Discovery of a novel series of medium-sized cyclic enteropeptidase inhibitors.

Enteropeptidase is located in the duodenum that involved in intestinal protein digestion. We have reported enteropeptidase inhibitors with low systemic exposure. The aim of this study was to discover novel enteropeptidase inhibitors showing more potent in vivo efficacy while retaining low systemic exposure.

Fully automated immunoassay for cholesterol uptake capacity to assess high-density lipoprotein function and cardiovascular disease risk.

High-density lipoprotein (HDL) cholesterol efflux capacity (CEC), which is a conventional metric of HDL function, has been associated with coronary heart disease risk. However, the CEC assay requires cultured cells and takes several days to perform. We previously established a cell-free assay to evaluate cholesterol uptake capacity (CUC) as a novel measure of HDL functionality and demonstrated its utility in coronary risk stratification.

Mirror-image streptavidin with specific binding to L-biotin, the unnatural enantiomer.

The streptavidin-biotin system is known to have a very high affinity and specificity and is widely used in biochemical immunoassays and diagnostics. However, this method is affected by endogenous D-biotin in serum sample measurements (biotin interference). While several efforts using alternative high-affinity binding systems (e.

Silinanyl Rhodamines and Silinanyl Fluoresceins for Super-Resolution Microscopy.

Single-molecule localization microscopy (SMLM) enables the visualization of biomolecules at unprecedented resolution and requires control of the fluorescent blinking (ON/OFF) states of fluorophores to detect single-molecule fluorescence without overlapping of the signals. Although SMLM probes based on the intramolecular spirocyclization of Si-xanthene fluorophores have been developed, fluorophores with lower ON/OFF ratios are required for SMLM visualization of high-density structures. Here, we describe a silinane structure that lowers the ON/OFF ratio of Si-xanthene fluorophores.

Sodium butyrate, a histone deacetylase inhibitor, regulates Lymphangiogenic factors in oral cancer cell line HSC-3.

Aim: Tumor angiogenesis is a focus of molecularly-targeted therapies. This study investigated the effect of sodium butyrate (SB), a histone deacetylase inhibitor, on the synthesis of antiangiogenic and lymphangiogenic factors in oral squamous cell carcinoma.

Design: Gene alterations in HSC-3 cells were assessed using cDNA microarrays before and after treatment with SB.

Discovery of a piperidine-4-carboxamide CCR5 antagonist (TAK-220) with highly potent Anti-HIV-1 activity.

We incorporated various polar groups into previously described piperidine-4-carboxamide CCR5 antagonists to improve their metabolic stability in human hepatic microsomes. Introducing a carbamoyl group into the phenyl ring of the 4-benzylpiperidine moiety afforded the less lipophilic compound 5f, which possessed both high metabolic stability and good inhibitory activity of HIV-1 envelope-mediated membrane fusion (IC(50) = 5.8 nM).

CCR5 antagonists as anti-HIV-1 agents. Part 3: Synthesis and biological evaluation of piperidine-4-carboxamide derivatives.

Replacement of the 5-oxopyrrolidin-3-yl fragment in the previously reported lead structure with a 1-acetylpiperidin-4-yl group led to the discovery of a novel series of potent CCR5 antagonists. Introduction of small hydrophobic substituents on the central phenyl ring increased the binding affinity, providing low to sub-nanomolar CCR5 antagonists. The selected compound 11f showed excellent antiviral activity against CCR5-using HIV-1 replication in human peripheral blood mononuclear cells (EC50=0.

CCR5 antagonists as anti-HIV-1 agents. Part 2: Synthesis and biological evaluation of N-[3-(4-benzylpiperidin-1-yl)propyl]-N,N'-diphenylureas.

We have previously reported the novel lead compound 1a as a CCR5 antagonist for treatment of HIV-1 infection. SAR studies on incorporating various acyl groups as a replacement for the 5-oxopyrrolidine-3-carbonyl group of the lead structure resulted in the discovery of N-[3-(4-benzylpiperidin-1-yl)propyl]-N,N'-diphenylurea (4a) with significantly improved CCR5 binding affinity. Substitutions (4-Cl, 4e,f; 4-Me, 4i) on the N'-phenyl ring further increased the binding affinity.

Palladium-Catalyzed Intramolecular Allylic Alkylation Reaction in Marine Natural Product Synthesis: Enantioselective Synthesis of (+)-Methyl Pederate, a Key Intermediate in Syntheses of Mycalamides.

A novel preparation of (+)-methyl pederate (4), a key intermediate in syntheses of mycalamides (1), marine natural products from a New Zealand sponge of the genus Mycale, is described. The key step involves palladium-catalyzed intramolecular allylic alkylation of the carbonate 21, derived from (+)-(4R,5R,E)-5-(tert-butyldimethylsiloxy)-4-methyl-2-hexenol (13), yielding lactones 5 in 87% yield. Demethoxycarbonylation of the cyclization products 5 and further functional group transformations led to (+)-methyl pederate (4).