Chelation controlled regioselective alkylation and 1,4 chirality transfer in optically active 1-alkoxy-1,4-cyclohexadienes

Chelation controlled alkylation of optically active 1-alkoxy-1,4-cyclohexadienes leads to a mixture of 1,4-cyclohexadienes 4a-c and 1,3-cyclohexadienes 5a-c. The regio- and diastereoselectivities depend upon the nature of the chiral auxiliary and the reaction conditions. Regio- and diastereoselectivities depend upon the nature of the chiral auxiliary and the reaction conditions (e.g. < 99 % regio- and 60 % diastereoselectivity for R5, R4 = i-Pr in Et2O)

Surface modification of cellulosic non-woven with sustainable nanotechnologies

Abstract: As an alternative for traditional chemical grafting techniques controlling surface properties of a cellulosic non-woven, the physical absorption of organic nanoparticles can be favourably applied for selective surface modification. This method offers benefits of a better control over the chemical composition and dosage of the chemical compounds, as they can be formulated independently from the fiber substrate. Good adhesion between the nanoparticles and the cellulose fiber was managed by dedicated chemical synthesis and positioning of functional groups over the nanoparticle surface, tuning the interactions with the cellulosic hydroxyl groups. Moreover, the combination of morphological and chemical surface changes is favourable to add specific functionalities, including adhesion, friction and wettability. As the continuous strife for design of sustainable materials requires limited usage organics and reduction in petroleum-based derivatives, our method is based on aqueous dispersions that incorporates high amounts of renewable oils

Quantitative high-throughput analysis of DNA methylation patterns by base-specific cleavage and mass spectrometry

Methylation is one of the major epigenetic processes pivotal to our understanding of carcinogenesis. It is now widely accepted that there is a relationship between DNA methylation, chromatin structure, and human malignancies. DNA methylation is potentially an important clinical marker in cancer molecular diagnostics. Understanding epigenetic modifications in their biological context involves several aspects of DNA methylation analysis. These aspects include the de novo discovery of differentially methylated genes, the analysis of methylation patterns, and the determination of differences in the degree of methylation. Here we present a previously uncharacterized method for high-throughput DNA methylation analysis that utilizes MALDI-TOF mass spectrometry (MS) analysis of base-specifically cleaved amplification products. We use the IGF2/H19 region to show that a single base-specific cleavage reaction is sufficient to discover methylation sites and to determine methylation ratios within a selected target region. A combination of cleavage reactions enables the complete evaluation of all relevant aspects of DNA methylation, with most CpGs represented in multiple reactions. We successfully applied this technology under high-throughput conditions to quantitatively assess methylation differences between normal and neoplastic lung cancer tissue samples from 48 patients in 47 genes and demonstrate that the quantitative methylation results allow accurate classification of samples according to their histopathology