scholarly journals A Simple, Label-Free, and High-Throughput Method to Evaluate the Epigallocatechin-3-Gallate Impact in Plasma Molecular Profile

2020 ◽  
Vol 9 (2) ◽  
pp. 9 ◽  
Author(s):  
Rúben Araújo ◽  
Luís Ramalhete ◽  
Helder Da Paz ◽  
Edna Ribeiro ◽  
Cecília R.C. Calado
Keyword(s):  
High Throughput ◽  
Biological Activities ◽  
High Density Lipoproteins ◽  
Molecular Profile ◽  
Second Derivative ◽  
Plasma Samples ◽  
Label Free ◽  
Derivative Spectra ◽  
Second Derivative Spectra ◽  
The Impact

Epigallocatechin-3-gallate (EGCG), the major catechin present in green tea, presents diverse appealing biological activities, such as antioxidative, anti-inflammatory, antimicrobial, and antiviral activities, among others. The present work evaluated the impact in the molecular profile of human plasma from daily consumption of 225 mg of EGCG for 90 days. Plasma from peripheral blood was collected from 30 healthy human volunteers and analyzed by high-throughput Fourier transform infrared spectroscopy. To capture the biochemical information while minimizing the interference of physical phenomena, several combinations of spectra pre-processing methods were evaluated by principal component analysis. The pre-processing method that led to the best class separation, that is, between the plasma spectral data collected at the beginning and after the 90 days, was a combination of atmospheric correction with a second derivative spectra. A hierarchical cluster analysis of second derivative spectra also highlighted the fact that plasma acquired before EGCG consumption presented a distinct molecular profile after the 90 days of EGCG consumption. It was also possible by partial least squares regression discriminant analysis to correctly predict all unlabeled plasma samples (not used for model construction) at both timeframes. We observed that the similarity in composition among the plasma samples was higher in samples collected after EGCG consumption when compared with the samples taken prior to EGCG consumption. Diverse negative peaks of the normalized second derivative spectra, associated with lipid and protein regions, were significantly affected (p < 0.001) by EGCG consumption, according to the impact of EGCG consumption on the patients’ blood, low density and high density lipoproteins ratio. In conclusion, a single bolus dose of 225 mg of EGCG, ingested throughout a period of 90 days, drastically affected plasma molecular composition in all participants, which raises awareness regarding prolonged human exposure to EGCG. Because the analysis was conducted in a high-throughput, label-free, and economic analysis, it could be applied to high-dimension molecular epidemiological studies to further promote the understanding of the effect of bio-compound consumption mode and frequency.

Second‐Derivative Spectra for Estimating Crop Residue Cover

1994 ◽  
Vol 86 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Haiping Su ◽  
Michel D. Ransom ◽  
Edward T. Kanemasu ◽  
Tanvir H. Demetriades‐Shah
Keyword(s):  
Crop Residue ◽  
Second Derivative ◽  
Derivative Spectra ◽  
Second Derivative Spectra

Multi-wavelength analyses of second-derivative spectra for rapid determination of acetaminophen in serum.

1988 ◽  
Vol 34 (6) ◽  
pp. 1119-1121 ◽  
Author(s):  
B Dingeon ◽  
M A Charvin ◽  
M T Quenard ◽  
H Thome
Keyword(s):  
Phosphate Buffer ◽  
Rapid Determination ◽  
Turnaround Time ◽  
Second Derivative ◽  
Derivative Spectra ◽  
Multi Wavelength ◽  
Precision And Accuracy ◽  
Second Derivative Spectra ◽  
Method Of Extraction

Abstract Measurement of acetaminophen by analysis of the second derivative of its spectrum is specific and sensitive. The method of extraction and the use of just one phosphate buffer as reagent makes this method very convenient. Readings are reliable from 10 to 1500 mg/L. A turnaround time of 20 min makes this method well suited for emergency cases. Precision and accuracy of the method are presented. Results are not biased by interferences, not even from N-acetylcysteine.

Response of Ovalbumin to Fructose Addition and pH Variations - Ultrasonic and FTIR Study

2021 ◽  
Author(s):  
Lakshmanan Palaniappan ◽  
Kathiroli Kavitha
Keyword(s):  
Second Derivative ◽  
Alkaline Ph ◽  
Ph Variation ◽  
Ultrasonic Methods ◽  
Main Variable ◽  
Ultrasonic Analysis ◽  
Second Derivative Spectra ◽  
Α Helix ◽  
The Impact ◽  
Ph Variations

Main aim of this work is to understand how the protein ovalbumin is affected by the presence of cosolvent and variations in pH of the medium.  The addition of cosolvent in many cases is found to control the extent of denaturation and pH is one of the main sources of denaturant of proteins.  In this work, keeping fructose solution as cosolvent and pH of the solution as main variable, the extent of denaturation is analysed by ultrasonic methods and are further confirmed by FTIR amide-I second derivative spectra at 303 K. Obtained results shows that denaturation is sensitive to pH, however, acidic and alkaline behave totally in a different way.  It was found that the impact of alkaline pH produces lesser denaturation and is slower whereas the impact of acidic pH is specific and instantaneous. Ultrasonic analysis shows that pH variation can denature the protein whereas the addition of cosolvent supports renaturation. FTIR spectra were recorded for the experimental samples from which the second derivative curve fitted spectra were constructed using Origin program.  Quantitative assignment of peaks and the variations in cumulative areas calculated for the structures like α-helix, β-sheets etc confirms the observations of ultrasonic analysis that the pH variations aid in denaturation whereas the cosolvent supports the renaturation of protein. 

