Effects of three azole derivatives on the lipids of different strains ofSporothrix schenckii

1997 ◽  
Vol 43 (12) ◽  
pp. 1197-1202 ◽  
Author(s):  
Agnes Kiesling Casali ◽  
Júnia Soares Hamdan

The comparative effects of ketoconazole, itraconazole, and fluconazole on the lipids of five Sporothrix schenckii strains were investigated. Quantitative analysis of lipids and sterols was completed, as well as qualitative analysis of sterols, by thin-layer chromatography and ultraviolet spectrophotometry. Growth of the S. schenckii isolates in the presence of azole derivative concentrations below the minimum inhibitory concentration (MIC) resulted in significant alterations in the lipid and sterol contents as compared with the control values. Furthermore, lanosterol was detected in these azole-treated cells. These results were in complete agreement with the proposed mechanism of action of azoles, which act by inhibiting ergosterol biosynthesis with a consequent accumulation of lanosterol. Concerning the MIC values, fluconazole was found to be the least effective drug. On the other hand, as determined from a comparison of the effects of the three azoles on the sterol content of the strains studied, no significant differences in efficacy were found among the tested drugs.Key words: Sporothrix schenckii, azole derivatives, lipids, sterols.

Author(s):  
Dian Ayu Eka Pitaloka ◽  
Elin Yulinah Sukandar

Objective: The resurgence of tuberculosis (TB) caused by Mycobacterium TB (MTB) is associated with the rapid spread of multidrug-resistant,therefore, the development of new antimycobacterial agents is necessary. The aim of this study was to evaluate the antimycobacterial activity ofursolic acid (UA) when it using alone and combination with TB drugs.Methods: MTB H37Rv strain, streptomycin-rifampicin resistant strain, and isoniazid-ethambutol resistant strain were evaluated by susceptibility testusing a serial number of UA (25-150 µg/mL). Minimum inhibitory concentration (MIC) was read as minimum concentration of drugs that completelyinhibit visible growth of organism. Activities of drug combination of UA with TB drug were determined in Lowenstein-Jensen media by calculatingthe fractional inhibitory concentration index.Results: The results showed that MIC of UA was 50 µg/mL against three different strains of MTB. The combination of UA and TB drugs displayedsynergistic interaction, and no antagonism result from the combination was observed for strains of MTB.Conclusion: These results indicate that UA may serve as a promising lead compound for future antimycobacterial drug development.Keywords: Ursolic acid, Tuberculosis, Drug combination, Susceptibility test


2020 ◽  
Author(s):  
Khaled El Khatib ◽  
Ribal Aby Hadeer ◽  
Anis Saad ◽  
Aline Kalaydjian ◽  
Elie Fayad ◽  
...  

Abstract Objective: This study investigated the antibacterial activity of Ilex paraguariensis extracts against 32 different strains of non-typhoidal Salmonella (NTS) through the determination of the Minimum Inhibitory Concentration (MIC), Mutant Prevention Concentration (MPC), Mutant Selection Window (MSW), and the detection of virulence genes by multiplex PCR assays. Results: The MIC values of Ilex paraguariensis against Salmonella spp. strains varied between 0.78 mg/ml and 6.25 mg/ml with a MIC 90 of 3.12 mg/ml. The highest MPC in this study was 48 mg/ml yielding a Mutant Selection Window of 41.75 mg/ml. The MSW values of the remaining strains varied between 1.56 and 8.87 mg/ml. Genes of pathogenicity detected in Salmonella spp. isolates were most commonly the stn, sdiA, invA, sopB, invH, and sopE genes. The antibacterial activity of Yerba Mate extracts was not affected by the antimicrobial resistance patterns or pathogenicity genes expressed. More work is needed to identify the active antibacterial compound(s) responsible for the antibacterial activity.


2020 ◽  
Vol 10 (2) ◽  
pp. 82
Author(s):  
Fatemeh Samieerad ◽  
Nematollah Gheibi

Background: Propolis is one of the useful bee colony products that have been used in traditional medicine for centuries. In this study, the physicochemical characters and their antibacterial effect of Iranian Propolis collected from Qazvin province was assessed.Methods: In this study, Thin Layer Chromatography and Vacuum Liquid Chromatography to detect different compounds of the extract have been used. In the initial evaluation of Propolis extract, it was found that the extract includes variable compounds with different polarity; so, the initial classification of extract with different polarity solvents was essential. Finally, 0.1 gr hydro alcoholic Propolis was injected to the HPLC by ultrasound. The antibacterial effect of Iranian ethanol extract Propolis was measured using a microdilution method against Pseudomonas aeruginosa: P. aeruginosa and Staphylococcus aureus: S.aureus standard strains and the minimum bactericidal and inhibitory concentration were defined.Results: Primary analysis of the ethanol extract by analytical Thin Layer Chromatography, demonstrated the presence of flavonoid and phenol in it. Minimum inhibitory concentration and Minimum Bactericidal Concentration for Staphylococcus aureus: S.aureus standard strain was 2.5mg/ml. The same procedure was done for Pseudomonas aeruginosa: P. aeruginosa standard strain and the Minimum inhibitory concentration and Minimum Bactericidal Concentration were 50mg/ml of Propolis extracts.  Conclusion: According to the results, the alcoholic extract of propolis from Qazvin province of Iran provides significant antimicrobial activity. Its powerful activity may be due to high total phenolic and flavonoid contents.Keywords: Iranian propolis, Antibacterial activity, Phenolic compounds, Flavonoid compound


1974 ◽  
Vol 1 (2) ◽  
pp. 183 ◽  
Author(s):  
KF Faull ◽  
BG Coombe ◽  
LG Paleg

Two gibberellins, one GA1-like, the other GA3-like, were identified in the extracts of roots and tops of 8-,11- and 15-day-old barley seedlings by paper chromatography, paper electrophoresis, thin-layer chromatography, gas-liquid chromatography and bioassay procedures, followed by combined gas chromatography-mass spectrometry. The amounts of gibberellins in the seedlings ranged from 7 to 11 ng per plant. The concentrations of gibberellins in the seedlings were 32-320 ng/g dry weight and 5-28 ng/g fresh weight; concentrations in the roots were higher than those in the shoots.


