Spectroscopy - Volume 26, issue 2

Authors: Falé, Pedro L.V. | Ascensão, Lia | Serralheiro, Maria L.M. | Haris, Parvez I.

Article Type: Research Article

Abstract: Anti-cholinesterase and antioxidant active constituents of Plectranthus barbatus aqueous extract were found in plasma of rats after its administration – rosmarinic acid, luteolin and apigenin. The aim of the present work is to determine if the extract components can interact with human plasma proteins, namely albumin and lysozyme. Protein intrinsic fluorescence analysis showed that the plant phenolic compounds may bind to albumin, the main transport protein in plasma, and to lysozyme. The estimated thermodynamic parameters suggest that the main intermolecular interaction is hydrophobic association. FTIR analysis of the protein amide bands showed that the plant extract components do not alter …the secondary structure of either albumin or lysozyme, however the rate of hydrogen–deuterium exchange suggests that tertiary structure changes might have occurred. An increase of hydrogen deuterium exchange suggests that rosmarinic acid may bind to the fatty acid binding sites in albumin, while luteolin and apigenin may bind to the drug binding sites. The plant extract components also inhibit lysozyme activity with IC50 values around 100 μM. Therefore P. barbatus herbal tea, rosmarinic acid, luteolin and apigenin interact and may be transported by albumin and lysozyme. The inhibition of lysozyme activity may be an additional mechanism for its anti-inflammatory activity. Show more

Keywords: Human serum albumin, lysozyme, spectroscopy, Plectranthus barbatus, rosmarinic acid

DOI: 10.3233/SPE-2011-0532

Citation: Spectroscopy, vol. 26, no. 2, pp. 79-92, 2011

Authors: Leopold, Loredana F. | Leopold, Nicolae | Diehl, Horst-A. | Socaciu, Carmen

Article Type: Research Article

Abstract: A combination of Fourier-transform infrared spectroscopy (FTIR) and multivariate statistics was applied as screening tool for the quantitative determination of carbohydrates, such as glucose, fructose and sucrose, in 28 processed commercial fruit juices and 5 genuine juices obtained from squeezed fruits. A number of 13 mixtures of glucose, fructose and sucrose standard solutions were prepared at different concentrations, scanned by attenuated total reflectance (ATR) FTIR spectroscopy and analyzed in the 900 and 1400 cm−1 spectral range. Principal component analysis (PCA) of the standard carbohydrate solutions enabled a better understanding of the main sources of variability affecting the FTIR spectra. …Also, PCA enabled the grouping of apple, orange and peach juices. Calibration models for each carbohydrate, using partial least squares (PLS) regression were developed and used for prediction purposes. Cross-validation procedures indicated correlations of 0.88, 0.92 and 0.98 for glucose, fructose and sucrose, respectively, between HPLC measured values and FTIR first derivative spectra estimates. Carbohydrates in the expected concentration ranges were found for most of the pure fruit labelled juices. The samples with 4–50% pure fruit juice content showed discrepancies from average concentration values of authentic juices, mainly a high sucrose concentration can flag sucrose addition to maintain the juice sweetness intensity. The present results confirmed the efficiency of FTIR spectroscopy, in combination with multivariate statistics, as a rapid, reliable and cost-effective tool for routine monitoring of multiple constituents in fruit juices, as quality indicators. Show more

Keywords: Glucose, fructose, sucrose, fruit juice, FTIR, PCA, PLS

DOI: 10.3233/SPE-2011-0529

Citation: Spectroscopy, vol. 26, no. 2, pp. 93-104, 2011

Authors: Khanmohammadi, M. | Dallali, N. | Bagheri Garmarudi, A. | Zarnegar, M. | Ghasemi, K.

