The UV and FTIR Fingerprint of Ocimum kilimandscharicum Guerke Essential oil: A Eugenol-Rich Chemo Type

Ocimum kilimandscharicum Guerke, a member of the family Lamiaceae, is a valuable medicinal plant used both in traditional and modern medicine. It is a perennial aromatic undershrub with tremendous phytochemical polymorphism. The present study aims to assess the amount of eugenol in the essential oil (EO) of O. kilimandscharicum. Eugenol is one of the most popular phenolic compounds, which is naturally synthesized and extracted from the EO of different plant species. The fresh leaves and flowers of O. kilimandsharicum were used to extract EO using a hydrodistillation method. Ultraviolet (UV) and Fourier Transform Infrared (FTIR) spectrometry techniques were used to assess and quantify the chemical fingerprint of the EO and their main phytoconstituents. In this study, eugenol showed its peak absorbance to be around 282 nm in both the EO and pure eugenol spectra. The FTIR spectra of the EO and eugenol showed different functional groups determined by comparing the vibration frequencies in wave numbers of the EO and eugenol spectra with those of an IR correlation chart. Eugenol is a well-known phenolic compound with medicinal and economic value. The UV and FTIR spectra of the EO of O. kilimandsharicum proved the presence of a high amount of eugenol in the O. kilimandscharicum plant.

Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks

FT-Raman, FTIR, and SERS spectra of the structurally related gallnut polyphenols tannic acid, gallic acid, pyrogallol, and syringic acid are reported in this work aiming at performing a comparative assignation of the bands and finding specific marker features that can identify these compounds in complex polyphenol mixtures. Tannic and gallic acids are the principal components in oak gallnuts, and they can be found in iron gall inks. The different functional groups existing in these molecules and their spatial distribution lead to slight changes of the vibrations. The Raman spectra are dominated by bands corresponding to the ring vibrations, but the substituents in the ring strongly affect these vibrations. In contrast, the FTIR spectra of these molecules are dominated by the peripheral oxygen-containing substituents of the aromatic ring and afford complementary information. SERS spectroscopy can be used to analyze trace amounts of these compounds, but the spectra of these polyphenols show strong changes in comparison with the Raman spectra, indicating a strong interaction with the metal. The most significant modification observed in the SERS spectra of these compounds is the weakening of the benzene 8a ring vibration and the subsequent intensification of the 19a mode of the benzene ring. This mode is also more intense in the FTIR spectra, and its intensification in the SERS spectra could be related to a drastic change in the molecular polarizability associated with the interaction of the polyphenol with the metal in Ag NPs.

Changes in Structural and Rheological Properties of Guar Gum Particles in Fluidized-Bed Agglomeration: Effect of Sucrose Binder Concentration

Fluidized-bed agglomeration (FBA) is known to modify the structure and rheology of food powders. In this study, guar gum (GG) powders with various concentrations of sucrose binder (0%, 10%, 20%, or 30%) were subjected to fluidized-bed agglomeration. Subsequently, changes in the characteristics of the GG powders were evaluated by using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), particle size distribution (PSD) analysis, and rheological and dispersibility measurements. SEM images and FTIR spectra revealed surface morphology changes and structural modification, respectively, in the original GG powder after FBA, although the changes observed in FTIR spectra were only slightly dependent on sucrose concentration at low concentrations (0–20%). XRD patterns confirmed that the crystallinity of the GG powder was affected by FBA, but not greatly so by binder concentration. The PSD results showed that the GG particle size was increased by FBA and there was a clear relationship between sucrose concentration (10–30%) and mean particle size. The rheological behavior and dispersibility of GG (properties that are known to be affected by the structure of a powder) were also influenced by sucrose concentration. To sum up, FBA and the concentration of sucrose binder used can serve as factors for modifying GG powder.

Extraction of Lignin from Empty Fruit Bunch Fiber via Microwave-Assisted Deep-Eutectic Solvent Heating