scholarly journals Unusual reactivity of Tyr-7 of GSH transferase P1-1

1993 ◽  
Vol 293 (2) ◽  
pp. 351-356 ◽  
Author(s):  
D J Meyer ◽  
C Xia ◽  
B Coles ◽  
H Chen ◽  
P Reinemer ◽  
...  
Keyword(s):  
Chemical Reactivity ◽  
Three Dimensional ◽  
Covalent Modification ◽  
Proton Acceptor ◽  
Dimensional Structure ◽  
Second Derivative ◽  
Tyrosine Residue ◽  
Derivative Spectra ◽  
Activity Sequence ◽  
Second Derivative Spectra

Reaction of human GSH transferase P1-1 (GSTP1-1) with diethylpyrocarbonate (DEPC) at pH 7.0 and 4 degrees C resulted in covalent modification of an equivalent of one histidine and one tyrosine residue per subunit, with loss of activity. Sequence analysis showed that His-71 and Tyr-7 were modified. Reference to the three-dimensional structure of GSTP1-1 [Reinemer, Dirr, Ladenstein, Huber, Lo Bello, Frederici and Parker (1992) J. Mol. Biol. 227, 214-226] shows that the modification of Tyr-7 is most likely to affect enzyme activity. Kinetic analysis of the DEPC modification of Tyr-7 in GSTP1-1 gave a k2 approx. 150 times that of a peptide comprising residues 1-11 of GSTP1-1. The reaction of Tyr-7 of GSTP1-1 with DEPC was poorly inhibited by 1 mM GSH (14%) or 10 microM S-hexylglutathione (18%). DEPC treatment of the enzyme altered the absorbance at 290 nm in second-derivative spectra, suggesting that a significant amount of tyrosinate ion occurs in the enzyme. GSH, however, did not significantly alter the A290. The data provide the first evidence of unusual chemical reactivity of Tyr-7 and are consistent with its proposed role as a proton acceptor during catalysis.

Approach for Increased Information from the Second-Derivative Spectra in UV-Vis Absorption Spectroscopy

1993 ◽  
Vol 47 (10) ◽  
pp. 1712-1715 ◽  
Author(s):  
Liudmil Antonov ◽  
Stefan Stoyanov
Keyword(s):  
Absorption Spectra ◽  
Wavelength Region ◽  
Second Derivative ◽  
Holographic Gratings ◽  
Long Wavelength ◽  
Derivative Spectra ◽  
Individual Bands ◽  
Basic Parameters ◽  
Computing Procedure ◽  
Second Derivative Spectra

The resolution of overlapping bands in the UV-Vis absorption spectra leading to determination of their basic parameters ([Formula: see text]) provides important information about the energies and probabilities of the electronic transitions. In the analysis of UV-Vis absorption spectra recorded linearly in wavelength by means of modern spectrophotometers with holographic gratings, the analytical shape describing individual bands is asymmetric. This factor leads to certain limitations in determining their number with the use of the second-derivative spectra and decreased effectiveness of the computing procedure. It was found that the loss of information in d2 A/dλ2 is due to its long-wavelength attenuation in comparison with d2 A/dν˜2. An analytical equation connecting d2 A/dλ2 with d2 A/dν˜2 is proposed, which restores the information from the second derivative in the long-wavelength region.

scholarly journals NIR Absorbance Characteristics of Deoxynivalenol and of Sound and Fusarium-Damaged Wheat Kernels

2009 ◽  
Vol 17 (4) ◽  
pp. 213-221 ◽  
Author(s):  
Kamaranga H.S. Peiris ◽  
Michael O. Pumphrey ◽  
Floyd E. Dowell
Keyword(s):  
Absorption Spectra ◽  
Near Infrared ◽  
Peak Height ◽  
Second Derivative ◽  
Absorption Bands ◽  
Derivative Spectra ◽  
Nir Absorption ◽  
Second Derivative Spectra ◽  
Food Reserves ◽  
Wheat Kernels

The near infrared (NIR) absorption spectra of deoxynivalenol (DON) and single wheat kernels with or without DON were examined. The NIR absorption spectra of 0.5–2000 ppm of DON in acetonitrile were recorded in the 350–2500 nm range. Second derivative processing of the NIR spectra and spectral subtractions showed DON absorption bands at 1408 nm, 1904 nm and 1919 nm. NIR spectra of sound and Fusarium-damaged kernels were also acquired using two instruments. Subtraction of average absorption spectra and second derivative spectra were evaluated to identify different NIR signatures of the two types of kernel. Differences in peak height and positions of the NIR absorption bands of the kernels were noted. At 1204 nm, 1365 nm and 1700 nm, the differences were in the heights of the absorption peaks. Such differences may be attributed to changes in the levels of grain food reserves such as starches, proteins and lipids and other structural compounds. Shifts in absorption peak positions between the two types of kernels were observed at 1425–1440 nm and 1915–1930 nm. These differences may arise from other NIR active compounds, such as DON, which are not common for the two types of kernel. Since the NIR absorption of DON may have contributed to the shifts between sound and Fusarium-damaged kernels, this study indicates the potential for NIR spectrometry to evaluate Fusarium damage in single kernels based on the DON levels.

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