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A novel species of amides formed from degradation of one of the most important key intermediates in Maillard hexose chemistry-1-deoxyhexo-2,3-diulose-was investigated. In 1-deoxyhexo-2,3-diulose/N(alpha)-t-BOC-lysine reaction mixtures four amides, N(epsilon)-acetyl lysine, N(epsilon)-formyl lysine, N(epsilon)-lactoyl lysine and N(epsilon)-glycerinyl lysine, were identified and their structures verified by authentic reference standards. Amides and corresponding carboxylic acids (acetic acid, formic acid, lactic acid and glyceric acid) accumulated over time. Both N(epsilon)-lysine amides and carboxylic acids were thus determined as stable Maillard end products. Results of model incubations suggested the synthesis of amides to be mechanistically closely related to the formation of their corresponding carboxylic acids by beta-dicarbonyl cleavage. Due to the different chemical properties of all the compounds monitored, various analytical strategies had to be carried out (LC-MS(2), GC-MS, GC-FID, enzymatic determination).

Originally published as:Wieloch, T., Helle, G., Heinrich, I., Voigt, M., Schyma, P. (2011): A novel device for batch-wise isolation of α-cellulose from small-amount wholewood samples. AbstractA novel device for the chemical isolation of α-cellulose from wholewood material of tree rings was designed by the Potsdam Dendro Laboratory. It allows the simultaneous treatment of up to several hundred micro samples. Key features are the batch-wise exchange of the chemical solutions, the reusability of all major parts and the easy and unambiguous labelling of each individual sample. Compared to classical methods labour intensity and running costs are significantly reduced.

The growth kinetics of ZnO nanorods in methanol is studied by a combination of scanning and high-resolution transmission electron microscopy and X-ray diffraction analysis. In the early stage of growth oriented attachment of 2−3 spheroidal crystallites to rod-like structures occurs. Later, rods of up to 90 nm in length with a hexagonal cross-section up to 18 nm in diameter form by ripening. Our main finding is that the growth follows a power law as a function of the ripening time with exponents of 0.32 to 0.39 for the length and 0.17 to 0.21 for the diameter. In contrast to previous studies on the growth of ZnO rods in alcohols our results indicate that the growth is dominated by anisotropic Ostwald ripening that is limited by volume diffusion.