Polypropylenimine (PPI) dendrimers have been widely used as effective delivery vehicles for drugs and nucleic acids during the past decade. However, biomedical applications of PPI dendrimers were limited because of their serious cytotoxicity and low drug loading capacity. In the present study, acetylated PPI dendrimers with different degrees of acetylation ranging from 14.2% to 94.3% were synth...

A procedure is described for the specific acetylation of the lysine residues of ovalbumin. Six acetylated ovalbumins varying in the degree of modification from 21 to 98% were prepared and were found to be homogeneous by polyacrylamide gel electrophoresis, immunodiffusion, and immunoelectrophresis. As expected, the anodic movement of ovalbumin increased and the isoionic point shifted to lower pH...

Cellulose, which comprises D-glucose and L-glucose (D,L-cellulose), was synthesized from (1D) (1L) via cationic ring-opening polymerization. Specifically, the copolymerization of 3-O-benzyl-2,6-di-O-pivaloyl-β-D-glucopyranoside (2D) (2L), compounds 1D 1L, respectively, in a 1:1 ratio, afforded 3-O-benzyl-2,6-di-O-β-D,L-glucopyranan (3DL) with degree polymerization (DPn) 28.5 (Mw/Mn = 1.90) quan...

tetrahydropyranylation of alcohols and phenols, acetylation of aldehydes and n-boc protection of amines are efficiently catalyzed by melamine trisulfonic acid (mtsa). all reactions were performed at room temperature in good to high yields.

The determination of the true molar mass distribution (MMD) lignin is highly important to understand physicochemical characteristics for lignin-based value-added applications. It imperative develop a universal method quantify accurate MMD using size exclusion chromatography (SEC), as conventional with polymer standards provides irregular results. This work aims evaluate five samples (Protobind ...

Increased acetylation at specific N-terminal lysines of core histones is a hallmark of active chromatin in vivo, yet the structural consequences of acetylation leading to increased gene activity are only poorly defined. We employed a new approach to characterize the effects of histone acetylation: A Drosophila embryo-derived cell-free system for chromatin reconstitution under physiological cond...

Escherichia coli topoisomerase I (TopA), a regulator of global and local DNA supercoiling, is modified by Nε-Lysine acetylation. The NAD+-dependent protein deacetylase CobB can reverse both enzymatic and non-enzymatic lysine acetylation modification in E. coli. Here, we show that the absence of CobB in a ΔcobB mutant reduces intracellular TopA catalytic activity and increases negative DNA super...

Wood is a porous three dimensional, hydroscopic, viscoelastic, anisotropic bio-polymer composite composed of an interconnecting matrix of cellulose, hemicelluloses and lignin with minor amounts of inorganic elements and organic extractives. Some, but not all, of the cell wall polymer hydroxyl groups are accessible to moisture and these accessible hydroxyls form hydrogen bonds with water. As the...