Co-Dissolved Isostructural Polyoxovanadates to Construct Single-Atom-Site Catalysts for Efficient CO2 Photoreduction.

We explored a co-dissolved strategy to embed mono-dispersed Pt center into V2 O5 support via dissolving [PtV9 O28 ]7- into [V10 O28 ]6- aqueous solution. The uniform dispersion of [PtV9 O28 ]7- in [V10 O28 ]6- solution allows [PtV9 O28 ]7- to be surrounded by [V10 O28 ]6- clusters via a freeze-drying process. The V centers in both [PtV9 O28 ]7- and [V10 O28 ]6- were converted into V2 O5 via a calcination process to stabilize Pt center. These double separations can effectively prevent the Pt center agglomeration during the high-temperature conversion process, and achieve 100 % utilization of Pt in [PtV9 O28 ]7- . The resulting Pt-V2 O5 single-atom-site catalysts exhibit a CH4 yield of 247.6 µmol g-1 h-1 , 25 times higher than that of Pt nanoparticle on the V2 O5 support, which was accompanied by the lactic acid photooxidation to form pyruvic acid. Systematical investigations on this unambiguous structure demonstrate an important role of Pt-O atomic pair synergy for highly efficient CO2 photoreduction.

BMSCs overexpressed ISL1 reduces the apoptosis of islet cells through ANLN carrying exosome, INHBA, and caffeine.

Early apoptosis of grafted islets is one of the main factors affecting the efficacy of islet transplantation. The combined transplantation of islet cells and bone marrow mesenchymal stem cells (BMSCs) can significantly improve the survival rate of grafted islets. Transcription factor insulin gene enhancer binding protein 1 (ISL1) is shown to promote the angiogenesis of grafted islets and the paracrine function of mesenchymal stem cells during the co-transplantation, yet the regulatory mechanism remains unclear. By using ISL1-overexpressing BMSCs and the subtherapeutic doses of islets for co-transplantation, we managed to reduce the apoptosis and improve the survival rate of the grafts. Our metabolomics and proteomics data suggested that ISL1 upregulates aniline (ANLN) and Inhibin beta A chain (INHBA), and stimulated the release of caffeine in the BMSCs. We then demonstrated that the upregulation of ANLN and INHBA was achieved by the binding of ISL1 to the promoter regions of the two genes. In addition, ISL1 could also promote BMSCs to release exosomes with high expression of ANLN, secrete INHBA and caffeine, and reduce streptozocin (STZ)-induced islets apoptosis. Thus, our study provides mechanical insight into the islet/BMSCs co-transplantation and paves the foundation for using conditioned medium to mimic the ISL1-overexpressing BMSCs co-transplantation.

A high-nuclearity CuI/CuII nanocluster catalyst for phenol degradation.

Herein, we report a 54-nuclei copper nanocluster, [Cu54S13O6(tBuS)20(tBuSO3)12] (Cu54), which is the largest atom-precise CuI/CuII mix-valent cluster reported. The Cu54 nanoclusters supported by TiO2 exhibit decent photocatalytic activity for phenol degradation under visible light. This work provides a platform to explore the catalytic behaviors of CuI/CuII nanosystems.

Boosting Room Temperature Sensing Performances by Atomically Dispersed Pd Stabilized via Surface Coordination.

The urgent requirement of monitoring air pollution worldwide evokes intensive research interest in developing chemiresistive gas sensing techniques. To overcome the limits in sensitivity and selectivity of room temperature (RT) chemiresistive sensing materials, a new strategy using single-atom catalysts (SACs) via surface coordination is proposed. As a proof-of-concept, single Pd atoms on TiO2 (Pd1-TiO2) possess high efficiency in generating adsorbed O2- as well as high activity and selectivity in catalyzing CO oxidation at RT. As a result, Pd1-TiO2 shows record high sensitivity among the reported RT sensing materials, which is even comparable to those of the best materials working at high temperature. It also provides an approximately 1 order of magnitude lower limit of detection than the best CO sensing materials. Moreover, Pd1-TiO2 presents high selectivity toward 12 kinds of interference gases. This work not only paves a way to design high-performance RT gas sensing materials but also extends the application of SACs.