1965 ◽  
Vol 48 (3) ◽  
pp. 569-573
Author(s):  
J B Haus ◽  
L Manolev ◽  
R W Price

Abstract A method for the assay of sulfoxide in insectieidal formulations involves separation of the sulfoxide from the other components by column chromatography on silicic acid with three successive eluting solutions: chloroform; 2% acetone in chloroform; and 10% acetone in chloroform. Sulfoxide is removed in the last eluate and is determined by ultraviolet spectrophotometry. Solvents, emulsifiers, pyrethrins, compounds related to sulfoxide, and other insecticides tested are separated by the column.


2001 ◽  
Vol 67 (2) ◽  
pp. 956-960 ◽  
Author(s):  
Tyler J. Avis ◽  
Richard R. Bélanger

ABSTRACT cis-9-Heptadecenoic acid (CHDA), an antifungal fatty acid produced by the biocontrol agent Pseudozyma flocculosa, was studied for its effects on growth and/or spore germination in fungi. Inhibition of growth and/or germination varied considerably and revealed CHDA sensitivity groups within tested fungi. Analysis of lipid composition in these fungi demonstrated that sensitivity was related primarily to a low intrinsic sterol content and that a high level of unsaturation of phospholipid fatty acids was not as involved as hypothesized previously. Our data indicate that CHDA does not act directly with membrane sterols, nor is it utilized or otherwise modified in fungi. A structural mechanism of CHDA, consistent with the other related antifungal fatty acids produced by P. flocculosa, is proposed in light of its activity and specificity. The probable molecular events implicated in the sensitivity of fungi to CHDA are (i) partitioning of CHDA into fungal membranes; (ii) a variable elevation in fluidity dependent on the buffering capability (sterol content) in fungi; and (iii) higher membrane disorder causing conformational changes in membrane proteins, increased membrane permeability and, eventually, cytoplasmic disintegration.


Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 281
Author(s):  
Adrian Zaragoza-Bastida ◽  
Saudy Consepcion Flores-Aguilar ◽  
Liliana Mireya Aguilar-Castro ◽  
Ana Lizet Morales-Ubaldo ◽  
Benjamín Valladares-Carranza ◽  
...  

Rattlesnakes have venoms with a complex toxin mixture comprised of polypeptides and proteins. Previous studies have shown that some of these polypeptides are of high value for the development of new medical treatments. The aim of the present study is to evaluate, in vitro, the antibacterial and hemolytic activity of Crotalus triseriatus and Crotalus ravus venoms. A direct field search was conducted to obtain Crotalus triseriatus and Crotalus ravus venom samples. These were evaluated to determine their antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa through the techniques of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Hemolytic activity was also determined. Antibacterial activity was determined for treatments (Crotalus triseriatus 2) CT2 and (Crotalus ravus 3) CR3, obtaining a Minimum Inhibitory Concentration of 50 µg/mL and a Minimum Bactericidal Concentration of 100 µg/mL against Pseudomonas aeruginosa. CT1 (Crotalus triseriatus 1), CT2, and CR3 presented hemolytic activity; on the other hand, Crotalus ravus 4 (CR4) did not show hemolytic activity. The results of the present study indicate for the first time that Crotalus triseriatus and Crotalus ravus venoms contain some bioactive compounds with bactericidal activity against Pseudomonas aeruginosa which could be used as alternative treatment in diseases caused by this pathogenic bacterium.


1967 ◽  
Vol 50 (4) ◽  
pp. 934-938
Author(s):  
Paul E Corneliussen

Abstract A rapid method for determining biphenyl in citrus fruits has been developed and was studied collaboratively. Biphenyl is separated from fruit tissue by steam liquidliquid extraction. The ra-heptane extract is subjected to preparative thin layer chromatography (TLC) on plates coated with silica gel containing phosphors for ready visibility of the biphenyl spots under UV light. The spots are removed from the plate and extracted with alcohol for spectrophotometric measurement at 248 mμ. The TLC cleanup adds specificity to the method; o-phenylphenol, if present, does not interfere and crop blanks are insignificant. The average of 36 recoveries (12 each at abovit 100, 50, and 10 ppm) was 96.7% with a mean deviation of 10.7%. It is recommended that the method be adopted as official, first action.


1973 ◽  
Vol 56 (4) ◽  
pp. 822-826
Author(s):  
Stanley Nesheim

Abstract To test the method of Nesheim et al., 6 samples wert; analyzed in 13 laboratories. The samples encompassed a blank and 5 samples containing one or more ochratoxins in the range 50–200 μg/kg. Two samples were spiked with the 4 ochratoxin standards and 3 were spiked with barley naturally contaminated with ochratoxin A. The confirmation of identity of ochratoxins A and B by preparation of their ethyl ester derivatives was also tested. The average recovery of standard ochratoxin A was 112% at levels of 45 and 90 μg/kg, with a 27.1% coefficient of variation calculated from analysis of variance, one analyst, one replicate. Similar satisfactory results were obtained for the ethyl esters of A and B at a level of 120 μg/kg. The results were unsatisfactory for ochratoxin B and for the esters of A and B at the 60 μg/kg level. The chemical confirmation test was satisfactory for both ochratoxins A and B. The method, including chemical confirmation, has been adopted as official first action as quantitative for ochratoxin A and qualitative for the other toxins.


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