Excitation Emission Matrix Spectral Subtraction Fluorescence to Check Adulteration of Petrol by Kerosene

Patra, Digambara; Mishra, Ashok Kumar

doi:10.1366/0003702011951740

Cited by 25 publications

(15 citation statements)

References 17 publications

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“…Upon 365-nm excitation, emission wavelengths were scanned from 422 to 432 nm using emission and excitation slits of 4.5 nm. In the 422-432-nm wavelength range, the value for fluorescence anisotropy of DPH is constant (19). The temperature of the samples was maintained at 30 or 4°C using a thermostatted water bath.…”

Section: Methodsmentioning

confidence: 99%

Energy Depletion Protects Candida albicans against Antimicrobial Peptides by Rigidifying Its Cell Membrane

Veerman

Valentijn-Benz

Nazmi

et al. 2007

Journal of Biological Chemistry

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Inhibitors of the energy metabolism, such as sodium azide and valinomycin, render yeast cells completely resistant against the killing action of a number of cationic antimicrobial peptides, including the salivary antimicrobial peptide Histatin 5. In this study the Histatin 5-mediated killing of the opportunistic yeast Candida albicans was used as a model system to comprehensively investigate the molecular basis underlying this phenomenon. Using confocal and electron microscopy it was demonstrated that the energy poison azide reversibly blocked the entry of Histatin 5 at the level of the yeast cell wall. Azide treatment hardly induced depolarization of the yeast cell membrane potential, excluding it as a cause of the lowered sensitivity. In contrast, the diminished sensitivity to Histatin 5 of energy-depleted C. albicans was restored by increasing the fluidity of the membrane using the membrane fluidizer benzyl alcohol. Furthermore, rigidification of the membrane by incubation at low temperature or in the presence of the membrane rigidifier Me 2 SO increased the resistance against Histatin 5, while not affecting the energy charge of the cell. In line, azide induced alterations in the physical state of the interior of the lipid bilayer. These data demonstrate that changes in the physical state of the membrane underlie the increased resistance to antimicrobial peptides.In the last few decades an expanding number of antimicrobial peptides have been isolated from virtually all classes of organisms, where they play an important role in the innate defense against microbial and viral infections. Characterization of these peptides has revealed a wide diversity in amino acid sequences, yet they share characteristic features; they are usually polycationic and amphipathic, containing both a hydrophilic and a hydrophobic side. This promotes their insertion into and transmigration over the cytoplasmic membrane of the target cell, with killing of the cell as a final consequence. Interestingly, cellular sensitivity to cationic proteins and peptides such as salivary histatins and defensins is diminished by conditions that affect the energy status of the target cell (1-6). This effect is not restricted to cationic peptides, because azoles are also sensitive to the energy status of Candida glabrata (7). In Chlorella metabolic inhibition abolishes the membrane-disruptive effects of the polyene nystatin and even of the detergent Triton X-100 (8). As explanation for the desensitizing effects of energy depletion, it has been proposed that interaction of cationic peptides with the target cell would involve active transport systems, which for their activity are dependent on the energy charge of the cell (1, 9 -12). However, direct experimental proof corroborating this hypothesis is still lacking.The present study addresses the question of how on a molecular level the energy metabolism is linked with the sensitivity of the Candida cell to antimicrobial peptides. Thus far, many different types of mechanisms have been identified that contr...

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Section: Methodsmentioning

confidence: 99%

Energy Depletion Protects Candida albicans against Antimicrobial Peptides by Rigidifying Its Cell Membrane

Veerman

Valentijn-Benz

Nazmi

et al. 2007

Journal of Biological Chemistry

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“…Although at higher concentration of petroleum products energy transfer among PAHs is substantial, an EEMF fingerprint cannot differentiate between contaminated and a neat sample of petroleum products (petrol-diesel). Recently Patra and Mishra were able to differentiate between contaminated and a neat sample of petrol [25] and diesel, [26] using the EEMF spectral subtraction method. PAHs generally found in the environment are low in concentration and it is expected that there is no energy transfer among PAHs at these low concentrations.…”

Section: Multicomponent Pahs Analysismentioning

confidence: 99%

Applications and New Developments in Fluorescence Spectroscopic Techniques for the Analysis of Polycyclic Aromatic Hydrocarbons

Patra¹

2003

Appl Sp Rev

Self Cite

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“…The technique is now used in the analysis of different liquids in various fields from environmental [11,12] and bio-medical research [13] to foodstuff [14][15][16]. Fluorescence EEM has also been applied to petroleum products and other industrial liquids [17][18][19][20] and its many applications were reviewed recently [21][22][23]. Fiber-coupled EEM spectroscopy has already demonstrated potential for the identification and quantification of jet fuel and jet turbine oil and lends itself to in-line and real-time analysis.…”

Section: Introductionmentioning

confidence: 99%

Assessment of the oxidative stability of lubricant oil using fiber-coupled fluorescence excitation–emission matrix spectroscopy

Omrani

Dudelzak

Hollebone

et al. 2014

Analytica Chimica Acta

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The fluorescence of antioxidant additives in lubricant oil was used as an indicator of oxidative stability of the oil. It was found that the decrease in fluorescence intensities of phenyl-α-napthylamine, its dimer, and another unidentified antioxidant coincide with the formation of decomposition products of the oil base stock. Simple kinetic models were developed that were capable of describing antioxidant reactions as a pseudo first-order processes. It is shown that fluorescence excitation emission matrix (EEM) spectroscopy coupled with an optical fiber probe can provide real-time assessment of the oxidative stability of the lubricant. Parallel factor (PARAFAC) analysis was used to correlate the component scores to the oil breakdown number.

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Excitation Emission Matrix Spectral Subtraction Fluorescence to Check Adulteration of Petrol by Kerosene

Cited by 25 publications

References 17 publications

Energy Depletion Protects Candida albicans against Antimicrobial Peptides by Rigidifying Its Cell Membrane

Energy Depletion Protects Candida albicans against Antimicrobial Peptides by Rigidifying Its Cell Membrane

Applications and New Developments in Fluorescence Spectroscopic Techniques for the Analysis of Polycyclic Aromatic Hydrocarbons

Assessment of the oxidative stability of lubricant oil using fiber-coupled fluorescence excitation–emission matrix spectroscopy

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