Terahertz time-domain absorption spectra of Cu(I) complexes bearing tetraphosphine ligands: the bridge between the C-Hπ and ππ interactions and photoluminescence properties.

The synthesis of four heteroleptic dinuclear Cu(i) complexes bearing tetraphosphine and diimine ligands was reported. Complexes 1-3 were successfully obtained through microwave synthesis while complex 4 was synthesized through traditionally stirring at room temperature. These complexes are listed as follows: [Cu2(Dpq)2(dppeda)](ClO4)2·1.5CH2Cl2 (1), [Cu2(neo)2(dppeda)](ClO4)2·1.3CH2Cl2·1.7C4H10O (2), [Cu2(batho)2(dppeda)](ClO4)2·C4H10O (3), and [Cu2(batho)2(dpppda)](ClO4)2·3CH2Cl2 (4) {(Dpq = pyrazino[2,3-f][1,10]phenanthroline, batho = 4,7-diphenyl-1,10-phenanthroline, neo = 2,9-dimethyl-1,10-phenanthroline, dppeda = N1,N1,N2,N2-tetrakis[(diphenylphosphino)methyl]-1,2-ethanediamine, and dpppda = N1,N1,N4,N4-tetrakis[(diphenylphosphino)methyl]-1,4-benzenediamine}. Their crystal structures have been elucidated by X-ray crystallography and their photophysical properties have been investigated in detail. Photophysical studies and time domain density functional theory (TD-DFT) calculations show that the luminescence performance of these four complexes is ascribed to metal-to-ligand charge transfer (MLCT) mixed with ligand-to-ligand charge transfer (LLCT), and complex 2 shows green emission at 574 nm with the highest quantum yield of up to 52.80%. In addition, the research of photoluminescence properties under the guidance of terahertz spectroscopy technology leads to the preliminary discovery of a correlation between crystal packing and luminescence. It is found that the terahertz spectrum and absorption peak are strongly interdependent on C-Hπ and ππ interactions, and the external weak interactions have negative effects on the luminescence performance. Herein, we predict that the terahertz spectroscopy analysis establishes a bridge between weak interactions (C-Hπ and ππ interactions) and the photoluminescence properties, and puts forward a problem that should be noticed in designing Cu(i) complexes.

Clinical effects of apatinib mesylate for treatment of multiple brain micrometastases: Two case reports.

BACKGROUND: Apatinib is a small-molecule multitargeted tyrosine kinase inhibitor. Apatinib has demonstrated encouraging antitumor activities. This study aimed to observe the efficacy and safety of apatinib for the treatment of multiple brain micrometastases. CASE SUMMARY: We report two patients with multiple brain micrometastases after failure of second-line treatment. Both patients had extracerebral metastases. When the patients took 250 mg/d apatinib orally, the intracerebral lesions disappeared. The extracerebral lesions were partially alleviated. Both patients had a progression-free survival of more than 12 mo and were still stable. The safety was good. The main adverse events (AEs) were mild hypertension and proteinuria, which could be controlled. CONCLUSION: Apatinib has clear efficacy and good tolerance in patients with multiple brain micrometastases after failure of second-line treatment.

Solvothermal Syntheses and Characterizations of Four Quaternary Copper Sulfides BaCu3MS4 (M = In, Ga) and BaCu2MS4 (M = Sn, Ge).

Hydro(solvo)thermal syntheses of quaternary copper sulfides containing alkaline earth metal ions remain a great challenge because of the low solubility of Cu-S compounds. Herein, a new facile solvothermal method was developed, and four quaternary copper sulfides, i.e., BaCu3InS4 (1), BaCu3GaS4 (2), BaCu2SnS4 (3), and BaCu2GeS4 (4), were prepared using excess sulfur as a mineralizer. Compound 1 possesses a novel three-dimensional (3D) anionic [Cu3InS4]2- framework constructed by an 8-membered ring of [Cu4S4] and [Cu2In2S4] alternatively. Compound 2 features a unique 3D anionic [Cu3GaS4]2- framework composed of [Cu3GaS10]n14n- anionic chains and 8-membered rings, in which [Cu4S4] and [Cu2Ga2S4] reside alternatively. Compounds 3 and 4 feature 3D anionic [Cu2MS4]2- (M = Sn, Ge) frameworks composed of CuS4 and MS4 tetrahedra with Ba2+ located in the channels. It is worth noting that different 3D Cu-S frameworks exist in the title crystal structures, in which main group ions are incorporated. This paper provides a new synthetic strategy for new quaternary sulfides.

