A highly selective and easily acquisitive near-infrared fluorescent probe for detection and imaging of hydrogen sulfide in cells.

Hydrogen sulfide (HS) plays a substantial role as a messenger in the physiological and pathological processes of many diseases. Recently, the fluorescence probe of HS based on organic dye has attracted great attention. However, the emission of many probes is in the UV-vis region (400-600 nm), so it has the disadvantages of shallow tissue penetration and more vulnerable to spontaneous fluorescence interference.

Two phenanthroimidazole turn-on probes for the rapid detection of selenocysteine and its application in living cells imaging.

Detection of selenocysteine (Sec) content in cells by fluorescence probe is of great significance for the identification of human related diseases. To achieve fast and sensitive detection of Sec, two isomers A4 and B4 as turn-on fluorescent probes to detect Sec were designed and synthesized. Both A4 and B4 display fast turn-on response, high selectivity and sensitivity toward Sec, which can be applied for fluorescence imaging of Sec in living cells.

A FRET-ICT Dual-Modulated Ratiometric Fluorescence Sensor for Monitoring and Bio-Imaging of Cellular Selenocysteine.

Since the fluctuation of cellular selenocysteine (Sec) concentration plays an all-important role in the development of numerous human disorders, the real-time fluorescence detection of Sec in living systems has attracted plenty of interest during the past decade. In order to obtain a faster and more sensitive small organic molecule fluorescence sensor for the Sec detection, a new ratiometric fluorescence sensor was designed based on the fluorescence resonance energy transfer (FRET) strategy with coumarin fluorophore as energy donor and 4-hydroxy naphthalimide fluorophore (with 2,4-dinitrobenzene sulfonate as fluorescence signal quencher and Sec-selective recognition site) as an energy acceptor. The sensor exhibited only a blue fluorescence signal, and displayed two well distinguished emission bands (blue and green) in the presence of Sec with ∆λ of 68 nm.

A Red Emissive Fluorescent Turn-on Sensor for the Rapid Detection of Selenocysteine and Its Application in Living Cells Imaging.

The content of selenocysteine in cells has an important effect on a variety of human diseases, and the detection of selenocysteine by fluorescent sensors in vivo has shown many advantages. In order to further develop fast-reaction-time, good-selectivity, and high-sensitivity long-wavelength selenocysteine fluorescent sensors, we designed and synthesized the compound as a turn-on fluorescent sensor to detect the content of selenocysteine. The quantitative detection range of the sensor to selenocysteine was from 0 to 32 μM, and the detection limit was as low as 11.

Design, synthesis and biological Evaluation of Dual acetyl cholinesterase and beta-secretase inhibitors in treatment for alzheimer's Disease.

With the recent research advances in molecular biology and technology multiple credible hypotheses about the progress of Alzheimer's disease (AD) have been proposed, among which the amyloid and cholinergic hypotheses are commonly used to develop reliable therapeutic agents. The multitarget-directed ligand (MTDL) approach was taken in this work to develop muilti-functional agents, which can mainly serve as dual beta-secretase (BACE 1) and Acetylcholinesterase (AChE) inhibitors. Series of new compounds were designed, synthesized and evaluated in this work, from which we identified 2-((4-(1,3-dioxoisoindolin-2-yl)benzyl)amino)-2-oxoethyl-2-(4-methoxyphenyl)acetate (1h) as a new dual cholinesterase and beta-secretase inhibitor without toxicity.

A new "off-on" NIR fluorescence probe for determination and bio-imaging of mitochondrial hypochlorite in living cells and zebrafish.

Hypochlorite anion (ClO) has been recognized as host defense destructing incursive bacteria and pathogens, a signal molecule inducing occurrence of apoptosis and a noxious agent when it is overproduced. It is significant to detect ClO in mitochondria for getting meaningful physiological and pathological information. Compared with the fluorescence probes of emission wavelength in ultraviolet or visible region, those with near-infrared (NIR) fluorescence signal are advantageous due to the deeper tissue penetrability and less photo-bleaching effect.

A novel "turn-on" mitochondria-targeting near-infrared fluorescent probe for HS detection and in living cells imaging.

Hydrogen sulfide (HS) has been considered to be involved in cytoprotective processes and redox signaling. It is very meaningful to track and analyze it in mitochondria. Herein, we report a novel "turn-on" mitochondria-targeting near-infrared fluorescent probe (Mito-NIR-SH) for detection of HS in living cells, which was designed and synthesized by introducing 2,4-dinitrophenyl as fluorescence quenching group and HS response moiety into Changsha near-infrared fluorophore (CS-OH).

