In this paper, the effect of chitosan molecular weight on the characteristics (size, encapsulation efficiency, zeta potential, surface morphology and release rate) of vitamin C encapsulated tripolyphosphate cross-linked chitosan (TPP-chitosan) microspheres. The molecular weight of chitosan had a noticeable influence on the size, encapsulation efficiency, zeta potential, surface morphology and c...

Rat liver mitochondria were found to hydroxylate E-Ntrimethyl+lysine to produce P-hydroxy-c-N-trimethyl-L-lysine, an intermediate in carnitine biosynthesis. The hydroxylating system requires a-ketoglutarate, Fez+, and ascorbate, but does not require NADPH nor NADH. No activity was found in the microsomal or soluble fractions of liver extracts. The hydroxylated a-amino acid was isolated and char...

A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3'-hydroxy-2',2',6'-trimethyl-3H-spiro[1-benzo-furan-2,1'-cyclohexane]-5-carboxylic acid(2), methyl 3'-acetyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (3), methyl 3'-isopentanoyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carbox...

The data shown in this article are related to the subject of an article in Carbohydrate Polymers, entitled "Synthesis and characterization of chitosan alkyl urea" [1]. 1H NMR and 13C NMR spectra of chitosan n-octyl urea, chitosan n-dodecyl urea and chitosan cyclohexyl urea are displayed. The chemical shifts of proton and carbon of glucose skeleton in these chitosan derivatives are designated in...

Chitosan is soluble in most acids. The protonation of the amino groups on the chitosan backbone inhibits the electrospinnability of pure chitosan. Recently, electrospinning of nanofibers based on chitosan has been widely researched and numerous nanofibers containing chitosan have been prepared by decreasing the number of the free amino groups of chitosan as the nanofibiers have enormous possibi...

Chitosan is widely applied in biomedical and cosmetic fields. For this reason, there is a need to modify this biopolymer to achieve new properties of chitosan-based materials. The properties of chitosan can be modified by several cross-linking methods. In this work, we used the chemical cross-linking of chitosan with tannic acid, after which cross-linked chitosan was shaped into a 3D structure ...

Polyelectrolyte-coated nanoparticles or microparticles interact with bioactive molecules (peptides, proteins or nucleic acids) and have been proposed as delivery systems for these molecules. However, the mechanism of adsorption of polyelectrolyte onto particles remains unsolved. In this study, cationic poly(lactide-co-glycolide) (PLGA) nanoparticles were fabricated by adsorption of various conc...

Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activ...