Antioxidant properties and qualitative analysis of phenolic constituents in Ephedra spp. by HPTLC together with injection port derivatization GC-MS.

Ephedra herb extracts are being extensively investigated in terms of their antioxidative, antimicrobial and antiproliferative properties, with phenolic components being the general carriers of these bioactivities. Here we describe a comprehensive set of analytical methods employed to determine and characterize both the antioxidative activity and the qualitative profile of phenolic acids and flavonoids present in several Ephedra species of different geographical origin. Spectrophotometric methods were used to determine the total phenolic content, total flavonoid content and antioxidative activity.

Self-organising maps for the exploration and classification of thin-layer chromatograms.

Thin-layer chromatography (TLC) allows the swift analysis of larger sample sets in almost any laboratory. The obtained chromatograms are patterns of coloured zones that are conveniently evaluated and classified by visual inspection. This manual approach reaches its limit when several dozens or a few hundred samples need to be evaluated.

Resource-Saving Production of Dialdehyde Cellulose: Optimization of the Process at High Pulp Consistency.

Oxidation of cellulose with periodate under aqueous conditions yields dialdehyde cellulose, a promising functional cellulose derivative. The main obstacles for this oxidation have been its slow kinetics and the dilute reaction conditions, requiring considerable amounts of water and energy. In this study, these drawbacks are overcome by conducting the oxidation at high cellulosic pulp consistency with a cellulose/water weight ratio of 1:4.

Profiling and quantification of grain anthocyanins in purple pericarp × blue aleurone wheat crosses by high-performance thin-layer chromatography and densitometry.

Background: Anthocyanins are abundant secondary metabolites responsible for most blue to blue-black, and red to purple colors of various plant organs. In wheat grains, anthocyanins are accumulated in the pericarp and/or aleurone layer. Anthocyanin pigmented wheat grains can be processed into functional foods with potential health benefits due to the antioxidant properties of the anthocyanins.

À côté calibration - Making optimal use of time and space in quantitative high performance thin layer chromatography.

Quantitative High Performance Thin Layer Chromatography (HPTLC) requires the application of several standards to each plate, reducing the number of actual samples that can be analyzed in a single run. Using pure standard compounds and a selective detection method, the standards for quantitation can be applied besides - à côté - the chromatography area. This frees the sample application space to accommodate the maximal number of sample on each plate.

SUB1 has photoreceptor dependent and independent functions in sexual development and secondary metabolism in Trichoderma reesei.

Light dependent processes are involved in the regulation of growth, development and enzyme production in Trichoderma reesei. The photoreceptors BLR1, BLR2 and ENV1 exert crucial functions in these processes. We analyzed the involvement of the transcription factor SUB1 in sexual development as well as secondary metabolism and its position in the light signaling cascade.

Preparation and analytical characterisation of pure fractions of cellooligosaccharides.

In the present work, a viable protocol was developed to prepare monodisperse cellooligomers up to a degree of polymerisation (DP) of 20. Peracetylated cellooligosaccharides were obtained from cellulose by acetolysis and subsequently purified by Normal Phase-High Performance Liquid Chromatography using toluene, ethyl acetate and acetone as eluents. In addition, we demonstrated how to efficiently monitor the purity and dispersity of the obtained compounds by High Performance Thin Layer Chromatography, Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry and Nuclear Magnetic Resonance.

Overview of Methods for the Direct Molar Mass Determination of Cellulose.

The purpose of this article is to provide the reader with an overview of the methods used to determine the molecular weights of cellulose. Methods that employ direct dissolution of the cellulose polymer are described; hence methods for investigating the molecular weight of cellulose in derivatized states, such as ethers or esters, only form a minor part of this review. Many of the methods described are primarily of historical interest since they have no use in modern cellulose chemistry.

Phenotypic and genotypic diversity among strains of Aureobasidium pullulans in comparison with related species.

Intra-specific diversity of 200 Aureobasidium pullulans strains isolated from different sources and their relatives Kabatiella lini CBS 125.21 T and Hormonema prunorum CBS 933.72 T were studied by assessment of macromorphological, and physiological tests, sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique (SDS-PAGE) of whole-cell proteins as well as enterobacterial repetitive intergenic consensus (ERIC)-, repetitive extragenic palindromic (REP)- and BOX-PCR techniques (collectively known as rep-PCR).

Genetic diversity among isolates of Paenibacillus larvae from Austria.

Genetic diversity of 214 Paenibacillus larvae strains from Austria was studied. Genotyping of isolates was performed by polymerase chain reaction (PCR) with primers corresponding to enterobacterial repetitive intergenic consensus (ERIC), BOX repetitive and extragenic palindromic (REP) elements (collectively known as rep-PCR) using ERIC primers, BOX A1R and MBO REP1 primers. Using ERIC-PCR technique two genotypes could be differentiated (ERIC I and II), whereas using combined typing by BOX- and REP-PCR, five different genotypes were detected (ab, aB, Ab, AB and alphab).