Fabrication of silver chalcogenolate cluster hybrid membranes with enhanced structural stability and luminescence efficiency.

The present study reports the fabrication of a silver chalcogenolate cluster hybrid membrane (SCC membrane) through self-assembly of SCCs, and then covalent cross-linking of the modified SCC assembled materials. This strategy provides access to silver clusters with superior chemical stability and enhanced luminescence efficiency for practical applications.

New sesquiterpenoids from the stems of Dendrobium nobile and their neuroprotective activities.

Three new sesquiterpenoids, (+)-(1R,2S,3R,4S,5R,6S,9R)-3,11,12-trihydroxypicrotoxane-2(15)-lactone (1), (-)-(1S,2R,3S,4R,5S,6R,9S,12R)-3,11,13-trihydroxypicrotoxane-2(15)-lactone (2), and (+)-(1R,5R,6S,8R,9R)-8,12-dihydroxy-copacamphan-3-en-2-one (3), together with five known compounds, were isolated from the n-butanol soluble fraction of a 95% EtOH extract of the stems of Dendrobium nobile. Their structures were determined by extensive spectroscopic analysis. Particularly, to solve difficult stereochemical problems, electronic circular dichroism calculations, NMR data calculations, and a single-crystal X-ray diffraction were performed. Interestingly, compounds 1 and 2 were picrotoxinin-type sesquiterpenoids with an unusual C15,2-lactone ring. All new sesquiterpenoids (1-3) showed a significant neuroprotective activity against H2O2-induced oxidative damage in PC12 cells. Notably, at 25 and 50 µM, compounds 1 and 2 showed the best protective effects, even better than the positive control (vitamin E).

In Vitro Metabolism by Aldehyde Oxidase Leads to Poor Pharmacokinetic Profile in Rats for c-Met Inhibitor MET401.

BACKGROUND AND OBJECTIVES: MET401 is a potent and selective c-Met inhibitor with a novel triazolopyrimidine scaffold. The aim of this study was to determine the pharmacokinetic profile of MET401 in preclinical species, and to identify the metabolic soft spot and enzyme involved, in order to help medicinal chemists to modify the compound to improve the pharmacokinetic profile. METHODS: A metabolite identification study was performed in different liver fractions from various species. Chemical inhibition with selective cytochrome P450 (CYP) and molybdenum hydroxylase inhibitors was carried out to identify the enzyme involved. The deuterium substitution strategy was adopted to reduce metabolism. Pharmacokinetic studies were performed in rats to confirm the effect. RESULTS: Although M-2 is a minor metabolite in liver microsomal incubations, it became the predominant metabolite in incubations with liver S9, cytosol, hepatocytes and rat pharmacokinetic study. M-2 was synthesized enzymatically and the structure was identified as a mono-oxidation on the triazolopyrimidine moiety. The M-2 formation was ascribed to aldehyde oxidase (AO)-mediated metabolism based on the following evidence-M-2 production was NADPH independent, pan-CYP inhibitor 1-aminobenzotriazole and xanthine oxidase inhibitor allopurinol did not inhibit M-2 formation, and AO inhibitors menadione and raloxifene inhibited M-2 formation. The deuterated analog MET763 demonstrated an improved pharmacokinetic profile with lower clearance, longer terminal half-life and double oral exposure compared with MET401 in rats. CONCLUSIONS: These results indicate that the main metabolic pathway of MET401 is AO-mediated metabolism, which leads to poor in vivo pharmacokinetic profiles in rodents. The deuterium substitution strategy could be used to reduce AO-mediated metabolism liability.

Semi-Rigid Molecular-Clip-Based Molecular Crystal Gearshift.