A novel "turn-on" mitochondria-targeting near-infrared fluorescent probe for determination and bioimaging cellular hydrogen sulfide.

Hydrogen sulfide (HS) has been regarded as an important gas transmitter playing vital role in cytoprotective processes and redox signaling. It is very meaningful to monitor and analyze it in biosystem for obtaining important physiological and pathological information. Despite numerous fluorescent probes for cellular HS have been reported in past decades, only a few have capability to detect mitochondrial HS with near-infrared (NIR) emission.

Hollow Fe₃O₄/Graphene Oxide Nanocomposites as Novel Rapamycin Carrier: Formulation Optimization and Characterization.

In the present research an attempt was made to develop and optimize rapamycin (Rapa) loaded hollow magnetic Fe3O4/graphene oxide (Fe3O4/GO) nanocomposites using solvent evaporation technique and response surface methodology (RSM). A Box-Behnken design (BBD) with a three-level, three-factor was used to determine preparation parameters that would achieve the highest encapsulation efficiency (EE) and drug loading capacity (DLC). At optimum conditions such as mass ratio of Rapa to Fe3O4/GO (Rapa: Fe3O4/GO) 0.

Design, synthesis and biological evaluation of dual acetylcholinesterase and phosphodiesterase 5A inhibitors in treatment for Alzheimer's disease.

With the recent research advances in molecular biology and technology, multiple credible hypotheses about the progress of Alzheimer's disease (AD) have been proposed; multi-target drugs have emerged as an innovative therapeutic approach for AD. Current clinical therapy for AD patients is mainly palliative treatment targeting acetylcholinesterase (AChE). Inhibition of phosphodiesterase 5A (PDE5A) has recently been validated as a potentially novel therapeutic approach for Alzheimer's disease (AD).

Multipotent AChE and BACE-1 inhibitors for the treatment of Alzheimer's disease: Design, synthesis and bio-analysis of 7-amino-1,4-dihydro-2H-isoquilin-3-one derivates.

In this paper, the preparation of a new class of multi-target-directed ligands (MTDLs) based on a 7-amino-1,4-dihydro-2H-isoquilin-3-one, whose lead (compound I) showed promising properties in acetylcholinesterase (AChE) inhibitory activity [1], is described. The results of in vitro activities and molecular docking demonstrated that the target molecule (compounds 10a-n) with three parts of aromatic moieties and appropriate structural length can interact with aromatic residues in catalytic active site (CAS), peripheral anionic site (PAS) and the channel of AChE. And the introduce of connecting amide bonds, enables the target molecules provide sufficient hydrogen bond donors and acceptors to interact with the catalytic site of BACE-1.

Paper-based microfluidic devices for electrochemical immunofiltration analysis of human chorionic gonadotropin.

An electrochemical immunofiltration analysis was introduced into microfluidic paper-based analytical devices (μPADs) for the first time, which was based on photolithography and screen-printing technology. The hydrophilic test zones of the aldehyde-functionalized screen-printed electrodes (SPEs) were biofunctionalized with capture antibodies (Ab). A sensitive immune detection method was developed by using primary signal antibody functionalized gold nanoparticles (GNPs/Ab) and alkaline phosphatase conjugated secondary antibody (ALP-IgG).

A New Two-Photon Ratiometric Fluorescent Probe for Detecting Alkaline Phosphatase in Living Cells.

Alkaline phosphatase (ALP) is an important diagnostic indicator of many human diseases. To quantitatively track ALP in biosystems, herein, for the first time, we report an efficient two-photon ratiometric fluorescent probe, termed probe and based on classic naphthalene derivatives with a donor-π-acceptor (D-π-A) structure and deprotection of the phosphoric acid moiety by ALP. The presence of ALP causes the cleave of the phosphate group from naphthalene derivatives and the phosphate group changes the ability of the intramolecular charge transfer (ICT) and remarkably alters the probe's photophysical properties, thus an obvious ratiometric signal with an isoemissive point is observed.

ESIPT-Based Photoactivatable Fluorescent Probe for Ratiometric Spatiotemporal Bioimaging.

