Anticancer effects of novel resveratrol analogues on human ovarian cancer cells.

Resveratrol, a naturally occurring phytoalexin, has long been known to play an important regulatory role in key functions in cell physiology. This multifunctional role of resveratrol is explained by its ability to interact with several targets of various cell pathways. In the recent past, synthetic chemical modifications have been made in an attempt to enhance the biological effects of resveratrol, including its anti-cancer properties. In this study, we investigated the molecular mechanisms of action of novel trans-restricted analogues of resveratrol in which the C-C double bond of the natural derivative has been replaced by diaryl-substituted imidazole analogues. In ovarian cancer models, the results of in vitro screening revealed that the resveratrol analogues exhibited enhanced anti-proliferative properties compared with resveratrol. We found that the resveratrol analogues also significantly inhibited Akt and MAPK signalling and reduced the migration of IL-6 and EGF-treated cells. Finally, in ascite-derived cancer cells, we demonstrated that the resveratrol analogues reduced the expression of epithelial mesenchymal transition (EMT) markers. Collectively, these findings indicate the enhanced anti-cancer properties of the resveratrol analogues.

Convenient synthesis of fluoride-alkoxides of Nb(V) and Ta(V): a spectroscopic, crystallographic and computational study.

The synthesis and the spectroscopic characterization of fluoride-alkoxides of niobium and tantalum in the highest oxidation state are reported. Suspensions of MF(5) (M = Nb, Ta) in a chlorinated solvent reacted with up to three equivalents of ROSiMe(3) (R = Me, Et, Ph) to afford polynuclear derivatives and variable amounts of FSiMe(3). Thus MF(4)(OR) (R = Et, Ph) and MF(3)(OR)(2) were obtained by selective 1 : 1 and 1 : 2 reactions almost exclusively as single isomeric products; otherwise mixtures of MF(4)(OMe) species were afforded from the equimolar reactions of MF(5) with MeOSiMe(3). The 1 : 3 reaction of TaF(5) with MeOSiMe(3) led to different forms of TaF(2)(OMe)(3). The synthesis of TaF(OPh)(4) was forced by high temperature conditions or the use of a large excess of PhOSiMe(3). DFT studies were carried out in order to predict, in the distinct cases, the most stable structures of the metal products. The molecular structures of [NbF(2)(OPh)(2)(µ-F)](3) and [TaF(OPh)(3)(µ-OPh)](2) were ascertained by X-ray diffraction.