogenic fungal strains.
Chemical and antifungal investigations of six Lippia species (Verbenaceae) from Brazil
2012
Made available in DSpace on 2013-09-27T14:52:47Z (GMT). No. of bitstreams: 1 WOS000310396700165.pdf: 536437 bytes, checksum: d267984ddfcb57d1406b069856adcc25 (MD5) Previous issue date: 2012-12-01 Made available in DSpace on 2013-09-30T19:10:31Z (GMT). No. of bitstreams: 1 WOS000310396700165.pdf: 536437 bytes, checksum: d267984ddfcb57d1406b069856adcc25 (MD5) Previous issue date: 2012-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:20:39Z No. of bitstreams: 1 WOS000310396700165.pdf: 536437 bytes, checksum: d267984ddfcb57d1406b069856adcc25 (MD5) Made available in DSpace on 2014-05-20T14:20:39Z (GMT). No. of bitstreams: 1 WOS000310396700165.pdf: …
Bioactive Steroidal Saponins from Smilax medica
2006
Two new spirostanol saponins ( 1 and 2) were isolated from the roots of Smilax medica, together with the known smilagenin 3-O-beta-D-glucopyranoside (3). Their structures were determined by spectroscopic methods including 1D- and 2D-NMR experiments. Compounds 1 and 2 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (MICs between 6.25 and 50 microg/mL) whereas 3 was inactive.
Antibacterial and Antifungal Activities of Acetonic Extract from Paullinia cupana Mart Seeds
2013
The antibacterial and antifungal activities of the acetone extract from Paullinia cupana var. sorbilis Mart. (Sapindaceae) seeds, commonly called guarana, were assessed against selected bacterial and fungal strains. We tested the extract against both standard American Type Culture Collection (ATCC) and clinically isolated (CI) bacterial strains and three fungal strains. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for bacteria and MIC and minimum fungicidal concentration for fungi were determined. The extract showed an activity against the nine bacterial strains tested, both CI and ATCC strains (MIC comprised between 32 and 128 μm/mL and MBC bet…
Novel isoquinoline derivatives as antimicrobial agents.
2013
The wide variety of potent biological activities of natural and synthetic isoquinoline alkaloids encouraged us to develop novel antimicrobial isoquinoline compounds. We synthesized a variety of differently functionalized 1-pentyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (THIQs), including dihydroisoquinolinium salts (2 and 5), methyl pentanoate-THIQ (6), 1-pentanol-THIQ (7), ester derivatives (8-15) and carbamate derivatives (16-23). We employed classic intramolecular Bischler-Napieralski cyclodehydration to generate the isoquinoline core. All the structures were characterized by nuclear magnetic resonance and mass spectrometry. The bactericide and fungicide activities were evaluated f…
Bioactivity of essential oils in phytopathogenic and post-harvest fungi control
2017
[EN] Commercial thyme and lavender essential oils were analysed by GC/MS. Sixty-six compounds accounting for 98.6¿99.6% of total essential oil were identified. Thymol (52.14 ± 0.21%), followed by pcymene (32.24 ± 0.16%), carvacrol (3.71 ± 0.01%) and ¿-terpinene (3.34 ± 0.02%), were the main compounds in thyme essential oil, while large amounts of oxygenated monoterpenes linalool acetate (37.07 ± 0.24%) and linalool (30.16 ± 0.06%) were found in lavender one. In vitro antifungal activity of the essential oils was evaluated at 200 and 300 ¿g/mL against 10 phytopathogenic and post-harvest fungi, which significantly affect agriculture. Micelial growth inhibition was calculated for each tested f…
Steroidal saponins from the roots of Smilax aspera subsp. mauritanica
2008
Two new steroidal saponins (1, 2) were isolated from the roots of Smilax aspera subsp. mauritanica (POIR.) ARCANG. (Liliaceae), together with the known curillin G (3), asparagoside E (4), asparoside A (5), asparoside B (6) and the phenolic compound resveratrol (7). Their structures were established mainly on the basis of 600 MHz 2D-NMR spectral data. 3 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (minimum inhibitory concentrations of 25, 25 and 50 microg/ml, respectively) whereas the other compounds were inactive.
Role of the virulence plasmid pR99 and the metalloprotease Vvp in resistance of Vibrio vulnificus serovar E to eel innate immunity
2007
Vibrio vulnificus biotype 2 serovar E (VSE) is a bacterial pathogen that produces a haemorrhagic septicaemia called vibriosis in eels. Its ability to grow in blood is conferred by a recently described virulence plasmid [Lee CT, Amaro C, Wu KM, Valiente E, Chang YF, Tsai SF, et al. A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid. Journal of Bacteriology, submitted for publication.]. In this study, we analyzed the role of this plasmid together with the role played by the metalloprotease (Vvp) in the interaction between bacteria and eel innate immunity. To this end, we compared and statistically analyzed the differences in resistance …