Photoactivatable fluorophores have become an important technique for the high spatiotemporal resolution of biological imaging. Here, we developed a novel photoactivatable probe (PHBT), which is based on 2-(2-hydroxyphenyl)benzothiazole (HBT), a small organic fluorophore known for its classic luminescence mechanism through excited-state intramolecular proton transfer (ESIPT) with the keto form and the enol form. After photocleavage, PHBT released a ratiometric fluorophore HBT, which showed dual emission bands with more than 73-fold fluorescence enhancement at 512 nm in buffer and more than 69-fold enhancement at 452 nm in bovine serum.

A naphthalene-based two-photon fluorescent probe for selective and sensitive detection of endogenous hypochlorous acid.

An efficient naphthalene-based two-photon fluorescent probe for endogenous HClO has been reported in the present study, which consists of a 6-(2-benzothiazolyl)-2-naphthalenol fluorophore connected with a 4-aminophenol (the fluorescence quenching and response group). This probe exhibits a high selectivity and excellent sensitivity with a detection limit of 7.6nM over other reactive oxygen species and analyte species, and the fluorescence intensity enhanced 103-fold when responsed.

Butyrylcholinesterase K variant and Alzheimer's disease risk: a meta-analysis.

Background: Although many studies have estimated the association between the butyrylcholinesterase (BCHE) K variant and Alzheimer's disease (AD) risk, the results are still controversial. We thus conducted this meta-analysis.

Material/methods: We searched NCBI, Medline, Web of Science, and Embase databases to find all eligible studies.

Chitosan coated on the layers' glucose oxidase immobilized on cysteamine/Au electrode for use as glucose biosensor.

A glucose biosensor was developed via direct immobilization of glucose oxidase (GOD) by self-assembled cysteamine monolayer on Au electrode surface followed by coating chitosan on the surface of electrode. In this work, chitosan film was coated on the surface of GOD as a protection film to ensure the stability and biocompatibility of the constructed glucose biosensor. The different application ranges of sensors were fabricated by immobilizing varied layers of GOD.

CoMFA, CoMSIA and HQSAR studies of acetylcholinesterase inhibitors.

A quantitative structure-activity relationship (QSAR) study has been carried out on acetylcholinesterase (AChE) inhibitors with comparative field analysis (CoMFA), comparative molecular similarity indices analysis (CoMSIA) and hologram quantitative structure-activity relationship (HQSAR). In order to investigate the effect of alignment on modeling and find out the best alignment strategy, three different alignment rules were applied to generate CoMFA and CoMSIA models. Statistical results of the highly significant models (CoMFA q² = 0.

Theoretical evaluation of flotation performance of carboxyl hydroxamic acids with different number of polar groups on the surfaces of diaspore (010) and kaolinite (001).

The adsorption behaviors of three carboxyl hydroxamic acids on diaspore (010) and kaolinite (001) have been studied by density functional theory (DFT) and molecular dynamics (MD) method. The results indicated that carboxyl hydroxamic acids could adsorb on diaspore surface by ionic bonds and hydrogen bonds, and adsorb on kaolinite surface by hydrogen bonds. The models of carboxyl hydroxamic acids adsorbed on diaspore and kaolinite surfaces are proposed.

Identification and synthesis of N-(thiophen-2-yl) benzamide derivatives as BRAF(V600E) inhibitors.

The V600E BRAF kinase mutation, which activates the downstream MAPK signaling pathway, commonly occurs in about 8% of all human malignancies and about 50% of all melanomas. In this study, we employed virtual screening and chemical synthesis to identify a series of N-(thiophen-2-yl) benzamide derivatives as potent BRAF(V600E) inhibitors. Structure-activity relationship studies of these derivatives revealed that compounds b40 and b47 are the two most potent BRAF(V600E) inhibitors in this series.

Novel topological index for research on structure-property relationships of complex organic compounds.

Based on bonding parameters such as Yang's Electronegative Force Gauge Y(i), electronic number of valence layer Z(i), number of combined hydrogen atoms h(i), number of bonding electron b(i), and quantum number such as the highest main quantum number of valence layer n(i), a novel atomic valence delta(i) (Y) is defined and a novel topological index (1)chi(Y) is derived from the atomic valence. The atomic valence is defined as delta(i) (Y) = (Z(i) - h(i))b(i)/n(i) (2)Y(i), while the topological index is expressed as (1)chi(Y) summation operator (i,j=1) (m) (delta(i) (Y)delta(j) (Y))(-1/2). Subsequently, the index (1)chi(Y) is utilized to study the structure-property relationships of complex organic compounds.