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Papers by Jitraporn Vongsvivut

An inclusion host-guest complex between β-cyclodextrin (β-CD) and L-phenylalanine (L-Phe) was inv... more An inclusion host-guest complex between β-cyclodextrin (β-CD) and L-phenylalanine (L-Phe) was investigated using 1 H nuclear magnetic resonance spectroscopy and molecular docking techniques. 1 H chemical shift changes of β-CD were used to calculate the stability constant (K stb ) of the complex. On the basis of the Hildebrand-Benesi method, the K stb of the 1:1 complex in D 2 O solution at 300 K, pD 7.6 was of 25.5 M -1 , implying a fast intermolecular exchange rate process. Interestingly, docking simulation indicates the toroidal space can be occupied by L-Phe with two favorable arrangements. For the predicted model with the higher probability score, the L-Phe aromatic ring is facing to the secondary hydroxyl groups of β-CD. Results from NMR and docking simulation are in good agreement with the x-ray structures of β-CD/L-phenylalanine derivatives.

Applied Spectroscopy, 2004

Cylinder-planar Ge waveguides are being developed as evanescentwave sensors for chemical microana... more Cylinder-planar Ge waveguides are being developed as evanescentwave sensors for chemical microanalysis. The only non-planar surface is a cylinder section having a 300-mm radius of curvature. This confers a symmetric taper, allowing for direct coupling into and out of the waveguide's 1-mm 2 end faces while obtaining multiple re ections at the cen tral ,30-mm -thick sensing region. Ray-optic calculations indicate that the propagation angle at the central minimum has a strong nonlinear dependence on both angle and vertical position of the input ray. This results in rather inef cient coupling of input light into the off-axis modes that are most useful for evanescent-w ave absorption spectro scopy. Mode-speci c performance of the cylinder-planar waveguides has also been investigated experimentally. As compared to a blackbody source, the much greater brightness of synchrotron-generated infrared (IR) radiation allows a similar total energy throughput, but restricted to a smaller fraction of the allowed waveguide modes. However, such angle-selective excitation results in a strong oscillatory interference pattern in the transmission spectra. These spectral oscillations are the principal technical limitation on using synchrotron radiation to measure evanescent-wave absorption spectra with the thin waveguides.

Nutrients, 2014

The utilization of food waste by microorganisms to produce omega-3 fatty acids or biofuel is a po... more The utilization of food waste by microorganisms to produce omega-3 fatty acids or biofuel is a potentially low cost method with positive environmental benefits. In the present study, the marine microorganisms Thraustochytrium sp. AH-2 and Schizochytrium sp. SR21 were used to evaluate the potential of breadcrumbs as an alternate carbon source for the production of lipids under static fermentation conditions. For the Thraustochytrium sp. AH-2, submerged liquid fermentation with 3% glucose produced 4.3 g/L of biomass and 44.16 mg/g of saturated fatty acids after seven days. Static fermentation with 0.5% and 1% breadcrumbs resulted in 2.5 and 4.7 g/L of biomass, and 42.4 and 33.6 mg/g of saturated fatty acids, respectively. Scanning electron microscopic (SEM) studies confirmed the growth of both strains on breadcrumbs. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy for both strains were consistent with the utilization of breadcrumbs for the production of unsaturated lipids, albeit at relatively low levels. The total lipid yield for static fermentation with bread crumbs was marginally lower than that of fermentation with glucose media, while the yield of unsaturated fatty acids was considerably lower, indicating that static fermentation may be more appropriate for the production of biodiesel than for the production of omega-3 rich oils in these strains.

Journal of Inorganic Biochemistry, 2011

and sharing with colleagues.

Food Chemistry, 2012

The research describes a rapid method for the determination of fatty acid (FA) contents in a micr... more The research describes a rapid method for the determination of fatty acid (FA) contents in a micro-encapsulated fish-oil (lEFO) supplement by using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic technique and partial least square regression (PLSR) analysis. Using the ATR-FTIR technique, the lEFO powder samples can be directly analysed without any pre-treatment required, and our developed PLSR strategic approach based on the acquired spectral data led to production of a good linear calibration with R 2 = 0.99. In addition, the subsequent predictions acquired from an independent validation set for the target FA compositions (i.e., total oil, total omega-3 fatty acids, EPA and DHA) were highly accurate when compared to the actual values obtained from standard GC-based technique, with plots between predicted versus actual values resulting in excellent linear fitting (R 2 P 0.96) in all cases. The study therefore demonstrated not only the substantial advantage of the ATR-FTIR technique in terms of rapidness and cost effectiveness, but also its potential application as a rapid, potentially automated, online monitoring technique for the routine analysis of FA composition in industrial processes when used together with the multivariate data analysis modelling.

