Search

Four undescribed bisbenzylisoquinoline alkaloids, designated as Stephtetrandrine A-D, were isolated from the roots of Stephania tetrandra. Their structures were elucidated by IR, HRESIMS, ECD spectra, 1 D and 2 D NMR spectra and comparison with the literature data. Additional five known compounds (limacine, tetrandrine, N-trans-Feruloyltyramine, 2′-N-chloromethyltetrandrine, 2,2'-N-N-dichloromethyltetrandrine) were also isolated. N-trans-Feruloyltyramine was isolated from Stephania tetrandra for the first time. The isolated compounds were tested for monoamine oxidase, acetylcholinesterase, phosphoinositide 3-kinase α and human hepatoma cell HepG2 inhibitory activities. Stephtetrandrine C showed obvious inhibitory effect on human hepatoma HepG2, with IC50 value of 16.2 μM. Limacine and 2′-N-chloromethyltetrandrine showed moderate monoamine oxidase inhibitory effect with the IC50 values of 37.7 and 29.2 μM, respectively. [ABSTRACT FROM AUTHOR]

An efficient approach for one-pot three-component reaction of aromatic amines, α,β-unsaturated aldehydes and β-keto esters using magnetic nanocrystalline Fe3O4 as a catalyst has been described. The corresponding 1,4-dihydropyridines are obtained in good yields under mild conditions. In addition, the catalyst can be recovered with a magnet and reused at least five consecutive cycles without appreciable loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

An efficient approach for one-pot three-component reaction of aromatic amines, α,β-unsaturated aldehydes and β-keto esters using magnetic nanocrystalline Fe3O4 as a catalyst has been described. The corresponding 1,4-dihydropyridines are obtained in good yields under mild conditions. In addition, the catalyst can be recovered with a magnet and reused at least five consecutive cycles without appreciable loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

The use of Fe3O4 nanoparticles as magnetically separable catalyst for the three-component, one-pot synthesis of 1,4-dihydropyridines is described. [ABSTRACT FROM AUTHOR]

A simple and efficient protocol for one-pot three-component coupling of isatoic anhydride, amines, and aldehydes in water using magnetically recoverable Fe(3)O(4) nanoparticles is reported. This methodology results in the synthesis of a variety of 2,3-dihydroquinazolin-4(1H)-ones in high yields. The catalyst can be recovered and recycled without a significant loss in the catalytic activity.

Myostatin, a member of the TGF-beta family, negatively regulates skeletal muscle development. Mutation of myostatin activity leads to increases muscle growth and carcass lean yield. The bovine myostatin mutation cDNA was amplified by polymerase chain reaction, and then sub-cloned into the expression vector pET-30a( + ) to form the expression plasmid pET30a (+)-action/ Myostatin. The recombinant plasmid was transformed into E. coli BL21. The overexpression product of pET30a (+)-action/ Myostatin was been showed in vitro. Sheep skeletal muscle cell were cultured with the purified myostatin mutation C-terminal peptide. The results of this study suggest that had a powerful activity to stimulate the hyperplasia and proliferation of sheep muscle cells and shows high biochemical activity.