Article Type: Research Article

Abstract: Partial Least Square (PLS) and Artificial Neural Network (ANN) techniques were compared during development of an analytical method for quantitative determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in Co-Trimoxazole® suspension. The procedure was based on Attenuated Total Reflectance Fourier Transform Infrared (ATR–FTIR) spectrometry. The 800–2500 cm−1 spectral region was selected for quantitative analysis. R2 and relative error of prediction (REP) in PLS technique were (0.989, 2.128) and (0.986, 1.381) for SMX and TMP, respectively. These statistical parameters were improved using the ANN models considering the complexity of the sample and the speediness and simplicity of the method. …R2 and RMSEC in modified method were (0.997, 1.064) and (0.997, 0.634) for SMX and TMP, respectively. Show more

Keywords: Artificial neural network, quantitative analysis, sulfamethoxazole, trimethoprim, ATR–FTIR spectrometry, partial least squares

DOI: 10.3233/SPE-2011-0520

Citation: Spectroscopy, vol. 26, no. 2, pp. 105-114, 2011

Authors: Mureşan-Pop, Marieta | Kacsó, Irina | Filip, Xenia | Vanea, Emilia | Borodi, G. | Leopold, N. | Bratu, I. | Simon, S.

Article Type: Research Article

Abstract: Ambazone monohydrate C8 H11 N7 S · H2 O (AMB), a well-known antimicrobial compound, was used together with Glutamic Acid C5 H9 NO4 (Glu) to obtain a new solid form using the solvent-drop grinding procedure. The screening of the new solid form was best achieved by the combined use of X-ray Powder Diffraction (XRPD) and several spectroscopic techniques (Fourier Transformed Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Raman and 13 C-NMR spectroscopy) together with Differential Scanning Calorimetry (DSC), Differential thermal analysis and thermogravimetry (DTA–TGA). The combination of the mentioned analytical techniques allows the compound to be assigned to an ambazone–glutamate salt …which crystallizes in monoclinic system having the following lattice parameters: a=9.8352, b=4.7014, c=40.0987 Å and β=94.505°. DSC, TGA data and the before mentioned spectroscopic techniques support the ambazone–glutamate salt formation. Show more

Keywords: Ambazone, glutamic acid, XRPD, DTA–TGA, DSC, FTIR, XPS, Raman, NMR, ambazone–glutamate salt

DOI: 10.3233/SPE-2011-0519

Citation: Spectroscopy, vol. 26, no. 2, pp. 115-128, 2011

Authors: Pandey, Jitendra Kumar | Gopal, R.

Article Type: Research Article

Abstract: The present study deals with laser-induced chlorophyll fluorescence (LICF) spectra, reflectance spectra and fluorescence induction kinetics (FIK) curves of Triticum aestivum L. plants treated with different concentrations of cadmium (0.01, 0.1 and 1.0 mM). LICF spectra were recorded in the region of 650–780 nm using violet diode laser (405 nm) and FIK curves were recorded at 685 and 730 nm using red diode laser (635 nm) for excitation. Reflectance spectra were recorded in the region of 400–800 nm using spectrophotometer with an integrating sphere. The fluorescence intensity ratios (FIR) were determined from LICF spectra, vitality index (Rfd ) from FIK …curves and narrow band vegetation index (NBVI) from reflectance spectra. These parameters along with plant growth parameters and photosynthetic pigment contents were used to analyze the effect of cadmium on wheat plants. The results clearly show that lower concentration of Cd (0.01 mM) shows stimulatory response; whereas higher concentrations (0.1 and 1.0 Mm) are hazardous for plant growth, photosynthetic pigments and photosynthetic activity of wheat plants. Show more

Keywords: Laser-induced chlorophyll fluorescence, fluorescence induction kinetics, reflectance spectra, photosynthetic pigment contents, wheat plants, cadmium stress

DOI: 10.3233/SPE-2011-0530

Citation: Spectroscopy, vol. 26, no. 2, pp. 129-139, 2011

Authors: Obeidat, Safwan M. | Al-Momani, Idrees | Haddad, Asma'a | Bani Yasein, Motasem

Article Type: Research Article

Abstract: In this paper dental ceramic samples from seven vendors were studied. The elemental composition for each type was investigated using the ICP-OES and the XRF. Assessment of the seven types of ceramic was also successfully achieved using the XRD spectral data and processed with Principal Component Analysis (PCA). Detecting possible adulteration in different mass percentages of ceramic was also possible by applying the XRD data for the adulterated samples to the original PCA model.

Keywords: Dental ceramics, ICP-OES, XRF, XRD, PCA

DOI: 10.3233/SPE-2011-0521

Citation: Spectroscopy, vol. 26, no. 2, pp. 141-149, 2011