Fettuntersuchung

Ohne Zusammenfassung     

Biodegradation of chlorolignin and lignin-like compounds contained in E1-Pulp bleaching effluent by fungal treatment

The ligninolytic system from the fungi Trametes villosa and Panus crinitus can efficiently degrade all fractions of different molecular mass contained in E1-bleaching effluent, but with different degradation rates. The lower-molecular-mass (MM) materials were better characterized when the elution in the size-exclusion high-performance liquid chromatography were monitored at 210 than at 280 nm, which indicates that these compounds may be ring cleavage byproducts from depolymerized chlorolignin. The biodegradation of E1 effluent by both fungi was a multistage process, involving an initial chemical modification of the higher-MM compounds and concomitant oxidation of the lower-MM materials. A subsequent depolymerization of chemically modified polymeric lignin-like compounds also took place. Each stage may require one or several different enzymes. The results suggested that laccase was involved in the initial stage.     

Enhanced Raman scattering provided by fullerene nanoclusters

Two new nonlinear optic effects are observed in crystalline solutions of fullerenes in toluene and carbon tetrachloride. Both are provided by a self-clustering of the solute molecules and are referred to fullerene-enhanced Raman scattering and solvent-enhanced luminescence. The effects are induced by the excitation of charge-transfer states of the fullerene nanoclusters, which makes the latter act as amplifiers of local electric fields. The text was submitted by the authors in English.     

Cumulative compressibility effects on slow reactive dynamics in turbulent flows

Reactions in turbulent flows, chemical reactions or combustion, are common. Typically reaction time scales are much shorter than turbulence timescales. In biological applications, as it is the case for bacterial and plankton populations living under the influence of currents in oceans and lakes, the typical lifetime can be long and thus can fall well within the inertial range of turbulence time scales. Under these conditions, turbulent transport interacts in a very complex way with the dynamics of growth and death of the individuals in the population. In the present paper, we quantitatively investigate the effect of the flow compressibility on the dynamics of populations. Small effective compressibility can be induced by several physical mechanisms, such as, e.g., by the density mismatch, by a small but finite size of microorganisms, and by gyrotaxis (an interaction between swimming and shear). We report, for the first time, how even a tiny effective compressibility can produce a dramatically large effect on global quantities like the carrying capacity of the ecosystem. We interpret our findings by means of a cumulative effect made possible by the long replication times of the organisms with respect to turbulence time scales. A statistical quantification of the fluctuations of population concentration is presented.     

Design,synthesis and spectroscopic characterisation of a focused library based on the polyandrocarpamine natural product scaffold

A focused library based on the marine natural products polyandrocarpamines A ( 1 ) and B ( 2 ) has been designed and synthesised using parallel solution‐phase chemistry. In silico physicochemical property calculations were performed on synthetic candidates in order to optimise the library for drug discovery and chemical biology. A library of ten 2‐aminoimidazolone products ( 3–12 ) was prepared by coupling glycocyamidine and a variety of aldehydes using a one‐step stereoselective aldol condensation reaction under microwave conditions. All analogues were characterised by NMR, UV, IR and MS. The library was evaluated for cytotoxicity towards the prostate cancer cell lines, LNCaP, PC‐3 and 22Rv1. Copyright © 2013 John Wiley & Sons, Ltd.     

Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found (p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength.     

Marine Algae Membrane Phospholipids Study by High Resolution 31P NMR

Abstract

Membrane phospholipids were extracted using a modified Folch, Lees and Sloane-Stanley method, from 21 different algae species covering three major divisions of the protista kingdom. In the modified method after chloroform/methanol (2:1 v/v) extraction and filtration, the solution was backwashed with K-EDTA, 0.6 M, instead of KCl, 1 M. Because algae samples are eavily loaded with cations that broaden NMR signals, the K-EDTA wash results in more highly resolved NMR signals. Following rotary evaporation, the crude algae lipid extract was dissolved in the chloroform-benzene(d6)/methanol-CsEDTA (2:l ml/ml) reagent and analyzed using a 500 MHz NMR spectrophotometer. Phospholipid chemical shifts were determined relative to standard phosphoric acid (85%), following the UIPAC convention. The internal reference used was phosphatidylcholine (PC, -0.84 δ) Division chlorophyta (8 sps.) yields phospholipid signals for phosphatidylglycerol (PG, 0.50), phosphatidic acid (PA, 0.25), cardiolipin (CL, 0.18), phosphatidylethanolamine (PE, 0.03), sphyngomyelin (SPH, -0.09), phosphatidylinositol (PI, -0.37) and PC; the lysoderivatives for lyso PG (LPG, 1.09) and lyso PC (LPC, -0.28), and one uncharacterized signal at 0.32. Phosphatidylserine (PS -0.05) and plasmalogens were not detected. Division rhodophyta (10 sps.) shows signal from PG, PA, CL, PE, SPH, PI, and PC; the lysoderivatives of lyso PA (LPA, 0.83), lyso PE (LPE, 0.43) and LPC; the plasmalogens PC plasmalogen (PC plas, -0.77), LPC plas (-0.20), and l-0-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (PAF-acether, -0.70); and an uncharacterized signal at -40 δ chemical shift. PS was not detected. Division Phaeophytas (3 sps.) showed signals for PG, PA, CL, PE, SPH, PI, and PC and lysoderivatives of LPG, LPA, LPE plas (0.53), LPE, LPC plas, and LPC. PS, PAF-acether and the uncharacterized signals at 0.32 δ and -0.40 δ were not detected.