Fourier Transform 13C NMR Analysis of Some Methaqualone Metabolites

The natural abundance carbon-13 nuclear magnetic resonance spectra of some methaqualone metabolites were recorded using the pulse fourier transform technique. The chemical shift of various carbon resonances have been assigned on the basis of the chemical shift theory, multiplicities observed in SFORD spectrum and comparison with the chemical shifts of the corresponding carbons of methaqualone.     

Alkali hydrolysis of trinitrotoluene

Data for alkali hydrolysis of 2,4,6-trinitrotoluene (TNT) in aqueous solution at pH 12.0 under static (pH-controlled) as well as dynamic (pH-uncontrolled) conditions are reported. The experiments were conducted at two different molar ratios of TNT to hydroxyl ions at room temperature. The TNT disappeared rapidly from the solution as a first-order reaction. The complete disappearance of aromatic structure from the aqueous solution within 24 h was confirmed by the ultraviolet-visible (UV-VIS) spectra of the samples. Cuvet experiments in a UV-VIS spectrophotometer demonstrated the formation of Meisenheimer complex, which slowly disappeared via formation of aromatic compounds with fewer nitro groups. The known metabolites of TNT were found to accumulate only in very small quantities in the liquid phase.     

The first total synthesis of a bioactive metabolite, a spirobenzofuran isolated from the fungi Acremonium sp. HKI 0230

The first total synthesis of a bioactive metabolite, isolated from the fungi Acremonium sp. HKI 0230, containing a cyclopentaspirobenzofuran carbon framework, employing an Ireland ester Claisen rearrangement and RCM reaction based strategy has been accomplished.     

Quantitative determination of alkylated quaternary amines and their n-hydroxylated metabolites in an enzyme incubation matrix by liquid chromatography electrospray ionization mass spectrometry

A simple, rapid and sensitive reversed-phase liquid chromatography method coupled to electrospray ionization mass spectrometry has been developed for studying the in vitro metabolism of the long-chain quaternary ammonium compounds dodecyltrimethylamine, tetradecyltrimethylamine and hexadecyltrimethylamine. Samples were prepared from the biological matrix by a simple protein precipitation stage. The separation was performed using a BDS Hypersil C8 3 microm particle size (100 x 3 mm i.d.) column with a fast gradient separation (60% B to 100% B) using a mobile phase of 10 mm aqueous ammonium acetate (pH 4.0, with 0.06% triethylamine; (A)-acetonitrile (B) at 0.7 mL min(-1). To minimize contamination of the MS source a switching value was used to divert the solvent front to waste. Decylammonium bromide was used as the internal standard and analytes were identified and quantified by positive ion electrospray selected ion monitoring of their intact molecular cations. The assay had a limit of quantitation of 0.25 microm (6.25 pmol on column) and was linear over the range 0.25--100 microm assay concentration for this series of long-chain quaternary amines. The precision of intra- and inter-day assays was better than 19% and the accuracy was between 93 and 109%. The method was used to assess the in vitro metabolism of the quaternary amines by wild-type cytochrome P450 enzyme CYP 4 A 1 and mutants in an artifical membrane system.     

Metabolic profile of lettuce leaves by high-field NMR spectra

A detailed analysis of the proton high-field NMR spectra of aqueous and organic extracts of lettuce leaves is reported for the first time. A combination of COSY, TOCSY, (1)H-(13)C HSQC, (1)H-(13)C HMBC bidimensional sequences and DOSY was used to assign each spin system and to separate the components of the complex patterns. A large number of water-soluble metabolites belonging to different classes such as carbohydrates, polyols, organic acids and amino acids were fully assigned. Moreover, the complex spectra of metabolites extracted in organic solvents belonging to sterols, fatty acids, diacylglycerophospholipids, galactosyldiacylglycerols, sulpholipids, pheophytins, carotenoids and hydrocarbons were also assigned.     

Applications of Infrared Spectroscopy to Biochemical,Food, and Agricultural Processes

Abstract

Integrated investigations on infrared spectroscopic characteristics of metabolites and on applications of infrared spectroscopy to foodstuff production, food processing, and tasting are described. As the important metabolites, saccharides, which play very important roles in various functions, located in the central position of the metabolic pathways, were selected, and the spectral features of the saccharides and related materials are discussed. Additionally, the applications of spectral analysis to the monitoring of the enzyme reaction and the sugar metabolic processes, which are the main materials in food processing, are described. Furthermore, the studies on the spectroscopic measurements during the cultivation of agricultural products as foodstuffs and in the tasting as the final quality evaluation of foods are represented. These results suggest that infrared spectroscopy could be very effective for evaluating foodstuff production and the tasting of the processed foods and that the applied topics should provide fundamental information about the spectral behavior of the metabolites and bioproducts.     

SERS as a valuable tool for detection and treatment follow‐up of fungal infection in mice lungs: use of Amphotericin B and its nanoencapsulation onto magnetic nanoparticles

This study reports on the use of surface‐enhanced Raman scattering (SERS) detection and follow‐up treatment of Paracoccidioides brasiliensis (Pb) infection in lung's mice. We also reports on the introduction of a new drug carrier system [nanoparticle‐Amphotericin B (NP‐AmB)], comprising magnetic NP surface functionalized with AmB, and its use in the treatment of infected and non‐infected mice. SERS was successfully used to monitor the efficacy of the mice's treatment using the new NP‐AmB, while free AmB (F‐AmB), considering the current drug of choice for treatment of Pb infection, was also used and taken as reference for the treatment. We found SERS provides a robust platform to discriminate infected lung tissues from non‐infected ones based on fingerprints assessed via SERS spectra and focused on the redox state of heme groups present in the collected biological material. Finally, SERS data reported in this study indicated that the new NP‐AmB formulation provides similar clinical response as the F‐AmB, although incorporating 40% lower content of AmB and administered in a time interval schedule (every 72 h) three times longer than F‐AmB (every 24 h). Copyright © 2013 John Wiley & Sons, Ltd.