stilbenes and acrylic-acid

A series of trans- or cis-stilbenes have been synthesized in good to excellent yields via a functional group-dependent decarboxylation process from the corresponding 2,3-diaryl acrylic acids in a neutral CuI/1,10-phen/PEG-400 system under microwave conditions. The in situ generation of the recyclable catalytic complex, the use of environmentally benign solvent PEG-400, the operational simplicity, the short reaction times, as well as the functional group-dependent chemo- and stereo-selectivity have made the decarboxylation process a highly efficient and applicable protocol.

Topics: Acrylates; Catalysis; Copper; Decarboxylation; Iodides; Microwaves; Molecular Structure; Organometallic Compounds; Phenanthrolines; Polyethylene Glycols; Stereoisomerism; Stilbenes

Topics: Acrylates; Catalysis; Decarboxylation; Hydroxylation; Palladium; Phenols; Stilbenes

Incorporation of osteoinductive factors in a suitable scaffold is considered a promising strategy for generating osteogenic biomaterials. Resveratrol is a polyphenol found in parts of certain plants, including nuts, berries and grapes. It is known to increase DNA synthesis and alkaline phosphatase (ALP) activity in osteoblasts and to prevent femoral bone loss in ovariectomized (OVX) rats. In the present study resveratrol was coupled through a hydrolysable covalent bond with the carboxylic acid groups in porous poly-ε-caprolactone (PCL) surface grafted with acrylic acid (AA). The osteogenic effect of this new scaffold was evaluated in mesenchymal cell culture and in the rat calvarial defect model. We found that the incorporation of resveratrol caused increased ALP activity of rat bone marrow stromal cells and enhanced mineralization of the cell-scaffold composites in vitro. After 8 weeks the calvarial defects implanted with resveratrol-conjugated PCL displayed a higher X-ray density than the defects implanted with control PCL. Bone-like structures, positively immunostained for bone sialoprotein, were shown to be more extensively formed in the resveratrol-conjugated PCL. These results show that incorporation of resveratrol into the AA-functionalized porous PCL scaffold led to a significant increase in osteogenesis.

Topics: Acrylates; Alkaline Phosphatase; Animals; Bone Regeneration; Calcification, Physiologic; Extracellular Matrix; Hydrolysis; Male; Mesenchymal Stem Cells; Osteogenesis; Polyesters; Porosity; Prosthesis Implantation; Radiography; Rats; Rats, Sprague-Dawley; Resveratrol; Skull; Spectroscopy, Fourier Transform Infrared; Stilbenes; Tissue Scaffolds