Block Electrochemiluminescence of Luminol through O-Etherification and Its Application in Sensing of β-Glucosidase.

Luminol is a well-known electrochemiluminescence (ECL) fluorophore that is applied in various sensing fields as an ECL reporter. Regulating the signal off/on transition of an ECL fluorophore offers great opportunities for sensors' design; however, such attempts on luminol are extremely scarce as it was regarded to lack promising modification sites. In this study, we developed four luminol derivatives with modification at the amine site and the enol site and systematically explored possible caging strategies to regulate ECL emission.

Ginkgolides with anti-PAF activity from Ginkgo biloba L.

Four undescribed ginkgolides, including two rare sesquiterpene ginkgolides (compounds 1 and 2) and two diterpenoid ginkgolides (compounds 3 and 4), were isolated from Ginkgo biloba L. The structures of these four ginkgolides were identified based on extensive spectroscopic analysis, DP4+ probability analysis and X-ray diffraction. Compounds 1 and 2 exhibited excellent antiplatelet aggregation activities with IC values of 1.

Boron-catalysed transition-metal-free arylation and alkenylation of allylic alcohols with boronic acids.

The development of efficient catalytic reactions with excellent atom and step economy employing sustainable catalysts is highly sought-after in chemical synthesis to reduce the negative effects on the environment. The most commonly-used strategy to construct allylic compounds relies on the transition-metal-catalysed nucleophilic substitution reaction of allylic alcohol derivatives. These syntheses exhibit good yield and selectivity, albeit at the expense of toxic and expensive catalysts and extra steps.

Quantitative chemical proteomics reveals anti-cancer targets of Celastrol in HCT116 human colon cancer cells.

Background: Celastrol (Cel) is a naturally-derived compound with anti-cancer properties and exerts beneficial effects against various diseases. Although an extensive body of research already exists for Cel, the vast majority are inductive studies with limited validation of specific pathways and functions. The cellular targets that bind to Cel remain poorly characterized, which limits attempts to uncover its mechanism of action.

Genomics-driven discovery of a new cyclodepsipeptide from the guanophilic fungus .

Two potential non-ribosomal peptide synthetases (NRPSs) were identified in the genome of a guanophilic fungus Amphichorda guana by bioinformatics analysis and gene knockout experiments. Liquid chromatography coupled with mass spectrometry (LC-MS) guided isolation led to the discovery of a new cyclodepsipeptide isaridin H (1) and seven known analogs, desmethylisaridin E (2), isaridin E (3), isariin A (4), iso-isariin B (5), iso-isariin D (6), isariin E (7), and nodupetide (8). The absolute configuration of isaridin H (1) was achieved by Marfey's method.

Magnetic Nanoparticle-Based Ligand Replacement Strategy for Chemical Luminescence Determination of Cholesterol.

Determination of serum cholesterol (Chol) is important for disease diagnosis, and has attracted great attention during the last few decades. Herein, a new magnetic nanoparticle-based ligand replacement strategy has been presented for chemical luminescence detection of Chol. The detection depends on ligand replacement from ferrocene (Fc) to Chol through a β-cyclodextrin (β-CD)-based host-guest interaction, which releases Fc-Hemin as a catalyst for the luminol/hydrogen peroxide chemical luminescence system.

Target Profiling of an Anticancer Drug Curcumin by an In Situ Chemical Proteomics Approach.

Interdisciplinary chemical proteomics approaches have been widely applied to the identification of specific targets of bioactive small molecules or drugs. In this chapter, we describe the application of a cell-permeable activity-based curcumin probe (Cur-P) with an alkyne moiety to detect and identify specific binding targets of curcumin in HCT116 colon cancer cells. Through click chemistry, a fluorescent tag or a biotin tag is attached to the probe-modified curcumin targets for visualization or affinity purification followed by mass spectrometric identification.

Recent Progresses in Cancer Nanotherapeutics Design Using Artemisinins as Free Radical Precursors.

Artemisinin and its derivatives (ARTs) are sort of important antimalarials, which exhibit a wide range of biological activities including anticancer effect. To solve the issues regarding poor solubility and limited bioavailability of ARTs, nanoformulation of ARTs has thus emerged as a promising strategy for cancer treatment. A common consideration on nanoARTs design lies on ARTs' delivery and controlled release, where ARTs are commonly regarded as hydrophobic drugs.

A new FRET probe for ratiometric fluorescence detecting mitochondria-localized drug activation and imaging endogenous hydroxyl radicals in zebrafish.

A new FRET probe has been prepared for ratiometric fluorescence detection of hydroxyl radicals. It has been successfully used for detecting mitochondria-localized drug activation in living cells and imaging endogenous hydroxyl radicals in zebrafish gastrointestinal (GI) tracts under normal culturing conditions.

A new fluorescent probe for sensing of biothiols and screening of acetylcholinesterase inhibitors.

A new N2O-type BODIPY probe (LF-Bop) has been proposed for the selective and sensitive detection of biologically relevant small molecular thiols. This detection is based on the Michael addition reaction between the thiol and nitrostyrene groups in the probe, which decreases the quenching effect from the nitro group, thus resulting in the recovery of the deep-red fluorescence from the BODIPY structure. The results show that LF-Bop is able to detect all tested free thiols through a fluorescence turn-on assay.