Showing papers by "Bao-Xiang Zhao published in 2004"

One-pot Synthesis of Symmetrical 1,4-Disubstituted Piperazine-2,5-diones

Abstract: The piperazine-2,5-dione moiety occurs in a variety of drugs and natural products which span a wide spectrum of biological activities, e.g., roquefortine, bicyclomycin, dipodazine, neihumicin, phomamide, and dihydrodysamide C. Additionally, this heterocyclic system has found unique applications as an acceptor for organic anions or metal cations and in material sciences. While numerous approaches to piperazine-2,5-diones have been reported, there is still considerable demand for more economic and versatile syntheses. Herein, we report a convenient, one-pot synthesis of 1,4-disubstituted piperazine-2,5-diones (2) based on the mild homoannulation of N-substituted 2chloroamides (1, eq. 1).

Safrole oxide induces apoptosis in A549 human lung cancer cells

Abstract: 3,4-(Methylenedioxy)-1-(2',3'-epoxypropyl)-benzene (safrole oxide) was synthesized in the authors' laboratory. To investigate the effects of safrole oxide on the growth and apoptosis of A549 human lung cancer cells, the authors treated the cells with safrole oxide, 112.36 to 449.44 micromol/L, for 24 to 48 hours. The results showed that the drug led A549 cells to apoptosis and blocked cell cycle completely at G1 phase and partly at G(2)-M phase. To further study the correlated mechanism, the authors examined P53 and H-Ras protein expressions by using immunofluorescence assay. They found that the expression of P53 was dramatically up-regulated but the expression of H-Ras was hardly affected by safrole oxide, 224.72 micromol/L, within 24 hours. Taken together, these results revealed that safrole oxide could induce apoptosis of A549 cells and suggested that safrole oxide might perform its function by blocking cells completely at G1 phase and partly at G(2)-M phase, and also by up-regulating the expression of P53 protein. These findings would raise exciting possibilities for cancer therapy in future.

Effects of novel safrole oxide derivatives, 1-propyl-3-(3,4-methylenedioxyphenyl)-2-propanol and 1-isopropoxy-3-(3,4-methylenedioxyphenyl)-2-propanol, on apoptosis induced by deprivation of survival factors in vascular endothelial cells.

Abstract: Two safrole oxide derivatives, 1-propoxy-3-(3,4-methylenedioxyphenyl)-2-propanol (FOD) and 1-isopropoxy-3-(3,4-methylenedioxyphenyl)-2-propanol (GOD), were newly synthesized as promoters of apoptosis in vascular endothelial cells The purpose of this study was to investigate the effects of these two safrole oxide derivatives on cell growth and apoptosis induced by deprivation of survival factors (serum and fibroblast growth factors, aFGF and bFGF) in vascular endothelial cells (VECs) MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium) method, agarose gel electrophoresis, laser scanning confocal microscopy, flow cytometry (FCM), and immunofluorescence assay were used The cells deprived of FGF and serum were exposed to FOD or GOD 30 to 90 mg x L(-1) for 24 h, cell growth was suppressed (p < 05), whereas detachment and DNA fragmentation of these cells were promoted (p < 01) When the cells were treated with FOD 90 mg x L(-) for 24 h, apoptosis rate was 1499% (p < 01) There were more cells in G2-M phase and less cells in S phase At 90 mg x L(-1) concentration, GOD blocked 7703%of the cells at G0-G1 phase, P53 level in VEC exposed to FOD or GOD was increased (p < 01) The data suggested that FOD and GOD might promote apoptosis of VEC by affect the cell cycle distribution, whereas P53 was involved in this pathway

One-Pot Synthesis of Symmetrical 1,4-Disubstituted Piperazine-2,5-diones.

Abstract: The piperazine-2,5-dione moiety occurs in a variety of drugs and natural products which span a wide spectrum of biological activities, e.g., roquefortine, bicyclomycin, dipodazine, neihumicin, phomamide, and dihydrodysamide C. Additionally, this heterocyclic system has found unique applications as an acceptor for organic anions or metal cations and in material sciences. While numerous approaches to piperazine-2,5-diones have been reported, there is still considerable demand for more economic and versatile syntheses. Herein, we report a convenient, one-pot synthesis of 1,4-disubstituted piperazine-2,5-diones (2) based on the mild homoannulation of N-substituted 2chloroamides (1, eq. 1).