Showing papers by "Zhen Hua Li published in 2009"
TL;DR: It is proposed that the antiangiogenic and vascular‐targeting activities of trans‐3,5,4′‐trimethoxystilbene result from the downregulation of VEGFR2 expression and cell‐cycle arrest at G2/M phase.
Abstract: Angiogenesis plays an important role in the development of neoplastic diseases such as cancer. Resveratrol and its derivatives exert antiangiogenic effects, but the mechanisms of their actions remain unclear. The aim of this study was to evaluate the antiangiogenic activity of resveratrol and its derivative trans-3,5,4'-trimethoxystilbene in vitro using human umbilical vein endothelial cells (HUVECs) and in vivo using transgenic zebrafish, and to clarify their mechanisms of action in zebrafish by gene expression analysis of the vascular endothelial growth factor (VEGF) receptor (VEGFR2/KDR) and cell-cycle analysis. trans-3,5,4'-Trimethoxystilbene showed significantly more potent antiangiogenic activity than that of resveratrol in both assays. In zebrafish, trans-3,5,4'-trimethoxystilbene caused intersegmental vessel regression and downregulated VEGFR2 mRNA expression. Trans-3,5,4'-trimethoxystilbene also induced G2/M cell-cycle arrest, most specifically in endothelial cells of zebrafish embryos. We propose that the antiangiogenic and vascular-targeting activities of trans-3,5,4'-trimethoxystilbene result from the downregulation of VEGFR2 expression and cell-cycle arrest at G2/M phase.
62 citations
TL;DR: CdSO 4 and ZnSO 4 as co-modifiers of RuLa/SBA-15 lead to improved catalysts for the partial hydrogenation of benzene to cyclohexene as mentioned in this paper.
51 citations
TL;DR: In this article, transition metal cation-π complexes of Zn2+ and Cd2+ with benzene and cyclohexene have been studied with density functional B3PW91 method.
Abstract: Transition metal cation-π complexes of Zn2+ and Cd2+ with benzene and cyclohexene have been studied with density functional B3PW91 method. Natural bond orbital (NBO) analyses on the direct cation-π complexes (with direct π-ion contact) indicate that the interaction between the π orbital of the π systems and the empty valance s orbital of the cation (πPI → s M2+ interactions) dominates the cation-π interactions. Energetical results indicate that formation of metal cation-π complexes in the gas phase is always energetically favourable and these complexes can thus be prepared and observed in experiments in the gas phase. However, in aqueous solution the desolvation penalty of Zn2+ and Cd2+ is so high that it is energetically unfavourable to form metal cation-π complexes from hydrated Zn2+ and Cd2+ at both 0 K and room temperature. It would thus be predicted that metal cation-π complexes of Zn2+ and Cd2+ are not likely to be observed in aqueous solution.
20 citations