Voltage-Gated Electrocatalysis of Efficient and Selective Methane Oxidation by Tricopper Clusters under Ambient Conditions.

Selective methane oxidation is difficult chemistry. Here we describe a strategy for the electrocatalysis of selective methane oxidation by immobilizing tricopper catalysts on the cathodic surface. In the presence of dioxygen and methane, the activation of these catalysts above a threshold cathodic potential can initiate the dioxygen chemistry for O atom transfer to methane.

A Carbon Electrode Functionalized by a Tricopper Cluster Complex: Overcoming Overpotential and Production of Hydrogen Peroxide in the Oxygen Reduction Reaction.

A study of the oxygen reduction reaction (ORR) on a screen printed carbon electrode surface mediated by the tricopper cluster complex Cu (7-N-Etppz(CH OH)) dispersed on electrochemically reduced carbon black, where 7-N-Etppz(CH OH) is the ligand 3,3'-(6-(hydroxymethyl)-1,4-diazepane-1,4-diyl)bis(1-(4-ethyl piperazin-1-yl)propan-2-ol), is described. Onset oxygen reduction potentials of about 0.92 V and about 0.

Design and Synthesis of Chiral Diene Ligands for Rh -Catalyzed Enantioselective Arylation of N-DPP-protected Aldimines: Synthesis of the Antifungal Agent Bifonazole.

Herein we describe the design and synthesis of a novel family of bifunctional, chiral bicyclo[2.2.1]heptadiene ligands bearing aryl and secondary amido groups, and demonstrate their usefulness in the Rh -catalyzed enantioselective addition reaction of arylboronic acids to N-diphenylphosphinyl (N-DPP)-protected aldimines.

Synthesis and biological evaluation of helioxanthin analogues.

Helioxanthin and analogues have been demonstrated to suppress gene expression of human hepatitis B virus. In the continuous attempt to optimize antiviral activity, various structural motifs were grafted on the helioxanthin scaffold. Many such analogues were synthesized and evaluated for their anti-hepatitis B virus activity.

Preparation of chiral 3-arylpyrrolidines via the enantioselective 1,4-addition of arylboronic acids to fumaric esters catalyzed by Rh(I)/chiral diene complexes.

A highly efficient rhodium-catalyzed protocol for the preparation of 2-arylsuccinic esters and 3-arylpyrrolidines of high optical purity has been achieved. In the presence of 1 mol % of a chiral diene/Rh(I) catalyst, asymmetric addition of various arylboronic acids to di-tert-butyl fumarate (3c) provides the corresponding adducts in up to 99% yield and 94→99.5% ee.

Synthesis and the biological evaluation of arylnaphthalene lignans as anti-hepatitis B virus agents.

We have previously shown that helioxanthin can suppress human hepatitis B virus gene expression. A series of helioxanthin analogues were synthesized and evaluated for their anti-hepatitis B virus activity. Modifications at the lactone rings and methylenedioxy unit of helioxanthin can modulate the antiviral activity.

Helioxanthin inhibits interleukin-1 beta-induced MIP-1 beta production by reduction of c-jun expression and binding of the c-jun/CREB1 complex to the AP-1/CRE site of the MIP-1 beta promoter in Huh7 cells.

An elevated level of macrophage inflammatory protein-1beta (MIP-1beta) induced by IL-1beta has been correlated with chronic hepatic inflammatory disease. However, molecular mechanism of IL-1beta-induced MIP-1beta expression in hepatic cells is obscure. Previously, we reported the mechanism of the anti-hepatitis B virus (HBV) activity of helioxanthin (HE-145).

The role of helioxanthin in inhibiting human hepatitis B viral replication and gene expression by interfering with the host transcriptional machinery of viral promoters.

A non-nucleosidic compound, Helioxanthin (HE-145), was found to suppress HBV gene expression and replication in HCC cells. To understand the molecular mode of action of HE-145 on HBV gene expression, the effects of HE-145 on four viral promoter activities using luciferase as a reporter were examined. It was found that HE-145 selectively suppresses surface antigen promoter II (SPII) and core promoter (CP) but has no effect on surface antigen promoter I (SPI) or promoter for X gene (Xp).