American Institute of …, 2010

Surface-enhanced Raman scattering (SERS) spectra of fonofos, an organophosphorous pesticide (OPP)... more Surface-enhanced Raman scattering (SERS) spectra of fonofos, an organophosphorous pesticide (OPP), were recorded using citrate-reduced silver (Ag) and gold (Au) colloidal nanoparticles in the form of dried films. In this study, significant enhancements were achieved with fonofos concentrations down to ∼10 ppm with the Ag colloids, demonstrating a potential for the technique in the analysis of fonofos residues. Successful formation of the SERS-active metal aggregates was indicated by the presence of a plasmon band at longer wavelengths in the UV-visible spectrum. Transmission electron microscopy (TEM) images revealed distinctively different morphologies of the aggregates formed by the two metals, while the observed SERS spectral features of fonofos were also found to be different for molecules adsorbed on Ag and Au colloidal surfaces. This evidence suggests metal-induced changes in adsorption behavior of the fonofos analyte, leading to the different binding structures onto the different metal surfaces. Comparisons between the most prominent SERS-enhanced bands and the precise mode descriptions predicted through density functional theory (DFT) simulations at the B3LYP/6-311+G(d,p) level allowed an in-depth orientation analysis of the adsorbed species on metal surfaces. Nevertheless, the ring vibrations were found to possess a major contribution in the observed SERS enhancements for both metal nanoparticles.

Protist, 2015

The superior characteristics of high photon flux and diffraction-limited spatial resolution achie... more The superior characteristics of high photon flux and diffraction-limited spatial resolution achieved by synchrotron-FTIR microspectroscopy allowed molecular characterization of individual live thraustochytrids. Principal component analysis revealed distinct separation of the single live cell spectra into their corresponding strains, comprised of new Australasian thraustochytrids (AMCQS5-5 and S7) and standard cultures (AH-2 and S31). Unsupervised hierarchical cluster analysis (UHCA) indicated close similarities between S7 and AH-7 strains, with AMCQS5-5 being distinctly different. UHCA correlation conformed well to the fatty acid profiles, indicating the type of fatty acids as a critical factor in chemotaxonomic discrimination of these thraustochytrids and also revealing the distinctively high polyunsaturated fatty acid content as key identity of AMCQS5-5. Partial least squares discriminant analysis using cross-validation approach between two replicate datasets was demonstrated to be a powerful classification method leading to models of high robustness and 100% predictive accuracy for strain identification. The results emphasized the exceptional S-FTIR capability to perform real-time in vivo measurement of single live cells directly within their original medium, providing unique information on cell variability among the population of each isolate and evidence of spontaneous lipid peroxidation that could lead to deeper understanding of lipid production and oxidation in thraustochytrids for single-cell oil development.

An inclusion host-guest complex between β-cyclodextrin (β-CD) and L-phenylalanine (L-Phe) was inv... more An inclusion host-guest complex between β-cyclodextrin (β-CD) and L-phenylalanine (L-Phe) was investigated using 1 H nuclear magnetic resonance spectroscopy and molecular docking techniques. 1 H chemical shift changes of β-CD were used to calculate the stability constant (K stb ) of the complex. On the basis of the Hildebrand-Benesi method, the K stb of the 1:1 complex in D 2 O solution at 300 K, pD 7.6 was of 25.5 M -1 , implying a fast intermolecular exchange rate process. Interestingly, docking simulation indicates the toroidal space can be occupied by L-Phe with two favorable arrangements. For the predicted model with the higher probability score, the L-Phe aromatic ring is facing to the secondary hydroxyl groups of β-CD. Results from NMR and docking simulation are in good agreement with the x-ray structures of β-CD/L-phenylalanine derivatives.

Applied Spectroscopy, 2004

Cylinder-planar Ge waveguides are being developed as evanescentwave sensors for chemical microana... more Cylinder-planar Ge waveguides are being developed as evanescentwave sensors for chemical microanalysis. The only non-planar surface is a cylinder section having a 300-mm radius of curvature. This confers a symmetric taper, allowing for direct coupling into and out of the waveguide's 1-mm 2 end faces while obtaining multiple re ections at the cen tral ,30-mm -thick sensing region. Ray-optic calculations indicate that the propagation angle at the central minimum has a strong nonlinear dependence on both angle and vertical position of the input ray. This results in rather inef cient coupling of input light into the off-axis modes that are most useful for evanescent-w ave absorption spectro scopy. Mode-speci c performance of the cylinder-planar waveguides has also been investigated experimentally. As compared to a blackbody source, the much greater brightness of synchrotron-generated infrared (IR) radiation allows a similar total energy throughput, but restricted to a smaller fraction of the allowed waveguide modes. However, such angle-selective excitation results in a strong oscillatory interference pattern in the transmission spectra. These spectral oscillations are the principal technical limitation on using synchrotron radiation to measure evanescent-wave absorption spectra with the thin waveguides.