This work study about the extraction of lignin from Empty Fruit Bunch (EFB). It is a type of lignocellulosic waste produced during the palm oil extraction process. There are three main components of lignocellulosic, which is one of them is lignin. A deep eutectic solvent (DES) with microwave-assisted heating has been used as a process to extract the lignin from EFB and turn it into a value-product. This convenient method was started with the mixing of EFB and DES. After that, the mixture was heated via microwave synthesis reactor at different temperature and time parameters. The extracted lignin yield was dried and ground into a powder form. The highest lignin yield recovered is 30 % by the highest time and temperature. Interestingly, the purity of all lignin yields are above than 80 %. The highest yield of lignin was characterized. According to Fourier-Transform Infrared (FTIR) spectra, there was a significant functional group of phenolic and aliphatic hydroxyl in lignin. Besides, the methoxy group was also configured in lignin spectra. The presence of conjugated alkene also conveyed the characteristic of lignin. The FTIR spectra were intensified with 1H Nuclear Magnetic Resonance (NMR) spectra where there was a chemical shift in lignin and raw EFB which was designated to aliphatic and aromatic protons bonded to a carbon atom. Three regions of decomposition occur in the Thermogravimetric Analysis (TGA) spectra. The initial decompose temperature of lignin was lower compare to raw EFB. Next, second-stage lignin decomposed at 434.14 ℃ with weight loss of 36.21 %. Lastly, for the final stage, lignin decomposes at 552.54 ℃. Moreover, Differential Scanning Calorimetry (DSC) spectra demonstrate that the Tg value of lignin managed to be identified. However, the Tg value of raw EFB cannot be well defined. As for the characterization in residual fractions of EFB, the lowest crystallinity index (CrI) value of raw EFB has proven the presence of lignocellulosic in its structure. The residual fractions that reacted at higher temperatures have an inflated value of CrI as they contain abundant left out cellulose.

Application of FTIR Spectroscopy for Quantitative Analysis of Blood Serum: A Preliminary Study

The aim of this study was to analyze the possibility of simultaneous determination of the concentration of components from the characteristics of FTIR spectra using the example of a model blood serum. To prepare model solutions, a set of freeze-dried control sera based on bovine blood serum was used, certified for approximately 38 parameters. Based on the values of the absorbance and areas of absorption bands in the FTIR spectra of model solutions, a regression equation was constructed by solving a nonlinear problem using the generalized reduced gradient method. By using the absorbance of the absorption bands at 1717 and 3903 cm−1 and the areas of the absorption bands at 616, 3750, and 3903 cm−1, it is possible to simultaneously determine the concentrations of 38 components with an error of less than 0.1%. The results obtained confirm the potential clinical use of FTIR spectroscopy as a reagent-free express method for the analysis of blood serum. However, its practical implementation requires additional research, in particular, analysis of real blood serum samples and validation of the method.

ARTIFICIAL NEURAL NETWORKS (ANNs) APPLIED TO ATR-FTIR SPECTRA TO CLASSIFY MEDICALLY IMPORTANT Trichosporon SPECIES

To distinguish clinically signicant fungus, Fourier transform infrared spectroscopy (FTIR) was used. In this work, 75 Trichosporon strains from ve different species were cultivated on SDA media and FTIR attenuated total reection (ATR) readings was taken. The classication (FTIR spectra) results of cluster analysis were compared to articial neural network (ANN) analysis (supervised approach). Validation of training set showed that both techniques properly categorized 100% of the spectra, at least for T. asahii (n = 62) and T. inkin (n = 8). With the addition of T. loubieri (n=1) and T. asteroids (n=1), the ANN's accuracy became reliant on the training database, resulting in 90% to 100% classication.

Electronic Structure of Two New Bis-Schiff Base Ligands using DFT Method

Two bis-Schiff Bases 1 and 2 are ligands that can coordinate with manganese metal to form stable complexes and have biological activity. Thermodynamic parameters, HOMO-LUMO energy levels and FTIR spectra of two ligands have been computed using B3LYP/6-311++G(d,p) functional of the DFT calculations. Both ligands are favored thermodynamically, and the ligand 1 has been shown to be more stable than ligand 2. The Polarizability values of two ligands have been investigated. The results refer that ligand 2 interacts earlier than ligand 1 to the metal ion. The FTIR spectra of two ligands have been evaluated. All results show the good agreement between the theoretical and experimental data.

3D Series Metal Complexes Containing Schiff Base Ligand with 2,2'-Bipyridine: Synthesis, Characterization and Assessment of Antifungal Activity

The rapid increase in the number of multidrug-resistant of most pathogenic organisms is fast becoming a global concern, thus, the discovery of novel active pharmacological compounds against new targets is a matter of urgency. The incorporation of metal ions into organic ligands has introduced metal-organic drugs framework with synergistic effects for novel applications in the biological system. In this research work, metal(II) chloride complexes of copper, nickel and zinc containing methylphenylketone thiosemicarbazone (MPK-TSC) with 2,2’-bipyridine (bipy) were synthesized; they were further characterized by satisfactory microelemental analysis, Fourier Transform InfraRed (FTIR) spectra as well as electronic spectra study. The complexes are proposed to have the formulae [L1ML2(Cl2)] where M=metal ion, L1=methylphenylketone thiosemicarbazone L2=2,2’-bipyridine. The complexes are of 1:2 (metal:ligand) stoichiometry and non-electrolytes in solution, the bidentate nature of the two ligands was evident from the FTIR spectra. The compounds were screened for their antifungal activity against four pathogenic fungi: Aspergillus niger, Penicillium Species, Rizopus and Candida albicans using disc diffusion method. The activities of the complexes have been found to be greater than those of the metal salts and the uncoordinated ligands.