Probing Synergies between Lignin-Rich and Cellulose Compounds for Gasification

The fixed-bed gasification of lignin-rich and -deficient mixtures was carried out to probe the synergistic effects between two model compounds, Lignin Pink (LP) rich in Na and Cellulose Microcrystalline (CM). Reaction conditions utilized the most commonly used air ratios in current wood gasifiers at 750 and 850 °C. It was found that by increasing the lignin content in the mixture, there was a selectivity change from solid to gas products, contrary to a similar study previously carried out for pyrolysis. This change in product mix was promoted by the catalytic effect of Na edge recession deposits on the surface of the char. As a result, the water gas shift reaction was enhanced at 850 °C for the LP48CM52 mixture across all air ratios. This was evidenced by a strong correlation between the produced H2 and COx. Meanwhile, by lowering the lignin content in the mixtures, the reactivity of cellulose microcrystalline was found to generate more char at higher temperatures, similar to lignin mixtures when undergoing pyrolysis.

Synthesis of Multivalent [Lys8]-Oxytocin Dendrimers that Inhibit Visceral Nociceptive Responses

Peptide dendrimers are a novel class of precisely defined macromolecules of emerging interest. Here, we describe the synthesis, structure, binding affinity, receptor selectivity, functional activity, and antinociceptive properties of oxytocin-related dendrimers containing up to 16 copies of [Lys8]-oxytocin or LVT. These were generated using a copper(i)-catalyzed azide–alkyne cycloaddition (CuAAc) reaction with azido-pegylated LVT peptides on an alkyne–polylysine scaffold. 2D NMR analysis demonstrated that each attached LVT ligand was freely rotating and maintained identical 3D structures in each dendrimeric macromolecule. The binding affinity Ki at the oxytocin receptor increased approximately 17-, 12-, 3-, and 1.5-fold respectively for the 2-, 4-, 8-, and 16-mer dendrimeric LVT conjugates, compared with monomer azido-pegylated LVT (Ki = 9.5 nM), consistent with a multivalency effect. A similar trend in affinity was also observed at the related human V1a, V1b, and V2 receptors, with no significant selectivity change observed across this family of receptors. All LVT dendrimers were functionally active in vitro on human oxytocin receptors and inhibited colonic nociceptors potently in a mouse model of chronic abdominal pain.