A new version of molecular clip, with a semi-rigid symmetrical crab-type architecture and flexible cavity size, has been successfully designed and synthesized via a one-pot Friedel-Crafts alkylation reaction. The X-ray single-crystal diffraction data provide a simple and intuitive explanation, not only for its well-preorganized and regulated conformation but also for its selective and tunable guest-binding capability. For the first time, the newly designed molecular clip was demonstrated to be not only a controllable variable-speed nonporous adsorption material in solution iodine capture, but also capable of on-off switching in volatile iodine capture. The presented new concept of molecular crystal gearshift directly from the molecular clip crystals represents an important advance in the development of synthetic receptor chemistry, which will exert a significant influence on small-molecule crystallography.

Metabolism of c-Met Kinase Inhibitors Containing Quinoline by Aldehyde Oxidase, Electron Donating, and Steric Hindrance Effect.

Some quinoline-containing c-Met kinase inhibitors are aldehyde oxidase (AO) substrates. 3-Substituted quinoline triazolopyridine analogs were synthesized to understand the electron-donating and steric hindrance effects on AO-mediated metabolism. Metabolic stability studies for these quinoline analogs were carried out in liver cytosol from mice, rats, cynomolgus monkeys, and humans. Several 3-N-substituted analogs were found to be unstable in monkey liver cytosolic incubations (half-life, <10 minutes), and five of them (63, 53, 51, 11, and 71) were chosen for additional mechanistic studies. Mono-oxygenation on the quinoline ring was identified by liquid chromatography tandem mass spectrometry. Metabolite formation was inhibited by the AO inhibitors menadione and raloxifene, but not by the xanthine oxidase inhibitor allopurinol. It was found that small electron-donating groups at the 3-quinoline moiety made the analogs more susceptible to AO metabolism, whereas large 3-substituents could reverse the trend. Although species differences were observed, this trend was applicable to all species tested. Small electron-donating substituents at the 3-quinoline moiety increased both affinity (decreased Michaelis constant) and V max maximum velocity toward AO in kinetic studies, whereas large substituents decreased both parameters probably as a result of steric hindrance. Based on our analysis, a common structural feature with high AO liability was proposed. Our finding could provide useful information for chemists to minimize potential AO liability when designing quinoline analogs.

Green synthesis of new pyrrolidine-fused spirooxindoles via three-component domino reaction in EtOH/H2O.

An efficient, green and sustainable approach for the synthesis of novel polycyclic pyrrolidine-fused spirooxindole compounds was developed. The synthesis included a one-pot, three-component, domino reaction of (E)-3-(2-nitrovinyl)-indoles, isatins and chiral polycyclic α-amino acids under catalyst-free conditions at room temperature in EtOH-H2O. The salient features of this methodology are eco-friendliness, high yields and the ease of obtaining target compounds without the involvement of toxic solvents and column chromatography. These novel polycyclic pyrrolidine-fused spirooxindoles provide a collection of structurally diverse compounds that show promise for future bioassays and medical treatments.

Development of a versatile and conventional technique for gene disruption in filamentous fungi based on CRISPR-Cas9 technology.

Filamentous fungi represent an invaluable source of pharmaceutically active compounds. The development of versatile methods to genetically manipulate filamentous fungi is of great value for improving the low yields of bioactive metabolites and expanding chemical diversity. The CRISPR-Cas9-based system has become a common platform for genome editing in a variety of organisms. However, recent application of this technology in filamentous fungi is limited to model strains, a versatile method for efficient gene disruption in different fungi is lacking. Here, we investigated the utility of the CRISPR-Cas9 system in a less-studied fungus Nodulisporium sp. (No. 65-12-7-1), and we have developed an efficient CRISPR-Cas9-based gene disruption strategy by simultaneous transformation of in vitro transcriptional gRNA and the linear maker gene cassette into the Cas9-expressing fungi. We found that the linear marker gene cassette could not only allow for selection of transformants, but also significantly enhance the gene disruption efficiency by inserting itself into the Cas9 cut site. Moreover, the above approach also demonstrated its efficiency in two other phylogenetically distinct strains Aspergillus oryzae NSAR1 and Sporormiella minima (No. 40-1-4-1) from two different classes of Ascomycota. These results suggested that a versatile CRISPR-Cas9-based gene disruption method in filamentous fungi was established.

