Protein Labeling Facilitates the Understanding of Protein Corona Formation via Fluorescence Resonance Energy Transfer and Fluorescence Correlation Spectroscopy.

Once nanoparticles enter into the biological milieu, nanoparticle-biomacromolecule complexes, especially the protein corona, swiftly form, which cause obvious effects on the physicochemical properties of both nanoparticles and proteins. Here, the thermodynamic parameters of the interactions between water-soluble GSH-CdSe/ZnS core/shell quantum dots (GSH-QDs) and human serum albumin (HSA) were investigated with the aid of labeling fluorescence of HSA. It was proved that the labeling fluorescence originating from a fluorophore (BDP-CN for instance) could be used to investigate the interactions between QDs and HSA.

1,3-Benzodioxole Derivatives Improve the Anti-Tumor Efficiency of Arsenicals.

Arsenicals have been widely used in the treatment of cancers such as leukemia and other tumors. However, their side effects limit their clinical application. Stiripentol, a second-line adjunctive treatment for epilepsy with a good safety profile, inhibits microsomal cytochrome-P450-family enzymes to extend the retention time of co-administration.

Fluorescent Labeling of Human Serum Albumin by Thiol-Cyanimide Addition and Its Application in the Fluorescence Quenching Method for Nanoparticle-Protein Interactions.

A boron-dipyrromethene (BODIPY)-based fluorescent probe, BDP-CN, was synthesized in this work. It had a fluorescence emission maximum at 512 nm and a high quantum yield (48%). As evidenced by agarose gel electrophoresis and liquid chromatography-mass spectrometry, it could realize the fluorescent labeling of human serum albumin (HSA) through a thiol-cyanimide addition.

A bright, red-emitting water-soluble BODIPY fluorophore as an alternative to the commercial Mito Tracker Red for high-resolution mitochondrial imaging.

With the emergence and rapid development of super-resolution fluorescence microscopy, monitoring of mitochondrial morphological changes has aroused great interest for exploring the role of mitochondria in the process of cell metabolism. However, in the absence of water-soluble, photostable and low-toxicity fluorescent dyes, ultra-high-resolution mitochondrial imaging is still challenging. Herein, we designed two fluorescent BODIPY dyes, namely Mito-BDP 630 and Mito-BDP 760, for mitochondrial imaging.

Pd(II)-catalyzed enantioselective synthesis of P-stereogenic phosphinamides via desymmetric C-H arylation.

We present the enantioselective synthesis of P-stereogenic phosphinamides through Pd-catalyzed desymmetric ortho C-H arylation of diarylphosphinamides with boronic esters. The method represents the first example of the synthesis of P-stereogenic phosphorus compounds via the desymmetric C-H functionalization strategy. The reaction proceeded efficiently with a wide array of reaction partners to afford the P-stereogenic phosphinamides in up to 74% yield and 98% ee.

The development of a complementary pathway for the synthesis of aliskiren.

The synthesis of aliskiren (1), a recently marketed drug for the treatment of hypertension, is presented. The focus of our synthetic effort is to develop an efficient pathway for the synthesis of (2S,7R,E)-2-isopropyl-7-(4-methoxy-3-(3-methoxypropoxy) benzyl)-N,N,8-trimethylnon-4-enamide (2a), which has been used as the advanced intermediate toward aliskiren. After an extensive investigation of three different strategies designed to construct the E-olefin functionality in 2a by employing the olefin cross-metathesis, Horner-Wadsworth-Emmons (HWE), and Julia-type olefinations, we have established a new protocol for the synthesis of 2a with a substantially improved overall efficiency in terms of the yield (ca.

[NiCl2(dppp)]-catalyzed cross-coupling of aryl halides with dialkyl phosphite, diphenylphosphine oxide, and diphenylphosphine.

We present a general approach to C-P bond formation through the cross-coupling of aryl halides with a dialkyl phosphite, diphenylphosphine oxide, and diphenylphosphane by using [NiCl(2) (dppp)] as catalyst (dppp=1,3-bis(diphenylphosphino)propane). This catalyst system displays a broad applicability that is capable of catalyzing the cross-coupling of aryl bromides, particularly a range of unreactive aryl chlorides, with various types of phosphorus substrates, such as a dialkyl phosphite, diphenylphosphine oxide, and diphenylphosphane. Consequently, the synthesis of valuable phosphonates, phosphine oxides, and phosphanes can be achieved with one catalyst system.

Efficient synthesis of 2,5-disubstituted tetrazoles via the Cu2O-catalyzed aerobic oxidative direct cross-coupling of N-H free tetrazoles with boronic acids.

We present a new protocol that allows for the synthesis of 2,5-disubstituted tetrazoles via the direct coupling of N-H free tetrazoles and low toxic boronic acids in the presence of only a catalytic amount of Cu(2)O (5 mol%) as catalyst and 1 atm of environmentally benign O(2) as oxidant, without the need for other additives. This method represents a simple, green, and atom-efficient synthesis of 2,5-disubstituted tetrazoles.

PdCl2-catalyzed efficient allylation and benzylation of heteroarenes under ligand, base/acid, and additive-free conditions.

We present a PdCl(2)-catalyzed protocol for highly efficient allylation and benzylation of a rich variety of N-, O-, and S-containing heteroarenes under base/acid, additive, and ligand-free conditions. The method represents the very few examples for simple, universally applicable, clean, and atom-efficient functionalization of heteroarenes.

Nickel-catalyzed cross-coupling of phenols and arylboronic acids through an in situ phenol activation mediated by PyBroP.

A new method for the Suzuki-Miyaura cross-coupling of phenols and arylboronic acids through in situ phenol activation mediated by PyBroP is presented. The reaction proceeds efficiently by using cost-effective, markedly stable [NiCl(2)(dppp)] (dppp=1,3-bis(diphenylphosphino)propane) as the catalyst in only 5 mol % loading, as well as in the absence of extra ligands. The method exhibits broad applicability and high efficiency towards a wide range of both phenols and boronic acids, including activated, nonactivated, deactivated, and heteroaromatic coupling partners.

Assignment of absolute configuration of cyclic secondary amines by NMR techniques using Mosher's method: a general procedure exemplified with (-)-isoanabasine.

A general procedure to determine the absolute configuration of cyclic secondary amines with Mosher's NMR method is demonstrated, with assignment of absolute configuration of isoanabasine as an example. Each Mosher amide can adopt two stable conformations (named rotamers) caused by hindered rotation around amide C--N bond. Via a three-step structural analysis of four rotamers, the absolute configuration of (-)-isoanabasine is deduced to be (R) on the basis of Newman projections, which makes it easy to understand and clarify the application of Mosher's method to cyclic secondary amines.

Enantioselective iodolactonization catalyzed by chiral quaternary ammonium salts derived from cinchonidine.

Chiral quaternary ammonium salts derived from cinchonidine have been applied to catalyze the stereoselective iodolactonizations of trans-5-aryl-4-pentenoic acids leading to a mixture of two regioselectively iodolactonized products with fair to excellent yield (37-98%) and moderate enantioselectivity (exo = 42.0% ee, endo = 31.0% ee) under mild conditions.