Discovery of memantyl urea derivatives as potent soluble epoxide hydrolase inhibitors against lipopolysaccharide-induced sepsis.

Sepsis, a systemic inflammatory response, caused by pathogenic factors including microorganisms, has high mortality and limited therapeutic approaches. Herein, a new soluble epoxide hydrolase (sEH) inhibitor series comprising a phenyl ring connected to a memantyl moiety via a urea or amide linkage has been designed. A preferential urea pharmacophore that improved the binding properties of the compounds was identified for those series via biochemical assay in vitro and in vivo studies. Molecular docking displayed that 3,5-dimethyl on the adamantyl group in B401 could make van der Waals interactions with residues at a hydrophobic pocket of sEH active site, which might indirectly explain the subnanomolar level activities of memantyl urea derivatives in vitro better than AR-9281. Among them, compound B401 significantly improved the inhibition potency with human and murine sEH IC50 values as 0.4 nM and 0.5 nM, respectively. Although the median survival time of C57BL/6 mice in LPS-induced sepsis model was slightly increased, the survival rate did not reach significant efficacy. Based on safety profile, metabolic stability, pharmacokinetic and in vivo efficacy, B401 demonstrated the proof of potential for this class of memantyl urea-based sEH inhibitors as therapeutic agents in sepsis.

Targeted Drug Delivery to Cancer Stem Cells through Nanotechnological Approaches.

Cancer Stem Cells (CSCs) are responsible for tumor development, invasion and metastasis and resistance to chemotherapy and radiotherapy. Therefore, treatment strategies have turned to targeting CSCs, and utilizing nanotechnological approaches to target CSCs has become increasingly fascinating. Functionalized nanoparticles (NPs), such as metallic NPs, liposomes, polymeric NPs, albumin microspheres and nanomicelles, can easily cross the cytoplasmic membrane and accumulate at their targets to continuously release therapeutic agents in response to the characteristics of the tumor microenvironment. Different kinds of NPs possess different characteristics. Inducing immune responses might be the disadvantage they commonly owned through the summary and analysis of these NPs. For natural polymers, they have many attractive properties, but deficiencies also exist such as poor water-solubility, high viscosity, high permeability, etc. The drug-encapsulated NPs launched in the market and those in the clinical trials exhibit a bright prospect in cancer targeted therapy. In addition, the application of nanodiagnostic techniques, such as nanocantilever and DNA microarray technology and early cancer detection has become an indispensable component in clinical practice to improve in vivo detection and enhance targeting efficiency. This review mainly determines the species and usages of NPs in drug delivery and disease diagnosis, the delivery mechanisms of NPs, the main factors that affect nanomedicine efficiency and toxicity and the further trends in the development of targeted therapy. Nevertheless, more and deeper investigations are still needed to avert potential adverse effects and improve the delivery efficiency to achieve better therapeutic effects.

5-Hydroxyindole-Based EZH2 Inhibitors Assembled via TCCA-Catalyzed Condensation and Nenitzescu Reactions.

5-Hydroxyindole derivatives have various demonstrated biological activities. Herein, we used 5-hydroxyindole as a synthetic starting point for structural alterations in a combinatorial process to synthesize 22 different compounds with EZH2 inhibitor pharmacophores. A series of 5-hydroxyindole-derived compounds were screened inhibitory activities against K562 cells. According to molecular modeling and in vitro biological activity assays, the preliminary structure-activity relationship was summarized. Compound L-04 improved both the H3K27Me3 reduction and antiproliferation parameters (IC50 = 52.6 µM). These findings revealed that compound L-04 is worthy of consideration as a lead compound to design more potent EZH2 inhibitors. During the preparation of compounds, we discovered that trichloroisocyanuric acid (TCCA) is a novel catalyst which demonstrates condensation-promoting effects. To gain insight into the reaction, in situ React IR technology was used to confirm the reactivity. Different amines were condensed in high yields with ß-diketones or ß-ketoesters in the presence of TCCA to afford the corresponding products in a short time (10~20 min), which displayed some advantages and provided an alternative condensation strategy.

Targeting cancer stem cells in drug discovery: Current state and future perspectives.

In recent decades, cancer stem cells (CSCs) have been increasingly identified in many malignancies. CSC-related signaling pathways and their functions provide new strategies for treating cancer. The aberrant activation of related signaling pathways (e.g., Wnt, Notch, and Hedgehog pathways) has been linked to multiple types of malignant tumors, which makes these pathways attractive targets for cancer therapy. CSCs display many characteristic features, such as self-renewal, differentiation, high tumorigenicity, and drug resistance. Therefore, there is an urgent need to develop new therapeutic strategies to target these pathways to control stem cell replication, survival, and differentiation. Notable crosstalk occurs among different signaling pathways and potentially leads to compensatory escape. Therefore, multitarget inhibitors will be one of the main methods to overcome the drug resistance of CSCs. Many small molecule inhibitors of components of signaling pathways in CSCs have entered clinical trials, and some inhibitors, such as vismodegib, sonidegib, and glasdegib, have been approved. Tumor cells are susceptible to sonidegib and vismodegib resistance due to mutations in the Smo protein. The signal transducers and activators of transcription 3 (STAT3) inhibitor BBI608 is being evaluated in a phase III trial for a variety of cancers. Structural derivatives of BBI608 are the main focus of STAT3 inhibitor development, which is another strategy for CSC therapy. In addition to the potential pharmacological inhibitors targeting CSC-related signaling pathways, other methods of targeting CSCs are available, such as nano-drug delivery systems, mitochondrion targeting, autophagy, hyperthermia, immunotherapy, and CSC microenvironment targeting. In addition, we summarize the latest advances in the clinical development of agents targeting CSC-related signaling pathways and other methods of targeting CSCs.

l -( -) -Quebrachitol as a Ligand for Selective Copper(0)-Catalyzed N-Arylation of Nitrogen-Containing Heterocycles.

l-(-)-Quebrachitol (QCT) has been found as a ligand of copper powder for selective N-arylation of nitrogen-containing heterocycles with aryl halides. Furthermore, another potential catalytic system (copper powder/QCT/ t-BuOK) was successfully adapted to unactivated aryl chlorides.

Design, synthesis and activity of BBI608 derivatives targeting on stem cells.

STAT3 plays a vital role in maintaining the self-renewal of tumor stem cells. BBI608, a small molecule identified by its ability to inhibit gene transcription driven by STAT3 and cancer stemness properties, can inhibit stemness gene expression and kill stemness-high cancer cells isolated from a variety of cancer types. In order to improve the pharmacokinetic properties of BBI608 and the antitumor activity, a series of BBI608 derivatives were designed and synthesized here. Most of these compounds were more potent than BBI608 on HepG2 cells, compound LD-8 had the most potent inhibitory activity among them and was 5.4-fold more potent than BBI608 (IC50 = 11.2 µM), but had considerable activity on normal liver cells L-02. Compounds LD-17 (IC50 = 3.5 µM) and LD-19 (IC50 = 2.9 µM) were found to possess significant inhibitory activities and good selectivity. The results showed that compound LD-19 was worthy to investigate further as a lead compound according to its potent inhibitory activity, ideal ClogP value and better water solubility.