Methylation, Glucuronidation, and Sulfonation of Daphnetin in Human Hepatic Preparations In Vitro: Metabolic Profiling, Pathway Comparison, and Bioactivity Analysis.

Our previous study demonstrated that daphnetin is subject to glucuronidation in vitro. However, daphnetin metabolism is still poorly documented. This study aimed to investigate daphnetin metabolism and its consequent effect on the bioactivity. Metabolic profiles obtained by human liver S9 fractions and human hepatocytes showed that daphnetin was metabolized by glucuronidation, sulfonation, and methylation to form 6 conjugates which were synthesized and identified as 7-O-glucuronide, 8-O-glucuronide, 7-O-sulfate and 8-O-sulfate, 8-O-methylate, and 7-O-suflo-8-O-methylate. Regioselective 8-O-methylation of daphnetin was investigated using in silico docking calculations, and the results suggested that a close proximity (2.03 Å) of 8-OH to the critical residue Lysine 144 might be the responsible mechanism. Compared with glucuronidation and sulfonation pathways, the methylation of daphnetin had a high clearance rate (470 µL/min/mg) in human liver S9 fractions and contributed to a large amount (37.3%) of the methyl-derived metabolites in human hepatocyte. Reaction phenotyping studies showed the major role of SULT1A1, -1A2, and -1A3 in daphnetin sulfonation, and soluble COMT in daphnetin 8-O-methylation. Of the metabolites, only 8-O-methyldaphnetin exhibited an inhibitory activity on lymphocyte proliferation comparable to that of daphnetin. In conclusion, methylation is a crucial pathway for daphnetin clearance and might be involved in pharmacologic actions of daphnetin in humans.

In Vitro Evaluation of the Effect of 7-Methyl Substitution on Glucuronidation of Daphnetin: Metabolic Stability, Isoform Selectivity, and Bioactivity Analysis.

The C-8 phenol group is essential to exert the bioactivities of daphnetin, but it is readily conjugated with glucuronic acid prior to excretion. In this study, daphnetin-7-methylether (7M-DNP) was used to investigate the effect of 7-methyl substitution on daphnetin glucuronidation in human/rat liver (HLM/RLM) and intestine (HIM/RIM) microsomes, and recombinant UDP-glucuronosyltransferases (UGTs). Compared with daphnetin, the Vmax /Km values of 7M-DNP via 8-O-glucuronidation were 2.1-fold lower in HLM, 1.7-fold lower in HIM, and 2.4-fold lower in RLM, suggesting an improvement in metabolic stability. Different from daphnetin 8-O-glucuronidation exclusively catalyzed by UGT1A6 and UGT1A9, UGT1A1, -1A3, -1A7, -1A8, and -1A9 showed glucuronidation activity toward 7M-DNP. Kinetics studies, chemical inhibition, and the relative activity factor approach were used to demonstrate that UGT1A9 was mainly responsible for the reaction in HLM, whereas UGT1A1 was a primary contributor in HIM. The Vmax /Km values of 7M-DNP glucuronidation in HLM and HIM were 0.61-0.74-fold lower than those of rat, suggesting the differences between the two species. The bioactivity analysis demonstrated that 7M-DNP had an anti-inflammatory activity comparable to that of daphnetin. These findings indicated that the outcomes of 7-methyl substitution on daphnetin might be positive, but this should be confirmed in future in vivo studies.

Facile synthesis of magnetic homochiral metal-organic frameworks for "enantioselective fishing".

Magnetic functionalized homochiral metal-organic frameworks (MOFs) were prepared and applied to efficient enantioselective fishing of chiral drug intermediates. Under optimized conditions, the enantiomeric excess (ee) value as high as 85.2% was achieved for methyl phenyl sulfoxide (MPS) within 3 min.

Meta-analysis of the efficacy and safety of long-acting non-ergot dopamine agonists in Parkinson's disease.