Nutrients, 2014

The utilization of food waste by microorganisms to produce omega-3 fatty acids or biofuel is a po... more The utilization of food waste by microorganisms to produce omega-3 fatty acids or biofuel is a potentially low cost method with positive environmental benefits. In the present study, the marine microorganisms Thraustochytrium sp. AH-2 and Schizochytrium sp. SR21 were used to evaluate the potential of breadcrumbs as an alternate carbon source for the production of lipids under static fermentation conditions. For the Thraustochytrium sp. AH-2, submerged liquid fermentation with 3% glucose produced 4.3 g/L of biomass and 44.16 mg/g of saturated fatty acids after seven days. Static fermentation with 0.5% and 1% breadcrumbs resulted in 2.5 and 4.7 g/L of biomass, and 42.4 and 33.6 mg/g of saturated fatty acids, respectively. Scanning electron microscopic (SEM) studies confirmed the growth of both strains on breadcrumbs. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy for both strains were consistent with the utilization of breadcrumbs for the production of unsaturated lipids, albeit at relatively low levels. The total lipid yield for static fermentation with bread crumbs was marginally lower than that of fermentation with glucose media, while the yield of unsaturated fatty acids was considerably lower, indicating that static fermentation may be more appropriate for the production of biodiesel than for the production of omega-3 rich oils in these strains.

Journal of Inorganic Biochemistry, 2011

and sharing with colleagues.

Food Chemistry, 2012

The research describes a rapid method for the determination of fatty acid (FA) contents in a micr... more The research describes a rapid method for the determination of fatty acid (FA) contents in a micro-encapsulated fish-oil (lEFO) supplement by using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic technique and partial least square regression (PLSR) analysis. Using the ATR-FTIR technique, the lEFO powder samples can be directly analysed without any pre-treatment required, and our developed PLSR strategic approach based on the acquired spectral data led to production of a good linear calibration with R 2 = 0.99. In addition, the subsequent predictions acquired from an independent validation set for the target FA compositions (i.e., total oil, total omega-3 fatty acids, EPA and DHA) were highly accurate when compared to the actual values obtained from standard GC-based technique, with plots between predicted versus actual values resulting in excellent linear fitting (R 2 P 0.96) in all cases. The study therefore demonstrated not only the substantial advantage of the ATR-FTIR technique in terms of rapidness and cost effectiveness, but also its potential application as a rapid, potentially automated, online monitoring technique for the routine analysis of FA composition in industrial processes when used together with the multivariate data analysis modelling.

American Institute of …, 2010

Surface-enhanced Raman scattering (SERS) spectra of fonofos, an organophosphorous pesticide (OPP)... more Surface-enhanced Raman scattering (SERS) spectra of fonofos, an organophosphorous pesticide (OPP), were recorded using citrate-reduced silver (Ag) and gold (Au) colloidal nanoparticles in the form of dried films. In this study, significant enhancements were achieved with fonofos concentrations down to ∼10 ppm with the Ag colloids, demonstrating a potential for the technique in the analysis of fonofos residues. Successful formation of the SERS-active metal aggregates was indicated by the presence of a plasmon band at longer wavelengths in the UV-visible spectrum. Transmission electron microscopy (TEM) images revealed distinctively different morphologies of the aggregates formed by the two metals, while the observed SERS spectral features of fonofos were also found to be different for molecules adsorbed on Ag and Au colloidal surfaces. This evidence suggests metal-induced changes in adsorption behavior of the fonofos analyte, leading to the different binding structures onto the different metal surfaces. Comparisons between the most prominent SERS-enhanced bands and the precise mode descriptions predicted through density functional theory (DFT) simulations at the B3LYP/6-311+G(d,p) level allowed an in-depth orientation analysis of the adsorbed species on metal surfaces. Nevertheless, the ring vibrations were found to possess a major contribution in the observed SERS enhancements for both metal nanoparticles.

Protist, 2015

The superior characteristics of high photon flux and diffraction-limited spatial resolution achie... more The superior characteristics of high photon flux and diffraction-limited spatial resolution achieved by synchrotron-FTIR microspectroscopy allowed molecular characterization of individual live thraustochytrids. Principal component analysis revealed distinct separation of the single live cell spectra into their corresponding strains, comprised of new Australasian thraustochytrids (AMCQS5-5 and S7) and standard cultures (AH-2 and S31). Unsupervised hierarchical cluster analysis (UHCA) indicated close similarities between S7 and AH-7 strains, with AMCQS5-5 being distinctly different. UHCA correlation conformed well to the fatty acid profiles, indicating the type of fatty acids as a critical factor in chemotaxonomic discrimination of these thraustochytrids and also revealing the distinctively high polyunsaturated fatty acid content as key identity of AMCQS5-5. Partial least squares discriminant analysis using cross-validation approach between two replicate datasets was demonstrated to be a powerful classification method leading to models of high robustness and 100% predictive accuracy for strain identification. The results emphasized the exceptional S-FTIR capability to perform real-time in vivo measurement of single live cells directly within their original medium, providing unique information on cell variability among the population of each isolate and evidence of spontaneous lipid peroxidation that could lead to deeper understanding of lipid production and oxidation in thraustochytrids for single-cell oil development.