Iga S.,Faculty for Biology |
Iga A.,Faculty for Biology |
Nicolescu A.,Petru PoniInstitute of Macromolecular Chemical |
Iga D.P.,Faculty for Biology
Revista de Chimie | Year: 2010
A new synthesis of D,L-a-tocopheryl- a-D-mannopyranoside, an antiallergic and antiinflammatory compound, has been accomplished. The synthesis was based on the following steps: the monosaccharide was stirred in a mbcture of pyridine and acetic anhydride on an ice-water bath in order to obtain penta-O-aceyl-ß-Dmannopyranoside. The protected mannopyranoside was dried exhaustively in vacuum on phosphorus pentoxide, mixed with D, L- α-tocopher of, dried again, and then glycosylation method according to Helferich was accomplished. Toluene constituted the reaction environment and p-toluenesulfonic acid was glycosylation promotor. Reaction mixture was submitted to Zemplen saponification and then to column chromatography on silica gel. Two mannosides have been separated in the molar ratio 40:1, the minor one migrating faster by thin layer and column chromatography. Being characterized by their 1H and 13C NMR spectra as well as by chemical and chromatographical means, the major mannoside proved to be D,L-α- tocopheryl-cc-Dmannopyranoside and the minor one D,L-α-tocopheryl-ß- D-mannofuranoside. They both could constitute new possible metabolites of a-tocopherol and mannose, as well as new substrates for a-mannosidases.
Spiridon I.,Petru PoniInstitute of Macromolecular Chemical |
Teaca C.-A.,Petru PoniInstitute of Macromolecular Chemical |
Bodirlau R.,Petru PoniInstitute of Macromolecular Chemical
Journal of Materials Science | Year: 2011
In this article, starch microparticles (SM) were prepared by delivering ethanol as the precipitant into starch paste solution dropwise. Adipic acid (AA)-modified starch microparticles (AASM) were fabricated using the dry preparation technique. The composites were prepared using AASM as the filler in glycerol plasticized-corn starch (GCS) matrix by the casting process. Two lignins were also compared in terms of structure and reactivity when incorporated within the AASM-GCS matrix. The effects of lignin on the morphology, surface properties, and water sorption, as well as mechanical and thermal properties of starch-lignin composite films were investigated. The surface water resistance and the thermal stability of materials were improved through addition of lignin. Starch-lignin composite materials presented higher tensile strength, but a lower elongation capacity comparatively with those without lignin. © 2010 Springer Science+Business Media, LLC.
Oprea A.-M.,Petru PoniInstitute of Macromolecular Chemical |
Ciolacu D.,Petru PoniInstitute of Macromolecular Chemical |
Neamtu A.,Grigore T. Popa University of Medicine and Pharmacy |
Mungiu O.C.,Grigore T. Popa University of Medicine and Pharmacy |
And 2 more authors.
Cellulose Chemistry and Technology | Year: 2010
The present study investigates some hydrogels, based on natural, biodegradable and biocompatible polysaccharides, such as cellulose (C) and chondroitin sulfate (CS), as sustained release carriers, and evaluates their biocompatibility. Investigations were performed on cellulose/chondroitin sulfate (C/CS) hydrogels, in different mixing ratios. Swelling and drug delivery studies were conducted in a phosphate buffer solution (pH = 7.4) that simulates the pH of the intestinal fluid, at 37 0C. Natural-based hydrogels were evaluated for the release of paracetamol and theophylline. The release profiles of the drugs from C/CS hydrogels depend on the CS content: for paracetamol, a decrease of the percent released and, for theophylline, a percentual increase with the increase of the CS content. The results showed good biocompatibility with the tested formulations.