A meta-analysis of randomized controlled trials (RCT) was performed to evaluate the efficacy and safety of long-acting non-ergot dopamine agonists (NEDA) versus placebo in Parkinson's disease (PD). A comprehensive literature search up to February 2013 was performed, and the weighted mean differences (WMD) and relative risks (RR) with 95% confidence intervals (CI) were calculated. Nine RCT (n=2857) which assessed the rotigotine transdermal patch, extended-release pramipexole, and ropinirole prolonged-release, were included. Compared with placebo, long-acting NEDA achieved greater improvements in Unified Parkinson's Disease Rating Scale activities of daily living (ADL) score (WMD -1.77, 95% CI -2.13 to -1.41), motor score (WMD -4.18, 95% CI -4.94 to -3.43) and the ADL and motor subtotal score (WMD -5.12, 95% CI -6.16 to -4.07), as well as a reduction in "off" time (WMD -1.29, 95% CI -1.64 to -0.93) and an increase in "on" time without troublesome dyskinesia (WMD 1.55, 95% CI 1.06 to 2.04). Compared with placebo, long-acting NEDA were associated with a higher risk of nausea, but no difference was found in headache incidence. Higher risks of dizziness, somnolence, constipation, vomiting, and insomnia were only found in early PD while higher risks of dyskinesia and hallucination were only found in advanced PD. The results of our meta-analysis showed that the use of long-acting NEDA can reduce the symptoms of PD patients. However, long-acting NEDA were also associated with a higher incidence of adverse events, especially in early PD patients, compared with placebo.

[Gene analysis and literature review of autosomal recessive polycystic kidney disease].

OBJECTIVE: The purpose of this study was to investigate the clinical and genetic characteristics of autosomal recessive polycystic kidney disease. METHOD: Targeted sequencing was used on a children who was accurately diagnosed as autosomal recessive polycystic kidney disease in Peking Union Medical College Hospital to analyze the major clinical manifestations of the disease. An analysis of the PKHD1 genes was made on the patient, and then verified by polymerase chain reaction (PCR). And the related literature was reviewed also. RESULT: The patient was a boy, 2 years and 3 months old, and had abdominal distention for about one year. The abdominal ultrasound suggested diffuse liver lesions, mild intrahepatic bile duct dilatation, structure disturbance of both kidneys, appearance of multiple strong echo. The child was clinically highly suspected of polycystic kidney disease. Targeted sequencing showed two mutations in exon 32 and exon 50 of PKHD1 gene, respectively, c.4274T > G, leading to p.Leu1425Arg, c.7973T > A, leading to p.Leu2658Ter. Verified by PCR, the father has one mutation of c.4274T > G. CONCLUSION: The clinical manifestations of autosomal recessive polycystic kidney disease are multiple renal cyst, cyst of liver and liver fibrosis, intrahepatic bile duct dilatation. Two mutations (c.4274T > G, c.7973T > A) in PKHD1 gene may be pathogenic.

Inhibitory effects of sanguinarine on human liver cytochrome P450 enzymes.

Sanguinarine (SAG) has been recognized as an anticancer drug candidate. However, the drug-drug interactions (DDI) potential for SAG via the inhibition against human cytochrome P450 (CYP) enzymes remains unclear. In the present study, the inhibitory effects of SAG on seven major human CYP isoforms 1A2, 2A6, 2E1, 2D6, 2C8, 2C9 and 3A4 were investigated with human liver microsomes (HLM). The results showed that SAG was a potent noncompetitive inhibitor of CYP2C8 activity (Ki=8.9 µM), and competitive inhibitor of CYP1A2, CYP2C9 and CYP3A4 activities (Ki=2.7, 3.8 and 2.0 µM, respectively). Furthermore, SAG exhibited time- and NADPH-dependent inhibition towards CYP1A2 and CYP3A4 with KI/kinact values of 13.3/0.087 and 5.58/0.029 min(-1) µM(-1), respectively. Weak inhibition of SAG against CYP2E1, CYP2D6 and CYP2A6 was also observed. In vitro-in vivo extrapolation (IV-IVE) from HLM data showed that more than 35.9% of CYP1A2, CYP2C9, CYP2C8 and CYP3A4 activities in vivo could be inhibited by SAG, suggesting that harmful DDIs could occur when SAG or its medical preparations are co-administered with drugs primarily cleared by these CYP isoforms. Further in vivo studies are needed to evaluate the clinical significance of the data presented herein.